This study showed that a patient's NAT-2 acetylator status, gender, and ethnic origin may be regarded as important risk factors for developing hepatotoxicity. Contrary to expectations, the CYP2E1 c1/c2 polymorphism did not show a significant association with hepatotoxicity in this study. Given the increases in TB cases and ATDH incidence levels, as well as the associated hospitalization costs, it may also be helpful to know patients' acetylator status prior to or at the beginning of the TB treatment regimen.

a Objectives This study evaluated the association between environmental factors and genetic variations in enzymes that metabolize antituberculosis (anti-TB) drugs [arylamine N-acetyltransferase 2, cytochrome P450 2E1 (CYP2E1), glutathione S-transferase theta 1 (GSTT1), and glutathione S-transferase mu 1] with antituberculosis drug-induced hepatotoxicity (ATDH). We also investigated the potential gene-gene and gene-environment interactions as well as their association with ATDH development in a population of hospitalized TB patients from Buenos Aires.Patients and methods We investigated 364 TB patients who received anti-TB drugs. Physicians collected demographic and clinical data to identify environmental risk factors for ATDH development. Polymorphisms were detected using gene sequencing, PCR, and PCR-restriction fragment length polymorphisms. A binary logistic regression analysis was carried out to compare the results of TB patients with and without the development of hepatotoxicity. The multifactor dimensionality reduction method was used to examine genetic and environmental interactions in association with ATDH.Results This study suggests that the slow acetylator profile [odds ratio (OR): 3.02; 95% confidence interval (CI): 1.82-5.00; P < 0.001], genotypes carrying the c2 variant (OR: 2.16; 95% CI: 1.33-3.51; P = 0.002) or the A4 variant of CYP2E1 (OR: 2.13; 95% CI: 1.06-4.29; P = 0.050), and female sex (OR: 1.94; 95% CI: 1.20-3.14; P = 0.006) were independent predictor variables for ATDH. Patients carrying the slow acetylator profile and the c2 variant showed an increased risk (OR: 7.068; 95% CI: 3.34-14.95; P < 0.001).We also identified a synergic interaction (epistasis) between GSTT1 and CYP2E1 associated with an increased risk for ATDH. A meaningful gene-environment interaction was associated with an increased risk of ATDH [testing balance accuracy = 0.675 (P = 0.001) and cross-validation consistency = 10/10].Conclusion ATDH is a severe and prevalent adverse drug reaction and leads to drug discontinuation in 11% of TB patients. Our study created a prediction model that properly classified the 67.5% of TB patients in their risk of developing ATDH. The considerable number of TB patients in our country supports the use of pharmacogenetic testing and a comprehensive clinical history to identify patients with a high risk of suffering hepatotoxicity. Pharmacogenetics and Genomics 00:000-000

A nearly perfect agreement between both predictors and the predicted acetylation profile was observed with very high levels of sensitivity (>97%) and specificity (>98.0%). Furthermore, and as expected, both the two-SNP (C282T, T341C) and tagSNP were found to be independent variables in predicting ATDH with the same strength as seven-SNP of NAT2.

Introduction: Arylamine N-acetyltransferase-2 (NAT-2) is a key human enzyme in drug detoxification and elimination. Mutations in NAT-2 affect the activity of anti-tuberculosis drugs and result in three different phenotypes: rapid (RA), intermediate (IA) and slow acetylators (SA). Methodology: The allelic, genotypic and phenotypic frequencies of NAT-2 were studied in 185 patients from Buenos Aires by restriction fragment length polymorphism. Results: The following allele frequencies were obtained: *4 = 29.9%, *5 = 37.0, *6 = 25.6%, *7 = 8% and *14 = 1.3%. With regard to the phenotype, we observed that 53.6% of the population was SA, 35.7% was IA and 10.7% was RA. Conclusion: A high prevalence of SA might have an impact on anti-TB drug-induced hepatotoxicity.

We investigated the relationship between the 4G/5G plasminogen activator inhibitor (PAI-1) and -308 A/G tumor necrosis factor-α (TNF-α) polymorphisms and the clinical and biochemical features of systemic lupus erythematosus (SLE) in an Argentinean patient cohort. A total of 402 patients were studied, including 179 SLE patients and 223 healthy individuals. PCR-RLFP was used to determine the genotypes of the 4G/5G PAI-1 and -308 A/G TNF-α polymorphisms. SLE patients with lupus nephritis (LN) (n = 86) were compared with patients without LN (n = 93). Additionally, LN patients were divided into proliferative LN and non-proliferative LN groups according to the results of the renal biopsies. No significant differences were noted in the genotype distributions or allele frequencies of these TNF-α and PAI-1 polymorphisms between SLE patients and controls. There were higher numbers of criteria for SLE, more lupus flares and higher damage scores in LN patients, but there were similar frequencies of anti-phospholipid antibody (APA) positivity and anti-phospholipid syndrome. No significant difference was noted for any studied variable between the proliferative LN and non-proliferative LN groups except for the presence of APA. We found no significant differences in the TNF-α and PAI-1 genotype distributions or allele frequencies between groups. We found that the -308 A/G TNF-α and 4G/5G PAI-1 polymorphisms are not associated with susceptibility to SLE in an Argentinean population. We also did not find any association between the presence of any specific allele or genotype and the development of LN in SLE patients. Finally, no association was noted between either of the two polymorphisms and the severity of renal disease.