Distinct lipid signatures identified in blood plasma and exhaled breath samples can differentiate between IPF and fibrotic hypersensitivity pneumonitis.
RT’s Three Key Takeaways:
- Noninvasive Differentiation: Distinct lipid signatures identified in blood plasma and exhaled breath samples can differentiate between idiopathic pulmonary fibrosis and fibrotic hypersensitivity pneumonitis, according to research shared in a news release.
- Severity Correlation: The study showed that specific lipid profiles in both plasma and breath condensate correlate with established clinical indicators of disease severity, including lung capacity and composite risk scores.
- Diagnostic Support: Investigators noted that noninvasive profiling could complement multidisciplinary evaluations to help clinicians select appropriate management strategies for fibrotic conditions.
Biological lipid profiles analyzed in blood plasma and exhaled breath condensate (EBC) differ significantly between patients with idiopathic pulmonary fibrosis (IPF) and those with fibrotic hypersensitivity pneumonitis (fHP), according to findings presented at Chest 2026.
The results indicate that targeted lipid analysis could provide a noninvasive tool to help clinicians characterize and monitor complex pulmonary conditions.
According to the release, fibrotic interstitial lung disease (ILD) includes multiple distinct disorders, such as IPF and fHP, that demand differing treatment approaches despite sharing overlapping clinical, radiographic, and pathologic features. Sphingolipids—bioactive lipids that play roles in cell membrane structure, immune regulation, and fibrogenic signaling—have been tied to ILD disease development, prompting researchers to evaluate whether their signatures could distinguish between conditions and reflect patient status, the announcement stated.
Subtype Signatures in Blood and Breath
To investigate these markers, investigators evaluated plasma samples from 40 patients with fHP, 33 patients with IPF, and 28 healthy control subjects, according to the news release. EBC was also collected and evaluated in a subgroup comprising 18 patients with fHP, 20 patients with IPF, and 11 healthy controls, with all patient diagnoses confirmed via multidisciplinary ILD conference reviews.
The research team performed targeted profiling using high-performance liquid chromatography–tandem mass spectrometry and determined that sphingolipid patterns differed significantly between individuals with fibrotic ILD and healthy controls across both sample types, the news release stated. Furthermore, subtype-specific patterns emerged: plasma levels of DHSo and ceramide C24:0 showed significant differences between IPF and fHP, while EBC analysis demonstrated that ceramide C24:0, sphingomyelin C24:1, and sphingomyelin C18:0 also distinguished the two diseases.
Links to Disease Severity
Beyond differentiating disease subtypes, several sphingolipid species demonstrated correlations with physiologic measures of illness severity, the study authors reported. Among individuals diagnosed with IPF, sphingolipids detected in plasma and EBC correlated with gender-age-physiology (GAP) scores, and EBC hexosylceramide C18:1 was associated with diffusing capacity of the lungs for carbon monoxide (DLCO) and forced vital capacity (FVC). In participants with fHP, specific sphingolipid species were associated with FVC and GAP scores tailored for ILD, according to the release.
“Differentiating IPF from fibrotic hypersensitivity pneumonitis remains a major clinical challenge,” said Jon Mullholand, MD, CHEST 2026 presenting author. “Noninvasive sphingolipid profiling in plasma and exhaled breath condensate may complement multidisciplinary evaluation by improving disease classification and providing biologically relevant markers of severity in fibrotic ILD.”
According to the presentation summary, the study supports further investigation into plasma and EBC sphingolipid profiling as a potential biomarker strategy, with physiologic associations offering valuable insight into fibrotic lung disease characteristics.
