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  <front>
    <journal-meta>
      <journal-id journal-id-type="publisher-id">87</journal-id>
      <journal-id journal-id-type="index">urn:lsid:arphahub.com:pub:A116C711-4C18-5A38-8F1E-5E97753A8A64</journal-id>
      <journal-title-group>
        <journal-title xml:lang="en">Folia Medica</journal-title>
        <abbrev-journal-title xml:lang="en">FM</abbrev-journal-title>
      </journal-title-group>
      <issn pub-type="ppub">0204-8043</issn>
      <issn pub-type="epub">1314-2143</issn>
      <publisher>
        <publisher-name>Plovdiv Medical University</publisher-name>
      </publisher>
    </journal-meta>
    <article-meta>
      <article-id pub-id-type="doi">10.3897/folmed.66.e115484</article-id>
      <article-id pub-id-type="publisher-id">115484</article-id>
      <article-categories>
        <subj-group subj-group-type="heading">
          <subject>Original Article</subject>
        </subj-group>
        <subj-group subj-group-type="scientific_subject">
          <subject>Dermatology</subject>
        </subj-group>
      </article-categories>
      <title-group>
        <article-title>Platelet-rich plasma efficacy in alopecia areata patients with normal and elevated levels of antibodies against thyroglobulin and thyroid peroxidase</article-title>
      </title-group>
      <contrib-group content-type="authors">
        <contrib contrib-type="author" corresp="yes">
          <name name-style="western">
            <surname>Abadjieva</surname>
            <given-names>Tsvetana I.</given-names>
          </name>
          <email xlink:type="simple">ts_abadjieva@yahoo.com</email>
          <uri content-type="orcid">https://orcid.org/0000-0003-4938-3076</uri>
          <xref ref-type="aff" rid="A1">1</xref>
        </contrib>
        <contrib contrib-type="author" corresp="no">
          <name name-style="western">
            <surname>Todorova</surname>
            <given-names>Lidiya N.</given-names>
          </name>
          <uri content-type="orcid">https://orcid.org/0000-0002-7873-4034</uri>
          <xref ref-type="aff" rid="A1">1</xref>
        </contrib>
        <contrib contrib-type="author" corresp="no">
          <name name-style="western">
            <surname>Gardjeva</surname>
            <given-names>Petya A.</given-names>
          </name>
          <xref ref-type="aff" rid="A1">1</xref>
        </contrib>
        <contrib contrib-type="author" corresp="no">
          <name name-style="western">
            <surname>Murdjeva</surname>
            <given-names>Mariana A.</given-names>
          </name>
          <uri content-type="orcid">https://orcid.org/0000-0002-1357-6717</uri>
          <xref ref-type="aff" rid="A1">1</xref>
        </contrib>
      </contrib-group>
      <aff id="A1">
        <label>1</label>
        <addr-line content-type="verbatim">Department of Dermatology and Venereology, Faculty of Medicine, Medical University of Plovdiv, Plovdiv, Bulgaria</addr-line>
        <institution>Medical University of Plovdiv</institution>
        <addr-line content-type="city">Plovdiv</addr-line>
        <country>Bulgaria</country>
      </aff>
      <aff id="A2">
        <label>2</label>
        <addr-line content-type="verbatim">Department of Medical Microbiology and Immunology, Faculty of Medicine, Medical University of Plovdiv, Plovdiv, Bulgaria</addr-line>
        <institution>Medical University of Plovdiv</institution>
        <addr-line content-type="city">Plovdiv</addr-line>
        <country>Bulgaria</country>
      </aff>
      <author-notes>
        <fn fn-type="corresp">
          <p>Corresponding author: Tsvetana Abadjieva, Faculty of Medicine, Medical University of Plovdiv, 15A Vassil Aprilov Blvd., Plovdiv, Bulgaria; Email: <email xlink:type="simple">ts_abadjieva@yahoo.com</email>; Tel.: +359 889 716 761</p>
        </fn>
      </author-notes>
      <pub-date pub-type="collection">
        <year>2024</year>
      </pub-date>
      <pub-date pub-type="epub">
        <day>29</day>
        <month>02</month>
        <year>2024</year>
      </pub-date>
      <volume>66</volume>
      <issue>1</issue>
      <fpage>66</fpage>
      <lpage>72</lpage>
      <uri content-type="arpha" xlink:href="http://openbiodiv.net/3A4104A6-51B4-5E02-8764-D157C1406BA2">3A4104A6-51B4-5E02-8764-D157C1406BA2</uri>
      <history>
        <date date-type="received">
          <day>08</day>
          <month>11</month>
          <year>2023</year>
        </date>
        <date date-type="accepted">
          <day>14</day>
          <month>01</month>
          <year>2024</year>
        </date>
      </history>
      <permissions>
        <copyright-statement>Tsvetana I. Abadjieva, Lidiya N. Todorova, Petya A. Gardjeva, Mariana A. Murdjeva</copyright-statement>
        <license license-type="creative-commons-attribution" xlink:href="http://creativecommons.org/licenses/by/4.0/" xlink:type="simple">
          <license-p>This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.</license-p>
        </license>
      </permissions>
      <abstract>
        <label>Abstract</label>
        <p><bold>Aim</bold>: To evaluate and compare the efficacy of platelet-rich plasma (<abbrev xlink:title="platelet-rich plasma" id="ABBRID0E2D">PRP</abbrev>) therapy in alopecia areata (<abbrev xlink:title="alopecia areata" id="ABBRID0E6D">AA</abbrev>) patients with normal and with elevated levels of anti-thyroglobulin antibodies and/or anti-thyroid peroxidase antibodies.</p>
