Impact of polymorphisms of the major histocompatibility complex class II, interleukin-10, tumor necrosis factor-α and cytotoxic T-lymphocyte antigen-4 genes on inhibitor development in severe hemophilia A

Abstract

Background: Approximately 25% of severe hemophilia A (HA) patients develop antibodies to factor VIII protein. Patients: In the present case-controlled cohort study, 260 severely affected, mutation-type-matched HA patients were studied for association of human leukocyte antigen (HLA) class II molecules and polymorphisms in the genes encoding interleukin-10 (IL-10), tumor necrosis factor-α (TNF-α) and cytotoxic T-lymphocyte antigen-4 (CTLA-4) and development of inhibitors. Results: Our results demonstrate a higher frequency of DRB1*15 and DQB1*0602 alleles as well as of the haplotype DRB1*15/DQB1*0602 in inhibitor patients [odds ratio (OR) 1.9; P<0.05]. In TNF-α, the A allele of the -308G>A polymorphism was found with higher frequency in the inhibitor cohort (0.22 vs. 0.13, OR 1.80). This finding was more pronounced for the homozygous A/A genotype (OR 4.7). For IL-10, the -1082G allele was observed more frequently in patients with inhibitors (0.55 vs. 0.43; P=0.008). The functional cytokine phenotype was determined for the first time, on the basis of the genetic background, and this showed that 12% of patients with inhibitors were high-TNF-α/high-IL-10 producers, as compared with 3% of non-inhibitor patients (OR 4.4). A trend for a lower frequency of the A allele of the CT60 polymorphism in CTLA-4 was found in inhibitor patients (0.42 vs. 0.50). Conclusions: In conclusion, the reported data clearly highlighted the participation of HLA molecules in inhibitor formation in a large cohort of patients. The higher frequencies of the -308G>A polymorphism in TNF-α and -1082A>G in IL-10 in inhibitor patients confirmed the earlier published data. The CT60 single-nucleotide polymorphism in CTLA-4 is of apparently less importance. © 2009 International Society on Thrombosis and Haemostasis.