Relationship between bronchial hyperreactivity and complete blood count derived inflammatory biomarkers

Aims: Studies specifically linking bronchoprovocation test (BPT) positivity with complete blood count (CBC)-derived biomarkers are limited. We investigated the relationship between CBC-derived biomarkers and BPT positivity in this study. Methods: We retrospectively evaluated patients who underwent methacholine BPT and simultaneous CBC from May 2017 to March 2020. Non-smoker patients without a prior diagnosis or treatment of asthma were selected. We investigated the relationship between bronchial hyperreactivity and CBC parameters white blood cell (WBC), neutrophil (NEU), lymphocyte (LYM), eosinophil (EOS), platelet counts (PLTs), mean platelet volume (MPV), neutrophil-to-lymphocyte ratio (NLR), eosinophil-to-lymphocyte ratio (ELR), platelet-tolymphocyte ratio (PLR), and the systemic immune-inflammation index (SII). Results: The study population consisted of 246 adult patients (69.1% female, mean age 40.5±13.1 years) evaluated for asthma-like symptoms. The BPT was negative in 156 (63.4%) patients and positive in 90 patients (36.6%). A relationship was found between EOS count and BPT positivity [135 (interquartile range (IQR) 167) vs 119 (IQR: 99 p=0.04)]. However, no statistically significant relationship was found between BPT positivity and other parameters, WBC, NEU, LYM, PLT, MPV, NLR, ELR, PLR, and the SII. Conclusions: We identified an association between BPT positivity and EOS count among CBC parameters. However, we found no relationship between BPT positivity and WBC, NEU, LYM, EOS, PLT, MPV, and CBC-derived inflammatory biomarkers such as NLR, ELR, PLR, and SII. In asthmatic patients, a relationship between asthma and CBCderived biomarkers may emerge after inflammation persists for a period of time.