        <p><bold>Materials and methods</bold>: The study included 30 <abbrev xlink:title="alopecia areata" id="ABBRID0EHE">AA</abbrev> patients divided into two groups: <abbrev xlink:title="alopecia areata" id="ABBRID0ELE">AA</abbrev> patients with normal (Group 1) and with elevated antithyroid antibodies (Group 2). <abbrev xlink:title="platelet-rich plasma" id="ABBRID0EPE">PRP</abbrev> was applied in three consecutive monthly sessions. Treatment results were evaluated by clinical photography, assessment of scalp hair, trichoscopy, and assessment of patients’ quality of life.</p>
        <p><bold>Results</bold>: The mean age of patients was 42.10 years, 23 (76.6%) patients were with normal and seven (23.3%) were with elevated antithyroid antibodies. Eleven (50%) patients from Group 1 had significant hair growth, of which ten with <abbrev xlink:title="alopecia areata" id="ABBRID0EXE">AA</abbrev> partialis (45.5%), one with <abbrev xlink:title="alopecia areata" id="ABBRID0E2E">AA</abbrev> reticularis (4.6%). Two patients with alopecia reticularis and two with alopecia totalis had insignificant hair growth. Worsening was found in four patients with alopecia reticularis and alopecia totalis. In Group 2 one patient with alopecia partialis (14.3%) had a significant hair growth, five patients with alopecia reticularis and one with alopecia totalis had insignificant hair growth, and none of the patients worsened.</p>
        <p><bold>Conclusions</bold>: <abbrev xlink:title="platelet-rich plasma" id="ABBRID0EDF">PRP</abbrev> therapy was effective in patients with mild to moderate form of <abbrev xlink:title="alopecia areata" id="ABBRID0EHF">AA</abbrev> and most had normal antithyroid antibodies. Patients with severe <abbrev xlink:title="alopecia areata" id="ABBRID0ELF">AA</abbrev>, <abbrev xlink:title="alopecia areata" id="ABBRID0EPF">AA</abbrev> ophiasis and alopecia totalis, with normal and elevated antibodies, did not benefit from <abbrev xlink:title="platelet-rich plasma" id="ABBRID0ETF">PRP</abbrev> therapy.</p>
      </abstract>
      <kwd-group>
        <label>Keywords</label>
        <kwd>alopecia areata</kwd>
        <kwd>anti-thyroglobulin antibodies</kwd>
        <kwd>anti-thyroid peroxidase antibodies</kwd>
        <kwd>platelet-rich plasma</kwd>
      </kwd-group>
    </article-meta>
    <notes>
      <sec sec-type="Citation" id="SECID0E5F">
        <title>Citation</title>
        <p>Abadjieva TI, Todorova LN, Gardjeva PA, Murdjeva MA. Platelet-rich plasma efficacy in alopecia areata patients with normal and elevated levels of antibodies against thyroglobulin and thyroid peroxidase. Folia Med (Plovdiv) 2024;66(1):66-72. doi: <ext-link xlink:type="simple" ext-link-type="doi" xlink:href="10.3897/folmed.66.e115484">10.3897/folmed.66.e115484</ext-link>.</p>
      </sec>
    </notes>
  </front>
  <body>
    <sec sec-type="﻿Introduction" id="SECID0EKG">
      <title>﻿Introduction</title>
      <p>Alopecia areata (<abbrev xlink:title="alopecia areata" id="ABBRID0EQG">AA</abbrev>) is an autoimmune disorder characterized by non-scarring hair loss of the scalp or body. It has an incidence rate of 0.1%–0.2% in the general population.‌<sup>[<xref ref-type="bibr" rid="B1">1</xref>]</sup><abbrev xlink:title="alopecia areata" id="ABBRID0E2G">AA</abbrev> manifests as a single or multiple well-defined oval bald patches of different sizes. It may present as hair loss of the entire scalp (alopecia totalis, AT), entire body (alopecia universalis, AU), or bodily parts.<sup>[<xref ref-type="bibr" rid="B2">2</xref>]</sup> The course of the disease is unpredictable and spontaneous remissions are reported to occur in 34%–50% of patients within a year.‌<sup>[<xref ref-type="bibr" rid="B3">3</xref>, <xref ref-type="bibr" rid="B4">4</xref>]</sup> The loss of the growing hair shafts is connected with the CD4+ and CD8+ T-lymphocytes, which violate the immune privilege of anagen hair follicles.<sup>[<xref ref-type="bibr" rid="B5">5</xref>, <xref ref-type="bibr" rid="B6">6</xref>]</sup> There are also environmental factors including viral infections, trauma and psychological stress.<sup>[<xref ref-type="bibr" rid="B7 B8 B9">7–9</xref>]</sup></p>
      <p>Data differ regarding the incidence of thyroid diseases in patients with <abbrev xlink:title="alopecia areata" id="ABBRID0EFAAC">AA</abbrev>.<sup>[<xref ref-type="bibr" rid="B10">10</xref>, <xref ref-type="bibr" rid="B1">11</xref>]</sup><abbrev xlink:title="alopecia areata" id="ABBRID0EUAAC">AA</abbrev> is associated with the existence of antithyroid antibodies, including antibodies against thyroglobulin (anti-TG-Ab) and antibodies against thyroid peroxidase (anti-TPO-Ab).<sup>[<xref ref-type="bibr" rid="B12">12</xref>]</sup> Routine thyroid screening for asymptomatic patients with <abbrev xlink:title="alopecia areata" id="ABBRID0E6AAC">AA</abbrev> remains controversial.‌<sup>[<xref ref-type="bibr" rid="B13">13</xref>]</sup> ﻿</p>
      <p>Diagnosis and activity of <abbrev xlink:title="alopecia areata" id="ABBRID0EMBAC">AA</abbrev> are based on clinical manifestation and trichoscopy.<sup>[<xref ref-type="bibr" rid="B14">14</xref>]</sup></p>
