Pachman Lauren M, Veis Arthur, Stock Stuart, Abbott Kathy, Vicari Frank, Patel Pravin, Giczewski Diana, Webb Catherine, Spevak Lyudmila, Boskey Adele L
Children's Memorial Hospital, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60614, USA.
Arthritis Rheum. 2006 Oct;54(10):3345-50. doi: 10.1002/art.22158.
Calcific deposits develop in 20-40% of children with juvenile dermatomyositis (juvenile DM), contributing to disease morbidity and mortality. This study was undertaken to define the structure and composition of these deposits and to characterize their association with chronic inflammation.
We examined calcific deposits from 5 children with juvenile DM (2 boys and 3 girls). The crystal structure and mineral content of the deposits was analyzed by x-ray diffraction, Fourier transform infrared spectroscopy, and imaging. The protein content of the deposits, following solubilization, was assayed by Western blotting.
All 5 children had both a young age at disease onset (mean +/- SD 3.3 +/- 1.9 years) and, despite therapy, persistent cutaneous inflammation (mean +/- SD duration 81.3 +/- 58.7 months). The bone proteins, osteopontin, osteonectin, and bone sialoprotein, were identified in the protein extracts; the only mineral detected was hydroxyapatite, but the tissue was distinct from bone, with an extremely high mineral content and an irregular distribution of mineral.
These results indicate that chronic cutaneous inflammation may contribute to the formation of hydroxyapatite-containing pathologic calcifications in children with juvenile DM.
20% - 40%的幼年皮肌炎（幼年型皮肌炎）患儿会出现钙质沉着，这会增加疾病的发病率和死亡率。本研究旨在明确这些沉积物的结构和组成，并描述其与慢性炎症的关联。
我们检查了5名幼年型皮肌炎患儿（2名男孩和3名女孩）的钙质沉着。通过X射线衍射、傅里叶变换红外光谱和成像分析沉积物的晶体结构和矿物质含量。溶解后，通过蛋白质印迹法检测沉积物的蛋白质含量。
所有5名患儿发病时年龄均较小（平均±标准差3.3±1.9岁），且尽管接受了治疗，但皮肤炎症仍持续存在（平均±标准差病程81.3±58.7个月）。在蛋白质提取物中鉴定出骨蛋白、骨桥蛋白、骨连接蛋白和骨唾液蛋白；检测到的唯一矿物质是羟基磷灰石，但该组织与骨骼不同，矿物质含量极高且分布不规则。
这些结果表明，慢性皮肤炎症可能导致幼年型皮肌炎患儿形成含羟基磷灰石的病理性钙化。
