Objective: Interaction of advanced glycation end products (AGEs) with their receptors (RAGE) plays an important role in inflammation in auto-immune diseases. Several functional polymorphisms of RAGE have been described. In this study we analysed the role of RAGE polymorphisms in disease susceptibility for systemic lupus erythematosus (SLE). In addition, we investigated whether these polymorphisms in SLE are associated with serum levels of soluble RAGE (sRAGE), renal involvement (lupus nephritis (LN)) and its outcome. Methods: For this cross-sectional study DNA samples of 97 SLE patients, 114 LN patients and 429 healthy controls (HC) were genotyped for four RAGE polymorphisms: −429 T/C, −374 T/A, 2184 A/G and Gly82Ser. Differences in genotype frequencies and allele frequencies were tested between patients and HCs. In SLE patients, sRAGE was measured by enzyme-linked immunosorbent assay (ELISA). In addition, association of genotypes with sRAGE and disease severity in LN was analysed. Results: The C allele of −429 T/C, the T allele of −374 T/A and the G allele of 2184 A/G were significantly more prevalent in SLE and LN compared with HC. In LN, the C allele of RAGE −429 T/C, the A allele of −374 T/A and the G allele of RAGE 2184 A/G polymorphism were significantly associated with more proteinuria and worse renal function during the first two years of treatment. No association of genotype with sRAGE was found. Conclusion: RAGE polymorphisms are associated with susceptibility to SLE and LN. In addition, some of these polymorphisms are likely to be associated with disease severity and initial response to treatment in LN.
Accumulation of advanced glycation endproducts in patients with systemic lupus erythematosus