      <p>Application of platelet-rich plasma (<abbrev xlink:title="platelet-rich plasma" id="ABBRID0EYBAC">PRP</abbrev>) is a therapeutic option in <abbrev xlink:title="alopecia areata" id="ABBRID0E3BAC">AA</abbrev>. Platelet-rich plasma includes concentrated platelets, 4-7 times above baseline values, that secrete growth factors (<abbrev xlink:title="growth factors" id="ABBRID0EACAC">GF</abbrev>) including: platelet derived (<abbrev xlink:title="platelet derived" id="ABBRID0EECAC">PDGF</abbrev>), vascular endothelial (<abbrev xlink:title="vascular endothelial" id="ABBRID0EICAC">VEGF</abbrev>), transforming (<abbrev xlink:title="transforming" id="ABBRID0EMCAC">TGF</abbrev>), fibroblast (<abbrev xlink:title="fibroblast" id="ABBRID0EQCAC">FGF</abbrev>), connective tissue (<abbrev xlink:title="connective tissue" id="ABBRID0EUCAC">CTGF</abbrev>), epidermal (<abbrev xlink:title="epidermal" id="ABBRID0EYCAC">EGF</abbrev>), and insulin-like growth factor-1 (<abbrev xlink:title="insulin-like growth factor-1" id="ABBRID0E3CAC">IGF-1</abbrev>). They stimulate hair follicle proliferation and differentiation, anagen phase, neoangiogenesis and development of adnexal structures.<sup>[<xref ref-type="bibr" rid="B15 B16 B17">15–17</xref>]</sup></p>
    </sec>
    <sec sec-type="Aim" id="SECID0EGDAC">
      <title>Aim</title>
      <p>The aim of this study was to evaluate and compare the efficacy of the <abbrev xlink:title="platelet-rich plasma" id="ABBRID0EMDAC">PRP</abbrev> therapy in <abbrev xlink:title="alopecia areata" id="ABBRID0EQDAC">AA</abbrev> patients with normal and with elevated levels of anti-TG-Ab and/or anti-TPO-Ab.</p>
    </sec>
    <sec sec-type="materials|methods" id="SECID0EUDAC">
      <title>Materials and methods</title>
      <p>The study was conducted from September 2020 to September 2022.</p>
      <sec sec-type="Patients" id="SECID0EZDAC">
        <title>Patients</title>
        <p>This study enrolled 30 patients with <abbrev xlink:title="alopecia areata" id="ABBRID0E6DAC">AA</abbrev>. The inclusion criterion was patients of both sexes with <abbrev xlink:title="alopecia areata" id="ABBRID0EDEAC">AA</abbrev> above 18 years of age. Exclusion criteria were: presence of acute or chronic infection of the scalp, anticoagulants and antiaggregants intake, coagulation disorders (decreased number of platelets, platelet dysfunction, hypofibrinogenemia), haemodynamic instability (collapse), chronic liver diseases, keloid formation, pregnancy or lactation. At first visit, a detailed medical history was taken, and physical examination was done. The following data were collected: patient demographics, age at onset, number of relapses, total duration of disease, duration of last relapse. Dermatological examination determined the pattern of hair loss, size, and localization of bald patches. Trichoscopy was performed, and quality of life was measured.</p>
        <p>Patients were divided into two groups: Group 1, <abbrev xlink:title="alopecia areata" id="ABBRID0EJEAC">AA</abbrev> patients with normal levels of anti-TG Ab and anti-TPO Ab, and Group 2 were <abbrev xlink:title="alopecia areata" id="ABBRID0ENEAC">AA</abbrev> patients with elevated levels of anti-TG-Ab and/or anti-TPO-Ab. The effect of the therapy was evaluated and compared between both groups.</p>
        <p>Serum for the evaluation of ﻿anti-TG-Ab of IgG class and anti-TPO-Ab of IgG class was taken before the treatment. The tests were performed with anti-thyroglobulin ELISA (IgG) test kit and anti-TPO ELISA (IgG) test kit, Euroimmun, respectively, according to the manufacturer’s instructions. Sera from <abbrev xlink:title="alopecia areata" id="ABBRID0ETEAC">AA</abbrev> patients were collected and stored at −80°C until assayed. Patients’ sera were diluted 1:201 in sample buffer. The upper limit of the normal range (cut off) for anti-TG-Ab was a value &lt;100 UI/ml, and a value equal or above 100 UI/ml was deemed to be elevated; for anti-TPO-Ab the normal range was &lt;50 UI/ml and a value equal or exceeding 50 UI/ml was elevated (EUROIMMUN Medizinische Labordiagnostika AG, Lübeck, Germany).</p>
      </sec>
      <sec sec-type="Treatment protocol" id="SECID0EXEAC">
        <title>Treatment protocol</title>
        <p>Therapy included application of autologous <abbrev xlink:title="platelet-rich plasma" id="ABBRID0E4EAC">PRP</abbrev> in three consecutive monthly sessions. For the preparation of <abbrev xlink:title="platelet-rich plasma" id="ABBRID0EBFAC">PRP</abbrev>, at each visit, 8-10 ml of the patient’s venous blood was drawn by venipuncture and collected in a Pure <abbrev xlink:title="platelet-rich plasma" id="ABBRID0EFFAC">PRP</abbrev> (RE-GEN Ltd). After centrifugation for 10 minutes at 3500 rpm, 5–6 ml of <abbrev xlink:title="platelet-rich plasma" id="ABBRID0EJFAC">PRP</abbrev> were obtained and aspirated into two 3-ml syringes. The skin of the scalp was cleaned with alcohol pads prior injections. About 0.1 ml of <abbrev xlink:title="platelet-rich plasma" id="ABBRID0ENFAC">PRP</abbrev> was injected in the scalp in the subfollicular plane through multiple intradermal injections, 1 cm apart with a 30 G needle.</p>
      </sec>
      <sec sec-type="Assessment and evaluation criteria" id="SECID0ERFAC">
        <title>Assessment and evaluation criteria</title>
        <p>Treatment evaluation was done by hair loss assessment, global photography, trichoscopy and quality of life at baseline (BL), before initiation of therapy, and at follow-up (FU) one month after completion of therapy. Severity of Alopecia Tool (SALT) Score was used to assess hair loss severity. Results at BL were denoted as SALT BL, those at FU (one month after last procedure) as SALT FU. Final results were denoted as SALT, representing hair regrowth as the percentage of change from BL. The percentage change from baseline is calculated as follows:</p>
        <p>Percentage change from baseline = (SALTbaseline − SALTfollow-up)/SALT baseline × 100%</p>
