IgG and IgM deposits in kidneys of dogs with visceral leishmaniasis (VL) were studied in 25 symptomatic dogs (case) and 15 asymptomatic dogs (control) by an immunohistochemical method. All tested dogs were positive for VL by polymerase chain reaction, enzyme-linked immunosorbent assay, and indirect immunofluorescence test. Kidney fragments were submitted to immunohistochemical reaction. Many morphological patterns of distribution of subendothelial granules were identified for IgG and IgM in glomerular capillaries: global, segmental, diffuse, or focal. Intensity of immunohistochemical reaction to IgG was not significantly different when comparing the symptomatic and the asymptomatic animal groups by Fisher's exact test. IgM reactions were significantly different between groups (P<0.01). Deposits of IgM on mesangial cells and in inflammatory interstitial infiltrate were rarely seen, although IgG reactions were frequent at these sites. This study concluded that immunohistochemical reactions for IgM were more intense than those observed for IgG in canine VL, and these reactions were characterized by distribution of subendothelial granules in glomerular capillaries.
dog; Leishmania; kidneys; glomerulonephritis; immunoglobulins
