HLA profile in paediatric ITP: Comparison with healthy controls and prognostic implications.

Immune thrombocytopenia (ITP) is an autoimmune disorder characterized by isolated low platelet counts. Although several studies have explored the relationship between the human leucocyte antigen (HLA) system and ITP, findings have been inconsistent. We compared HLA typing between paediatric ITP patients and healthy controls to assess its role in ITP susceptibility. We also evaluated the association between HLA alleles and clinical outcomes in our paediatric ITP cohort. This retrospective observational study included 135 patients with primary ITP and a control group of 929 healthy individuals. The median age of ITP patients was 5.71 years (Interquartile range 2.71-10.21). The HLA-DRB1*07 and HLA-DRB1*13 alleles were more prevalent in healthy controls than in ITP patients, suggesting a potential protective role (p < 0.05). In contrast, HLA-A*68, HLA-B*40 and HLA-DRB1*14 alleles were associated with an increased risk of ITP (p < 0.05). Regarding prognosis, HLA-A*26 allele correlated with lower recovery rates, while HLA-C*03 allele was associated with a higher recovery likelihood (p < 0.05). In addition, HLA-A*02 and HLA-C*04 alleles and the HLA-A02 supertype showed a significant association with a higher probability of chronicity (p < 0.05). Our results highlight the potential role of HLA typing as a diagnostic and prognostic tool for ITP. However, larger studies are required to validate these associations.