多發性肌炎與皮肌炎病患之存活及預後因子分析

Prognostic factors of survival in patients with dermatomyositis and polymyositis

背景：探討多發性肌炎（polymyositis, PM）及皮肌炎（dermatomyositis, DM）病患死亡之發生率，臨床特徵，及預後因子。材料及方法：本回溯性研究分析於2000年至2007年間，因PM/DM 在長庚醫院接受治療之151個 PM/DM 病患的病例資料。結果：151個PM/DM的病患中有25個（16.6%）罹患相關惡性腫瘤；有32個（21.2%）病患發生間質性肺病（interstitial lung disease, ILD）。在追蹤期間共有 30位（19.9%）病患死亡。本研究的病患總體存活率：一年為81.0%，兩年為77.6%，五年為74.6%。利用單變項迴歸分析，發現PM/DM的發病年齡較晚，惡性腫瘤，合併ILD，皮肌炎，合併糖尿病，低肌酸磷化酶值（creatine phosphokinase, CPK），以及使用 IVIG 皆和較高的死亡率有關（p 值分別為0.018，0.011，<0.001，0.002，0.001，0.009，及0.007）。在排除 anti-Jo-1抗體並調整CPK值後進行多變項分析，得到結果僅ILD（OR = 12.93, 95% CI = 3.97-42.13, p<0.001）與惡性腫瘤（OR = 4.10, 95% CI = 1.21-13.91, p=0.023）為死亡的相關因子。若將anti-Jo-1列入多變項分析 （n = 80），則得到ILD（OR = 15.40, 95% CI = 2.68-88.02, p=0.002）以及皮肌炎診斷（OR = 12.56, 95% CI = 1.21-130.62, p=0.034）和較高的死亡率有關。結論：本研究顯示PM/DM病患有相當高的死亡率。合併ILD、惡性腫瘤或皮肌炎的病患之存活時間明顯地較無上述因子的病患來得短。

Background: To determine the incidence, characteristics, and prognostic factors of mortality in patients with polymyositis (PM) and dermatomyositis (DM). Materials and Methods: Medical records of 151 PM/DM patients treated at Chang Gung Memorial Hospital between 2000 and 2007 were retrospectively reviewed. Results: Twenty-five (16.6%) of the 151 PM/DM patients had associated cancer. Thirty-two (21.2%) of the 151 PM/DM patients had interstitial lung disease (ILD). During follow-up, 30 (19.9%) patients died. Overall patient cumulative survival rates were 81.0, 77.6, and 74.6% at 1, 2, and 5 years, respectively. In univariate analysis, old age at PM/DM onset, cancer, ILD, DM, diabetes mellitus, low creatine phosphokinase (CPK) level, and use of intravenous immunoglobulin were associated with increased mortality (p=0.018, 0.011, <0.001, 0.002, 0.001, 0.009, and 0.007, respectively). Multivariate analysis excluding anti-Jo-1 antibody was performed after adjusting for CPK level. Only ILD (OR = 12.93, 95% CI = 3.97-42.13, p<0.001) and cancer (OR = 4.10, 95% CI = 1.21-13.91, p=0.023) were associated with mortality. If the anti-Jo-1 antibody was included in multivariate analysis (n = 80), then ILD (OR = 15.40, 95% CI = 2.68-88.02, p=0.002) and DM (OR = 12.56, 95% CI = 1.21-130.62, p=0.034) were associated with increased mortality. Conclusion: This study underlines the high mortality rate that associated with PM/DM. Survival time was significantly shorter for patients with ILD, cancer or DM than those without.