Interleukin‐4 single nucleotide polymorphisms in juvenile systemic lupus erythematosus

Summary Juvenile systemic lupus erythematosus ( JSLE ) is a chronic, recurrent multisystem inflammatory disease, caused by a combination of environmental events and genetic risk factors. As cytokines, including interleukin‐4 ( IL ‐4), seem to have a role in the pathogenesis of JSLE , the investigation was performed to evaluate the associations of specific single nucleotide polymorphisms ( SNP s) of IL ‐ 4 and IL‐4RA genes in a case–control study. Fifty‐nine patients with JSLE were recruited in this study as patients' group and compared with 140 healthy volunteers. Genotyping was performed for IL‐4 gene at positions −1098, −590 and −33, as well as IL ‐4 receptor α ( IL‐4RA ) gene at position +1902, using polymerase chain reaction with sequence‐specific primers method. Following alleles were found to be more common among patients with JSLE : C at −590 and −33 and T at −1098 of IL‐4 gene ( P value < 0.001; OR  = 4.6, P value < 0.001; OR  = 2.7 and P value < 0.001; OR  = 2.1, respectively). Additionally, significant positive associations for the following genotypes were recognized in JSLE cases, compared with controls: C/C at −33, C/C at −590 and T/T at −1098 of IL‐4 gene ( P value < 0.001; OR  = 5.3, P value < 0.001; OR  = 29.5 and P value < 0.001; OR  = 3.3, respectively), while following genotypes were less frequent among patients with JSLE : T/C at −33 and −590 and T/G at −1098 of IL‐4 gene ( P value < 0.001; OR  = 0.1, P value < 0.001; OR  = 0.03 and P value < 0.001; OR  = 0.3, respectively). Furthermore, we noticed an astonishing negative haplotypic association for JSLE for IL ‐4 (positions −1098, −509 and −33) TTC , GCC and TTT haplotypes ( P value < 0.001). There was also a significant relationship between TCC haplotype ( IL‐4 gene at positions −1098, −590 and −33) and having JSLE ( P value < 0.001). On the other hand, we found no significant associations between IL ‐4R polymorphisms and the susceptibility to JSLE . Cytokine gene polymorphisms may influence susceptibility to JSLE . Particular IL‐4 gene variants are associated with JSLE and might have a role in the pathophysiology of disease.