Comparative Evaluation of Systemic Inflammatory Indices in Bronchiectasis: Identification of Exacerbation Phenotype

Background: Bronchiectasis is a heterogeneous chronic inflammatory airway disease characterized by recurrent exacerbations. Data on composite inflammatory biomarkers for assessing disease activity remain limited. Methods: This retrospective study included 97 patients with non-cystic fibrosis bronchiectasis categorized as stable (n = 39) or with exacerbated bronchiectasis (n = 58). Demographic, clinical, and laboratory data were analyzed, and inflammatory indices—NLR (neutrophil–lymphocyte ratio), PLR (platelet–lymphocyte ratio), SII (Systemic Immune-Inflammation Index), PIV (Pan-Immune-Inflammation Value), CAR (C-reactive protein-to-albumin ratio), and HALP score (hemoglobin × albumin × lymphocyte/platelet)—were calculated, followed by multivariate logistic regression and ROC analyses. Results: Patients with bronchiectasis exacerbations had a higher NLR, PLR, PIV, SII, and CAR and lower HALP (all p < 0.001). The C-reactive protein-to-albumin ratio demonstrated the highest discriminative ability (AUC = 0.995), followed by SII and NLR, while lower HALP and SII were independent predictors of exacerbation. The C-reactive protein-to-albumin and sedimentation-to-albumin ratios were strongly correlated with hospitalization duration (both p < 0.001). Conclusions: Composite inflammatory indices are strongly associated with disease activity in bronchiectasis. CAR showed excellent discriminative performance, while HALP and SII independently predicted exacerbation. These simple, cost-effective biomarkers may support risk stratification and clinical monitoring in routine practice.