Association of slow N-acetyltransferase 2 profile and anti-TB drug-induced hepatotoxicity in patients from Southern Brazil.

PURPOSE: To determine the frequency of N-acetyltransferase 2 (NAT2) polymorphisms, the NAT2 acetylation profile and its relation to the incidence of gastrointestinal adverse drug reactions (ADRs), anti-tuberculosis (TB) drug-induced hepatotoxicity, and the clinical risk factors for hepatotoxicity in a population from Brazil. METHODS: Two hundred and fifty-four Brazilian TB patients using isoniazid (INH), rifampicin (RMP), and pirazinamide (PZA) were tested in a prospective cohort study. NAT2 genotyping was performed by direct PCR sequencing. The association between gastrointestinal ADRs/hepatotoxicity and the NAT2 profile genotype was evaluated by univariate analysis and multiple logistic regression. RESULTS: Of the 254 patients analyzed, 69 (27.2%) were slow acetylators and 185 (72.8%) were fast acetylators. Sixty-five (25.6%) patients were human immunodeficiency virus (HIV)-positive. Thirty-three (13%) and 14 (5.5%) patients developed gastrointestinal ADR and hepatotoxicity, respectively. Of the 14 hepatotoxicity patients, nine (64.3%) were slow acetylators and five (35.7%) were fast acetylators. Sex, age, presence of hepatitis C virus, alcohol abuse, and baseline aminotransferases were not found to be risk factors for hepatotoxicity. However, logistic regression analysis revealed that slow acetylator status and the presence of HIV (p < 0.05) were independent risk factors for hepatotoxicity. CONCLUSIONS: Our findings show that HIV-positive patients that have the slow acetylation profile are significantly associated with a higher risk of developing hepatotoxicity due to anti-TB drugs.

Differential expression of nifH and anfH genes in Paenibacillus durus analysed by reverse transcriptase-PCR and denaturing gradient gel electrophoresis.

AIMS: The aim of this study was to develop an approach based on a reverse transcriptase (RT)-PCR/denaturing gradient gel electrophoresis (DGGE) for the detection of the functional genes nifH and anfH in Paenibacillus durus. METHODS AND RESULTS: Two sets of primers were employed to study the expression of the nitrogen fixation genes in a pure-culture system of P. durus grown in media with increasing concentrations of ammonium (NH(4)(+)), tungsten (W) or molybdenum (Mo). The results obtained indicate that the expression of nitrogenase genes from P. durus can take place in the presence of relatively high levels of fixed nitrogen. It was also observed that the addition of 20 micromol l(-1) molybdenum and 2 mmol l(-1) tungstate did not interfere in the mRNA levels of nifH and anfH genes. CONCLUSIONS: Our results demonstrate the presence and transcription of nifH and anfH in P. durus under a variety of growth conditions. A specific set of primers was designed for the detection of the alternative system for nitrogen fixation in P. durus. SIGNIFICANCE AND IMPACT OF THE STUDY: The RT-PCR/DGGE system enables the rapid gathering of incremental data about the regulation of conventional and alternative nitrogenase genes in P. durus strains.