Distinct Clinical Phenotypes in Interstitial Lung Disease May Better Predict Outcomes

The recent identification of 4 distinct clinical phenotypes of patients with interstitial lung disease may lead to better prediction of clinical outcomes, according to a study published in Chest.

Researchers retrospectively reviewed the records of 770 patients with interstitial lung disease, determined 24 baseline variables, and then classified them into 4 distinct cluster groups: younger white obese females, younger black females with elevated antinuclear antibody titers and lower prevalence of CT honeycombing and emphysema, older white male smokers with coexistent emphysema, and older white male smokers (highest number of pack years) with severe honeycombing and lowest baseline diffusion capacity of the lung for carbon monoxide.

The primary outcome was longitudinal pulmonary function and secondary outcomes included progression-free and transplant-free survival.

Significant differences in monthly forced vital capacity decline were revealed as a result of stratification by phenotypic clusters (Cluster 4, –0.30% vs Cluster 2, +0.01%; P <.0001). Clustering was also shown to independently predict progression-free and transplant-free survival (P <.001 and P <.001, respectively). 

The investigators concluded that the identification and use of these 4 distinct clinical phenotypes may better assist clinicians in predicting meaningful outcomes in patients with interstitial lung disease compared with the current diagnostic criteria. In addition, the new cluster classifications allows previously “unclassifiable” patients with interstitial lung disease to be classified into clinically meaningful subgroups.

Reference

Adegunsoye A, Oldham JM, Chung J, et al.  Phenotypic clusters predict outcome in longitudinal interstitial lung disease cohort [published online September 27, 2017].  Chest.  doi:10.1016/j.chest.2017.09.026