Department of Physiology, University Hospital, Faculty of Medicine, University of Franche-Comté, Besançon, France.
Respiration. 2012;84(6):461-8. doi: 10.1159/000335473. Epub 2012 Jan 31.
Interstitial lung disease (ILD) is a leading cause of death in systemic sclerosis (SSc). Sensitivities and specificities of the current pulmonary function tests (PFTs) for the detection of ILD in SSc are poor.
To determine whether diffusion capacity of the lungs for carbon monoxide (DLCO) partitioned into membrane conductance for CO (DmCO) and alveolar capillary blood volume (Vcap) could provide more sensitive clues to ILD than current PFTs.
DmCO and Vcap were determined in 35 consecutive SSc patients in whom a cardiac and/or pulmonary vascular abnormality had been rejected according to the recommended screening algorithm. ILD was diagnosed with high-resolution computed tomography.
Among 35 patients [6 men; median age (first-third quartile) 61.9 years (49.5-67.7)], 22 had no ILD and 13 did. Total lung capacity (TLC), vital capacity and DLCO [percentage of predicted value (%pred)] were lower in patients with ILD [86 (82-103) vs. 106 (98-112), p = 0.01, 96 (88-112) vs. 114 (104-121), p = 0.04, and 67 (59-81) vs. 80 (71-94), p = 0.02, respectively]. DmCO (%pred) and the ratio of DmCO to Vcap were much lower in patients with ILD [54 (48-72) vs. 83 (66-92), p < 0.001, and 0.22 (0.21-0.27) vs. 0.40 (0.35-0.53), p < 0.0001, respectively]. According to receiver operating characteristic analysis, the DmCO:Vcap ratio displayed higher sensitivity and specificity than TLC, vital capacity and DLCO in identifying ILD in our study group (p < 0.01).
These results suggest that the partitioning of DLCO might be of interest for identifying ILD in SSc patients.
间质性肺病（ILD）是系统性硬化症（SSc）患者的主要致死原因。目前用于检测 SSc 患者ILD 的肺功能检查（PFT）的敏感性和特异性均较差。
确定一氧化碳弥散量（DLCO）中膜 CO 传导率（DmCO）和肺泡毛细血管血容量（Vcap）的划分是否比目前的 PFT 更能为ILD 提供更敏感的线索。
根据推荐的筛查算法，排除了心脏和/或肺血管异常的 35 例连续 SSc 患者中，测定了 DmCO 和 Vcap。采用高分辨率计算机断层扫描诊断ILD。
35 例患者中（6 例男性；中位年龄（第一四分位数-第三四分位数）为 61.9 岁（49.5-67.7）），22 例无ILD，13 例有ILD。ILD 患者的肺总量（TLC）、肺活量和 DLCO [预测值百分比（%pred）]更低[86（82-103）比 106（98-112），p=0.01，96（88-112）比 114（104-121），p=0.04，67（59-81）比 80（71-94），p=0.02]。ILD 患者的 DmCO（%pred）和 DmCO 与 Vcap 的比值明显更低[54（48-72）比 83（66-92），p<0.001，0.22（0.21-0.27）比 0.40（0.35-0.53），p<0.0001]。根据受试者工作特征分析，与 TLC、肺活量和 DLCO 相比，DmCO：Vcap 比值在识别本研究组中的ILD 时具有更高的敏感性和特异性（p<0.01）。
这些结果表明，DLCO 的划分可能有助于识别 SSc 患者的ILD。
