Immune complex glomerulonephritis of suspected iatrogenic origin in five Japanese Black calves

BERNIER GOSSELIN, Véronique; KIM, Dae Y.; NAGY, Dusty W.; SHOEMAKE, Brian M.; SHAW, Daniel P.; ROYAL, Angela B.; EVANS, Tim J.; MIDDLETON, John R.

Microscopically, the most consistent lesions were in the kidney (Cases 1, 2, 4 and 5). Glomerular tufts were segmentally thickened with increased cellularity and multifocal microthrombi. The renal tubules contained proteinaceous fluid and occasional cellular casts (Fig. 1) . Periodic-acid Schiff stain revealed irregular thickening of the glomerular basement membranes (Fig. 2) . Congo-Red stain of the affected kidneys was negative, ruling out amyloidosis. These findings were consistent with membranoproliferative glomerulonephritis (MPGN). There was fibrinoid vasculitis in multiple organs including heart, kidney, adrenal gland, intestinal wall, and uterus of Case 1, uterus of Case 4, and heart and adrenal gland of Case 5. Fibrinoid vasculitis is a unique form of vasculitis and is often associated with high concentrations of circulating immune complexes and their resultant deposition in the vasculature.