Calprotectin and Gut Disease Study

Necrotising enterocolitis (NEC) is a serious gut disease that can develop in infants born with cardiac defects. It causes inflammation and injury to the gut mucosa and may be life-threatening.1 The aetiology of NEC in cardiac infants is multifactorial, associated with poor cardiac outflow and poorly oxygenated systemic circulation, resulting in suboptimal blood flow to the intestines.2 Making an accurate and timely diagnosis of NEC is a significant clinical challenge.3 The clinical presentation of NEC is difficult to identify correctly in the early stages of the disease. Of concern, infants who are diagnosed with NEC at a later stage have worse disease.4 Due to the potentially life-threatening effects of NEC, clinicians who suspect a baby has NEC but are unable to confirm it, temporarily manage infants as if they have NEC as a precautionary measure. This leads to infants without NEC having their milk feeds stopped for several days and being given unnecessary antibiotics. Compared to infants with confirmed NEC, the care of infants with suspected NEC is widely variable in terms of antibiotic regimen chosen, length of antibiotic treatment, and length of time nil-by-mouth - all these variabilities may adversely contribute to the length of hospital stay.5 We want to study a method to improve the accuracy of diagnosing NEC. We want to measure a protein marker found in babies' stools that, if combined with currently available tests (clinical features, lab tests and abdominal X-rays), 6,7 may improve the timeliness and accuracy of making a NEC diagnosis, crucially at an early stage of gut disease. The protein marker is called calprotectin and monitoring levels in a baby's stools before and after heart surgery may help us to understand its relationship to NEC. Calprotectin is a biomarker that is released by white blood cells and is present in the gut when it is inflamed and can be measured in stool.8 The amount of calprotectin in the stool may indicate the level of gut inflammation and the presence of NEC in infants with heart defects.9 The addition of calprotectin measurement to the current routine parameters (clinical features, lab tests and abdominal X-rays) may improve the timeliness and accuracy of diagnosing NEC in infants with cardiac defects, hence improving their care pathway and outcomes.