Chest
Volume 144, Issue 2, August 2013, Pages 586-592
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Original Research
Diffuse Lung Disease
Radiographic Fibrosis Score Predicts Survival in Hypersensitivity Pneumonitis

https://doi.org/10.1378/chest.12-2623Get rights and content

Background

It is unknown if the radiographic fibrosis score predicts mortality in persistent hypersensitivity pneumonitis (HP) and if survival is similar to that observed in idiopathic pulmonary fibrosis (IPF) when adjusting for the extent of radiographic fibrosis.

Methods

We reviewed records from 177 patients with HP and 224 patients with IPF whose diagnoses were established by multidisciplinary consensus. Two thoracic radiologists scored high-resolution CT (HRCT) scan lung images. Independent predictors of transplant-free survival were determined using a Cox proportional hazards analysis. Kaplan-Meier survival curves were constructed, stratified by disease as well as fibrosis score.

Results

HRCT scan fibrosis score and radiographic reticulation independently predicted time to death or lung transplantation. Clinical predictors included a history of cigarette smoking, auscultatory crackles on lung examination, baseline FVC, and FEV1/FVC ratio. The majority of HP deaths occurred in patients with both radiographic reticulation and auscultatory crackles on examination, compared with patients with only one of these manifestations (P < .0001). Patients with IPF had worse survival than those with HP at any given degree of radiographic fibrosis (hazard ratio 2.31; P < .01).

Conclusions

Survival in patients with HP was superior to that of those with IPF with similar degrees of radiographic fibrosis. The combination of auscultatory crackles and radiographic reticulation identified patients with HP who had a particularly poor outcome.

Section snippets

Study Population

Patients with HP (n = 190) and IPF (n = 242) were prospectively enrolled from the University of California San Francisco (UCSF) Interstitial Lung Disease (ILD) Clinic from March 2000 to October 2010. Data from all patients were collected prospectively using standardized questionnaires and physician review. The diagnostic criteria for HP or IPF were based upon consensus agreement by experts at a multidisciplinary conference after thorough review of all available data in accordance with

Study Population

Baseline demographics are shown in Table 1. Compared with IPF, patients with persistent HP were younger, more likely to be female, less likely to be ever smokers, had fewer pack-years of smoking, and had less crackles on auscultatory lung examination. Patients with HP had greater physiologic obstruction (based on FEV1 and FEV1/FVC), whereas patients with IPF had greater restriction and lower diffusing capacity. Patients with HP had a lower radiographic fibrosis score (median score, 11.04 for HP

Discussion

The results from this study extend prior observations regarding the role of radiographic fibrosis in survival in patients with persistent HP and identified several novel findings. These include (1) that the radiographic fibrosis score is an independent predictor of mortality in persistent HP, (2) that patients with both fibrosis (reticulation and/or honeycombing) and auscultatory crackles on chest examination have a particularly poor outcome compared with patients with just one of these

Conclusions

We found that radiographic fibrosis, specifically the extent of fibrosis (reticulations and honeycombing), predicts worse outcome in patients with HP. The combination of reticulations on CT scan and crackles on lung examination may identify patients with a particularly poor outcome and deserves further evaluation in future HP studies. Transplant-free survival in patients with HP remains superior to that of patients with IPF with similar degrees of radiographic fibrosis. These findings highlight

Acknowledgments

Author contributions: Dr Mooney had full access to the data and takes responsibility for the integrity of the data and the accuracy of the data analysis.

Dr Mooney: contributed to study design; data collection and analysis; and writing, review, and approval of the final manuscript and served as principal author.

Dr Elicker: contributed to CT scan data collection and analysis and review and approval of the final manuscript.

Dr Urbania: contributed to CT scan data collection and analysis and review

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  • Cited by (0)

    Drs Elicker, Urbania, and Agarwal contributed equally to this article.

    Part of this article was presented in abstract form at the American Thoracic Society International Conference, May 18-23, 2012, San Francisco, CA (abstract 4365).

    Funding/Support: This study was supported by departmental sources from the University of California San Francisco.

    Reproduction of this article is prohibited without written permission from the American College of Chest Physicians. See online for more details.

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