Association between the HAL score and the development of progressive pulmonary fibrosis in idiopathic interstitial pneumonia: A prospective observational study

Background

Progressive pulmonary fibrosis (PPF) is a critical concern in interstitial lung disease (ILD) management. The HAL score, which incorporates honeycombing (H), age >75 years (A), and serum lactate dehydrogenase >222 U/L (L), can predict acute exacerbations in patients with idiopathic interstitial pneumonia (IIP). This study aims to evaluate the predictive utility of the HAL score for PPF development.

Methods

This study was a post-hoc analysis of a multicenter prospective cohort study involving patients with IIP. PPF was diagnosed if at least two of the following three criteria were met: worsening respiratory symptoms, radiological progression, and physiological progression.

Results

Among the 144 patients, 29 (22.3%) developed PPF during the observation period. Among the three criteria for PPF, a higher HAL score significantly correlated with worsening respiratory symptoms (p = 0.001) and radiological progression (p = 0.022), but not with physiological progression (p = 0.717). Therefore, a higher HAL score significantly correlated with an increased PPF risk (12.5% for a score of 0, 25.9% for a score of 1, and 33.3% for a score of ≥2; p = 0.032). The HAL score also correlated with overall survival (p < 0.001). For the 92 patients (70.8%) with non-idiopathic pulmonary fibrosis (IPF), the HAL score was significantly associated with PPF development (p = 0.021), while not for the 38 patients (29.2%) with IPF (p = 0.872).

Conclusion

In patients with non-IPF, the HAL score correlated with PPF development and could be useful to monitor those patients and to avoid missed treatment opportunities.