        <p>Patients’ improvement after <abbrev xlink:title="platelet-rich plasma" id="ABBRID0EZFAC">PRP</abbrev> therapy was considered a significant improvement for SALT ≥50%, insignificant for SALT &lt;50, no change for SALT=0, and worsening for SALT&lt;0.<sup>[<xref ref-type="bibr" rid="B18">18</xref>, <xref ref-type="bibr" rid="B19">19</xref>]</sup></p>
        <p>Trichoscopy was performed using a Dino-Lite Edge Digital Microscope AM7915MZT(R7), magnification ×70. Quality of life was assessed with the Dermatology Life Quality Index (DLQI) questionnaire.<sup>[<xref ref-type="bibr" rid="B20">20</xref>]</sup> Verbal Numerical Rating Scale (VNRS) was used to measure the level of pain during manipulation at the first <abbrev xlink:title="platelet-rich plasma" id="ABBRID0EQGAC">PRP</abbrev> application. VNRS ranged from 0 (no pain) to 10 (most severe pain).</p>
        <p>Each patient provided written informed consent before participation. The study was performed according to the Declaration of Helsinki. The Ethics Committee at the Medical University of Plovdiv approved the study.</p>
      </sec>
      <sec sec-type="Statistical analysis" id="SECID0EVGAC">
        <title>Statistical analysis</title>
        <p>Data were collected, computerized, and statistically analyzed using SPSS v. 23.0., (SPSS, Inc., Chicago, IL, USA). Continuous variables are given as means and standard deviations (±SD), and category variables in percentages. The Kolmogorov-Smirnov test was applied to establish the distribution of data about SALT change and disease duration. Bivariate Pearson correlation was used to test the relationship between the variables disease duration and SALT change. ﻿Statistical significance was considered significant at <italic>p</italic>&lt;0.05.</p>
      </sec>
    </sec>
    <sec sec-type="Results" id="SECID0E4GAC">
      <title>Results</title>
      <p><abbrev xlink:title="alopecia areata" id="ABBRID0EDHAC">AA</abbrev> patients ranged in age from 20 to 67, with a mean age of 42.10 (±11.684) years. Of these, 25 (83.3%) were women and five (16.7%) were men. The mean disease duration was 14.1657 (±13.57472) years, ranging from 0.08 to 41, and the mean duration of the last relapse was 2.5067 (±4.98603) years, ranging from 0.08 to 19. First episode of <abbrev xlink:title="alopecia areata" id="ABBRID0EHHAC">AA</abbrev> was reported by nine patients (30.0%), while 21 (70.0%) had recurrent episodes. Eleven patients (36.7%) had <abbrev xlink:title="alopecia areata" id="ABBRID0ELHAC">AA</abbrev> reticularis (AAR), 11 (36.7%) had <abbrev xlink:title="alopecia areata" id="ABBRID0EPHAC">AA</abbrev> partialis (AAP), six patients (20.0%) alopecia totalis (AT), one (3.3%) <abbrev xlink:title="alopecia areata" id="ABBRID0ETHAC">AA</abbrev> ophiasis (AAO), and one (3.3%) <abbrev xlink:title="alopecia areata" id="ABBRID0EXHAC">AA</abbrev> barbae (AAB). Sixteen patients (53.3%) reported involvement of other bodily parts. Normal levels of antithyroid antibodies were found in 23 (76.7%) and elevated levels in seven (23.3%) <abbrev xlink:title="alopecia areata" id="ABBRID0E2HAC">AA</abbrev> patients. In 12 (41.4%) of all patients, SALT was more than 50% and 91.7% were with normal antithyroid antibody levels. In eight (27.6%) patients, hair growth was less than 50%. No improvement was observed in five (17.2%) patients and worsening of <abbrev xlink:title="alopecia areata" id="ABBRID0E6HAC">AA</abbrev> in four (13.8%). In five patients (16.7%) SALT was 100% <bold>(Table <xref ref-type="table" rid="T1">1</xref>)</bold>. The types of <abbrev xlink:title="alopecia areata" id="ABBRID0EKIAC">AA</abbrev> and SALT change are presented in <bold>Table <xref ref-type="table" rid="T2">2</xref></bold>. The duration of the disease and SALT change showed a negative, insignificant correlation (<italic>r</italic>=−0.277, <italic>p</italic>&gt;0.05). Trichoscopy findings in patients with significant and insignificant improvement were upright regrowing hairs, pigtail hairs and vellus hairs; in patients with worsening: black dots, exclamation mark hairs, yellow dots, broken hairs and tapered hairs <bold>(Fig. <xref ref-type="fig" rid="F1">1</xref>)</bold>. DLQI measured at BL and FU is presented in <bold>Table <xref ref-type="table" rid="T3">3</xref></bold>. Thirteen patients (43.3%) reported the procedure as moderately painful. The mean value of patients’ pain was 4.83±2.451, which counts as an ‘average level of pain’. No side effects were observed in this study.</p>
      <table-wrap id="T1" position="float" orientation="portrait">
        <label>Table 1.</label>
        <caption>
          <p>SALT score and SALT change in <abbrev xlink:title="alopecia areata" id="ABBRID0E6GAE">AA</abbrev> patients treated with <abbrev xlink:title="platelet-rich plasma" id="ABBRID0EDHAE">PRP</abbrev></p>
        </caption>
        <table id="TID0E1BAE" rules="all">
          <tbody>
            <tr>
              <td rowspan="1" colspan="1">
                <bold>SALT</bold>
              </td>
              <td rowspan="1" colspan="1">
                <bold><abbrev xlink:title="alopecia areata" id="ABBRID0EXHAE">AA</abbrev> patients n=29 (%)</bold>
              </td>
              <td rowspan="1" colspan="1">
                <bold>Group 1 n=22 (%)</bold>
              </td>
              <td rowspan="1" colspan="1">
                <bold>Group 2 n=7(%)</bold>
              </td>
            </tr>
            <tr>
              <td rowspan="1" colspan="1">SALT BL</td>
              <td rowspan="1" colspan="1"/>
              <td rowspan="1" colspan="1"/>
