Effects of SLCO1B1 and GATM gene variants on rosuvastatin-induced myopathy are unrelated to high plasma exposure of rosuvastatin and its metabolites.

Myotoxicity is a significant factor contributing to the poor adherence and reduced effectiveness in the treatment of statins. Genetic variations and high drug plasma exposure are considered as critique causes for statin-induced myopathy (SIM). This study aims to explore the sequential influences of rosuvastatin (RST) pharmacokinetic and myopathy-related single-nucleotide polymorphisms (SNPs) on the plasma exposure to RST and its metabolites: rosuvastatin lactone (RSTL) and N-desmethyl rosuvastatin (DM-RST), and further on RST-induced myopathy. A total of 758 Chinese patients with coronary artery disease were enrolled and followed up SIM incidents for 2 years. The plasma concentrations of RST and its metabolites were determined through a validated ultra-performance liquid chromatography mass spectrometry method. Nine SNPs in six genes were genotyped by using the Sequenom MassArray iPlex platform. Results revealed that ABCG2 rs2231142 variations were highly associated with the plasma concentrations of RST, RSTL, and DM-RST (Padj < 0.01, FDR < 0.05). CYP2C9 rs1057910 significantly affected the DM-RST concentration (Padj < 0.01, FDR < 0.05). SLCO1B1 rs4149056 variant allele was significantly associated with high SIM risk (OR: 1.741, 95% CI: 1.180-2.568, P = 0.0052, FDR = 0.0468). Glycine amidinotransferase (GATM) rs9806699 was marginally associated with SIM incidents (OR: 0.617, 95% CI: 0.406-0.939, P = 0.0240, FDR = 0.0960). The plasma concentrations of RST and its metabolites were not significantly different between the SIM (n = 51) and control groups (n = 707) (all P > 0.05). In conclusion, SLCO1B1 and GATM genetic variants are potential biomarkers for predicting RST-induced myopathy, and their effects on SIM are unrelated to the high plasma exposure of RST and its metabolites.

Impact of HLA-B*58:01 allele and allopurinol-induced cutaneous adverse drug reactions: evidence from 21 pharmacogenetic studies.

Allopurinol is widely used for hyperuricemia and gouty arthritis, but is associated with cutaneous adverse drug reactions (CADRs). Recently, HLA-B*58:01 allele was identified as a strong genetic marker for allopurinol-induced CADRs in Han Chinese. However, the magnitude of association and diagnosis value of HLA-B*58:01 in allopurinol-induced CADRs remain inconclusive. To investigate this inconsistency, we conducted a meta-analysis of 21 pharmacogenetic studies, including 551 patients with allopurinol-induced CADRs, and 2,370 allopurinol-tolerant controls as well as 9,592 healthy volunteers. The summary OR for allopurinol-induced CADRs among HLA-B*58:01 carriers was 82.77 (95% CI: 41.63 - 164.58, P < 10-5) and 100.87 (95% CI: 63.91 - 159.21, P < 10-5) in matched and population based studies, respectively. Significant results were also observed when stratified by outcomes and ethnicity. Furthermore, the summary estimates for quantitative analysis of HLA-B*58:01 allele carriers in allopurinol-induced CADRs screening were as follows: sensitivity, 0.93 (95% CI: 0.85 - 0.97); specificity, 0.89 (95% CI: 0.87 - 0.91); positive likelihood ratio, 8.24 (95% CI: 6.92 - 9.81); negative likelihood ratio, 0.084 (95% CI: 0.039 - 0.179); and diagnostic odds ratio, 98.59 (95% CI: 43.31 - 224.41). The AUSROC was 0.92 (95% CI: 0.89-0.94), indicating the high diagnostic performance. Our results indicated that allopurinol-SCAR is strongly associated with HLA-B*58:01, and HLA-B*58:01 is a highly specific and effective genetic marker for the detection allopurinol-induced CADRs, especially for Asian descents.