OBJECTIVETo explore the interactions of gene polymorphisms of cytotoxic T lymphocyte antigen 4 (CTLA-4) and programmed cell death 1 (PDCD-1) with risk environmental factors in individuals with systemic lupus erythematosus (SLE) from Han nationality female population in South of Changjiang River region of China.

METHODSWith a case-only design, a total of 258 cases were enrolled in this study, and single nucleotide polymorphisms (SNPs) of the PDCD-1 and CTLA-4 genes were determined by means of PCR-RFLP. With the aid of Poisson loglinear mode, interactions between gene-gene and gene-environment were fitted under the dominant, recessive, additive and multiple models, respectively.

RESULTSIt was found that interaction existed between GG genotype of PD1.6 and UV history under separate inherent models of the recessive mode (OR = 3.714, 95%CI: 1.235 - 11.179) and additive mode (OR = 3.199, 95%CI: 1.023 - 10.004). For CTLA-4 locus, there existed interactions between TT/TC genotype of -1722T-->C and UV history under the dominant model (OR = 4.874, 95%CI: 1.119 - 21.242), and interaction between T allele and UV history was also found under the multiple model (OR = 1.470, 95%CI: 1.047 - 2.065). While, under the additive mode for CTLA-4, it was found that interactions existed between TT genotype of -1722T-->C and UV history (OR = 4.744, 95%CI: 1.037 - 21.737), as well as between TC genotype of -1722T-->C and UV history (OR = 4.973, 95%CI: 1.110 - 22.287).

CONCLUSIONThe interactions between UV history and polymorphisms of CTLA-4 and PDCD-1 gene for SLE were observed, which indicates that there may be association of their interactions with the development of SLE in Han nationality females population in the south regions of Changjiang River in China.