Early detection of acute kidney injury in preterm newborns with perinatal asphyxia using serum cystatin

Abstract

Introduction: The diagnosis of acute kidney injury (AKI) in preterm newborns with perinatal asphyxia based on increased serum creatinine (sCr) value and oliguria/anuria is usually delayed. The Aim of this paper is to evaluate serum cystatin C as an early predictor of AKI. Materials and methods:The study included 42 preterm newborns (24-37 weeks) with perinatal asphyxia (Apgar score (AS) ≤ 3 at 5 minutes of life or blood pH on admission ≤ 7.00). The sCr and sCys-C levels were measured on the 1st, 3rd, and 7th day of life. According to KDIGO criteria, the newborns were classified into groups, and sCr and sCys-C values were compared. Results: The mean gestational age was 29.9 ± 3.0 weeks. AKI was diagnosed in 62.8% of patients. Of these patients, 81.5% belonged to AKI 1 group, and 18.5% to AKI 2 group. No newborns had the criteria for AKI 3. On day 7 the mean sCr values were significantly higher in AKI (65.4 ± 21.8) compared with the non-AKI group (168.4 ± 38.2) (p < 0.001), but not on day 1 and 3 (p = 0.322, 0.012, respectively). The sCys-C values were significantly higher in the AKI group on day 3 (AKI vs. non-AKI group, 0.69 ± 0.22 vs. 1.22 ± 0.20; p < 0.001) and day 7 (AKI vs. nonAKI group, 0.62 ± 0.41 vs. 1.68 ± 0.20; p < 0.001). The sCys-C was also an earlier marker of a more severe stage of AKI than sCr. Conclusion: The sCys-C was elevated earlier than sCr, making it a valuable diagnostic tool for AKI in preterm newborns.