              <td rowspan="1" colspan="1"/>
            </tr>
            <tr>
              <td rowspan="1" colspan="1">S0 = no hair loss</td>
              <td rowspan="1" colspan="1">0 (0)</td>
              <td rowspan="1" colspan="1">0 (0)</td>
              <td rowspan="1" colspan="1">0 (0)</td>
            </tr>
            <tr>
              <td rowspan="1" colspan="1">S1 &lt;25% hair loss</td>
              <td rowspan="1" colspan="1">13 (44.8)</td>
              <td rowspan="1" colspan="1">12 (54.6)</td>
              <td rowspan="1" colspan="1">1 (14.3)</td>
            </tr>
            <tr>
              <td rowspan="1" colspan="1">S2 = 25%–49% hair loss</td>
              <td rowspan="1" colspan="1">6 (20.7)</td>
              <td rowspan="1" colspan="1">4 (18.2)</td>
              <td rowspan="1" colspan="1">2 (28.6)</td>
            </tr>
            <tr>
              <td rowspan="1" colspan="1">S3 = 50%–74% hair loss</td>
              <td rowspan="1" colspan="1">2 (6.9)</td>
              <td rowspan="1" colspan="1">0 (0)</td>
              <td rowspan="1" colspan="1">2 (28.6)</td>
            </tr>
            <tr>
              <td rowspan="1" colspan="1">S4 = 75%–99% hair loss</td>
              <td rowspan="1" colspan="1">5 (17.2)</td>
              <td rowspan="1" colspan="1">4 (18.2)</td>
              <td rowspan="1" colspan="1">1 (14.3)</td>
            </tr>
            <tr>
              <td rowspan="1" colspan="1">S5 = 100% hair loss</td>
              <td rowspan="1" colspan="1">3 (10.3)</td>
              <td rowspan="1" colspan="1">2 (9.1)</td>
              <td rowspan="1" colspan="1">1 (14.3)</td>
            </tr>
            <tr>
              <td rowspan="1" colspan="1">SALT FU</td>
              <td rowspan="1" colspan="1"/>
              <td rowspan="1" colspan="1"/>
              <td rowspan="1" colspan="1"/>
            </tr>
            <tr>
              <td rowspan="1" colspan="1">S0 = no hair loss</td>
              <td rowspan="1" colspan="1">5 (17.2)</td>
              <td rowspan="1" colspan="1">4 (18.2)</td>
              <td rowspan="1" colspan="1">1 (14.3)</td>
            </tr>
            <tr>
              <td rowspan="1" colspan="1">S1 &lt;25% hair loss</td>
              <td rowspan="1" colspan="1">10 (34.5)</td>
              <td rowspan="1" colspan="1">9 (40.2)</td>
              <td rowspan="1" colspan="1">1 (14.3)</td>
            </tr>
            <tr>
              <td rowspan="1" colspan="1">S2 = 25%–49% hair loss</td>
              <td rowspan="1" colspan="1">3 (10.3)</td>
              <td rowspan="1" colspan="1">1 (4.6)</td>
              <td rowspan="1" colspan="1">2 (28.6)</td>
            </tr>
            <tr>
              <td rowspan="1" colspan="1">S3 = 50%–74% hair loss</td>
              <td rowspan="1" colspan="1">5 (17.2)</td>
              <td rowspan="1" colspan="1">3 (13.7)</td>
              <td rowspan="1" colspan="1">2 (28.6)</td>
            </tr>
            <tr>
              <td rowspan="1" colspan="1">S4 = 75%–99% hair loss</td>
              <td rowspan="1" colspan="1">1 (3.5)</td>
              <td rowspan="1" colspan="1">1 (4.6)</td>
              <td rowspan="1" colspan="1">0</td>
            </tr>
            <tr>
              <td rowspan="1" colspan="1">S5 = 100% hair loss</td>
              <td rowspan="1" colspan="1">5 (17.2)</td>
              <td rowspan="1" colspan="1">4 (18.2)</td>
              <td rowspan="1" colspan="1">1 (14.3)</td>
            </tr>
            <tr>
              <td rowspan="1" colspan="1">SALT change</td>
              <td rowspan="1" colspan="1"/>
              <td rowspan="1" colspan="1"/>
              <td rowspan="1" colspan="1"/>
            </tr>
            <tr>
              <td rowspan="1" colspan="1">SALT ≥50%</td>
              <td rowspan="1" colspan="1">12 (41.4)</td>
              <td rowspan="1" colspan="1">11 (50.0)</td>
              <td rowspan="1" colspan="1">1 (14.3)</td>
            </tr>
            <tr>
              <td rowspan="1" colspan="1">0&lt; SALT &lt;50</td>
              <td rowspan="1" colspan="1">8 (27.6)</td>
              <td rowspan="1" colspan="1">3 (13.6)</td>
              <td rowspan="1" colspan="1">5 (71.4)</td>
            </tr>
            <tr>
              <td rowspan="1" colspan="1">SALT = 0 (no change)</td>
              <td rowspan="1" colspan="1">5 (17.2)</td>
              <td rowspan="1" colspan="1">4 (18.2)</td>
              <td rowspan="1" colspan="1">1 (14.3)</td>
            </tr>
            <tr>
              <td rowspan="1" colspan="1">SALT &lt;0 (worsening)</td>
              <td rowspan="1" colspan="1">4 (13.8)</td>
              <td rowspan="1" colspan="1">4 (18.2)</td>
              <td rowspan="1" colspan="1">0 (0)</td>
            </tr>
          </tbody>
        </table>
      </table-wrap>
      <table-wrap id="T2" position="float" orientation="portrait">
        <label>Table 2.</label>
        <caption>
          <p>Types of <abbrev xlink:title="alopecia areata" id="ABBRID0EQQAE">AA</abbrev> and change in SALT score</p>
        </caption>
        <table id="TID0EWOAE" rules="all">
          <tbody>
            <tr>
              <td rowspan="1" colspan="1">
                <bold>Type of <abbrev xlink:title="alopecia areata" id="ABBRID0E6QAE">AA</abbrev></bold>
              </td>
              <td rowspan="1" colspan="1">
                <bold>n=29(%)</bold>
              </td>
              <td rowspan="1" colspan="1">
                <bold>Group 1 n=22 (%)</bold>
