Association of HPA Antigens with Immune Thrombocytopenia: A Case-Control Study by PCR-SSP Method

Background: Human platelet antigens (HPAs) play a clinically significant role in alloimmunization and the development of immune-mediated disorders such as immune thrombocytopenia (ITP), fetal and neonatal alloimmune thrombocytopenia (FNAIT), and post-transfusion purpura (PTP). Understanding the genetic profiles of HPAs is critical for preventing and treating these conditions. Given the limitations of serological methods in determining HPA genotypes, this study aims to investigate the association between the genotypes of HPA1, HPA2, HPA3, HPA4, and HPA15 antigens and autoimmune thrombocytopenia in Lorestan Province, utilizing the PCR-SSP method. Materials and Methods: This case-control study involved 80 individuals diagnosed with ITP and 120 healthy controls. DNA samples were extracted using a commercial DNA extraction kit, with concentrations quantified via a Nanodrop spectrophotometer. Genotyping was performed using the PCR-SSP method with specific primers for each HPA gene. The genotype data were verified using previously established sample sets. The frequencies of each HPA genotype were recorded, and a comparative analysis was conducted between the patient and control groups to evaluate the study hypothesis. Results: The results revealed that individuals carrying the HPA2b allele had a 5.31-fold increased risk of developing ITP, a statistically significant finding (P < 0.05, OR = 5.31). Similarly, the presence of the HPA15b allele was associated with a 6.54-fold increased risk (P < 0.05, OR = 6.54). Conclusion: These findings, in conjunction with previous studies, suggest the need for larger-scale investigations across different populations. Such research could aid in the early diagnosis and prediction of thrombocytopenia severity, inform treatment strategies, and facilitate the removal of pathogenic antibodies from circulation.