DIAGNOSTIC VALUE OF MALONIC ALDEHYDE IN URINE AS A MARKER OF RENAL DYSFUNCTION IN FULL-TERM NEONATES WITH PERINATAL PATHOLOGY

Abstract

Introduction. One of the mechanisms of pathologic oxidative stress in neonates is intensification of membrane lipid peroxide oxidation. Malonic aldehyde (MA) is a secondary product used as an indicator of lipid peroxidation processes and therefore a marker of cellular membrane damage. Meanwhile, nowadays the mechanisms determining organ peculiarities of lipid and protein peroxidation as well as resistance to ischemic kidney damage are not studied completely and require further development. 
 Objective: to determine diagnostic value of MA in urine as a marker of renal dysfunction in full-term neonates with perinatal pathology of various degrees of severity. 
 Material and methods. One-centered cohort prospective study was carried out including 41 full-term children with disorders of general condition of a moderate degree of severity (І group); 36 full-term children with disorders of general condition of a severe degree without acute kidney damage (ІІА group); 30 full-term children with disorders of general condition of a severe degree with acute kidney damage (ІІB group) and 40 healthy children (ІІІ group). МА level in urine was determined by means of reaction with thiobarbituric acid at the end of the 3rd day of life.
 Results. The lack of a negative test diagnostic value with determination of MA in urine was determined when renal dysfunction had been found in full-term neonates with signs of perinatal pathology of a moderate severity. It was evidenced by AUROC 0,53 (95% CІ 0,50; 0,65, р>0,05) with a threshold value of the parameter ≤9,57 mcmol/L.
 A perfect discriminating ability to determine MA level in urine was demonstrated in diagnostics of disorders of the functional kidney state in children who had signs of severe postnatal adaptation disorders. It was evidenced by AUROC 0,81 (95% CІ 0,71; 0,91, р<0,001) with a threshold value of the parameter ≥ 9,58 mcmol/L; specificity 97,6% (95% CІ 87,1%; 99,9%), prognostic value of a positive result 95,7% (95% CІ 75,7%; 99,4%) and likelihood ratio of a positive result 25,1 (95% CІ 3,55; 76,7).
 Diagnostics of acute kidney injury in critically sick term neonates found a proper quality of the diagnostic pattern with determination of MA level in urine. It was evidenced by AUROC 0,80 (95% CІ 0,66; 0,89, р<0,05) with a threshold value of the parameter ≥12,9 mcmol/L; specificity 91,4% (95% CІ 76,9%; 98,2%), %), prognostic value of a positive result 85,7% (95% CІ 66,2; 94,9%) and likelihood ratio of a positive result 7,0 (95% CІ 2,28; 21,5).
 Conclusions. Considering the value of reactions of pathologic oxidative stress in the formation of maladjustment syndromes, determination of MA in urine is suggested to be used as one of the possible markers of renal dysfunction in neonates which reflects the state of lipid peroxidation processes in the kidney structures and degree of their damage.