The value of heparin-binding protein in bronchoalveolar lavage fluid in acute respiratory distress syndrome.

Summary

Using both a CLP-induced mouse model and a human comparative study (44 ARDS vs 38 cardiogenic pulmonary edema), BALF and plasma HBP levels were elevated with lung injury and correlated with severity. BALF HBP showed a stronger correlation than plasma HBP, supporting its role as a diagnostic and severity biomarker for ARDS.

Key Findings

• In CLP-induced mice, lung wet-to-dry ratio, BALF protein, BALF HBP, and plasma HBP were significantly higher than controls and correlated with injury severity.
• In humans (44 ARDS vs 38 CPE), BALF HBP, BALF protein, and plasma HBP differed significantly between groups and correlated with lung injury severity.
• BALF HBP had a stronger correlation with lung injury than plasma HBP, suggesting superior utility as a biomarker.

Clinical Implications

BALF HBP could be incorporated into diagnostic algorithms to distinguish ARDS from cardiogenic edema and to stage severity, particularly when BAL is clinically indicated.

Limitations

• Modest human sample size and cross-sectional design limit causal inference.
• BALF sampling is invasive and may not be feasible in all ARDS patients; timing relative to disease course may influence levels.

Future Directions

Validate BALF HBP thresholds prospectively, assess temporal kinetics, and develop less-invasive surrogates (e.g., exhaled breath condensate) reflecting alveolar HBP.