IL-6 and TGF-β gene polymorphisms, their serum levels, as well as HLA profile, in patients with systemic lupus erythematosus

Objective The aim of the study was to explore whether TGF-beta and IL-6 gene polymorphisms may be associated with SLE and assess the frequency of HLA-DRB1 alleles in Polish systemic lupus erythematosus (SLE) patients. Methods 216 SLE patients and 552 healthy individuals were examined for TGF-beta rs1800469 and rs1800470 by TaqMan SNP genotyping assay and for and IL-6(rs2069827 and rs1800795 using the PCR-RFLP method. Results An increased frequency of TT genotype and T allele of the TGF beta-509 C/T was found in SLE patients (p=0.02). The TGF-beta 869 C allele was more frequent in SLE patients. The genotype-phenotype analysis showed association between the TGF beta-509 C/T and mean value of CRP, ESR, haemoglobin, APTT, Pt and INR (p=0.05, p=0.03, p<0.001, p=0.03, p=0.03 and p=0.05, respectively) as well as anti-SSA and anti-Sm presence (p=0.04 and p=0.03, respectively); the TGF-beta 869 T/C and mean value of APTT and INR (p=0.01 and p=0.05, respectively); the IL-6-174 G/C and SLICC (p=0.05), anti-SSA (p=0.05) and anti-SSB (p=0.05). A higher TGF-beta and IL-6 serum level were found in SLE patients compared to controls (both p<0.0001). In SLE patients with the TGF-beta-509 TT genotype have shown positive association with the TGF-beta serum levels. Polish SLE patients have strong positive association with HLA-DRB1*52.1, and negative with the HLA-DRB1*07:01 allele. HLA-DRB1*52.1 was also associated with higher TGF-beta serum levels in the Polish population. Conclusion Our results suggested that the TGF beta-509 C/T variant may be considered as a genetic marker for SLE in the Polish population.