Progressive phenotype predicts transplantation-free survival in ILD, IPF patients

Nearly one in four nonidiopathic pulmonary fibrosis (non-IPF) patients with a fibrosing form of interstitial lung disease (FILD) develop a progressive phenotype relative to almost 60 percent of IPF patients, reveals a study. Survival of non-IPF FILD patients with such phenotype is similar to IPF.

A team of investigators examined consecutive patients seen for initial assessment of FILD and evaluated them for evidence of progressive fibrosis over the first 24 months of follow-up.

A progressive phenotype was defined as the presence of at least one of the following: a relative decline in forced vital capacity (FVC) of ≥10 percent; a relative decline in FVC of ≥5 percent to <10 percent with a relative decline in diffusing capacity of the lung for carbon monoxide of ≥15 percent, increased fibrosis on HRCT, or progressive symptoms.

A total of 844 patients were included in the final analysis, of whom 397 had IPF and 447 had non-IPF FILD. Some 355 participants (42.1 percent) met the progressive phenotype criteria, of whom 59.4 percent were IPF patients and 26.6 percent non-IPF FILD patients (p<0.01). Notably, transplantation-free survival varied between those with a progressive phenotype and those without (p<0.01).

In multivariable analysis, a progressive phenotype was independently associated with transplantation-free survival (hazard ratio [HR], 3.36, 95 percent confidence interval [CI], 2.68‒4.23; p<0.01). Furthermore, transplantation-free survival was comparable between non-IPF FILD with a progressive phenotype and IPF (HR, 1.12, 95 percent CI, 0.85‒1.48; p=0.42).