Predictive value of increased C-reactive protein levels in preterm infants on respiratory function at five to six years of age: a cohort study

Objective The multifactorial pathophysiology of chronic lung disease in very low birthweight infants (VLBWI) includes inflammatory driven trauma of the lungs. Study Design Multicentre observational study to evaluate the predictive value of C-reactive protein (CrP) levels in VLBWI within the first 28 days of life on forced expiratory volume (FEV ₁ ) at 5-6 years of age. A CrP level exceeding 10 mg/l was considered as elevated, with recurrent elevations defined as at least two values >10 mg/l at intervals of 14 days or more. Univariate analyses, linear regression models, and predictive models with adjustments for gestational age, birth weight, born small-for-gestational age, antenatal steroid usage, cerebral haemorrhage, periventricular leukomalacia, cerebral palsy, surgical treatment of necrotizing enterocolitis, duration of mechanical ventilation, duration of oxygen therapy within the first 28 days, presence of BPD, intelligence quotient, and weight at five year follow-up were used. Result 353 VLBWI born between 2009 and 2015 with median gestational age of 27.6 (25.7-29.4) weeks were included. Infants with recurrent CrP elevations demonstrated significantly higher rates of bronchopulmonary dysplasia (BPD) (59.5% vs. 17.3%, p < 0.001) and z-scores of FEV ₁ < 5 ^th percentile at five to six years (71.9% vs. 35.3%, p < 0.001). Absence of recurrent CrP elevations showed a negative predictive value of 94.2%, but the positive predictive value was only 19.8%. Conclusion The absence of recurrent CRP elevations in VLBWI seems to be associated with better long-term pulmonary outcome, highlighting the potential utility of inflammatory biomarkers in risk stratification for chronic lung disease.