Risk Factors
Some human leukocyte antigen (HLA) class I and II antigens have been well correlated with different autoimmune diseases. Some are thought to contribute to the pathophysiology of the aberrant immunologic response, whereas others may be associated with protective effects. In the patients with anti-HMGCR myopathy, HLA-DR11 was strongly associated with developing the disease. More specifically, the DRB1*11:01 allele, when present, had an odds ratio of 24.5 in whites and 56.5 in blacks in those with the disease compared with the general population. Interestingly, HLA alleles DQA1 and DQB6 had a protective effect.
In contrast to self-limited statin myopathy, anti-HMGCR myopathy patients do not have a higher prevalence of the SLC01B1 SNP that is associated with statin intolerance. Apart from statin exposure, these patients have no other known significant environmental exposures.