An immunohistological study of feline glomerulonephritis using the peroxidase-antiperoxidase method

Twenty-two cases of feline glomerulonephritis were investigated for the presence of immune complexes within the glomerulus using the peroxidase-antiperoxidase (PAP) method. This method was used with formalin-fixed paraffin-wax embedded tissues which were pretreated with trypsin and with frozen sections of kidney tissue. Of a total of 25 kidney specimens examined (two cats had repeated biopsies) the composition of the deposits was 23/25 IgG, 17/25 C3, 11/25 IgM and 2/25 IgA. Serial studies of two cats showed a progression of the disease from initial nephrotic syndrome to chronic renal failure. With the more severe form of the disease there was a tendency for the deposition of complement and more than one class of immunoglobulin within the glomeruli.