Abstract

Introduction

In patients with interstitial lung disease (ILD), response to immunosuppressive and antifibrotic treatment is often difficult to predict. Electronic nose (eNose) sensor technology profiles exhaled volatile organic compounds and can identify patients with ILD. We evaluated whether an eNose can predict treatment response in patients with ILD.

Methods

Patients with ILD starting on treatment were included. Exhaled breath analysis using an eNose (SpiroNose) was performed before treatment. Response to immunosuppression was defined as forced vital capacity (FVC) improvement of =5% 1-3 months after treatment start, and to antifibrotics as FVC decline of =2.5% (Khan et al. AJRCCM 2022) 3 months after treatment start. Data was analysed with partial least squares discriminant and receiver operating characteristic analysis.

Results

22 patients starting on immunosuppressive (59% male, median FVC 79.0% (IQR 64.0-92.5)) and 20 on antifibrotic treatment (80% male, median FVC 78.5% (IQR 62.8-87.5)) were included. Breath profiles before treatment differed between patients with and without treatment response (Figure 1), both for immunosuppressive (AUC 0.84, 95% CI 0.68-1.00) and antifibrotic treatment (AUC 0.75, 95% CI 0.52-0.98).

Conclusions

This study suggests that eNose technology may predict treatment response in patients with ILD before treatment start, which implies potential value to guide treatment decisions.