Objective: To investigate the possible association of CCR2 and CCR5 chemokine receptor gene polymorphisms with the susceptibility, clinical features, and the outcome of systemic lupus erythematosus (SLE).
Methods: We studied 276 patients with SLE and 194 ethnically matched healthy controls. Patients were stratified according to their clinical features and outcome. Genotyping of 190 (A/G) CCR2 and D32CCR5 was performed using polymerase chain reaction techniques.
Results: No association between the polymorphisms studied and susceptibility to SLE was found. However, when patients were stratified according to their clinical features, an increase in the frequency of individuals bearing D32CCR5 among patients with anti-dsDNA antibodies was found [15.1% vs 6.4% in negative patients (p = 0.03, pcorr > 0.05, OR 2.61, 95% CI 1.04-7.40) and 8% in controls (p = 0.04, pcorr > 0.05, OR 1.97, 95% CI 0.97-4.11)]. Moreover, a significant increase in the frequency of D32CCR5 individuals was observed among patients with biopsy-proven nephritis [20.5% vs 8.5% in patients without nephritis (p = 0.03, pcorr > 0.05, OR 2.79, 95% CI 0.93-7.70) and 8% in controls (pFisher = 0.04, pcorr > 0.05, OR 2.87, 95% CI 0.97-7.82)]. Regarding the outcome, a higher median severity index was found among patients bearing D32CCR5 (33.5 +/- 17.9 vs 26.6 +/- 17.1 in CCR5/CCR5 individuals; p = 0.04).
Conclusion: Polymorphisms of CCR2 and CCR5 do not seem to be involved in susceptibility to SLE, although a slight contribution of the CCR5 polymorphism in the production of anti-dsDNA autoantibodies, in the development of lupus nephritis, and in the outcome of the disease could be postulated.