Successful treatment of rapidly progressive lupus nephritis associated with anti-MPO antibodies by intravenous immunoglobulins.

We report a case of systemic lupus erythematosus (SLE) associated with crescentic glomerulonephritis and myeloperoxidase-specific anti-neutrophil cytoplasmic antibodies (MPO-ANCA). A 34-year-old Japanese female patient diagnosed with SLE developed rapidly progressive renal failure and nephrotic syndrome. Haemodialysis was required to restore renal function. Methylprednisolone pulse therapy followed by plasmapheresis did not suppress the progression of renal failure, so she was treated with high-dose intravenous immunoglobulin (IV-IG) therapy, which was well tolerated and effectively prevented renal failure. A renal biopsy showed diffuse proliferative lupus nephritis (WHO classification IVc) with predominant crescent formation and scant subendothelial immune deposits. These findings indicate that, in addition to lupus nephritis, which usually results from the deposition of circulating or locally formed immune complexes, MPO-ANCA may be involved in the pathogenesis of crescentic glomerulonephritis. Furthermore, we propose that IV-IG is an effective therapy for MPO-ANCA-related renal crisis in lupus nephritis.