National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD.
National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD.
Chest. 2021 Jul;160(1):199-208. doi: 10.1016/j.chest.2021.01.077. Epub 2021 Feb 5.
Lymphangioleiomyomatosis (LAM) is a rare lung disease found primarily in women of childbearing age, characterized by the formation of air-filled cysts, which may be associated with reductions in lung function. An experimental, regional ultra-high resolution CT scan identified an additional volume of cysts relative to standard chest CT imaging, which consisted primarily of ultra-small cysts.
What is the impact of these ultra-small cysts on the pulmonary function of patients with LAM?
A group of 103 patients with LAM received pulmonary function tests and a CT examination in the same visit. Cyst score, the percentage lung volume occupied by cysts, was measured by using commercial software approved by the US Food and Drug Administration. The association between cyst scores and pulmonary function tests of diffusing capacity of the lungs for carbon monoxide (Dlco) (% predicted), FEV (% predicted), and FEV/FVC (% predicted) was assessed with statistical analysis adjusted for demographic variables. The distributions of average cyst size and ultra-small cyst fraction among the patients were evaluated.
The additional cyst volume identified by the experimental, higher resolution scan consisted of cysts of 2.2 ± 0.8 mm diameter on average and are thus labeled the "ultra-small cyst fraction." It accounted for 27.9 ± 19.0% of the total cyst volume among the patients. The resulting adjusted, whole-lung cyst scores better explained the variance of Dlco (P < .001 adjusted for multiple comparisons) but not FEV and FEV/FVC (P = 1.00). The ultra-small cyst fraction contributed to the reduction in Dlco (P < .001) but not to FEV and FEV/FVC (P = .760 and .575, respectively). The ultra-small cyst fraction and average cyst size were correlated with cyst burden, FEV, and FEV/FVC but less with Dlco.
The ultra-small cysts primarily contributed to the reduction in Dlco, with minimal effects on FEV and FEV/FVC. Patients with lower cyst burden and better FEV and FEV/FVC tended to have smaller average cyst size and higher ultra-small cyst fraction.
ClinicalTrials.gov; No.: NCT00001465; URL: www.clinicaltrials.gov.
淋巴管平滑肌瘤病（LAM）是一种主要发生在育龄妇女中的罕见肺部疾病，其特征是形成充满空气的囊肿，这可能与肺功能下降有关。一项实验性的区域性超高分辨率 CT 扫描发现，与标准胸部 CT 成像相比，囊肿的体积增加，主要由超小囊肿组成。
这些超小囊肿对 LAM 患者的肺功能有什么影响？
一组 103 名 LAM 患者在同一次就诊时接受了肺功能检查和 CT 检查。使用美国食品和药物管理局批准的商业软件测量囊肿评分，即囊肿占肺体积的百分比。通过统计分析评估囊肿评分与弥散量一氧化碳（Dlco）（%预计值）、FEV（%预计值）和 FEV/FVC（%预计值）之间的相关性，该分析调整了人口统计学变量。评估了患者之间平均囊肿大小和超小囊肿分数的分布。
实验性更高分辨率扫描所识别的额外囊肿体积由平均直径为 2.2±0.8mm 的囊肿组成，因此被标记为“超小囊肿分数”。它占患者总囊肿体积的 27.9±19.0%。调整后的全肺囊肿评分更好地解释了 Dlco 的变化（P<0.001，经多次比较调整），但不能解释 FEV 和 FEV/FVC 的变化（P=1.00）。超小囊肿分数与 Dlco 降低有关（P<0.001），但与 FEV 和 FEV/FVC 无关（P=0.760 和 0.575）。超小囊肿分数和平均囊肿大小与囊肿负担、FEV 和 FEV/FVC 相关，但与 Dlco 相关性较低。
超小囊肿主要导致 Dlco 降低，对 FEV 和 FEV/FVC 的影响较小。囊肿负担较低、FEV 和 FEV/FVC 较好的患者，其平均囊肿大小较小，超小囊肿分数较高。
ClinicalTrials.gov；编号：NCT00001465；网址：www.clinicaltrials.gov。
