The prognostic value of peripheral hematological biomarkers in patients with hypersensitivity pneumonitis: A single-center retrospective study.

BACKGROUND/AIM: Investigating inflammation-related biomarkers in hypersensitivity pneumonitis (HP) patients may provide valuable insights, particularly in determining their clinical course and prognosis. This study aimed to explore the potential role of peripheral hematological biomarkers in predicting the clinical course and prognosis of HP patients. MATERIALS AND METHODS: This retrospective study included 75 patients diagnosed with HP. Demographic data, symptoms, exposure history, pulmonary function tests, systemic immune-inflammation index (SII), and aggregate index of systemic inflammation (AISI) were analyzed. RESULTS: Elevated SII (1353.6±915.15) and AISI (1001.1±695.38) values were significantly higher in patients with fibrotic HP compared to non-fibrotic HP (SII: 607.84±334.53, AISI: 375.01±235.18) (p<0.001). ROC analysis showed that SII (cut-off: 644.9, AUC: 0.788) and AISI (cut-off: 438.79, AUC: 0.767) had good predictive value for fibrotic HP. For mortality, SII ≥690.12 (AUC: 0.736) and AISI ≥490.35 (AUC: 0.753) were significant predictors. These elevated values were also associated with higher mortality (46.3% vs. 8.8%, p=0.001 for SII, and 42.5% vs. 14.3%, p=0.004 for AISI). In univariate analysis, older age, digital clubbing, low FVC%, and high SII/AISI were associated with fibrotic HP, while multivariate analysis identified only increased SII (OR: 1.45, p=0.021) and reduced FVC% (OR: 0.999, p=0.043) as independent predictors. CONCLUSION: SII and AISI appear as valuable prognostic tools in determining the clinical course and prognosis of HP patients. These biomarkers could be beneficial in the early diagnosis and management of HP, offering high sensitivity and specificity.