Independent Predictors of Severity and Hospitalization in Acute Bronchiolitis: Neutrophil/Lymphocyte Ratio and Mean Platelet Volume

Abstract

Background and Aim Acute bronchiolitis is the most common cause of hospitalization in the first year of life. The neutrophil/lymphocyte ratio (NLR) and mean platelet volume (MPV) are readily calculable laboratory markers used to evaluate systemic inflammation. We aim to evaluate the optimal values of these markers for the prediction of severity and hospitalization in infants with acute bronchiolitis. Materials and Methods A total of 105 patients with acute bronchiolitis and 62 healthy controls aged 1 to 12 months were prospectively enrolled to the study. The patients' group was classified into two groups, namely, outpatient and inpatient, also divided into three groups according to clinical scoring: mild, moderate, and severe. The association of NLR and MPV with clinical severity and hospitalization was investigated. Results The mean age was 7.75 ± 2.98 months in patients and 7.69 ± 2.87 months in controls. The means of NLR were 0.47 and 0.64 in controls and patients, respectively (p = 0.032) and of MPV were 9.64 and 8.9 (p < 0.001), respectively. The means of NLR were 0.73 and 0.50 in inpatient and outpatient groups, respectively (p = 0.014) and of MPV were 8.65 and 9.32 (p = 0.046), respectively. NLR of 0.64 value was calculated as a cutoff for the prediction of hospitalization with 45% sensitivity and 83% specificity (positive predictive value = 81%, negative predictive value = 19%). Conclusion We found that blood neutrophil percentage and blood NLR are increased and also weakly predictive—but insufficient to be clinically useful—for the decision of hospitalization in acute bronchiolitis. When the positive predictive value of an NLR of 0.64 is sufficient to decide hospitalization, the negative predictive value is impractical. MPV value was less in infants with acute bronchiolitis than healthy controls and in inpatients than outpatients with acute bronchiolitis. Low MPV might be marker of inflammation in acute bronchiolitis.