The predictive value of the lymphocyte transformation test in isoniazid-associated hepatitis

Sixty-one patients receiving isoniazid (INH) for chemotherapy or chemoprophylaxis were assessed by the lymphocyte-transformation test (LTT) shortly after starting treatment. Thirty-eight per cent exhibited stimulation with INH, isonicotinic acid (INA) or human-serum albumin conjugates of these haptens. In the LTT-positive group, liver dysfunction subsequently developed in 58.8%, as compared to 22.7% in the LTT-negative group (P less than 0.01). The difference was not accountable on the basis of age, ethnic background, sex or chemotherapy vs chemoprophylaxis. Although there was an excess of alcohol abusers in the LTT-positive group, the probability of developing liver dysfunction amongst alcohol abusers in that group was twice as great as for LTT-negative alcohol abusers. The specificity of the LTT in predicting liver damage was 83-90% (depending upon the criteria used for determining positivity), while the sensitivity of the test was only 50%.