Cytotoxic T-lymphocyte antigen-4 (CTLA-4) gene polymorphism and susceptibility to non-Hodgkin's lymphoma.

The CTLA-4 molecule plays an important role in immune regulation by downregulating activation of T cells. Polymorphisms in the CTLA-4 gene have been shown to be associated to a number of autoimmune diseases including blood disorders. In this study, the intragenic polymorphisms of the CTLA-4 gene at position -318C/T, +49A/G, and the dinucleotide (AT)(n) repeat polymorphism in exon 3 were analyzed in patients with non-Hodgkin's lymphoma. Genotype and haplotype analysis showed that the exon 1+49AA genotype was over-represented among patients with NHL (P = 0.002), whereas no difference was observed for the -318C/T promoter and the (AT)(n) polymorphisms (P > 0.05). The data obtained indicate that the CTLA-4+49A/G polymorphism may have a role in genetic susceptibility to NHL.