Kharitonov S A, Cailes J B, Black C M, du Bois R M, Barnes P J
Department of Thoracic Medicine, National Heart and Lung Institute, Imperial School of Medicine, Royal Brompton Hospital, London, UK.
Thorax. 1997 Dec;52(12):1051-5. doi: 10.1136/thx.52.12.1051.
Systemic sclerosis (SSc) may be complicated by pulmonary hypertension (PHT), which can occur both in the setting of fibrosing alveolitis or as lone pulmonary vascular disease. Nitric oxide (NO) is a powerful vasodilator and is produced by various cells in the respiratory tract including pulmonary vascular endothelial cells and can be measured in expired air. A study was undertaken to test the hypothesis that exhaled NO levels would be decreased in patients with SSc with PHT and to assess the utility of this measurement in discriminating between patients with and without PHT, regardless of concurrent fibrosing alveolitis.
Exhaled NO was measured with a chemiluminescence analyser in 23 patients with SSc (six with PHT, 17 subjects without) and in 67 normal individuals. Doppler echocardiography was used to assess pulmonary artery pressure in subjects with SSc, and lung function tests were performed at the same visit as NO measurements. Thin section CT scans were analysed for the presence of abnormality consistent with fibrosing alveolitis.
Patients with SSc with PHT had a greater reduction in arterial oxygen tension (PaO2) and carbon monoxide gas transfer (TLCO) than patients with SSc without PHT. Exhaled NO was significantly higher in patients with SSc without PHT than in normal individuals, and was significantly decreased in patients with SSc with PHT (mean (SD) 20 (6) ppb) compared with 149 (19) ppb in those with SSc without PHT (mean difference 129 (95% CI 112 to 146) ppb) and 80 (7) ppb in normal individuals (mean difference 60 (95% CI 54 to 66) ppb).
Exhaled NO is decreased in patients with SSc with PHT compared with both normal individuals and patients with SSc without PHT.
系统性硬化症（SSc）可能并发肺动脉高压（PHT），其可发生于纤维化肺泡炎的情况下或作为孤立的肺血管疾病出现。一氧化氮（NO）是一种强大的血管扩张剂，由呼吸道中的各种细胞产生，包括肺血管内皮细胞，并且可以在呼出气体中测量。进行了一项研究，以检验SSc合并PHT患者呼出NO水平会降低的假设，并评估该测量在区分有无PHT患者中的效用，无论是否并发纤维化肺泡炎。
使用化学发光分析仪测量23例SSc患者（6例合并PHT，17例未合并）和67名正常个体的呼出NO。使用多普勒超声心动图评估SSc患者的肺动脉压力，并在与NO测量相同的就诊时进行肺功能测试。分析薄层CT扫描以确定是否存在与纤维化肺泡炎一致的异常。
SSc合并PHT患者的动脉血氧分压（PaO2）和一氧化碳气体转运（TLCO）的降低幅度大于SSc未合并PHT患者。SSc未合并PHT患者的呼出NO显著高于正常个体，而SSc合并PHT患者的呼出NO显著降低（均值（标准差）为20（6）ppb），相比之下，SSc未合并PHT患者为149（19）ppb（均值差异129（95%可信区间112至146）ppb），正常个体为80（7）ppb（均值差异60（95%可信区间54至66）ppb）。
与正常个体和SSc未合并PHT患者相比，SSc合并PHT患者的呼出NO降低。
