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.

To further characterize the renal lesions, formalin-fixed kidney tissue from Case 2 was prepared for transmission electron microscopy, which demonstrated multifocal subendothelial deposition of electro-dense material (Fig. 3) . Immunohistochemistry (IHC) was performed with EnVision TM system (Dako, Carpinteria, CA, U.S.A.) and rabbit polyclonal bovine IgG antibody (GeneTex, Irvine, CA, U.S.A.) as the primary antibody. Immunohistochemistry revealed multifocally deposited IgG antibodies in the glomerular tufts (Fig. 4) . Electron microscopy and IHC findings were consistent with immune-complex associated glomerulonephritis and morphologically highly compatible with type I MPGN. In humans, type I MPGN is the most common and classical type of MPGN, often associated with idiopathic or systemic immune complex disorders such as systemic lupus erythematosus or chronic infection [1, 11] . In an attempt to identify the antigen in the deposited immune complexes and given the history of administration of a S. Typhimurium-based core antigen vaccine and passively administered antibody against Salmonella, IHC was also performed with rabbit anti-Salmonella polyclonal antibodies obtained from the vaccine manufacturer, but was unsuccessful. This finding is not unexpected, however, because it is highly likely that the binding site for the anti-Salmonella antibody was already bound due to immune complex formation. These follow-up tests (transmission electron microscopy and IHC) were not performed on tissues with evidence of fibrinoid vasculitis.