Lian J B, Pachman L M, Gundberg C M, Partridge R E, Maryjowski M C
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.
含有γ-羧基谷氨酸（Gla）的蛋白质存在于患有皮肌炎或硬皮病的成年人的皮下钙化中。对16名青少年皮肌炎患儿进行了研究，其中7名有皮下钙化，以确定是否发生了含Gla蛋白质的异常合成或代谢。所有研究患儿的该氨基酸排泄量均增加，且高于年龄和性别匹配的对照组。患有青少年皮肌炎且有钙化的患者Gla排泄量增加了3倍，而无钙质沉着症的患者增加了2倍。其他5名患有各种结缔组织疾病和皮下钙化的儿童Gla排泄量增加了2倍。该氨基酸排泄量降低与水杨酸盐治疗（80mg/kg/24小时）有关。数据表明青少年皮肌炎中含Gla蛋白质的代谢异常。这些蛋白质的代谢可能参与了儿童软组织钙化的病理生理过程。
