Panagopoulos Panagiotis K, Goules Andreas V, Georgakopoulou Vasiliki E, Kallianos Anastasios, Chatzinikita Eirini, Pezoulas Vasileios C, Malagari Katerina, Fotiadis Dimitrios I, Vlachoyiannopoulos Panayiotis, Vassilakopoulos Theodoros, Tzioufas Athanasios G
Department of Pathophysiology, School of Medicine, National and Kapodistrian University of Athens, Athens, Greece.
Research Institute of Systemic Autoimmune Diseases, Athens, Greece.
Front Med (Lausanne). 2022 Nov 14;9:1016898. doi: 10.3389/fmed.2022.1016898. eCollection 2022.
A number of studies report small airways involvement in patients with systemic sclerosis (SSc). Furthermore, small airways dysfunction is increasingly recognized in patients with interstitial lung disease (ILD) of idiopathic or autoimmune etiology. The objectives of this study were to evaluate small airways function in SSc patients with ILD and explore the effect of treatment on small airways function by using conventional and contemporary pulmonary function tests (PFTs).
This single-center, prospective, observational study included a total of 35 SSc patients, with and without ILD based on HRCT scan, evaluated by a special radiologist blindly. Clinical data were collected from all patients who were also assessed for HRCT findings of small airways disease. Small airways function was assessed by classic spirometry, measurement of diffusing capacity for carbon monoxide, body plethysmography, single breath nitrogen washout (NSBW) and impulse oscillometry (IOS). The prevalence of small airways dysfunction according to R5-R20, phase III slope and CV/VC methodologies was calculated in the total SSc population. Pulmonary function tests were compared between: (a) SSc-ILD and non-ILD patients and (b) two time points (baseline and follow up visit) in a subset of SSc-ILD patients who received treatment for ILD and were re-evaluated at a follow up visit after 12 months.
Phase III slope and R5-R20 showed the highest diagnostic performance for detecting small airways dysfunction among SSc patients (61 and 37.5%, respectively). Twenty three SSc patients were found with ILD and 14 of them had a 12-month follow up visit. SSc-ILD patients compared to those without ILD exhibited increased phase III slope ≥120% ( = 0.04), R5-R20 ≥0.07 kPa/L/s ( = 0.025), airway resistance (Raw) ( = 0.011), and special airway resistance (sRaw) ( = 0.02), and decreased specific airway conductance (sGaw) ( = 0.022), suggesting impaired small airways function in the SSc-ILD group. Radiographic features of SAD on HRCT were observed in 22% of SSc-ILD patients and in none of SSc-non-ILD patients. Comparison of PFTs between baseline and follow-up visit after 12 months in the 14 SSc-ILD treated patients, showed improvement of phase III slope ( = 0.034), R5-R20 ( = 0.035) and Raw ( = 0.044) but not sRaw and sGaw parameters.
Phase III slope and R5-R20 may reveal small airways dysfunction in SSc associated ILD before structural damage and may be partially improved in a subset of patients receiving treatment for ILD.
多项研究报告称系统性硬化症（SSc）患者存在小气道受累情况。此外，特发性或自身免疫性病因的间质性肺疾病（ILD）患者中，小气道功能障碍也日益受到认可。本研究的目的是通过使用传统和现代肺功能测试（PFT）评估合并ILD的SSc患者的小气道功能，并探讨治疗对小气道功能的影响。
这项单中心、前瞻性、观察性研究共纳入35例SSc患者，根据HRCT扫描结果分为有ILD和无ILD两组，由一名专业放射科医生进行盲法评估。收集所有患者的临床数据，并对其进行小气道疾病的HRCT检查。通过经典肺量计、一氧化碳弥散量测量、体容积描记法、单次呼吸氮洗脱（NSBW）和脉冲振荡法（IOS）评估小气道功能。根据R5-R20、III期斜率和CV/VC方法计算整个SSc人群中小气道功能障碍的患病率。比较以下两组的肺功能测试结果：（a）SSc-ILD患者和非ILD患者；（b）在接受ILD治疗并在12个月后随访时重新评估的SSc-ILD患者亚组中的两个时间点（基线和随访）。
III期斜率和R5-R20在检测SSc患者小气道功能障碍方面表现出最高的诊断性能（分别为61%和37.5%）。发现23例SSc患者合并ILD，其中14例进行了12个月的随访。与无ILD的患者相比，SSc-ILD患者的III期斜率≥120%（P = 0.04）、R5-R20≥0.07 kPa/L/s（P = 0.025）、气道阻力（Raw）（P = 0.011）和比气道阻力（sRaw）（P = 0.02）增加，而比气道传导率（sGaw）降低（P = 0.022），提示SSc-ILD组小气道功能受损。22%的SSc-ILD患者在HRCT上观察到小气道疾病的影像学特征，而SSc-非ILD患者均未观察到。对14例接受治疗的SSc-ILD患者在基线和12个月随访后的肺功能测试进行比较，结果显示III期斜率（P = 0.034）、R5-R20（P = 0.035）和Raw（P = 0.044）有所改善，但sRaw和sGaw参数未改善。
III期斜率和R5-R20可能在结构性损伤之前揭示SSc相关ILD患者的小气道功能障碍，并且在接受ILD治疗的部分患者中可能会部分改善。
