Henoch-Schonlein purpura nephritis: an update

Henoch-Schonlein purpura (HSP) is a form of systemic vasculitis characteris ed by vascular wall deposits of predominally IgA typically involving small vessels in skin, gut and glomeruli and associated with purpura, colic, haem aturia and arthralgia or arthritis. HSP nephritis (HSPN) leads to chronic r enal failure in up to 20% of paediatric patients after 20 years of followup in selected series. The risk is related to the initial clinical presentati on and the percentage of glomeruli presenting with epithelial crescents. Th e pathogenesis of HSPN might be related to an increased production of abnor mally glycosylated IgA, which is not sufficiently cleared by the liver and leads to the formation of IgA macromolecules, accumulating in the circulati on with subsequent deposition in vessel walls and in the glomerular mesangi um. HSPN is related to IgA nephropathy. These two diseases can be encounter ed consecutively in the same patient, have been described in identical twin s and bear similar pathological and biological abnormalities. No consensus about treatment has been reached up to now. Recent studies indicate that ea rly treatment with methylprednisolone or a combination of steroids and cyto toxic drugs might prevent evolution to chronic renal failure. Conclusion: d espite numerous studies, the pathogeny of Henoch-Schonlein nephritis remain s incompletely elucidated and controlled therapeutic trials are still neede d.