Immunotactoid Glomerulopathy and Cutaneous Vasculitis

Abstract

A 22-year-old woman presented glomerulonephritis with Schönlein-Henoch-like syndrome and monoclonal abnormality. One month later, she developed a rapidly progressive glomerulonephritis with hypertension and persistent purpura. In the two renal biopsies performed during the first and the second attack, mesangial expansion and thickening of the glomerular capillary walls (associated with 50% of crescents in the second biopsy) were observed on light microscopy. By immunofluorescence faint deposits of immunoglobulins (light and heavy chains) and complement components were found present in the mesangium. Electron microscopy showed tubular microfibrils measuring 19-24 nm in the mesangium, subendothelial and subepithelial areas. A skin biopsy performed during the first attack demonstrated leukocytoclastic skin vasculitis. By immunofluorescence, no deposits were observed. Congo red staining for amyloid and cryoglobulinemia were negative. This case is similar to an entity recently described and named immunotactoid glomerulopathy.