Effect of atorvastatin on muscle tissues of dermatomyositis and antisynthetase syndrome patients with dyslipidemia.

Introduction: In a recent study, we have shown that atorvastatin is clinically safe for dermatomyositis (DM) and antisynthetase syndrome (ASS) patients with dyslipidemia. Herein, we showed in an unprecedented way, the safety of atorvastatin on the muscular tissues of these patients.

Methods: Transcriptome analysis was performed on samples of the vastus lateralis muscle obtained at baseline and after 12 weeks of atorvastatin (20 mg/day) intervention in DM or ASS patients with dyslipidemia [6DM and 5ASS received atorvastatin, and 2DM and 3ASS received placebo]. The results were analyzed considering differences in expression fold change before and after treatment. Histological and histochemical analyses were also performed.

Results: In both groups, no significant changes were observed in genes related to the mitochondrial, oxidative, insulin, lipid, and fibrogenic pathways. Histological analysis showed a slight variability in the fiber size that was preserved after the intervention. In addition, the mosaic of muscle fibers was preserved in the internal architecture of the fibers and all histological regions. No fiber necrosis or atrophy, focal failures, subsarcolemmal accumulation, lipids, areas of fibrosis, or alterations in mitochondrial activity were observed. All muscle fibers were labeled for MHC I.

Conclusion: Atorvastatin did not promote significant changes in the expression of genes related to mitochondrial, oxidative, insulin, lipid, and fibrogenic pathways in the muscle tissues of DM and ASS patients with dyslipidemia. Atorvastatin did not also promote histological and histochemical changes in muscle tissues. Our results reinforce the safety of the administration of atorvastatin to treat dyslipidemia in patients with DM and ASS.