Studies of the influence of ochratoxin A on immune and defence reactions in weaners

Even in subtoxic amounts, the mycotoxin, ochratoxin A, produced immunomodul ation in weaner pigs in a dose-dependent mode. In addition to increased cou nts of total leukocytes and neutrophils in the blood, reduced lymphocyte le vels were observed. There was a striking increase in the counts of eosinoph ils and of apoptotic phagocytes. Functionally, there was a predominance of the production of reactive oxygen radicals in whole blood, reduced phagocyt osis performance and reduced expression of a swine-specific surface marker (SWC1) on lymphocytes. In a few single experiments, clinical manifestations could be demonstrated. Lung clearance and the degree of severity of experi mental pneumonia as well as cutaneous hypersensitization may be influenced by ochratoxin A.