Membranous nephropathy in systemic lupus erythematosus: long-term outcome and prognostic factors of 103 patients.

OBJECTIVES: The objective of this study was to evaluate the clinical features, course, outcome, and prognostic indicators in lupus membranous nephritis (LMN) and to compare data of "pure" LMN vs "mixed" forms. METHODS: We retrospectively examined medical records and kidney biopsies of 103 patients with a diagnosis of LMN. RESULTS: Sixty-seven patients had "pure" LMN and 36 had "mixed" forms. Patients with mixed LMN had more frequent nephrotic syndrome (66.6 vs 44.7%, P = 0.05), low C3 (83.3 vs 62.6%, P = 0.05) and C4 (80.5 vs 52.2%, P = 0.005), anti-DNA positivity (86.0 vs 62.6%, P = 0.03), and a tendency toward a lower creatinine clearance (93 ± 29 vs 112 ± 50 mL/min, P = 0.07). Moreover, mixed membranous nephritis had a higher activity and chronicity index (6.5 ± 2.1 vs 1.4 ± 2.03, P = 0.005 and 2.4 ± 1.7 vs 1.4 ± 1.8, P = 0.0001, respectively). Methylprednisolone pulses and immunosuppressive therapy were more often used in patients with mixed forms (86.1 vs 60.6%, P = 0.016 and 83.3 vs 57.5%, P = 0.008, respectively). After a mean follow-up of 156.5 ± 104.5 months, there was no difference in the 2 subgroups concerning the number of patients achieving remission and patient/renal survival (94.5 vs 94.0% and 85.8 vs 86% at 10 years). At multivariate analysis, serum creatinine at presentation (P = 0.0013), chronicity index (P = 0.007), failure of achieving remission (P = 0.000001), and occurrence of nephritic flares (P = 0.00167) were independent predictors of chronic renal insufficiency. CONCLUSIONS: Despite the differences in clinical and histological presentation, a therapy tailored on the grounds of clinical and histological features may reduce the differences in the outcome of white patients with mixed and pure membranous nephritis.

PTPN22 R620W polymorphism in the ANCA-associated vasculitides.

OBJECTIVES: PTPN22 is involved in T-cell activation and its R620W single-nucleotide polymorphism (SNP) has been shown to predispose to different autoimmune diseases. The aims of this study were to investigate the role of the PTPN22 R620W SNP in conferring susceptibility to the ANCA-associated vasculitides (AAVs), and to explore potential associations between the PTPN22 genotype and the disease manifestations. METHODS: PTPN22 R620W SNP was genotyped in a cohort of 344 AAV patients [143 with granulomatosis with polyangiitis (Wegener's) (GPA), 102 with microscopic polyangiitis (MPA) and 99 with Churg-Strauss syndrome (CSS)] and in 945 healthy controls. RESULTS: The frequency of the minor allele (620W) was significantly higher in GPA patients than in controls [P = 0.005, χ(2 )= 7.858, odds ratio (OR) = 1.91], while no statistically significant association was found with MPA or CSS. Among GPA patients, the 620W allele was particularly enriched in ANCA-positive patients as compared with controls (P = 0.00012, χ(2 )= 14.73, OR = 2.31); a particularly marked association was also found with ENT involvement (P = 0.0071, χ(2 )= 7.258, OR = 1.98), lung involvement (P = 0.0060, χ(2 )= 7.541, OR = 2.07) and skin manifestations of all kinds (P = 0.000047, χ(2 )= 16.567, OR = 3.73). CONCLUSION: The PTPN22 620W allele confers susceptibility to the development of GPA (but not of MPA or CSS), and particularly of its ANCA-positive subset.