Electronic nose technology may facilitate accurate diagnosis of sarcoidosis

Electronic nose technology accurately distinguished patients with sarcoidosis from those with interstitial lung disease and healthy controls, researchers reported in Chest.

“Currently, diagnosis of sarcoidosis is challenging due to great differences in clinical presentation often requiring invasive diagnostic procedures such as biopsies,” Iris G. van der Sar, MD, PhD candidate in the department of respiratory medicine at Erasmus Medical Center, Rotterdam, the Netherlands, told Healio. “There is a high need for more accurate, noninvasive and quick diagnostics in suspected sarcoidosis patients.”

The single-center, cross-sectional study included 252 patients with sarcoidosis (mean age, 53.1 years; 53.2% men), 317 patients with ILD (mean age, 70 years; 61.5% men) and 48 healthy controls (mean age, 36.5 years; 31.3% men). Researchers evaluated exhaled breath of all patients using SpiroNose (Breathomix), an electronic nose (eNose) device, and collected clinical characteristics from patients’ medical files.

The training cohort comprised 168 patients with sarcoidosis and 32 healthy controls and the validation cohort comprised 84 patients with sarcoidosis and 16 healthy controls.

The eNose device was able to distinguish patients from sarcoidosis from healthy controls (area under the curve = 1), from other ILD (AUC = 0.87) and from hypersensitivity pneumonitis (AUC = 0.88) in the validation cohort. For the training cohort, the AUCs were 1 for distinguishing patients with sarcoidosis from healthy controls, 0.90 from other ILD and 0.95 from hypersensitivity pneumonitis. There were no distinct differences between the exhaled breath of patients with sarcoidosis with and without pulmonary involvement, pulmonary fibrosis, multiple organ involvement, pathology-supported diagnosis and immunosuppressive treatment, according to the researchers.

Researchers observed different breath profiles between patients with a slightly elevated soluble interleukin (IL)-2 receptor level and those with a highly elevated soluble IL-2 receptor level with a median cutoff of 772 U/mL and an AUC of 0.78.

According to van der Sar, “the accuracy of eNose technology ... is much higher than for other diagnostic tests used in clinical practice for sarcoidosis patients.”

Moving forward, it is necessary to validate the results of this study in an external patient cohort, van der Sar told Healio.

“Building a diagnostic algorithm will allow doctors to use the eNose technology in clinical decision-making in the future,” van der Sar said.

For more information:

Iris G. van der Sar, MD, can be reached at i.g.vandersar@erasmusmc.nl.