[Phenomenon of secondary immunodeficiency in the use of antilymphocytic serum]

Studies on immune reactions of the cellular and humoral types in late periods after administering antilymphocytic serum (ALS) showed that CBA mice preserve deficiency of humoral response to sheep red blood cells. Repeated administration of ALS aggravated depression of the humoral immune response and virtually did not affect the survival of allotransplants. The evidence obtained is discussed with due regard for ALS effect on immunity and for the role of diverse mechanisms of the rejection reaction.