Safety and efficacy of isoniazid chemoprophylaxis administered during liver transplant candidacy for the prevention of posttransplant tuberculosis

Background. Optimal timing of initiation of isoniazid chemoprophylaxis in liver transplant recipients who test positive on the tuberculin skin test has not been defined. We sought to determine whether isoniazid prophylaxis administered during liver transplant candidacy was safe and effective for the prevention of posttransplantation tuberculosis. Methods. During a 9-year period, 18 liver transplant candidates with tuberculin skin test greater than 5 mm or recent conversion to positive tuberculin skin test were identified and received isoniazid chemoprophylaxis for 12 months. For each case, a control matched with the patient for underlying liver disease and age (within 5 years of the case) was included. Liver function tests were assessed monthly. The median follow-up was 55 months and ranged up to 107 months for the cases. Results. At baseline, the cases had a total bilirubin of 2.2 mg/dL, alanine aminotransferase of 106 IU/L, prothrombin time of 14.2 sec, and serum albumin of 2.9 gm/dL (mean values). Hepatic function tests did not differ significantly for the cases at 3, 6, 9, and 12 months when compared with those at baseline or between the cases and controls at each of the above time points. Discontinuation. of prophylaxis was not required in any of the patients. The outcome (proportion of patients who underwent transplantation or were dead or alive at the last follow-up) and survival time for the cases did not differ significantly from those of the controls (P>0.20). Conclusion. In liver transplant candidates at risk for M. tuberculosis infection after transplantation, isoniazid chemoprophylaxis used during candidacy was well tolerated and did not adversely effect hepatic function or outcome as compared with the control patients.