Isoniazid prophylaxis in liver transplant recipient with latent tuberculosis: Is it harmful for transplanted liver?

Background Liver transplantation (LT) is considered the only treatment for patients with end-stage liver disease and, despite its incredible impacts on the patients' health status, places them in an immunocompromised state in which opportunistic infection would find a way to present. Latent tuberculosis infection (LTBI) is the most common form of TB and can be diagnosed through tuberculin skin test (TST) or Interferon-Gamma Release Assays (IGRA). LT recipients are at significant risk of TB activation. There is no strict guideline to approaching these cases though, in most centers, Isoniazid (INH) would be prescribed prophylactically. INH is a hepatotoxic medication and can have adverse effects on the transplanted liver. There is no consensus on this issue; therefore, we aimed to survey the potential hepatotoxic effects of INH among LT recipients in Shiraz, Iran. Methods A retrospective cohort study was conducted among LT candidates and recipients at Abu Ali Sina Organ Transplantation Center between 1993 and 2019. All the cases underwent TST and chest X-ray to detect LTBI. All the LTBI were treated with INH from 6-9 months and followed by the level of liver enzymes for quick detection of hepatotoxicity. A control group was selected among LT recipients and matched for age, gender, MELD score, and donor age. Results Among 4895 medical records reviewed, 55 (1.12%) cases had LTBI. Neither INH-related hepatotoxicity, nor signs and symptoms that were suspicious to TB reactivation were reported. Overall, three deaths were reported, two because of myocardial infarction and one due to pneumonia. Ten patients (18.2%) experienced acute rejection as confirmed with pathology and responded to methylprednisolone. Aspartate aminotransferase (AST) was diminished from pre-LT time to the first time after transplantation; after that, it showed a steady pattern. Meanwhile, Alanine transaminase (ALT) was constant before and one stage later and decreased after that. Statistical analyses only showed significant changes in the total bilirubin titer between the case and control groups. Conclusion This survey showed prophylactic management of LTBI with INH in LT candidates and recipients was associated with no hepatotoxicity or related death. It seems that INH prophylaxis is safe in LT settings and can efficiently prevent TB activation; however, careful monitoring for adverse effects and liver enzymes elevation is highly recommended.