BackgroundThe systemic lupus erythematosus (SLE) is a heterogeneous disorder with the involvement of different environmental, immunological, and genetic factors. T-cell immunoglobulin and mucin domain (TIM)-3 and TIM-4 genes are the two members of the TIM gene family with different immunological roles in Th-1 and antigen-presenting cells respectively. Methods131 cases diagnosed with SLE and 131 healthy volunteers as a control group enrolled in the study to investigate the association of rs1036199 of TIM-3, rs7700944 and rs6882076 polymorphisms of TIM-4 gene with susceptibility to SLE using amplification refractory mutation system-polymerase chain reaction (ARMS-PCR) for TIM-3 rs1036199 and TIM-4 rs6882076 polymorphisms and tetra-ARMS PCR for TIM-4 rs7700944 polymorphism. ResultsWhile no association found between TIM-3 rs1036199 polymorphism and SLE, there was a significant difference in the distribution of the G allele among cases and controls for TIM-4 rs7700944 polymorphism (P = .007). Regarding TIM-4 rs6882076 polymorphism, investigations showed that the frequency of the CC genotype was 38.9% in cases and 32.8% in controls (P = .033). ConclusionsThe results suggest that TIM gene family variants, especially TIM-4 gene polymorphisms, may have important roles in the SLE pathogenesis, although further investigations are needed to analyze the precise roles of these polymorphisms in SLE pathogenesis.