This recently emerging entity is the topic of a review in the Cleveland Clinic Journal of Medicine.
Some points of interest:
The principal cause is autoantibody to HMG coenzyme A reductase, the site of action of statins.
Unlike other statin associated myopathies it does not resolve with stopping the drug and requires immunosuppression.
In the spectrum of statin associated myopathy three principal entities have emerged: 1) simple myalgias without CK elevation; 2) myositis with elevated CK which resolves on drug discontinuation; and 3) the autoimmune entity just described.