Yildiz UCAR, Muhammed KAMILOGLU, Gaye ULUBAY, Keziban Ucar KARABULUT
Eurasian Clinical and Analytical Medicine - 2026;14(3):48-53
Objective: Influenza A and influenza B infections may differ in clinical course and inflammatory response. This study aimed to compare conventional hematological parameters and next-generation inflammatory indices in patients with influenza A and influenza B infections and to evaluate type-related differences in systemic inflammation. Methods: This retrospective observational study included adults (>=18 years) presenting to the pulmonary clinic with flu-like symptoms and RT-PCR-confirmed influenza A or B infection. Demographic characteristics and laboratory parameters at presentation were recorded. Neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR), systemic immune-inflammatory index (SII), systemic inflammatory response index (SIRI), and pan-immune inflammation value (PIV) were calculated. Discriminative performance was assessed using ROC analysis and multivariate logistic regression. Results: A total of 363 patients were included, comprising 232 with influenza A and 131 with influenza B. Patients with influenza A were significantly older than those with influenza B. CRP, leukocyte and neutrophil counts, as well as NLR, SII, SIRI, PIV, and MLR values, were significantly higher in the influenza A group. Although individual biomarkers showed limited discriminative ability, multivariate logistic regression improved type classification, yielding an AUC of 0.727. Conclusion: Influenza A infection is associated with a more pronounced systemic inflammatory response than influenza B. Next-generation inflammatory indices derived from routine laboratory tests may provide useful information for clinical evaluation. The combined assessment of multiple parameters may improve differentiation between influenza A and influenza B.
