ABSTRACT
Objective : Acute bronchiolitis, primarily caused by
Respiratory syncytial virus (RSV), is the most common cause of
hospitalization in young children. Despite international guidelines
supporting clinical diagnosis, laboratory evaluations are often
conducted with limited validity. We aim to evaluate the association
between C-reactive protein (CRP) levels at admission and disease
severity in children hospitalized due to RSV bronchiolitis.
Study design: This single center retrospective cohort
study included children (0-24 months old) who were hospitalized due to
RSV bronchiolitis (January 2018 – March 2022) with CRP levels taken
upon admission. Clinical data and severity parameters were extracted
using MD-clone platform and the clinical research unit at SUMC.
Results: 1,874 children (mean age of 6.7 months, 59%
males) with a median CRP level of 1.92mg/dL were included. Children with
elevated CRP (>1.92mg/dL) were significantly older (5.1 vs.
3.8 months, p<0.001 ), had higher rates of pneumonia
(9.4% vs. 4.3%, p<0.001 ) , urinary tract
infection (UTI), (2.2% vs. 0.2%, p<0.001 ), acute
otitis media (AOM), (1.7% vs 0.2%, p<0.001 ),
admissions to pediatric intensive care unit (PICU) (7.4% vs 3.7%,p<0.001 ), antibiotic treatment (49.8% vs 37.2%,p<0.001 ) and longer hospitalizations (3.83 vs 3.31
days, p=0.001 ). Multivariable analysis predicted increased risk
for UTI, PICU admission, pneumonia, and longer hospitalization (relative
risk of 11.6, 2.25, 1.98, 1.44, respectively,p<0.001 )). CRP thresholds of 3.51, 1.9, and 2.81 mg/dL
for PICU admission, UTI, and pneumonia, were calculated using Youden’s
index with AUC of 0.72, 0.62, and 0.61, respectively.
Conclusions : Elevated CRP levels at admission are
associated with increased disease severity and higher complication rates
in children hospitalized with RSV bronchiolitis.