Antituberculosis Drug - Induced Elevation in Serum Alanine Aminotransferase (ALT) Levels: A Comparison between Patients with and without HIV Seropositivity in Yenagoa, Nigeria

Introduction: The prevalence of rifampicin, isoniazid and pyrazinamide induced elevations in serum alanine aminotransferase (ALT) levels were compared in a cohort of Nigerians with and without HIV seropositivity.

Methods: Records of all the patients with pulmonary tuberculosis (251 HIV positive and 205 HIV negative), aged above 15 years treated in the TB program of the Federal Medical Centre, Yenagoa from January 2013 to December 2014 were analysed for this study. The WHO 4 grades of hepatotoxicity using ALT were used. ALT of less than 50 U/L was taken as normal. Grade 1 (very mild hepatotoxicity): <2.5 x upper limit of normal (ULN) i.e. ALT 51-125 U/L. Grade 2 (mild): 2.6 – 5 x the ULN (ALT 126-250 U/L). Grade 3 (moderate): 5-10 x the ULN (ALT 251 – 500 U/L). Grade 4 (severe) >10 x the ULN (ALT > 500 U/L).

Results: No patient with or without HIV seropositivity had ALT value in the grade 3 and 4 category ≥251 U/L. There was no statistically significant difference in ALT values between cohorts with or without HIV in the 3 ALT categories obtained while on antituberculous drugs (P = 0.761, 0.367 and 0.197).

Conclusion: All the observed hepatotoxicity were mild. The average rate of hepatotoxicity in the HIV uninfected pulmonary tuberculosis cohort was 16.6%, 9.8% and 5.4% for ALT1, ALT2 and ALT3 respectively. The rate in the HIV infected cohorts was 15.5%, 8.8% and 16.4% for ALT1, ALT2 and ALT3. It is encouraging to find a low rate of antituberculosis drug induced hepatotoxicity than one would expect based on the high prevalence of risk factors in our environment.