POS1142 INTERLEUKIN-37: ASSOCIATIONS OF PLASMA LEVELS AND GENETIC VARIANTS IN GOUT

Abstract

Background:IL-37, recently characterized IL-1 family member, has anti-inflammatory effects by suppression of IL-1ß and other proinflammatory cytokines. In this study we investigated the effects of genetics variants in IL-37 link with IL-37 plasma levels in a cohorts of patients with hyperuricemia/gout.Objectives:The aim of this study was to determine the association of IL-37 gene polymorphism and plasma IL-37 levels in patients with hyperuricemia and gout.Methods:The cohorts consisted of 50 control subjects, 50 subjects of primary hyperuricemia, 50 subjects of primary gout, 28 subjects of tophaceous gout and 19 subjects of acute gout flare. The analyzed cohorts were selected from a previously reported set of 250 hyperuricemia/gout patients and 132 normouricemic subjects (1) according to the descending level of serum urate. All coding regions and intron-exon boundaries of IL-37, exon 1-5, were amplified and sequenced directly. Comparisons of presence/absence of identified variants was performed using P-values binomial test. Levels of plasma IL-37 were measured using Enzyme-Linked ImmunoSorbent Assay. All tests were performed in accordance with standards set by the institutional ethics committees, which approved the project in Prague (no.6181/2015).Results:We identified 12 IL-37 genetic variants: five intron (rs28947188, rs2466448, rs3811045, rs3811048, rs2708944), and seven non-synonymous allelic variants (rs3811046, rs3811047, rs2708943, rs2723183, rs2723187, rs2708947, rs27231927). Minor allele frequency (MAF) of those variants in European population from ExAC databases were used for comparison. Our data showed that the rs28947188, rs3811045, rs3811046, rs3811047, rs2723187, rs2708947, and rs27231927 variants were under-represented in the Czech hyperuricemia, gout, and tophaceous gout cohort compared with the control cohort and general European population (P = 0.0082 – 0.0395).The levels of plasma IL-37 were significantly higher in patients with tophaceous gout compared to control subjects (P 0.0329) whereas no changes were observed in subjects with primary hyperuricemia, primary gout or acute gout flare compared to control subjects. However, IL-37 was elevated in cohorts of patients with gout, tophaceous gout and acute gout flare compared to primary hyperuricemia subjects (P 0.0198, 0.0005, 0.0099; respectively).Conclusion:Although further analyzes are needed to elucidate the role of IL-37 in the gout, our results show that genetic variants in anti-inflammatory cytokine IL-37 are probably implicated in the pathogenesis of gout.