Ramírez-Venegas A, Sansores R H, Pérez-Padilla R, Carrillo G, Selman M
Instituto Nacional de Enfermedades Respiratorias, México DF, México.
Am J Respir Crit Care Med. 1998 Sep;158(3):862-9. doi: 10.1164/ajrccm.158.3.9710036.
Chronic hypersensitivity pneumonitis (CHP) can be difficult to differentiate from other interstitial lung diseases (ILD). To determine the diagnostic usefulness of a provocation test (PT), 17 patients with CHP induced by avian antigens, 17 with other ILD, and five healthy control subjects were challenged with pigeon serum. After PT, an increase in body temperature (BT) and a decrease in FVC, PaO2 and SaO2% were observed in all patients with CHP and in three with ILD. No reaction was noticed in healthy subjects. ROC curves showed that for FVC the best cut point was a drop of 16% displaying sensitivity (S): 76%, specificity (SP): 81%, positive predictive value (PPV): 81%, and negative predictive value (NPV): 83%. For a drop of 3 mm Hg in PaO2 or 3% SaO2, S was 88% for both, SP was 82 and 86%, PPV was 81 and 82%, and NPV was 82 and 86%, respectively. An increase of BT > 0.5(o) C showed S, 100%; SP, 82%; PPV, 100%; NPV, 86%. A univariate regression analysis confirmed that changes in BT and FVC are predicting values of CHP: RR, 82.5 (CI, 10.43 to 651.76) and 1.21 (CI, 1.06 to 1.36). There were no challenge test complications. These findings suggest that PT is a useful tool for diagnosis of CHP.
慢性过敏性肺炎（CHP）可能难以与其他间质性肺病（ILD）相鉴别。为了确定激发试验（PT）的诊断价值，对17例由禽类抗原诱发的CHP患者、17例其他ILD患者和5名健康对照者进行鸽血清激发试验。激发试验后，所有CHP患者和3例ILD患者均出现体温（BT）升高以及用力肺活量（FVC）、动脉血氧分压（PaO2）和动脉血氧饱和度（SaO2%）下降。健康受试者未出现反应。ROC曲线显示，对于FVC，最佳切点为下降16%，其敏感性（S）为76%，特异性（SP）为81%，阳性预测值（PPV）为81%，阴性预测值（NPV）为83%。对于PaO2下降3 mmHg或SaO2下降3%，两者的S均为88%，SP分别为82%和86%，PPV分别为81%和82%，NPV分别为82%和86%。BT升高>0.5（°）C时，S为100%，SP为82%，PPV为100%，NPV为86%。单因素回归分析证实，BT和FVC的变化是CHP的预测指标：相对危险度（RR）分别为82.5（95%可信区间为10.43至651.76）和1.21（95%可信区间为1.06至1.36）。激发试验无并发症发生。这些结果表明，激发试验是诊断CHP的一种有用工具。
