Association of genetic variants of interleukin-1β gene -511T/C (rs16944) and +3954C/T (rs1143634) and serum levels of pentaxin (PTX3) and interleukin -1β (IL-1β) with disease activity of systemic lupus erythematosus patients

This study aimed to assess the association of two genetic variants of interleukin-1β gene −511T/C (rs16944) and +3954C/T (rs1143634) and serum levels of pentaxin (PTX3) and interleukin -1β (IL-1β) with systemic lupus erythematosus (SLE) susceptibility and disease activity. Methods: 50 SLE patients and 50 apparently healthy subjects serving as control group were included in this study; they were subjected to full history and clinical examinations and lab investigations including assessment of serum levels of PTX3, IL-1B using ELISA technique. Genomic DNA for IL-1β polymorphism was extracted from the peripheral blood of patients and controls for identification of IL-1β polymorphisms (−511T/C (rs16944) and +3954C/T (rs1143634)) using Real-time PCR. Results: Serum levels of PTX3 and IL1β were significantly higher in cases (8.2 ng/mL & 45.9 pg/mL respectively) when compared to control group (5.4 ng/mL & 41 pg/mL respectively). Regarding rs16944; TT genotype and T allele showed significantly higher frequency in SLE when compared to the control group (p = 0.005, <0.001 respectively) with susceptibility to develop SLE (OR = 4.125, 3.245 respectively). PTX3 level was higher in rs1143634 CT + CC when compared to TT; rs16944 TC + TT when compared to CC. serum levels of IL1β increased gradually in rs1143634 TT, CT, CC respectively; and in rs16944 CC, TC, TT respectively with significant differences between genotypes. Linear regression analysis was conducted for prediction of higher SLEDAI, rs16944 (TC + TT), higher PTX3 and IL1β were significantly associated with higher SLE Disease Activity Index (SLEDAI) in univariate analysis, the multivariable analysis revealed that PTX3 and IL1β were independent predictors for higher SLEDAI. Conclusion: Serum PTX3 and IL1β levels were significantly elevated in SLE patients when compared to controls and they were associated with high disease activity. TT genotype and T allele of rs16944 was associated with increased susceptibility to SLE development, higher disease activity and high PTX3 and IL-1β serum levels.