SERUM AND BILE ANTIBODY-RESPONSES (IGG AND IGA) DURING SUBCLINICAL FASCIOLA-HEPATICA INFECTION IN SHEEP

The kinetics of serum and bile immunoglobulins (IgG and IgA) directed against Fasciola hepatica in the course of subclinical infection induc ed experimentally was investigated in sheep, Serum activities of gluta mate dehydrogenase and gamma-glutamyltransferase were used as markers of the different fluke stages during infection and associated liver da mage, Specific serum and bile immunoglobulins followed a similar kinet ic pattern, increasing progressively from infection throughout the pre patent period and tended to decrease when adult flukes became establis hed in the bile duct, IgA titres were lower than those of IgG. Specifi c IgG and IgA bile titres reached maximum values at 14 weeks postinfec tion that were considerably lower than the serum titres during the who le experimental period, The major bile immunoglobulins are probably de rived directly from plasma, The immunoglobulin kinetic pattern could b e related to changes in serum liver enzyme activities.