Pathologic and radiologic differences between idiopathic and collagen vascular disease-related usual interstitial pneumonia.
BACKGROUND
Patients with usual interstitial pneumonia (UIP) associated with collagen vascular disease (CVD) have been reported to have a better prognosis than those with idiopathic pulmonary fibrosis with a UIP pattern (IPF/UIP) seen on histology. The aim of this study was to evaluate the pathologic and radiologic differences between the two conditions and their relationship with clinical outcome.


METHODS
A retrospective review of 100 patients (CVD-UIP, 39 patients; IPF/UIP, 61 patients) with UIP pattern diagnosed by surgical lung biopsy at one tertiary referral center.


RESULTS
The median follow-up period was 34.4 months. The CVD-UIP group was younger, included more women and nonsmokers, and showed better survival than the IPF/UIP group. Pathologically, CVD-UIP patients had fewer fibroblastic foci and smaller honeycombing (HC) spaces with higher germinal centers and total inflammation scores than IPF/UIP patients. Radiologically, CVD-UIP patients had a lower emphysema score and more likely a nontypical UIP pattern without HC. The germinal centers score was the best distinguishing feature between CVD-UIP and IPF/UIP patients (odds ratio, 2.948; p = 0.001) and was marginally related to survival (p = 0.076). The HC score (hazard ratio [HR], 1.134; p < 0.001), total lung capacity (TLC) [HR, 0.932; p = 0.004], and age (HR, 1.052; p = 0.017) were significant predictors of survival in all patients with UIP histology, regardless of the presence of CVD. Among IPF/UIP patients, those with positive autoantibodies were pathologically more similar to CVD-UIP than to IPF/UIP without autoantibodies, despite no difference in survival between them.


CONCLUSIONS
The germinal centers score was the best discriminative between CVD-UIP and IPF/UIP patients; it was of marginal prognostic significance. Age, TLC, and HC score were independent prognostic factors in all patients with UIP histology.
Song
Jin Woo
JW
Department of Pulmonary and Critical Care Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea.
Do
Kyung-Hyun
KH
Department of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea.
Kim
Mi-Young
MY
Department of Pulmonary and Critical Care Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea. Electronic address: dskim@amc.seoul.kr.
Jang
Se Jin
SJ
Department of Pathology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea.
Colby
Thomas V
TV
Department of Pathology, Mayo Clinic, Rochester, MN.
Kim
Dong Soon
DS
Department of Pulmonary and Critical Care Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea.
D000328:Adult; D000368:Aged; D015331:Cohort Studies; D003095:Collagen Diseases / Q000150:complications* / Q000175:diagnosis / Q000401:mortality; D005260:Female; D006801:Humans; D054990:Idiopathic Pulmonary Fibrosis / Q000000981:diagnostic imaging* / Q000209:etiology / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors; D016019:Survival Analysis; D014057:Tomography, X-Ray Computed; D014652:Vascular Diseases / Q000150:complications* / Q000175:diagnosis / Q000401:mortality