Background In T-cells of the systemic lupus erythematosus (SLE), the gene expression of two variants of CD44; CD44v3 and CD44v6 are increased and their expression correlates with disease activity. Moreover, the existence of these two variants is related with kidney involvement and anti-DNA positivity. Increased CD44v3 and CD44v6 expressions were shown in cells that infiltrated the kidney in SLE. It was also revealed that the hyperactivity of the B-cells in the SLE were related to increased plasmablasts and naive B-cells, increased stimulation through TLR9, activation and longer survival through BAFF, and decreased suppressor signals.
Objectives Genetic variations related to signal cell transduction in the adaptive immune system were seen to be active in SLE in different studies, and their association with clinical findings in different populations should be known.
Methods Eighty three SLE patients and 116 healthy control subjects were included into the study. The clinical features, organ involvements, laboratory values and outcome of SLE patients were obtained from hospital records. SLE patients' treatment modalities since diagnosis, their response to therapy and relapses were recorded. Polymorphisms of BANK1 gene (rs10516487 and rs10516483) –involved in B-lymphocyte intracellular signal transduction pathway-, and polymorphisms of CD44 gene (rs507230 and rs2732552) –playing a role in T-cell signal transduction- were studied from blood samples of patients by PCR method.
Results In the SLE group, rs570230 (CD44) polymorphism CT genotype was significantly more frequent than in the control group (39.8% vs. 22.4%, p=0.014). SLE group had significantly less frequent rs10516487 (BANK1) polymorphism AA genotype (1.2% vs. 8.6%); and significantly more frequent GG genotype (59% vs. 44%) and A allele than controls (p values, 0.027, 0.036 and 0.013). No significant differences were found in terms of rs10516483 (BANK1) and rs2732552 (CD44) polymorphisms. In SLE patients with nephritis, rs570230 polymorphism TT genotype was significantly more frequent (50% vs. 20.7%, p=0.009), whereas the CT genotype was less frequent in the active disease group (31% vs. 61.4%, p=0.01). rs10516487 polymorphism GG genotype was significantly more frequent in SLE patients with arthritis (62.5% vs. 40%, p=0.045).
While SLE patients with neurologic involvement had more frequent rs2732552 polymorphism AA genotype (35.3% vs. 11.5%, p=0.038), GG genotype was more frequent in patients with lupus nephritis (57.7% vs. 29.6%) and anti-nucleosome positivity (78.6% vs. 31.3%) (p values, 0.023 and 0.004). rs10516483 polymorphism CC genotype was higher in patients with alopecia in contrast to others (77.8% vs. 34.8%, p=0.042).
Conclusions In our SLE group, there is a significant association between BANK 1 (rs10516487) and rs570230 polymorphisms.
Disclosure of Interest None declared