Authors: Babintseva A.G.
Introduction. Considering universality of hypoxic lesions of various systems of organs, morpho-functional immaturity of the body, absence of specific clinical manifestation of renal lesions in newborns and the necessity to use potentially nephrotoxic therapeutic means in sick newborns, the study of enzymuria and interrelations between separate components in general cohort of children with disturbed process of early postnatal adaptation is topical. It will enable furthere laboration of diagnostic-therapeutic algorithm of management of such children considering severity of perinatal pathology but not a separate nosologic unit.
Purpose: to detect activity of enzymes in the urine of newborns with perinatal pathology of various severity with the aim to find the depth of lesion of the structural-functional elements of the kidneys and localization of pathological process.
Materials and Methods.
A comprehensive clinical-paraclinical examination of 121 term newborns was conducted. The children were distributed according to the degree of severity of the processes of early neonatal adaptation. The first main group included 36 newborns with severe disorders of general condition (IA group), these condmain group – 48 children with disorders of adaptive processes of moderate severity (IB group). The control group included 37 healthy newborns (II group). The degree of severity of clinical-paraclinical signs of perinatal pathology was detected by means of neonatal scale of acute physiology (Score for Neonatal Acute Physiology Perinatal Extension – SNAP-PE). Exception criteria were gestation term less than 37 weeks, body weight less 2500 g, congenital defects of the urinary system.
Absolute activity of the following enzymes was examined: cholinesterase (ЕС 188.8.131.52), aspartate aminopeptidase (ЕС 184.108.40.206), alanine aminopeptidase (ЕС 220.127.116.11), alkalin phosphatase (18.104.22.168), lactate dehydrogenase (ЕС 22.214.171.124), gamma-glutamyltransferase (ЕС 126.96.36.199) of urine by means of biochemical methods as well as correlation of activity of these enzymes to the level of creatinine in urine.
Discussion. Term newbornswith clinical signs of perinatal pathology were indicated to constitute the high risk group concerning functional disorders of the urinary system, and traditional methods of their confirmation are of not high diagnostics value. Term children with intensification of the degree of severity of perinatal pathology show are liable increase of enzymatic activity (alkalin phosphatase, gamma-glutamyltransferase), cytosol (alanine aminopeptidase) and mitochondria (aspartate aminopeptidase, lactate dehydrogenase) which is indicative of deep lesions of the nephrothelial structure and requires a certain correction of therapeutic measures. At the same time, under conditions of perinatal pathology in term newborns the canalicular structures are mostly disturbed against the ground of a high risk of development of glomerular filter dysfunction, which under unfavourable conditions may result in the formation of terminal renal lesions – acute renal failure. Timely prognosis and diagnostics of functional disorders of the urinary system in general cohort of sick newborns in the first days of life considering classical criteria and activity of urinary enzymes will enable to prevent the formation of severe renal pathology, to decrease levels of morbidity and mortality of children of this group.
Keywords: newborn, enzymuria, cholinesterase, alkaline phosphatase, gamma-glutamyltransferase, aminopeptidases, lactate dehydrogenase.