Association of Anti-3-Hydroxy-3-Methylglutaryl-Coenzyme A Reductase Autoantibodies With DRB1*07:01 and Severe Myositis in Juvenile Myositis Patients

Arthritis Care Res (Hoboken). 2017 Jul;69(7):1088-1094. doi: 10.1002/acr.23113.

Abstract

Objective: Autoantibodies recognizing 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR) are associated with statin exposure, the HLA allele DRB1*11:01, and necrotizing muscle biopsies in adult myositis patients. The aim of this study was to characterize the features of juvenile anti-HMGCR-positive myositis patients.

Methods: The sera of 440 juvenile myositis patients were screened for anti-HMGCR autoantibodies. Demographic and clinical features, responses to therapy, and HLA alleles were assessed. The features of anti-HMGCR-positive patients were compared to those of previously described adult patients with this autoantibody and to children with other myositis-specific autoantibodies (MSAs).

Results: Five of 440 patients (1.1%) were anti-HMGCR-positive; none had taken statin medications. Three patients had rashes characteristic of juvenile dermatomyositis and 2 patients had immune-mediated necrotizing myopathies. The median highest creatine kinase (CK) level of anti-HMGCR-positive subjects was 17,000 IU/liter. All patients had severe proximal muscle weakness, distal weakness, muscle atrophy, joint contractures, and arthralgias, which were all more prevalent in HMGCR-positive subjects compared to MSA-negative patients or those with other MSAs. Anti-HMGCR-positive patients had only partial responses to multiple immunosuppressive medications, and their disease often took a chronic course. The DRB1*07:01 allele was present in all 5 patients, compared to 26.25% of healthy controls (corrected P = 0.01); none of the 5 juvenile patients had DRB1*11:01.

Conclusion: Compared to children with other MSAs, muscle disease appears to be more severe in those with anti-HMGCR autoantibodies. Like adults, children with anti-HMGCR autoantibodies have severe weakness and high CK levels. In contrast to adults, in anti-HMGCR-positive children, there is a strong association with HLA-DRB1*07:01.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acyl Coenzyme A / blood*
  • Adolescent
  • Autoantibodies / blood*
  • Biomarkers / blood
  • Child
  • Child, Preschool
  • Female
  • Humans
  • Male
  • Myositis / blood*
  • Myositis / diagnosis*
  • Nerve Tissue Proteins / blood*
  • RNA-Binding Proteins / blood*
  • Severity of Illness Index*

Substances

  • Acyl Coenzyme A
  • Autoantibodies
  • Biomarkers
  • Nerve Tissue Proteins
  • RBM45 protein, human
  • RNA-Binding Proteins
  • 3-hydroxy-3-methylglutaryl-coenzyme A