Late-onset biopsy-proven lupus nephritis without other associated autoimmune diseases: severity and long-term outcome:

Background/PurposeLupus nephritis (LN) usually develops within the first years of systemic lupus erythematosus (SLE) onset and rarely after that. There are scarce studies comparing early- versus late-onset nephritis (before versus after five years of SLE diagnosis). The aim of this study was to compare the severity and long-term outcome (after 7 years) in these two, late-onset and early-onset, nephritis groups.MethodsThis study included 93 patients from rheumatology tertiary centers from Brazil and Italy, all of them with biopsy-proven LN with > 7 years follow-up. Patients were divided in two groups: early-onset nephritis (n = 75) and late-onset nephritis (n = 18). Clinical and laboratorial data were obtained using a standardized electronic chart database protocol carried out at 1–6 months interval and established in 2000. Patients >50 years or with concomitant autoimmune diseases were excluded. Variables evaluated at the LN presentation were Systemic Lupus Erythematosus Disease Activity Index (SLEDAI), c...