              </td>
              <td rowspan="1" colspan="1">
                <bold>Group 2 n=7(%)</bold>
              </td>
            </tr>
            <tr>
              <td rowspan="1" colspan="1"><abbrev xlink:title="alopecia areata" id="ABBRID0EASAE">AA</abbrev> partialis</td>
              <td rowspan="1" colspan="1">11 (37.9)</td>
              <td rowspan="1" colspan="1">10 (45.5)</td>
              <td rowspan="1" colspan="1">1 (14.3)</td>
            </tr>
            <tr>
              <td rowspan="1" colspan="1">SALT ≥50</td>
              <td rowspan="1" colspan="1">11 (37.9)</td>
              <td rowspan="1" colspan="1">10 (45.5)</td>
              <td rowspan="1" colspan="1">1 (14.3)</td>
            </tr>
            <tr>
              <td rowspan="1" colspan="1">0 &lt;SALT &lt;50</td>
              <td rowspan="1" colspan="1">0 (0)</td>
              <td rowspan="1" colspan="1">0 (0)</td>
              <td rowspan="1" colspan="1">0 (0)</td>
            </tr>
            <tr>
              <td rowspan="1" colspan="1">SALT = 0 (no change)</td>
              <td rowspan="1" colspan="1">0 (0)</td>
              <td rowspan="1" colspan="1">0 (0)</td>
              <td rowspan="1" colspan="1">0 (0)</td>
            </tr>
            <tr>
              <td rowspan="1" colspan="1">SALT &lt;0 (worsening)</td>
              <td rowspan="1" colspan="1">0 (0)</td>
              <td rowspan="1" colspan="1">0 (0)</td>
              <td rowspan="1" colspan="1">0 (0)</td>
            </tr>
            <tr>
              <td rowspan="1" colspan="1">АA reticularis</td>
              <td rowspan="1" colspan="1">11 (37.9)</td>
              <td rowspan="1" colspan="1">6 (27.3)</td>
              <td rowspan="1" colspan="1">5 (71.4)</td>
            </tr>
            <tr>
              <td rowspan="1" colspan="1">SALT ≥50</td>
              <td rowspan="1" colspan="1">1 (3.5)</td>
              <td rowspan="1" colspan="1">1 (4.6)</td>
              <td rowspan="1" colspan="1">0 (0)</td>
            </tr>
            <tr>
              <td rowspan="1" colspan="1">0 &lt;SALT &lt;50</td>
              <td rowspan="1" colspan="1">8 (27.6)</td>
              <td rowspan="1" colspan="1">3 (13.6)</td>
              <td rowspan="1" colspan="1">5 (71.4)</td>
            </tr>
            <tr>
              <td rowspan="1" colspan="1">SALT = 0 (no change)</td>
              <td rowspan="1" colspan="1">0 (0)</td>
              <td rowspan="1" colspan="1">0 (0)</td>
              <td rowspan="1" colspan="1">0 (0)</td>
            </tr>
            <tr>
              <td rowspan="1" colspan="1">SALT &lt;0 (worsening)</td>
              <td rowspan="1" colspan="1">2 (6.9)</td>
              <td rowspan="1" colspan="1">2 (9.1)</td>
              <td rowspan="1" colspan="1">0 (0)</td>
            </tr>
            <tr>
              <td rowspan="1" colspan="1"><abbrev xlink:title="alopecia areata" id="ABBRID0EHWAE">AA</abbrev> totalis</td>
              <td rowspan="1" colspan="1">6 (20.7)</td>
              <td rowspan="1" colspan="1">5 (22.7)</td>
              <td rowspan="1" colspan="1">1 (14.3)</td>
            </tr>
            <tr>
              <td rowspan="1" colspan="1">SALT ≥50</td>
              <td rowspan="1" colspan="1">0 (0)</td>
              <td rowspan="1" colspan="1">0 (0)</td>
              <td rowspan="1" colspan="1">0 (0)</td>
            </tr>
            <tr>
              <td rowspan="1" colspan="1">0&lt;SALT &lt;50</td>
              <td rowspan="1" colspan="1">0 (0)</td>
              <td rowspan="1" colspan="1">0 (0)</td>
              <td rowspan="1" colspan="1">0 (0)</td>
            </tr>
            <tr>
              <td rowspan="1" colspan="1">SALT = 0 (no change)</td>
              <td rowspan="1" colspan="1">4 (13.8)</td>
              <td rowspan="1" colspan="1">3 (13.6)</td>
              <td rowspan="1" colspan="1">1 (14.3)</td>
            </tr>
            <tr>
              <td rowspan="1" colspan="1">SALT &lt; 0 (worsening)</td>
              <td rowspan="1" colspan="1">2 (6.9)</td>
              <td rowspan="1" colspan="1">2 (9.1)</td>
              <td rowspan="1" colspan="1">0 (0)</td>
            </tr>
            <tr>
              <td rowspan="1" colspan="1"><abbrev xlink:title="alopecia areata" id="ABBRID0ENYAE">AA</abbrev> ophiasis</td>
              <td rowspan="1" colspan="1">1 (3.5)</td>
              <td rowspan="1" colspan="1">1 (4.5)</td>
              <td rowspan="1" colspan="1">0 (0)</td>
            </tr>
            <tr>
              <td rowspan="1" colspan="1">SALT = 0 (no change)</td>
              <td rowspan="1" colspan="1">1(3.5)</td>
              <td rowspan="1" colspan="1">1 (4.5)</td>
              <td rowspan="1" colspan="1">0 (0)</td>
            </tr>
          </tbody>
        </table>
      </table-wrap>
      <fig id="F1" position="float" orientation="portrait">
        <object-id content-type="arpha">234F05A3-81F7-57AD-B6FF-FA2C5BD6B509</object-id>
        <label>Figure 1.</label>
        <caption>
          <p>Comparison between trichoscopic markers at baseline (BL) and at follow-up (FU).</p>
        </caption>
        <graphic xlink:href="foliamedica-66-1-e115484-g001.jpg" position="float" orientation="portrait" xlink:type="simple" id="oo_994228.jpg">
          <uri content-type="original_file">https://binary.pensoft.net/fig/994228</uri>
        </graphic>
      </fig>
      <table-wrap id="T3" position="float" orientation="portrait">
        <label>Table 3.</label>
        <caption>
