Effect of ochratoxin A on immunoglobulins in broiler chicks.

The effect of ochratoxin A (OA) on the immune system was investigated in broiler chicks fed graded dietary levels of OA up to 4 ppm for 20 days from hatch. Immunofluorescent demonstration of IgG, IgA and IgM in sections of liver, kidney and lymphoid tissues was used to assess immune competence. Serum immunoglobulin levels were measured by radial immunodiffusion. Ochratoxin caused a significant depression in immunoglobulin-containing cells in all the lymphoid organs studied. Correspondingly, total immunoglobulin levels were also reduced in the sera from OA fed birds, immunosuppression being similar at both the 2 and 4 ppm OA levels. Deposition of immunoglobulins, especially IgG, in the glomerular basement membrane was seen with greater frequency in kidneys from OA fed fowls. Immunoglobulin-containing lymphoid cells occurred more frequently in the kidney parenchyma of these birds.