Reticulation is associated with the risk of disease progression in interstitial lung diseases

Abstract

<b>Background:</b> Progressive fibrosing interstitial lung disease (PF-ILD) has been defined to improve the treatment and follow-up among the diverse diagnoses of ILDs. This study aimed to evaluate the risk factors of PF-ILD. <b>Methods:</b> Patients with a suspected ILD in 2015-2019 were included in a prospective study. All 100 patients underwent a transbronchial lung cryobiopsy procedure. The presence and extent of several high-resolution computed tomography (HRCT) patterns were assessed. PF-ILD was defined according to the recommendation of an international expert group as a relative decline of ≥ 10 % in FVC, or a relative decline in FVC of ≥ 5 % and one of the three additional criteria (1. a decline in DLCO ≥ 15 %, 2. increased fibrosis on HRCT, 3. progressive symptoms), or progressive symptoms and increased fibrosis on HRCT over 24 months despite treatment. PF-ILD was categorized similarly in patients with idiopathic pulmonary fibrosis (IPF) and patients with other ILDs. Risk factors of PF-ILD were evaluated in a multivariable model. <b>Results:</b> PF-ILD was revealed in 52 % of the patients with ILD, 51 % of patients with IPF and in 53 % of patients with other ILDs. A high extent of reticulation in the HRCT (Odds ratio [OR] 3.107, 95 % Confidence interval [CI] 1.209-7.983, P = 0.019), platelet count (OR 1.007, CI 1.000-1.015, P = 0.065), and ever smoking (OR 0.321, CI 0.116-0.890, P = 0.029) were associated with the risk of PF-ILD. <b>Conclusions:</b> A high extent of reticulation in the HRCT was associated with the risk of PF-ILD. Approximately half of the patients with ILD presented PF-ILD, and similar proportions were observed in patients with IPF and those with other types of ILD.