[Fcgamma receptor polymorphisms and systemic lupus erythematosus]

The G Immunoglobulin Fc Receptors (FcgammaR) belong to the TNFR5 receptors family, of the immunoglobulin superfamily and are widely expressed in the immune system; their function follows in importance after the complement receptors for immunocomplexes clearance. On the other hand, the systemic lupus erythematosus (SLE) is the prototype of the autoimmune diseases mediated by immunocomplexes and several studies have shown an impaired handle of these ones in part due to dysfunction of the FcgammaR. Among all types of Fcgamma receptors, the FcgammaRIIA, FcgammaRIIB, FcgammaRIIIA and FcgammaRIIIB have well characterized polymorphisms that produce an alteration in the receptor function. A number of studies have been done worldwide to probe an association between these polymorphism and SLE or some of its clinical features, among these the most important are two meta-analyses in which it is shown that the FcygammaRIIA-R131 polymorphism present a significant association with SLE susceptibility (OR: 1.3, 95% CI: 1.10-1.52), while the FcgammaRIIIA F176 polymorphism showed to be associated with lupic nephritis (OR: 1.47, 95% CI: 1.11-1.93, p = 0.006) but not with SLE susceptibility, the results in the rest of the polymorphisms studied are still contradictories.