Humoral immunodeficiency in chickens induced by chemical bursectomy with colchicine applied on the anal lips.

Colchicine was applied on the anal lips of chickens on 4 consecutive days after hatching. At the ages of 4 and 10 weeks the agglutinin responses to Brucella abortus and to sheep red blood cells (SRBC) after intraperitoneal and per anum immunization were decreased in these animals. IgG and IgM antibodies to Brucella, measured by enzyme-linked immunosorbent assay (ELISA), were also diminished in 12-week-old chickens. The total concentration of plasma IgG, measured by the ELISA-inhibition method, was diminished whereas the IgM level was not influenced by the colchicine treatment. These results broadly resemble the findings after surgical bursectomy or cyclophosphamide treatment. It can be concluded that colchicine applied on the anal lips of chickens causes a long-lasting deficiency of humoral immunity and thus seems to be a useful new tool in the exploration of the humoral-immune functions of the chickens.