Prevalence and prognosis of chronic fibrosing interstitial lung diseases with a progressive phenotype

Abstract

Background and objective: The development of clinically progressive fibrosis complicates a wide array of interstitial lung diseases (ILDs). However, there are limited data regarding its prevalence and prognosis. Methods: We analysed consecutive patients seen for initial evaluation of a fibrosing form of ILD (FILD). Patients were evaluated for evidence of progressive fibrosis over the first 24 months of follow-up. We defined a progressive phenotype as the presence of at least one of the following: a relative decline in forced vital capacity (FVC) of ≥10%; a relative decline in FVC of ≥5%-<10% with a relative decline in diffusing capacity of the lung for carbon monoxide of ≥15%, increased fibrosis on HRCT or progressive symptoms. Results: Eight hundred and forty-four patients (397 with idiopathic pulmonary fibrosis [IPF] and 447 non-IPF FILD) made up the final analysis cohort. Three hundred and fifty-five patients (42.1%) met the progressive phenotype criteria (59.4% of IPF patients and 26.6% of non-IPF FILD patients, p <0.01). In both IPF and non-IPF FILD, transplantation-free survival differed between patients with a progressive phenotype and those without (p <0.01). Multivariable analysis showed that a progressive phenotype was an independent predictor of transplantation-free survival (hazard ratio [HR]: 3.36, 95% CI: 2.68-4.23, p <0.01). Transplantation-free survival did not differ between non-IPF FILD with a progressive phenotype and IPF (HR: 1.12, 95% CI: 0.85-1.48, p = 0.42). Conclusion: Over one-fourth of non-IPF FILD patients develop a progressive phenotype compared to approximately 60% of IPF patients. The survival of non-IPF FILD patients with a progressive phenotype is similar to IPF.

Reticulation pattern without honeycombing on high-resolution CT is associated with the risk of disease progression in interstitial lung diseases

“…The proportion of patients with disease progression was similar in our study compared to other recently published studies [ 13 , 14 ]. Disease progression was presented in 50% of ILD patients in the Canadian study and in 42% in the Japanese study compared to the 51% in our study [ 13 , 14 ].…”

“…The proportion of patients with disease progression was similar in our study compared to other recently published studies [ 13 , 14 ]. Disease progression was presented in 50% of ILD patients in the Canadian study and in 42% in the Japanese study compared to the 51% in our study [ 13 , 14 ]. The Japanese study used the same definition of disease progression as we did, but they did not include HRCT analysis since they estimated that the proportion of patients who would be defined as progressive due to HRCT changes would be small [ 14 ].…”

“…Disease progression was presented in 50% of ILD patients in the Canadian study and in 42% in the Japanese study compared to the 51% in our study [ 13 , 14 ]. The Japanese study used the same definition of disease progression as we did, but they did not include HRCT analysis since they estimated that the proportion of patients who would be defined as progressive due to HRCT changes would be small [ 14 ]. The Canadian study had different definition for disease progression but most of the patients (49%) in that study presented FVC decline ≥ 10% as the sign of disease progression [ 13 ].…”

“…In our study, never smoking was associated with the risk of disease progression in ILD and never smokers had shorter median survival than current or former smokers. Instead, in recent studies, smoking was not associated with mortality in patients with progressive ILD [ 14 ] and an increase in pack years did not associate with the risk of disease progression in patients with ILD in a multivariable model [ 13 ]. Thus, the association between smoking and disease progression in ILD merits further investigations.…”

“…In the results of the above-mentioned studies, the patients with disease progression were older and had lower baseline pulmonary function tests than the patients with a stable disease [ 13 ]. Furthermore, disease progression was independently associated with mortality in the whole cohort and when patients with IPF and other ILDs were analyzed separately [ 14 ]. Recent studies revealed that more deterioration on high-resolution computed tomography (HRCT) was observed in the progressive patients treated with pirfenidone than in the stable patients with IPF after the initial forced vital capacity (FVC) decline [ 15 ].…”