Different mechanisms of ‘in vitro’ lymphocytotoxicity against isolated rabbit hepatocytes during the course of acute viral hepatitis

In order to characterize the effector mechanism of ‘in vitro’ lymphocytotoxicity against isolated rabbit liver cells in acute viral hepatitis (AVH). the test was performed in 4 patients with type A, in 8 with type B. and in 2 patients with non-A non-B AVH: (a) using peripheral blood lymphocytes; (b) after enzymatic digestion of the surface membrane immunoglobulins of these lymphocytes, and (c) as in b with addition of patients’ sera. 78.5% of the patients had an elevated cytotoxicity which did not change when the lymphocytes were treated as in b and c. Only the 2 patients which progressed to chronicity had an elevated cytotoxicity which disappeared after enzymatic exposure and reappeared with the addition of patients’ sera. The results suggest that ‘in vitro’ cytotoxicity in recovering AVH is not antibody dependent, but probably of spontaneous type. On the contrary an antibodydependent cytotoxicity is present in the 2 cases of AVH who progressed to chronicity.