Interleukin 1beta gene polymorphism association with severe renal manifestations and renal sequelae in Henoch-Schönlein purpura.

OBJECTIVE To assess the influence of the interleukin (IL)-1beta gene (-511 C/T) in the incidence of Henoch-Schönlein purpura (HSP) and determine its possible implication in severe systemic complications of HSP, in particular severe renal involvement and permanent renal dysfunction (renal sequelae). METHODS Patients from Northwest Spain with primary cutaneous vasculitis classified as HSP according to proposed criteria were studied. All patients were required to have had at least 2 years' followup. Patients and ethnically matched controls were genotyped for IL-1beta gene (-511 C/T) polymorphism by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). RESULTS Forty-nine Caucasian patients (38 of them younger than 21 years) who fulfilled classification criteria for HSP and 148 controls were examined. No allele or genotype differences between the whole group of HSP and controls were observed. However, all 5 patients who developed severe nephropathy during the course of disease carried the rare T allele compared with only 16 of the remaining 44 patients (pcorr = 0.01). A significant association between carriage of the -511(IL-1beta) T allele and renal sequelae (pc = 0.02; OR: 3.6, 95% CI: 1.3-10.0) was also found. CONCLUSION In unselected patients with cutaneous vasculitis who fulfill classification criteria for HSP, carriage of IL-1beta (-511) T allele appears to influence severity of renal involvement.