          <p>DLQI of <abbrev xlink:title="alopecia areata" id="ABBRID0E3ZAE">AA</abbrev> patients at base line (BL), and at follow-up (FU)</p>
        </caption>
        <table id="TID0E51AE" rules="all">
          <tbody>
            <tr>
              <td rowspan="1" colspan="1">
                <bold>DLQI Score</bold>
              </td>
              <td rowspan="1" colspan="1">
                <bold>DLQI BL n=30 (%)</bold>
              </td>
              <td rowspan="1" colspan="1">
                <bold>Group 1 DLQI BL n=23 (%)</bold>
              </td>
              <td rowspan="1" colspan="1">
                <bold>Group 2 DLQI BL n=7 (%)</bold>
              </td>
              <td rowspan="1" colspan="1">
                <bold>DLQI FU n=30 (%)</bold>
              </td>
              <td rowspan="1" colspan="1">
                <bold>Group 1 DLQI FU n=23 (%)</bold>
              </td>
              <td rowspan="1" colspan="1">
                <bold>Group 2 DLQI FU n=7 (%)</bold>
              </td>
            </tr>
            <tr>
              <td rowspan="1" colspan="1">0–1</td>
              <td rowspan="1" colspan="1">4 (13.33)</td>
              <td rowspan="1" colspan="1">4 (17.39%)</td>
              <td rowspan="1" colspan="1">0 (0%)</td>
              <td rowspan="1" colspan="1">13 (43.33)</td>
              <td rowspan="1" colspan="1">11 (47.83%)</td>
              <td rowspan="1" colspan="1">2 (28.57%)</td>
            </tr>
            <tr>
              <td rowspan="1" colspan="1">2–5</td>
              <td rowspan="1" colspan="1">10 (33.33)</td>
              <td rowspan="1" colspan="1">9 (39,13%)</td>
              <td rowspan="1" colspan="1">1 (14.29%)</td>
              <td rowspan="1" colspan="1">11 (36.67)</td>
              <td rowspan="1" colspan="1">7 (30.43%)</td>
              <td rowspan="1" colspan="1">4 (57.14%)</td>
            </tr>
            <tr>
              <td rowspan="1" colspan="1">6–10</td>
              <td rowspan="1" colspan="1">8 (26.67)</td>
              <td rowspan="1" colspan="1">3 (13.04%)</td>
              <td rowspan="1" colspan="1">5 (71.43%)</td>
              <td rowspan="1" colspan="1">4 (13.33)</td>
              <td rowspan="1" colspan="1">3 (13.04%)</td>
              <td rowspan="1" colspan="1">1 (14.29%)</td>
            </tr>
            <tr>
              <td rowspan="1" colspan="1">11–20</td>
              <td rowspan="1" colspan="1">8 (26.67)</td>
              <td rowspan="1" colspan="1">7 (30.43%)</td>
              <td rowspan="1" colspan="1">1 (14.29%)</td>
              <td rowspan="1" colspan="1">2 (6.67)</td>
              <td rowspan="1" colspan="1">2 (8.70%)</td>
              <td rowspan="1" colspan="1">0 (0%)</td>
            </tr>
            <tr>
              <td rowspan="1" colspan="1">21-30</td>
              <td rowspan="1" colspan="1">0 (0)</td>
              <td rowspan="1" colspan="1">0 (0%)</td>
              <td rowspan="1" colspan="1">0 (0%)</td>
              <td rowspan="1" colspan="1">0 (0)</td>
              <td rowspan="1" colspan="1">0 (0%)</td>
              <td rowspan="1" colspan="1">0 (0%)</td>
            </tr>
          </tbody>
        </table>
      </table-wrap>
    </sec>
    <sec sec-type="Discussion" id="SECID0EFJAC">
      <title>Discussion</title>
      <p>Twelve patients showed significant hair growth, 11 with AAP, one with AAR, and most had normal antithyroid antibody levels. Insignificant treatment outcomes were found in eight patients (27.6%) with AAR, three with normal and five with elevated antibodies. Five patients remained unchanged, four of whom had AT and one had AAO, four with normal and one with elevated antibody levels. Worsening was established in four patients, two with AAT and two with AAR, and all had normal antithyroid antibody levels.</p>
      <p>The present study showed that <abbrev xlink:title="platelet-rich plasma" id="ABBRID0EMJAC">PRP</abbrev> application resulted in significant improvement in hair restoration in patients with mild to moderate forms of <abbrev xlink:title="alopecia areata" id="ABBRID0EQJAC">AA</abbrev>. Trichoscopy results at FU showed a decrease in dystrophic hairs and an increase in growing hairs in comparison to BL. These findings are consistent with the results of other <abbrev xlink:title="platelet-rich plasma" id="ABBRID0EUJAC">PRP</abbrev> studies. A nonrandomized, placebo-controlled study has established that <abbrev xlink:title="platelet-rich plasma" id="ABBRID0EYJAC">PRP</abbrev> therapy is effective in mild cases of <abbrev xlink:title="alopecia areata" id="ABBRID0E3JAC">AA</abbrev>.<sup>[<xref ref-type="bibr" rid="B21">21</xref>]</sup> A placebo-controlled, randomized study of 90 <abbrev xlink:title="alopecia areata" id="ABBRID0EHKAC">AA</abbrev> patients compared the results of application of topical minoxidil 5%, <abbrev xlink:title="platelet-rich plasma" id="ABBRID0ELKAC">PRP</abbrev> injections, and placebo. ﻿Both <abbrev xlink:title="platelet-rich plasma" id="ABBRID0EPKAC">PRP</abbrev> and minoxidil showed a significant increase in hair growth. <abbrev xlink:title="platelet-rich plasma" id="ABBRID0ETKAC">PRP</abbrev> treatment led to significant hair regrowth in <abbrev xlink:title="alopecia areata" id="ABBRID0EXKAC">AA</abbrev> partialis (70%) and AU (30%), but not in AT. Patients treated with <abbrev xlink:title="platelet-rich plasma" id="ABBRID0E2KAC">PRP</abbrev> had better and earlier response in terms of fully pigmented hair regrowth, reduction of short vellus hair, yellow dots, and dystrophic hair.