Henoch Schonlein purpura with nephritis in adults: adverse prognostic indicators in a UK population

Background: Henoch Schonlein purpura with nephritis (HSN) in adults may cause severe organ injury, but its rarity has contributed to a lack of data. Aim: To evaluate clinical outcomes and risk factors in adult HSN patients. Design: Retrospective analysis. Methods: Thirty-seven patients with adult HSN attending the Regional Vasculitis Clinic between 1974 and 2004 were assessed. For inclusion, a renal biopsy showing predominant mesangial IgA immune deposits was required, plus at least two of: purpuric rash, arthralgia, abdominal pain. Results: Ten patients (27%) progressed to end-stage renal failure (ESRF). Renal failure rates were highest in the first decade, with survival rate 72% at 5 years, 68% at 10 years and 46% at final review. Risk factors for ESRF were: proteinuria >= 1 g/day during follow-up (RR 83.8, p = 0.0006); hypertension at presentation (RR = 53.3, p = 0.0045) and during follow-up (RR = 5.9, p = 0.05); renal impairment at presentation (RR 8.0, p = 0.0015); age < 30 years (RR 7.6, p = 0.02); and male sex (RR = 6.0, p = 0.05). Biopsies frequently showed crescents, mostly affecting < 50% of glomeruli; their presence predicted ESRF, as did interstitial fibrosis and tubular atrophy. Renal remission, in contrast, was also high (43%). Cytotoxics were used in 32%, with no clear effect on outcome. Relapses affecting the classical extra-renal systems were common, but were not associated with declines in renal function. A high proportion of patients (41%) also suffered vasculitic organ injuries outside the classical systems. Discussion: HSN in adults is a serious relapsing disease, causing renal failure as frequently as in small-vessel ANCA-positive vasculitides. Prognosis and risks differed in this series from those in other countries, including a higher risk of ESRF than in previous series. Distinct groups developed either ESRF, or remitted. The absence of clear benefit suggests that corticosteroids should be reserved for patients with serious disease, and that cytotoxics may not be merited for those at high risk of renal failure.