Role of Serum Cystatin C in Early Diagnosis of Acute Kidney Injury in Neonates with Bronchopulmonary Dysplasia

Background: The neonate is more susceptible to acute kidney injury (AKI) than others due to functional and developmental immaturity, hemodynamic changes that occur at birth, and possibility of hypovolemia due to increased insensible water losses. The aim of this work was early detection of the occurrence of AKI through measurement of serum cystatin C (CysC) and assessment of renal function in patients with bronchopulmonary dysplasia (BPD) in order to initiate early and appropriate therapeutic measures as indicated. Methods: This prospective observational study was carried out on 50 neonates diagnosed as cases of BPD with gestational age ranging from 28w to 38w. Urea, creatinine and serum CysC were measured twice, the first measurement was at the time of diagnosis of BPD and the second one was 3 days later with estimation of creatinine based Glomerular filtration rate (GFR) and cystatin based GFR.renal Doppler ultrasound was performed to measure peak systolivc velocity, end diastolic velocity and resistive index. Results: There were 7 cases with abnormal GFR According to the first creatinine based GFR. There were 16 cases with abnormal GFR according to the first cystatin C based GFR with no statistically significance difference between both measurements. 5 patients were classified to have AKI based on serum creatinine level. There was statistically significant increase in 1st, 2nd serum creatinine, 1st and 2nd serum cystatin C levels in the AKI patients in comparison to non AKI group. On the other hand, there was statistically significant decrease in 1st, 2nd creatinine based GFR, 1st and 2nd cystatin C based GFR. There was statistically significant increase in mortality in the AKI patients if compared to non AKI patient. There was statistically significant increase in SBP, DPB and PCO2 in the AKI patients in comparison to non AKI group. Conclusions: Measurement of serum CysC and estimation of cystatin based GFR can help in early detection of cases with renal malfunction among the patients with BPD before rise of serum creatinine Early diagnosis will lead to improvement of the outcome and shortening of the hospital stay.