Mycophenolate mofetil for the treatment of Henoch-Schönlein purpura nephritis; current knowledge and new concepts

Henoch-Schönlein purpura (HSP) is the most common primary systemic vasculitis of childhood (1). It is generally considered a self-limited disease, and majority of patients improve completely (2,3). Shortand long-term outcomes of HSP are generally favorable, and predicted by the severity of initial manifestations and renal involvement (1,2). Henoch-Schönlein purpura nephritis (HSPN) is the major cause of mortality and morbidity in children with HSP (1), which occurs in 30%-80% of patients during the first three weeks of the initial presentation (1,4). Majority of patients with HSPN have a mild disease, presenting with hematuria and/or low-grade proteinuria. A small percentage of patients present with nephrotic syndrome or renal impairment (1). However, severe renal involvement is rare in children, compared that in adults (3). HSPN accounts for 1.8%–3% of children with chronic kidney disease (5), and chronic renal failure might occur in 11%–38% of patients with severe manifestations and pathologic changes (4). Severity of initial manifestations and histopathologic lesions have been considered the best prognostic factor of HSPN in children (1,6). Accordingly, older age at presentation, hypertension, crescentic glomerulonephritis, significant glomerulosclerosis and tubulointerstitial changes, increased serum creatinine, massive proteinuria, nephrotic or mixed nephritic– nephrotic syndrome have been suggested the major risk factors of future renal impairment (1,2), and imply for aggressive treatment in patients with HSPN (5). There is no absolute consensus for the best management of severe HSPN and the most effective treatment remains controversial (5-7). Early aggressive immunosuppressive drugs such as cyclosporine, cyclophosphamide, azathioprine, steroid pulse therapy, IV-IgG, rituximab, methotrexate, plasmapheresis, chlorambucil, tacrolimus, and mycophenolate mofetil (MMF) have been suggested for treatment of severe and rapidly progressive HSPN (2,6,8). There are limited data regarding MMF in children with severe HSPN. It is an immunosuppressive drug, which inhibits B and T cell proliferation, decreases antibody production, prevents glycosylation of adhesion molecules and intercellular adhesion to endothelial cells, inhibits mesangial cell proliferation, and induces apoptosis of activated T cells. It has been reported a safe and effective treatment for inducing and maintaining E di to ri al ARTICLE INFO