Lewandowska Katarzyna B, Sobiecka Małgorzata, Boros Piotr W, Dybowska Małgorzata, Barańska Inga, Jędrych Małgorzata E, Gładzka Agata, Tomkowski Witold Z, Szturmowicz Monika
1st Department of Lung Diseases, National Research Institute of Tuberculosis and Lung Diseases, 01-138 Warsaw, Poland.
Department of Respiratory Physiopathology, National Research Institute of Tuberculosis and Lung Diseases, 01-138 Warsaw, Poland.
Diagnostics (Basel). 2023 Mar 15;13(6):1109. doi: 10.3390/diagnostics13061109.
The six-minute-walking test (6MWT) is an easy-to-perform, cheap and valuable tool to assess the physical performance of patients. It has been used as one of the endpoints in many clinical trials investigating treatment efficacy in pulmonary arterial hypertension and idiopathic pulmonary fibrosis. However, the utility of 6MWT in patients diagnosed with hypersensitivity pneumonitis (HP) is still under investigation. The aim of the present retrospective study was to assess the value of different 6MWT parameters, including the newly developed distance-desaturation index (DDI), to evaluate immunomodulatory treatment outcomes in HP patients.
6MWT parameters (distance, initial saturation, final saturation, desaturation, distance-saturation product (DSP), and DDI) were analyzed at baseline and after 3 to 6 months of treatment with corticosteroids alone or in combination with azathioprine.
91 consecutive HP patients diagnosed and treated in a single pulmonary unit from 2005 to 2017 entered the study. There were 44 (48%) males and 52 (57%) patients with fibrotic HP (fHP). Sixty-three patients (69%) responded to treatment (responders) and 28 (31%) did not respond (non-responders). In the responders group, all parameters assessed during 6MWT significantly improved, whereas in non-responders, they worsened. Medians (95% CI) of best indices were post-treatment DDI/baseline DDI-1.67 (1.85-3.63) in responders versus 0.88 (0.7-1.73) in non-responders ( = 0.0001) and change in walking distance-51 m (36-72 m) in responders, versus 10.5 m (-61.2-27.9) in non-responders ( = 0.0056). The area under the curve (AUC) of receiver operating characteristics (ROC) for post-treatment DDI/baseline DDI was 0.74 and the optimal cut-off was 1.075, with 71% of specificity and 71% of sensitivity.
6MWT may be used as a tool to assess and monitor the response to immunomodulatory therapy in HP patients, especially if indices incorporating both distance and desaturation are used. Based on the present study results, we recommend 6MWD and DDI use, in addition to FVC and TL,co, to monitor treatment efficacy in patients with interstitial lung diseases.
六分钟步行试验（6MWT）是一种易于实施、成本低廉且有价值的评估患者身体机能的工具。它已被用作许多调查肺动脉高压和特发性肺纤维化治疗效果的临床试验的终点指标之一。然而，6MWT在诊断为过敏性肺炎（HP）患者中的效用仍在研究中。本回顾性研究的目的是评估不同的6MWT参数，包括新开发的距离-血氧饱和度指数（DDI），以评估HP患者免疫调节治疗的效果。
在基线时以及单独使用皮质类固醇或联合硫唑嘌呤治疗3至6个月后，分析6MWT参数（距离、初始血氧饱和度、最终血氧饱和度、血氧饱和度下降、距离-血氧饱和度乘积（DSP）和DDI）。
2005年至2017年在单个肺科病房诊断并治疗的91例连续HP患者进入研究。有44例（48%）男性和52例（57%）纤维化HP（fHP）患者。63例患者（69%）对治疗有反应（反应者），28例（31%）无反应（无反应者）。在反应者组中，6MWT期间评估的所有参数均显著改善，而在无反应者中，这些参数恶化。反应者组最佳指标的中位数（95%CI）为治疗后DDI/基线DDI - 1.67（1.85 - 3.63），无反应者为0.88（0.7 - 1.73）（P = 0.0001），步行距离变化在反应者中为51米（36 - 72米），无反应者为10.5米（-61.2 - 27.9米）（P = 0.0056）。治疗后DDI/基线DDI的受试者工作特征（ROC）曲线下面积（AUC）为0.74，最佳截断值为1.075，特异性为71%，敏感性为71%。
6MWT可作为评估和监测HP患者免疫调节治疗反应的工具，特别是如果使用结合距离和血氧饱和度下降的指标。基于本研究结果，我们建议除用力肺活量（FVC）和一氧化碳肺弥散量（TL,co）外，使用6MWD和DDI来监测间质性肺疾病患者的治疗效果。
