en Pediatric Hematology & Oncology Pediatric Hematology & Oncology پژوهشي Original Article <p><strong>Background:</strong> It is suggested that HA-1 mismatching among hematopoietic stem cell transplanted recipients-donors is associated with acute graft-versus-host disease (aGVHD). So the aim of this study was to evaluate HA-1 frequency and examine the correlation between HA-1 disparity and GVHD patients who received transplantation from a HLA-identical sibling. </p><p><strong>Samples and Methods:</strong> the DNA was extracted from 30 pairs of HLA-A2-positive Iranian recipients-donors with GVHD I-IV and 25 pairs without GVHD. All the patients received HSCT from HLA-identical siblings. HA-1 was detected by SSP-PCR method. The HA-1 typing was performed using SSP method (SSP Minor Histocompatibility Antigen primer sets). </p><p><strong>Results:</strong> The frequency of HA-1R and HA-1H alleles in patients were 0.55 and 0.45 respectively, and showed no significant difference with these alleles frequency in donors 0.53 and 0.47 respectively (p>0.05). The HA-1 disparity was detected in 8 out of 55 donor/recipient pairs (14.5%). The aGVHD (grades I-IV) occurred in 6 (75%) out of 8 patients but in spite of higher incidence of it in the group of patients with HA-1 incompatibility, it was not statistically significant. </p><p><strong>Conclusion:</strong> In spite of higher frequency of HA-1 disparity in GVHD+ group our data did not reflect a significant association between the HA-1 disparity and risk of acute GVHD. </p> HA-1 disparity, GVHD, Hematopoietic Stem cell transplantation (HSCT), Iranian 33 38 http://ijbc.ir/browse.php?a_code=A-10-2-32&slc_lang=en&sid=1 S Mohammadi 1003194753284600218 1003194753284600218 Yes M Shaiegan 1003194753284600219 1003194753284600219 No KA Moghadam 1003194753284600220 1003194753284600220 No GR Babaee 1003194753284600221 1003194753284600221 No S Samiei 1003194753284600222 1003194753284600222 No A Ghavamzadeh 1003194753284600223 1003194753284600223 No F Shakerpour 1003194753284600224 1003194753284600224 No