Evaluation of the state of tubular epithelium in low birth weight infants with ischemic ­nephropathy

Abstract

Aim. The study of the diagnostic value of KIM-1 and NGAL in urine and cystatin C in the blood plasma of low birth weight infants with ischemic nephropathy.

Methods. 150 newborns were divided into 3 groups: main group — 72 low birth weight infants with manifestations of ischemic nephropathy divided into three subgroups: group 1A — mild (n=36), 1B — moderate (n=20), 1C — severe (n=16); comparioson group — 28 low birth weight infants without the evidence of ischemic nephropathy; control group — 50 healthy newborns (20 full-term and 30 preterm).To assess the state of tubular epithelium of the kidneys, the levels of KIM-1 and NGAL were measured in the urine of neonates, to assess the state of glomerular filtration the level of сystatin C in the blood plasma was determined. Samples of blood and urine were collected twice, on days 1 to 3 and 7 to 10. Biomarker levels were determined by solid-phase enzyme immunoassay.

Results. In the main group on day 1 to 3 of life KIM-1 and NGAL in the urine were significantly elevated compared to the control group (p <0.001). On day 7 to 10 the level of KIM-1 in the urine in subgroup 1A decreased (0.98±0.09 ng/dl), while remaining significantly higher compared to the control group, and in subgroups 1B and 1C it increased to 1.24±0.10 and 1.36±0.12 ng/dl, respectively. On day 7 to 10 of life the concentration of NGAL in the urine of children of all three subgroups declined, remaining significantly high compared to the control values. Сoncentration of cystatin C was significantly high only in newborns of subgroup 1C (p <0.001).

Conclusion. Molecules of NGAL and KIM-1 are early markers of the renal ischemic injury in low birth weight infants who suffered perinatal hypoxia, and cystatin C cannot be considered an early predictor of renal damage in low birth weight infants with ischemic nephropathy as its level in the blood rises only in severe damage.

Keywords

ischemic nephropathy / low birth weight infant / KIM-1 / NGAL / cystatin C

RIGHTS & PERMISSIONS

Akhundova A.A.