Department of Respiratory Physiology, National Institute of Respiratory Diseases, Mexico City, Mexico.
Interstitial Lung Diseases Clinic, National Institute of Respiratory Diseases, Mexico City, Mexico.
Respirology. 2017 Nov;22(8):1637-1642. doi: 10.1111/resp.13124. Epub 2017 Jul 26.
Lung biopsies from patients with hypersensitivity pneumonitis (HP) have demonstrated small airway (SA) involvement, but there is no information concerning SA function in HP, and it is unknown whether pharmacological treatment could modify its function. SA function in patients with chronic HP using ultrasonic pneumography (UPG) and impulse oscillometry (IOS) was explored. We also compared initial results with those obtained after 4 weeks of standardized treatment with azathioprine and prednisone.
The study group consisted of adults with recent diagnoses of HP. All patients completed UPG, IOS, spirometry, body plethysmography, single-breath carbon monoxide diffusing capacity (DL ) and the 6-min walk test (6MWT). The fraction of exhaled nitric oxide (FE ) was obtained to assess eosinophilic airway inflammation. Measurements were taken at diagnosis and after 4 weeks of treatment.
A total of 20 consecutive patients (16 women) with chronic HP participated in the study. Median age was 50 years (interquartile range (IQR): 42-54). At diagnosis, the UPG phase 3 slope was abnormally high, consistent with maldistribution of ventilation. For IOS, all patients had low reactance at 5 Hz (X5) and elevated reactance area (AX) reflecting low compliance, and only eight (40%) patients had elevated R5 (resistance at 5 Hz (total)) and R5-20 (resistance at 5 Hz-resistance at 20 Hz (peripheral)) attributed to SA resistance. In contrast, FE parameters were within normal limits. After treatment, forced vital capacity (FVC), the 6-min walk distance and the distribution of ventilation showed significant improvement, although DL did not.
Patients with chronic HP have SA abnormalities that are partially revealed by the UPG and IOS tests. Lung volumes, but not gas exchange, improved after treatment with azathioprine and prednisone.
过敏性肺炎（HP）患者的肺活检显示小气道（SA）受累，但关于 HP 患者的 SA 功能尚无相关信息，也不知道药物治疗是否能改变其功能。本研究通过超声肺功能检查（UPG）和脉冲震荡（IOS）探索了慢性 HP 患者的 SA 功能，并比较了在接受硫唑嘌呤和泼尼松标准治疗 4 周后的初始结果。
研究组由近期诊断为 HP 的成年人组成。所有患者均完成了 UPG、IOS、肺量测定、体描法、单次呼吸一氧化碳弥散量（DL ）和 6 分钟步行试验（6MWT）。通过检测呼出气一氧化氮（FE ）分数来评估嗜酸性气道炎症。这些测量在诊断时和治疗 4 周后进行。
共有 20 例连续的慢性 HP 患者（16 名女性）参与了这项研究。中位年龄为 50 岁（四分位距：42-54）。在诊断时，UPG 第 3 相斜率异常升高，提示通气分布不均。对于 IOS，所有患者的 5Hz 电抗（X5）较低（提示顺应性低），电抗面积（AX）升高（提示顺应性低），只有 8 例（40%）患者的 5Hz 阻力（R5）和 5-20Hz 阻力（R5-20）升高（提示 SA 阻力升高）。相反，FE 参数在正常范围内。治疗后，用力肺活量（FVC）、6 分钟步行距离和通气分布均有显著改善，尽管 DL 没有改善。
慢性 HP 患者存在 SA 异常，UPG 和 IOS 检查部分显示这些异常。在接受硫唑嘌呤和泼尼松治疗后，肺容积而非气体交换得到改善。
