The impact of CYP3A4 and CYP3A5 genetic variations on tacrolimus treatment of living-donor Egyptian kidney transplanted patients.

BACKGROUND: Tacrolimus (TAC) is the mainstay of immunosuppressive regimen for kidney transplantations. Its clinical use is complex due to high inter-individual variations which can be partially attributed to genetic variations at the metabolizing enzymes CYP3A4 and CYP3A5. Two single nucleotide polymorphisms (SNPs), CYP3A4*22 and CYP3A5*3, have been reported as important causes of differences in pharmacokinetics that can affect efficacy and/or toxicity of TAC. OBJECTIVE: Investigating the effect of CYP3A4*22 and CYP3A5*3 SNPs individually and in combination on the TAC concentration in Egyptian renal recipients. METHODS: Overall, 72 Egyptian kidney transplant recipients were genotyped for CYP3A4*22 G>A and CYP3A5*3 T>C. According to the functional defect associated with CYP3A variants, patients were clustered into: poor (PM) and non-poor metabolizers (Non-PM). The impact on dose adjusted through TAC concentrations (C0) and daily doses at different time points after transplantation was evaluated. RESULTS: Cyp3A4*1/*22 and PM groups require significantly lower dose of TAC (mg/kg) at different time points with significantly higher concentration/dose (C0/D) ratio at day 10 in comparison to Cyp3A4*1/*1 and Non-PM groups respectively. However, CyP3A5*3 heterozygous individuals did not show any significant difference in comparison to CyP3A5*1/*3 individuals. By comparing between PM and Non-PM, the PM group had a significantly lower rate of recipients not reaching target C0 at day 14. CONCLUSION: This is the first study on Egyptian population to investigate the impact of CYP3A4*22 and CYP3A5*3 SNPs individually and in combination on the TAC concentration. This study and future multicenter studies can contribute to the individualization of TAC dosing in Egyptian patients.

Efficacy and Safety of Entecavir 0. 5 mg in Treating Naive Chronic Hepatitis B Virus Patients in Egypt: Five Years of Real Life Experience.

BACKGROUND: The aim of the study was to evaluate the efficacy and safety of entecavir (ETV) among chronic hepatitis B (CHB) nucleos(t)ide-naive Egyptian patients. METHODS: Forty-eight CHB patients on ETV were included. Males comprised 83.3% (40 cases), while females comprised 16.7% (eight cases). Minimum age was 19 years, while maximum age was 64 years. Hepatitis B envelope antigen (HBeAg)-negative cases were 60.4%. HBeAg-positive cases were 39.6%. Factors including sex, positive HBeAg, baseline hepatitis B virus (HBV) DNA level, baseline alanine aminotransferase (ALT) and aspartate aminotransferase (AST), were evaluated in terms of their predictive role in treatment response, which was defined as a serum HBV DNA decrease of < 10 IU/mL. RESULTS: Mean age of patients was 38.2 years; males were 83.3% and females were 16.7%. HBeAg-negative cases were 60.4%, while HBeAg-positive cases were 39.6%. Mean baseline DNA level was 44 × 106 IU/mL. Ultrasound results showed 14 cases had hepatomegaly, 10 cases had bright liver, seven cases had coarse liver, and eight cases had cirrhosis. Of the cases, 45.8% showed a negative PCR after the first 6 months of therapy to reach 64.6% by the end of the first year. HBV DNA undetectability reached 91.3% and 100% after 4 and 5 years, respectively for those who completed the study period. ALT reduction started after 6 months of treatment and reached 53.37% after 5 years. Similarly AST showed the same pattern of decline and reached 54.37% after 5 years. Only two cases achieved HBeAg seroconversion. Three patients experienced virological breakthrough and the three cases shared similar characteristics of being less than 40 years, with baseline HBV DNA of ≥ 105 IU/mL and positive HBeAg. None of the cases showed hepatitis B surface antigen (HBsAg) seroconversion. CONCLUSION: ETV proved to have a potent antiviral efficacy and safety in nucleoside/tide-naive Egyptian patients. Rate of HBV DNA undetectability was higher in patients above 40 years of age and in patients who initially had a low viral load. ETV was well tolerated during the treatment period with a good overall safety profile.