<sup>[<xref ref-type="bibr" rid="B22">22</xref>]</sup> A placebo-controlled, randomized trial that included 45 participants assigned to receive <abbrev xlink:title="platelet-rich plasma" id="ABBRID0EGLAC">PRP</abbrev>, triamcinolone acetonide (TrA) or placebo found that both <abbrev xlink:title="platelet-rich plasma" id="ABBRID0EKLAC">PRP</abbrev> and TrA led to significant hair growth in <abbrev xlink:title="alopecia areata" id="ABBRID0EOLAC">AA</abbrev> lesions compared to the placebo and baseline. <abbrev xlink:title="platelet-rich plasma" id="ABBRID0ESLAC">PRP</abbrev> was found to be more effective than TrA based on dermoscopic findings.‌<sup>[<xref ref-type="bibr" rid="B23">23</xref>]</sup> A non-randomized trial compared the effect of intralesional TrA and <abbrev xlink:title="platelet-rich plasma" id="ABBRID0E4LAC">PRP</abbrev> application among 74 <abbrev xlink:title="alopecia areata" id="ABBRID0EBMAC">AA</abbrev> patients with hair loss involvement less than 25%. The study found complete hair regrowth of all patients in both groups. Patients treated with <abbrev xlink:title="platelet-rich plasma" id="ABBRID0EFMAC">PRP</abbrev> had an earlier response than patients treated with TrA with statistically insignificant difference.‌<sup>[<xref ref-type="bibr" rid="B24">24</xref>]</sup> A prospective study to assess the effectiveness of <abbrev xlink:title="platelet-rich plasma" id="ABBRID0EQMAC">PRP</abbrev> applied in six sessions at 4-week intervals included 20 patients with chronic <abbrev xlink:title="alopecia areata" id="ABBRID0EUMAC">AA</abbrev> followed up at one year. The majority of the participants showed good hair regrowth, except for one patient who experienced minimal hair regrowth and relapse.<sup>[<xref ref-type="bibr" rid="B25">25</xref>]</sup> A case report of a successful <abbrev xlink:title="platelet-rich plasma" id="ABBRID0E6MAC">PRP</abbrev> treatment of <abbrev xlink:title="alopecia areata" id="ABBRID0EDNAC">AA</abbrev> barbae aligns with the results of the patient with <abbrev xlink:title="alopecia areata" id="ABBRID0EHNAC">AA</abbrev> barbae in this study.<sup>[<xref ref-type="bibr" rid="B26">26</xref>]</sup> In a case series of nine patients suffering from chronic <abbrev xlink:title="alopecia areata" id="ABBRID0ESNAC">AA</abbrev> with more than half of the scalp affected, <abbrev xlink:title="platelet-rich plasma" id="ABBRID0EWNAC">PRP</abbrev> treatment had no substantial effect at one-year follow-up.‌<sup>[<xref ref-type="bibr" rid="B27">27</xref>]</sup> In ﻿a case report, <abbrev xlink:title="alopecia areata" id="ABBRID0EBOAC">AA</abbrev> ophiasis was treated successfully with <abbrev xlink:title="platelet-rich plasma" id="ABBRID0EFOAC">PRP</abbrev>.<sup>[<xref ref-type="bibr" rid="B28">28</xref>]</sup></p>
      <p>To the best of our knowledge, this is the first study to estimate the efficacy of <abbrev xlink:title="platelet-rich plasma" id="ABBRID0EROAC">PRP</abbrev> therapy in <abbrev xlink:title="alopecia areata" id="ABBRID0EVOAC">AA</abbrev> patients with normal or elevated levels of thyroid antibodies. The mechanism of relationship between <abbrev xlink:title="alopecia areata" id="ABBRID0EZOAC">AA</abbrev> and thyroid autoimmunity is not well established. Genetic and racial factors probably play a role in this relationship. A potential risk of autoimmune thyroid disease particularly in severe and refractory <abbrev xlink:title="alopecia areata" id="ABBRID0E4OAC">AA</abbrev> was suspected.<sup>[<xref ref-type="bibr" rid="B12">12</xref>]</sup></p>
      <p>The study also established improved quality of life due to hair growth stimulation.</p>
      <p>Limitations of the study are the insufficient number of cases, lack of a control group, and a short follow-up period. A long-term follow-up may not be very informative because of the high rate of spontaneous remissions and relapses in <abbrev xlink:title="alopecia areata" id="ABBRID0EKPAC">AA</abbrev>.</p>
    </sec>
    <sec sec-type="Conclusions" id="SECID0EOPAC">
      <title>Conclusions</title>
      <p>Autologous <abbrev xlink:title="platelet-rich plasma" id="ABBRID0EUPAC">PRP</abbrev> is a safe, relatively effective, minimally invasive treatment method. <abbrev xlink:title="platelet-rich plasma" id="ABBRID0EYPAC">PRP</abbrev> therapy was effective in patients with mild to moderate form of <abbrev xlink:title="alopecia areata" id="ABBRID0E3PAC">AA</abbrev> and most had normal antithyroid antibodies. Patients with severe <abbrev xlink:title="alopecia areata" id="ABBRID0EBAAE">AA</abbrev>, <abbrev xlink:title="alopecia areata" id="ABBRID0EFAAE">AA</abbrev> ophiasis and alopecia totalis, with normal and elevated antibodies, did not benefit from the <abbrev xlink:title="platelet-rich plasma" id="ABBRID0EJAAE">PRP</abbrev> therapy. Controlled trials with more subjects are needed to validate the reported results.</p>
    </sec>
    <sec sec-type="Funding" id="SECID0ENAAE">
      <title>Funding</title>
      <p>The study was financed by the Department of Science and Research at the Medical University of Plovdiv (Project No. DPDP-05/2020).</p>
    </sec>
    <sec sec-type="Competing interests" id="SECID0ESAAE">
      <title>Competing interests</title>
      <p>The author has declared that no competing interests exist.</p>
    </sec>
    <sec sec-type="Acknowledgements" id="SECID0EXAAE">
      <title>Acknowledgements</title>
      <p>The author has no support to report.</p>
    </sec>
  </body>
  <back>
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