血清肺表面活性蛋白-A，D检测在多发性肌炎／皮肌炎合并间质性肺病中的意义

Surfactant proteins-A and D as important serum markers for interstitial lung disease in patients with polymyositis or dermatomyositis

目的探讨血清肺表面活性蛋白-A、D（sP-A，sP-D）的检测在多发性肌炎／皮肌炎（PM／DM）合并间质性肺病（ILD）中的重要意义。方法采用酶联免疫吸附试验（ELISA）方法测定2005年7月至2011年5月中日友好医院的100例PM／DM患者，20例肺部感染患者以及42名健康对照组血清中sP—A，sP—D水平。分析sP．A，sP—D与PM／DM合并ILD的关系及诊断ILD的敏感性及特异性。判断PM／DM临床特点以及预后与血清中sP—A，SP—D水平相关性。结果合并ILD的PM／DM组血清sP—A，SP—D水平分别较未合并ILD的PM／DM组及正常对照组显著升高（均P〈0．01），但与肺部感染组比较差异均无统计学意义（均P〉0．05）。sP．A，sP．D，sP．A＋SP．D诊断PM／DM合并ILD的敏感性分别为66．1％、64．3％和80．0％，特异性分别为72．7％、72．7％和70．4％，PM／DM患者血清sP—A水平与血清铁蛋白（r=0．364，P〈0．05）、CRP（r=0．458，P〈0．05）呈显著正相关，而与DLCO％（r=-0．474，P〈0．05）、VC％（r=-0．404，P〈0．05）呈显著负相关。sP-D水平与外周血CD3＋T细胞计数（r=-0．244，P〈0．05）、CD4＋T细胞（r=-0．277，P〈0．05）存在负相关关系。血清sP—A升高是PM／DM合并ILD死亡的独立危险因素（P〈0．05）。结论sP—A，SP—D可作为PM／DM合并ILD的潜在血清学标志物，对PM／DM合并ILD的诊断具有一定价值，其联合诊断ILD优于单个指标诊断。血清sP-A水平作为PM／DM合并ILD的死亡独立危险因素，对预后有重要的提示作用。

Objective To explore the possible diagnostic values of serum surfactant protein-A （SP- A） and surfaetant protein-D （SP-D） for interstitial lung diseases （ILD） in patients with polymyositis or dermatomyositis （PM/DM）. Methods Serum MCP-1 concentrations were measured by enzyme-linked immunosorbent assay （ELISA） in 100 adult PM/DM patients, 20 patients with pulmonary infection and 42 healthy controls. And the association with their clinical features and serum levels of SP-A and SP-D was analyzed. Results The serum levels of SP-A and SP-D in the PM/DM patients with ILD were both significantly higher than those without ILD and healthy controls （ all P 〈 0. 01 ） while there were no significance differences with those with infectious lung diseases （ P 〉 0. 05 ） . The sensitivity of serum abnormal levels of SP-A, SP-D and combination of SP-A and SP-D for ILD in PM/DM patients were 66. 1% , 64. 3% and 80. 0% and the specificity 72. 7%, 72. 7% and 70. 2% respectively. The serum levels of SP-A were positively correlated with serum ferritin and C-reactive protein （CRP） and negatively with percent carbon monoxide diffusing capacity （ DLCO% ） （ r = - 0. 474, P 〈 0. 05 ）, VC% （ r = - 0. 404, P 〈 0. 05） while the serum levels of SP-D were negatively correlated with circulating CD3 ＋ T cells （ r =- 0. 244, P 〈 0. 05） and CD4 ＋ T cells （ r = - 0. 277, P 〈 0. 05 ） in PM/DM patients. Furthermore, SP-A was an independent risk factor for death of ILD in PM/DM （ OR 1. 032, 95% CI 1. 006 - 1. 059, P 〈 0. 05）. Conclusion SP-A and SP-D may be potential useful serum markers for the diagnosis of ILD in PM/DM patients. And the combined detection of SP-A and SP-D offers a higher sensitivity than either marker alone. As a risk factor, serum SP-A can predict the prognosis of PM/DM patients with ILD.