Gamma-carboxyglutamate excretion and calcinosis in juvenile dermatomyositis

Arthritis Rheum. 1982 Sep;25(9):1094-1100. doi: 10.1002/art.1780250910.


Proteins containing gamma-carboxyglutamic acid (Gla) are present in subcutaneous calcifications of adults with dermatomyositis or scleroderma. Sixteen children with juvenile dermatomyositis, including 7 with subcutaneous calcifications, were studied to determine if abnormal synthesis or turnover of Gla-containing proteins occurred. All study children had increased excretion of the amino acid that was greater than that of age- and sex-matched controls. Patients who had juvenile dermatomyositis with calcifications had a 3-fold increase in Gla excretion, and those without calcinosis had a 2-fold increase. Five other children with various connective tissue disorders and subcutaneous calcification had 2-fold increased Gla excretion. Decreased excretion of this amino acid was associated with salicylate therapy (80 mg/kg/24 hours). The data suggest an abnormal turnover of Gla-containing proteins in juvenile dermatomyositis. Metabolism of these proteins may be involved in the pathophysiology of soft-tissue calcification in children.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • 1-Carboxyglutamic Acid / urine*
  • Adolescent
  • Adult
  • Aged
  • Aspirin / therapeutic use
  • Calcinosis / blood
  • Calcinosis / complications*
  • Calcinosis / urine
  • Calcium-Binding Proteins / blood
  • Child
  • Child, Preschool
  • Dermatomyositis / blood
  • Dermatomyositis / complications
  • Dermatomyositis / drug therapy
  • Dermatomyositis / urine*
  • Female
  • Glutamates / urine*
  • Humans
  • Male
  • Middle Aged
  • Osteocalcin
  • Prothrombin / blood


  • Calcium-Binding Proteins
  • Glutamates
  • Osteocalcin
  • 1-Carboxyglutamic Acid
  • Prothrombin
  • Aspirin