Ab0269 Slco1b1 Polymorphism Is Not Associated With Anti-Hmgcoar Immune-Mediated Necrotizing Myopathy

Background: Anti-3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR) immune-mediated necrotizing myopathy (IMNM) is a subgroup of idiopathic inflammatory myopathy that shows distinctive features from non-immune-mediated statin myotoxicity. A genomewide scan showed a strong association of statin myotoxicity with the rs4363657 single-nucleotide polymorphism (SNP) C allele within the SLCO1B1 gene. However, it remains unknown if it is also associated with anti-HMGCGR-IMNM. Objectives: To determine whether Anti-HMGCR IMNM and non-immune-mediated statin myotoxicity exhibit a different SLCO1B1 association. Methods: The rs4149056 (c.521T>C) SNP within the SLCO1B1 gene was genotyped in 11 patients with anti-HMGCR IMNM diagnosis, 20 patients with non-immune- mediated statin myotoxicity and 31 ethnically matched controls receiving statins without myotoxicity. Comparisons were performed between the three groups. Results: Anti-HMGCR IMNM patients and non-immune-statin myotoxicity patients showed well-differentiated clinical features (Table 1). Anti-HMGCR were older, had more frequently hypertension and diabetes mellitus type2, were more commonly exposed to atorvastatine and showed more severe clinical symptoms and laboratory abnormalities. The prevalence of the rs4149056 C allele was 9.09%, 27.5% and 17.7% in anti-HMGCR IMNM, statin myotoxicity and controls, respectively. No statistically significant differences in the genotype and allele frequencies of SLCO1B1 rs4149056 polymorphism were found when anti-HMGCR IMNM patients were compared to non-immune-statin myotoxicity patients and controls (Table 2). The prevalence of C allele and CC homozygotes was higher in patients with non-immune-statin myotoxicity when compared to anti-HMGCR IMNM and controls, but these differences were not statistically significant (Table 2). Conclusion: We found that SLCO1B1 is not associated with an increased risk of anti-HMGCR IMNM. REFERENCES: NIL. Table 1. Demographic, clinical features and genetic distribution of SLCO1B1 rs4149056 in patients with anti-HMGCR IMNM, non-immune-mediated statin myotoxicity and patients taking statins without myotoxicity (controls). Table 2. Genetic differences of SLCO1B1 rs4149056 between patients with non-immune-mediated statin myotoxicity, patients with ant-HMGCR MNIM, and controls. Acknowledgements: NIL. Disclosure of Interests: None declared.