Histologic features suggesting connective tissue disease in idiopathic pulmonary fibrosis

Ho Cheol Kim,Eun Jin Chae,Se Jin Jang,Sojung Park,Jin Woo Song,So Yun Lim,Joon Seon Song,Hee-Young Yoon

doi:10.1038/s41598-020-78140-5

Ho Cheol Kim, Eun Jin Chae + Show 6 more

Open Access

https://doi.org/10.1038/s41598-020-78140-5

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Abstract

Some patients with idiopathic pulmonary fibrosis (IPF) have histopathologic features suggesting connective tissue disease (CTD); however, their clinical course and prognosis remain unclear. Thus, we aimed to investigate the clinical course and prognosis of these patients with histologic autoimmune features. Among 114 patients with biopsy-proven IPF, the histologic features were semi-quantitatively graded, and CTD scores (range: 0–9) were calculated as the sum of each score of plasma cell infiltration, lymphoid aggregates, and germinal centres. Patients with high CTD scores (≥ 4) were classified into the interstitial pneumonia with histologic autoimmune features (IP-hAF) group. The mean age of the patients was 60.0 years; 74.6% were men, 69.3% were ever-smokers, and 35.1% had IP-hAF. During follow-up, the IP-hAF group showed slower decline in lung function, and better prognosis (median survival, 48.7 vs. 40.4 months; p = 0.015) than the no-IP-hAF group. On multivariate Cox analysis, IP-hAF was an independent prognostic factor (hazard ratio, 0.522; p = 0.016), along with the lower diffusing capacity for carbon monoxide, higher scores of reticulation and honeycombing, and usual interstitial pneumonia pattern on high-resolution computed tomography. Patients with IPF having histologic autoimmune features show distinct clinical characteristics and better outcome than those without histologic autoimmune features.

Highlights

Some patients with idiopathic pulmonary fibrosis (IPF) have histopathologic features suggesting connective tissue disease (CTD); their clinical course and prognosis remain unclear
A previous study on 100 patients with the usual interstitial pneumonia (UIP) pattern diagnosed via surgical lung biopsy (39 with CTD and 61 with IPF) showed that patients with CTD-UIP had higher germinal centre and total inflammation scores than those with IPF/UIP, and that a high germinal centre score was an independent discriminating factor for CTD-UIP7
Likewise CTD score, interstitial pneumonia with histologic autoimmune features (IP-hAF) was an independent prognostic factor (HR, 0.522; 95% CI, 0.307–0.886; p = 0.016) in patients with IPF, along with lower DLco, higher scores of reticulation and honeycombing, and a UIP pattern on high-resolution computed tomography (HRCT), as seen on multivariate Cox analysis (Table 6, Supplementary Material Table 7)

Summary

Introduction

Some patients with idiopathic pulmonary fibrosis (IPF) have histopathologic features suggesting connective tissue disease (CTD); their clinical course and prognosis remain unclear. Patients with high CTD scores (≥ 4) were classified into the interstitial pneumonia with histologic autoimmune features (IP-hAF) group. A previous study on 100 patients with the usual interstitial pneumonia (UIP) pattern diagnosed via surgical lung biopsy (39 with CTD and 61 with IPF) showed that patients with CTD-UIP had higher germinal centre and total inflammation scores than those with IPF/UIP, and that a high germinal centre score (odds ratio [OR], 2.948; p = 0.001) was an independent discriminating factor for CTD-UIP7. The impact of histopathologic findings suggesting CTD on the clinical course and prognosis of patients with IPF remains unknown. We compared the clinical course and outcomes between patients with IPF having histopathologic autoimmune features and those without histopathologic autoimmune features

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