Clinical Immunology, Dokkyo Medical University, 880 Kita-Kobayashi, Mibu, Tochigi, 321-0293, Japan.
Mod Rheumatol. 2013 Sep;23(5):872-83. doi: 10.1007/s10165-012-0756-0. Epub 2012 Sep 17.
The aim of this study is to determine whether serum KL-6 and surfactant protein D (SP-D) levels predict the prognosis of patients with interstitial pneumonia (IP) in cases of polymyositis (PM) and dermatomyositis (DM).
Fifty consecutive patients with PM (n = 17) or DM (n = 33) and active IP, 6 of whom died of respiratory failure, were enrolled in this study. Serum KL-6 and SP-D levels were measured every 2-4 weeks. Medical records were reviewed retrospectively. Univariate analyses and multivariate analyses with a logistic regression model were conducted.
Serum KL-6 and SP-D levels were elevated in patients with active IP. At the time of diagnosis of active IP, the serum KL-6 level was within the normal range in 28 % of patients and the SP-D level was within the normal range in 46 % of patients. Serum KL-6 level increased up to 3 months after starting treatment and then decreased gradually to baseline, whereas SP-D level peaked within the first 4 weeks after treatment and decreased rapidly to normal levels. Patients with poor prognosis showed increases in KL-6 and SP-D levels during the first 4 weeks after treatment, which was confirmed by uni- and multivariate analyses. Comparing the marker levels at 2-4 weeks after treatment with those at 0 weeks, an increase in the ratio over 1.70 for KL-6 and over 1.75 for SP-D, and an increase in KL-6 over 850 U/ml during the first 4 weeks after treatment, were poor prognostic factors.
Increases in serum KL-6 and SP-D levels during the first 4 weeks after starting therapy, but not their levels at any one time point, predict poor prognosis in patients with PM/DM. When marked increases of KL-6 and SP-D levels during the first 4 weeks are found or are predicted by serial measurement of the markers, patients have risks of poor prognosis and additional therapy should be considered.
本研究旨在确定血清 KL-6 和表面活性剂蛋白 D（SP-D）水平是否可预测多发性肌炎（PM）和皮肌炎（DM）合并间质性肺炎（IP）患者的预后。
本研究纳入了 50 例连续的 PM（n=17）或 DM（n=33）合并活动性 IP 的患者，其中 6 例死于呼吸衰竭。每 2-4 周检测一次血清 KL-6 和 SP-D 水平。回顾性分析病历资料。采用单变量分析和多变量逻辑回归模型分析。
活动性 IP 患者的血清 KL-6 和 SP-D 水平升高。在诊断为活动性 IP 时，28%的患者血清 KL-6 水平处于正常范围，46%的患者 SP-D 水平处于正常范围。血清 KL-6 水平在开始治疗后 3 个月内升高，然后逐渐降至基线，而 SP-D 水平在治疗后 4 周内达到峰值，然后迅速降至正常水平。预后不良的患者在治疗后 4 周内 KL-6 和 SP-D 水平升高，这通过单变量和多变量分析得到了证实。与治疗 0 周时相比，治疗后 2-4 周标志物水平增加，KL-6 比值超过 1.70，SP-D 比值超过 1.75，以及治疗后 4 周内 KL-6 超过 850 U/ml，是预后不良的因素。
治疗开始后 4 周内血清 KL-6 和 SP-D 水平的升高，但不是任何一个时间点的水平，可预测 PM/DM 患者的预后不良。如果在治疗的前 4 周内发现或通过连续测量标志物预测 KL-6 和 SP-D 水平显著升高，患者有预后不良的风险，应考虑额外的治疗。
