DISCUSSION
This study evaluated the association between CRP levels and measures of disease severity in infants who were hospitalized due to acute RSV bronchiolitis. The findings revealed that infants with elevated CRP levels were older, had lower MOS, longer LOS, and higher rates of secondary infections such as pneumonia, UTI, and AOM. Additionally, there were more likely to receive antibiotics and require hospitalization in the PICU. The study also proposes cutoff values for CRP that could predict the likelihood of UTI, pneumonia, and PICU admission.
The mean age of the children was 6.7 months, with a male predominance, and most were term infants, while 10.8% were born prematurely. These results align with previous medical literature regarding the demographic characteristics of pediatric patients with RSV bronchiolitis and those treated at the SUMC. Younger age is a known risk factor for severity in RSV, and indeed older age was a protective factor, according to the regression model. A relative immaturity of the immune system, supported by studies that demonstrate a severe RSV infection associated with lower levels of Interferon-gamma (IFN-γ) and lower fever due to inappropriate inflammatory response, could explain a more severe course of the disease in younger children. Our study revealed a significant correlation between elevated CRP and older children (rather than younger children), indicating the independent role of CRP in association with more severe disease. This finding is further supported by the lack of influence of prematurity and gestational age, which are prominent risk factors for severe disease, on CRP as a severity marker. This holds true even for premature infants under 35 weeks who routinely receive Palivizumab during RSV season. Additionally, we observed equal distribution of CRP levels, sex, and ethnicity in both the higher and lower CRP groups.