Evaluation of HLA-B*05, *07, *08, *27 and *51 Allele Expression in Adults with Immune Thrombocytopenic Purpura

Background: Immune thrombocytopenic purpura (ITP) is an immune mediated acquired disease characterized by isolated thrombocytopenia. Since there is no specific and sensitive biomarkers to guide treatment of ITP patients, this study aimed to evaluate the possible application of human leukocyte alleles HLA-B5, 7, 8, 27 and 51 and their association with patients' laboratory data and clinical findings. Methods:Thirty-one adult patients with chronic ITP were included in the present study. Human leukocyte antigen (HLA) typing was done using the standard lymphocytotoxicity HLA typing method. Moreover, patients' medical records were used to collect data about disease presentations, platelet count at diagnosis. Results:Our study included 31 patients (25 females and six males) with a mean age of 40.23±17.06 years. Among all participants, HLA-B5 (25.8%) and HLA-B51 (22.6%) alleles were the most prevalent alleles, followed by HLA-B7 (9.7%) and HLA-B8 (9.7%), HLA-B27 (3.2%). The mean platelet count significantly was lower in patients with HLA-B5 (16.13x10³/μL versus 36.63x10³/μL) (P=0.01) and HLA-B51 (14.14x10³/μL versus 36.24x10³/μL) (P=0.04). Also, epistaxis and gingival bleeding were observed in patients with 11.5x10³/μL mean platelet count (P=0.04). In addition, lymphocyte and neutrophil cell counts were significantly associated with the expression of HLA-B*05 and HLA-B*51 antigens (P <0.05). Conclusions:According to the present study results, it seems that HLA-B5 and HLA-B51 alongside complete blood count test parameters may have a positive relationship in ITP patients.