リウマチ

強皮症腎クリーゼ（Scleroderma renal crisis, SRC）
・ 日本人強皮症患者ではまれであるが、生命予後に影響する合併症（欧米ではびまん型の12%、限局型の2%と稀ではない, QJM 2007; 100:485-494）.
・ 血管病変：内膜肥厚（血管内皮細胞、血管平滑筋、線維芽細胞の増殖）による血管内腔の狭小化(arcuate~ interlobular arteries レベル).
・ 突然の悪性高血圧、乏尿性腎不全をきたす（10％は高血圧がなく、正常血圧強皮症腎normotensive SRCと呼ばれる）.
・ 血栓性微小血管障害(thrombotic microangiopathy, TMA)によるCoombs陰性溶血性貧血（Microangiopathic hemolytic anemia）や血小板減少をきたす.
・ 治療はACEI（カプトリル）.

Risk Factors for Scleroderma Renal Crisis（Curr Opin Rheumatol 20(6):692,2008）
① びまん型：dcSSc (65-86%) オッズ比は7以上
② 発症4年以内：Early dcSSc (An estimated 66% of patients with SSc develop SRC within a year of diagnosis, rising to 86% at 4 years) (罹病期間の中間値：８ヵ月)
③ 急速に進行する　Rapidly progressive skin disease (found in the early phase of dcSSc)
④ 高用量の副腎皮質ステロイド薬の投与　Corticosteroid therapy (a recent history of high-dose corticosteroid use (e.g. prednisolone or equivalent at >15 mg/day) preceded SRC diagnosis.
The patients with SSc most likely to receive corticosteroids are those with early dcSSc, who are the same patients at greatest risk of SRC. Causal effect is difficult to prove, but physicians may wish to consider alternative immunosuppressants; or use of low doses (<10 mg prednisolone/day) if corticosteroid administration is unavoidable.
⑤ Other risk factors for SRC include
1. 貧血の合併　Anaemia
2. Hormone replacement therapy (HRT),
心病変の合併　
3. Pericardial effusion
4. New cardiac events.
5. Cardiac insufficiency
6. High skin score and large joint contractures
7. 抗RNAポリメラーゼ抗体陽性　Presence of antibodies to RNA polymerase (I and III)
8. Recent data have also demonstrated an association between an endothelin B receptor polymorphism and SRC, suggesting a role of this signalling system in the pathogenesis of SRC.

鑑別診断　The DDx of SSc with thrombocytopenia, MAHA (microangiopathic hemolytic anemia), and renal involvement included SRC and SSc complicated by TTP (Mod Rheumatol 10:256,2000). A low level (ie, <5 percent) of ADAMTS13 favors the diagnosis of TTP (Semin Arthritis Rheum. 2005 Feb;34(4):683-8, 2005).