IMMUNOTACTOID GLOMERULOPATHY WITH UNUSUALLY THICK EXTRACELLULAR MICROTUBULES AND NODULAR GLOMERULOSCLEROSIS IN DIABETIC PATIENT

It has recently been suggested that immunotactoid glomerulopathy be se parated from much move common fibrillary glomerulonephritis by ultrast ructural features of highly organized immune deposits containing tubul es of more than 30 nm in diameter. We report and discuss the results o f a light, immunofluorescence and electron microscopic study of a need le renal biopsy from a 75-year-old, non-insulin dependant diabetic fem ale presented with nephrotic syndrome, hypertension and a progressive renal failure. A unique coexistence of nodular glomerulosclerosis, as traditionally ascribed to diabetes with a peculiar type of immunotacto id glomerulopathy was confirmed by the exclusion of amyloidosis, monoc lonal gammopathies, systemic auto-immune diseases and cryoglobulinemia . Mesangial, scattered subepithelial and segmentally prominent subendo thelial immune deposits were found highly organized in mostly parallel arrays of 40 to 91 nm thick tubules. The average thickness of 67 nm e xceeds the average diameter of tubules in all other 11 published cases of immunotactoid glomerulopathy to date. By immunofluorescence, predo minantly capillary wall, thick, ribbon-like glomerular deposits contai ned IgG, IgM, kappa and lambda Eight chains of equal intensity, C3, C4 and fibrin related antigens. Mild to moderate glomerular cell prolife ration associated with nodular sclerosis has been assumed to be causal ly related to immunotactoid deposits.