3 | RESULTS
In total, 179 patients aged 1–24 months were included in this study, with a median age of 8 months (range, 1–24 months): 116 (64.80%) of these patients were male and 63 (35.20%) were female. The control group included 80 healthy children, also with a median age of 8 months (range, 2–24 months): 49 (61.2%) of them were male and 31 (38.8%) were female. The patient and control group did not differ significantly in age or sex (p = 0.619 and p = 0.583, respectively). Patients had significantly higher WBC, PLT, MPV, IPF, and PDW values compared with the control group (p = 0.000). The frequency of eosinophilia did not differ significantly between the patient and control groups (p = 0.756; Table I).
The patient group included 48 (26.80%), 104 (58.10%), and 27 (15.10%) children classified as having mild, moderate, and severe bronchiolitis, respectively. The median CSS was 6 (range, 2–12). No significant correlation was found between acute bronchiolitis CSS and age, sex, body temperature, oxygen saturation (%), PLT, WBC, proportion of lymphocytes, or proportion of eosinophils (p > 0.05). The MPV value of the mild clinical severity group was significantly lower than those of the moderate (p = 0.002) and severe (p = 0.000) group, but MPV values did not differ significantly between the moderate and severe groups (p = 0.142). IPF values differed significantly among the mild, moderate, and severe groups (p < 0.001). A positive correlation was observed between the CSS and the IPF (p < 0.001). The mild clinical severity group had a significantly lower PDW compared with the moderate and severe groups (p = 0.000), but the PDW values of the moderate and severe groups did not differ significantly.
ROC curve analyses were used to evaluate the performance of each biomarker in distinguishing acute bronchiolitis patients from controls, and in assessing acute bronchiolitis severity. The AUC for IPF, MPV, PDW, WBC, and PLT was 0.95, 0.85, 0.58, 0.79, and 0.71, respectively. ROC curve analysis suggested that the cut-off for using IPF to predict bronchiolitis was >3.2, with a sensitivity of 84% and a specificity of 97%. The positive and negative predictive values of the IPF were 98.7% and 73.5%, respectively. The AUC was greatest for IPF (Fıgure1). IPF, MPV, and PDW ROC curves showed significant sensitivity and selectivity in patients (p < 0.001; Table III). For all patients, this was the first bronchiolitis attack. At admission, the median body temperature of patients was 37°C (36–39.3°C) and their median oxygen saturation was 91% (75–99%). In total, 99 patients had a chest X-ray finding (e.g., diffuse interstitial consolidation or increased aeration), 68 patients were given antibiotics, and 71 patients received steroid therapy (all patients in the severe group and 42.3% of patients in the moderate group). All patients were provided with supportive therapy such as hydration, oxygen, and salbutamol nebules if indicated.