This is an evaluation of genetic associations with atazanavir (ATV) discontinuation for bilirubin-related causes within 12 months of treatment. Patients were treated at an HIV primary care clinic in Nashville TN from 1998 to 2012. A previously known SNP in UGT1A1 (rs887829) was used to define metabolizer genotypes (extensive, intermediate, slow metabolizer). Over 500,000 SNPs from genome-wide genotyping were used to define MDS (Multidimensional Scaling) coordinates to account for population stratification. Patients were defined as cases if they discontinued ATV for bilirubin-related causes within 12 months of treatment, otherwise they were defined as controls if they did not stop treatment. Among 321 evaluable patients, 15 (4.6%) had bilirubin-related atazanavir discontinuation within 12 months. Homozygosity for rs887829 T/T was present in 28.1% of black, 21.4% of Hispanic, and 8.6% of white patients. Among all patients the hazard ratio (HR) for bilirubin-related discontinuation with T/T versus C/C genotype was 7.3 (95% C.I.: 1.7 to 31.5; p = 0.007). Among 152 white patients the HR was 14.4 (95% CI: 2.6 to 78.7; p = 0.002), but among 153 black patients the HR was 0.8 (95% C.I. 0.05 to 12.7; p = 0.87).

Pharmacogenomics of HIV Therapy - Atazanavir Bilirubin-related Side Effects