Genetic susceptibility to Gilbert's syndrome in a Valencian population; efficacy of the fasting test

The efficacy and safety of direct-acting antiviral agents in patients with chronic HCV infection and UGT1A1*28 polymorphism

Objective. To determine the efficacy and safety of direct-acting antiviral agents (DAA) in patients with chronic HCV infection and UGT1A1*28 polymorphism. Materials and Methods. An open-label, non-randomized, observational study to assess efficacy and safety of DAA in patients (n = 143) with chronic hepatitis C (CHC) and liver cirrhosis and UGT1A1*28 polymorphism was performed. A total of 139 patients with chronic HCV infection were included in the efficacy analysis (absence of HCV RNA in blood by PCR) by the rate of sustained virologic response at week 12 (SVR12). Results. The SVR12 rate in patients with CHC and HCV-CP was 92.5% and 87.9%, respectively (p = 0.508), regardless of the presence of UGT1A1*28 polymorphism. The SVR12 rate in patients with chronic HCV infection and (TA)7/(TA)7 was 84.8%, with (TA)6/(TA)7 – 92.2% compared with (TA)6/ (TA)6 – 90,5% (p = 0.518). The rate of SVR12 in patients with CHC and (TA)7/(TA)7 or (TA)6/(TA)7 was 80% and 95%, respectively, with (TA)6/(TA)6 – 95.2%. The rate of SVR12 in patients with liver cirrhosis and (TA)7/(TA)7 or (TA)6/(TA)7 was 92.3% and 87.5%, respectively, with (TA)6/(TA)6 – 85.7%. The rate of SVR12 in patients with 12- and 24-week treatment duration was 88.2% and 96.6%, respectively (p = 0.30). As many as 96.2% of patients with the previous treatment with interferon and ribavirin had SVR12 compared to 88.5% of patients who have not previously taken antiviral drugs (p = 0.486). Grade 1 adverse events (AE) occurred in 24% of patients with chronic HCV infection treated with DAA; two patients developed Grade 4 AE. Conclusions. The treatment with DAA was shown to be effective and safe in patients with chronic HCV infection and UGT1A1*28 polymorphism.

UGT1A1 (TA)n Promoter Genotype: Diagnostic and Population Pharmacogenetic Marker in Serbia

The UGT1A1 enzyme is involved in the metabolism of bilirubin and numerous medications. Unconjugated hyperbilirubinemia, commonly presented as Gilbert syndrome (GS), is a result of decreased activity of the UGT1A1 enzyme, variable number of TA repeats in the promoter of the UGT1A1 gene affects enzyme activity. Seven and eight TA repeats cause a decrease of UGT1A1 activity and risk GS alleles, while six TA repeats contribute to normal UGT1A1 activity and non-risk GS allele. Also, the UGT1A1 (TA)_n promoter genotype is recognized as a clinically relevant pharmacogenetic marker. The aim of this study was to assess diagnostic value of UGT1A1 (TA)_n promoter genotyping in pediatric GS patients. Correlation of the UGT1A1 (TA)_n genotypes and level of unconjugated bilirubin at diagnosis and after hypocaloric and phenobarbitone tests in these patients was analyzed. Another aim of the study was to assess pharmacogenetic potential of UGT1A1 (TA)_n variants in Serbia. Fifty-one pediatric GS patients and 100 healthy individuals were genotyped using different methodologies, polymerase chain reaction (PCR) followed by acrylamide electrophoresis, fragment length analysis and/or DNA sequencing. Concordance of the UGT1A1 (TA)_n promoter risk GS genotypes with GS was found in 80.0% of patients. Therefore, UGT1A1 (TA)_n promoter genotyping is not a reliable genetic test for GS, but it is useful for differential diagnosis of diseases associated with hyperbilirubinemia. Level of bilirubin in pediatric GS patients at diagnosis was UGT1A1 (TA)_n promoter genotype-dependent. We found that the frequency of pharmacogenetic relevant UGT1A1 (TA)_n promoter genotypes was 63.0%, pointing out that UGT1A1 (TA)_n promoter genotyping could be recommended for preemptive pharmacogenetic testing in Serbia.