Indicators of nitrosative and oxidative stress as non-invasive markers of bacterial meningitis in preterm infants

Abstract

UDC 616.831.9-002-022.7-053.32-07:616-008.9-092.18 DOI: 10.22141/2224-0551.14.3.2019.168765 G.O. Lezhenko1, O.Ye. Pashkova1, A.V. Abramov1, L.O. Volotko2 1Zaporizhzhia State Medical University, Zaporizhzhia, Ukraine 2MI “Zaporizhzhia Regional Clinical Children’s Hospital” of ZRС, Zaporizhzhia, Ukraine Indicators of nitrosative and oxidative stress as non-invasive markers of bacterial meningitis in preterm infants For cite: Zdorov’e Rebenka. 2019;14(3):149-153. doi: 10.22141/2224-0551.14.3.2019.168765 Abstract. Background. In oxidative and nitrosative stresses, the brain is vulnerable to oxidant damage due to high oxygen consumption, large amounts of iron, relatively low antioxidant expression, high concentration of polyunsaturated fatty acids. One of the markers of nitrosative stress is nitrotyrosine. Cerebrospinal fluid high concentration of nitrotyrosine is associated with the adverse course of the disease. Homocysteine is also considered as an indicator of the intensity of oxidative stress. Increased concentrations of homocysteine have cytotoxic effects that leads to cell death. Materials and methods. The study included 52 preterm infants. The basic group consisted of 14 preterm infants (mean gestation period 31.7 ± 0.9 weeks) with bacterial meningitis. The experimental group included 20 newborns with the perinatal disorders of the central nervous system (10 preterm infants with an average gestational age of 32.3 ± 0.4 weeks and 10 full-term newborns). Control group consisted of full-term healthy 18 newborns. Anamnesis, somatic and neurological status of newborns, neurosonography data were evaluated. The nitrotyrosine blood serum concentration was evaluated using enzyme-linked immunosorbent assay. Results. The results of the study demonstrated that nitrotyrosine content in the blood serum of newborns in the basic group was significantly lower than in the experimental and control groups (1.38 ± 0.06 vs 1.53 ± 0.07 and 1.61 ± 0.04 mmol/L, respectively, p < 0.05) and depended on the gestational age of a child (r = +0.63; p < 0.05). The homocysteine level in blood serum had an inverse correlation with a gestational age of the child (r = –0.62; p < 0.05) and in newborns in the main group statistically exceeded the rates of newborns in the experimental group and the control group (17.10 ± 1.13 versus 10.80 ± 1.10 and 9.56 ± 1.42 μmol/L, respectively; p < 0.05). Conclusions. Low levels of nitrotyrosine in serum and hyperhomocysteinemia observed in preterm infants may contribute to damage to the vascular bed, penetration of microorganisms through the blood-brain barrier and the development of the infectious process. The maximum content of homocysteine in blood serum is observed with the development of bacterial meningitis. Keywords: newborns; meningitis; nitrotyrosine; homocysteine