PT  - JOURNAL ARTICLE
AU  - K.R. Flaherty
AU  - G.B. Toews
AU  - W.D. Travis
AU  - T.V. Colby
AU  - E.A. Kazerooni
AU  - B.H. Gross
AU  - A. Jain
AU  - R.L. Strawderman III
AU  - R. Paine
AU  - A. Flint
AU  - J.P. Lynch III
AU  - F.J. Martinez
TI  - Clinical significance of histological classification of idiopathic interstitial pneumonia
AID  - 10.1183/09031936.02.00182002
DP  - 2002 Feb 01
TA  - European Respiratory Journal
PG  - 275--283
VI  - 19
IP  - 2
4099  - http://erj.ersjournals.com/content/19/2/275.short
4100  - http://erj.ersjournals.com/content/19/2/275.full
SO  - Eur Respir J2002 Feb 01; 19
AB  - Patients with idiopathic interstitial pneumonias (IIPs) can be subdivided into groups based on the histological appearance of lung tissue obtained by surgical biopsy. The quantitative impact of histological diagnosis, baseline factors and response to therapy on survival has not been evaluated. Surgical lung biopsy specimens from 168 patients with suspected IIP were reviewed according to the latest diagnostic criteria. The impact of baseline clinical, physiological, radiographic and histological features on survival was evaluated using Cox regression analysis. The predictive value of honeycombing on high-resolution computed tomography (HRCT) as a surrogate marker for usual interstitial pneumonia (UIP) was examined. The response to therapy and survival of 39 patients treated prospectively with high-dose prednisone was evaluated. The presence of UIP was the most important factor influencing mortality. The risk ratio of mortality when UIP was present was 28.46 (95% confidence interval (CI) 5.5–148.0; p=0.0001) after controlling for patient age, duration of symptoms, radiographic appearance, pulmonary physiology, smoking history and sex. Honeycombing on HRCT indicated the presence of UIP with a sensitivity of 90% and specificity of 86%. Patients with nonspecific interstitial pneumonia were more likely to respond or remain stable (9 of 10) compared to patients with UIP (14 of 29) after treatment with prednisone. Patients remaining stable had the best prognosis. The risk ratio of mortality for stable patients compared to nonresponders was 0.32 (95% CI 0.11–0.93; p=0.04) in all patients and 0.33 (95% CI 0.12–0.96; p=0.04) in patients with UIP. The histological diagnosis of usual interstitial pneumonia is the most important factor determining survival in patients with suspected idiopathic interstitial pneumonia. The presence of honeycombing on high-resolution computed tomography is a good surrogate for usual interstitial pneumonia and could be utilized in patients unable to undergo surgical lung biopsy. Patients with nonspecific interstitial pneumonia are more likely to respond or remain stable following a course of prednisone. Patients remaining stable following prednisone therapy have the best prognosis. This study was supported in part by National Institutes of Health (NIH) National Heart, Lung, and Blood Institute (NHLBI) Grant #P50HL46487, NIH/NCRR 3 MO1 RR00042-33S3, NIH/NIA P60 AG08808-06 and NHLBI, 1 K24 HL04212-01.