Background: The objective of this research was to identify the impact of genetic variants of P-glycoprotein (ABCB1) and cytochrome P450 (CYP) on nelfinavir pharmacokinetics and response to highly active antiretroviral therapy (HAART) in HIV-1-infected children.
Methods: HIV-1-infected children (n = 152) from Pediatric AIDS Clinical Trial Group 366 or 377 receiving nelfinavir as a component of HAART were evaluated. Genomic DNA was assayed for ABCB1 and CYP genetic variants using real-time polymerase chain reaction Nelfinavir oral clearance (CL/F), M8 to nelfinavir ratios, CD4 T cells, and HIV-1-RNA were measured during HAART.
Results: Nelfinavir CL/F and M8 to nelfinavir ratios were significantly associated with the CYP2C19-G681A genotypes (P < 0.001). Furthermore, the CYP2C19-G681A genotype was related to virologic responses at week 24 (P = 0.01). A multivariate analysis demonstrated that age (P = 0.03), concomitant protease inhibitor use (P < 0.001), and the CYP2C19-G681A genotype (P < 0.001) remained significant covariates associated with nelfinavir CL/F.
Conclusions: CYP2C19 genotypes altered nelfinavir pharmacokinetics and the virologic response to HAART in HIV-1-infected children. These findings suggest that CYP2C19 genotypes are important determinants of nelfinavir pharmacokinetics and virologic response in HIV-1-infected children.