RESUMO
Background: Oxidant stress is defined as either an overproduction of free radicals or diminution in antioxidant defenses. Determination of lipid peroxide products is used as a measure of oxygen radical activation. Vitamin E [alpha- tocopherol], a nutritional antioxidant, blocks the chain reaction of lipid peroxidation
Aim: To determine lipid peroxidation as measured by malondialdhyde [MDA] and the level of an enzymatic antioxidant glutathione reductase [GSH-reductase], as well as, ci-tocopherol in children suffering from chronic liver disease [CLD] and try to find out if they are affected by the etiology or the severity of liver disease
Methodology: Thirty seven children suffering from CLD aged [1-15] years were selected from the specialized hepatology outpatient clinic, Children's Hospital, Ain Shams University. They were divided according to Child-Pugh classification to [A=18, B=11 and C=8]. Thirty healthy children of similar age and sex, were selected as controls. All children were subjected to history taking, clinical examination, laboratory investigation: complete blood picture, liver function tests, hepatitis markers, urine and stool analysis; and abdominal ultrasonography. Plasma alpha-tocopherol, GSH-reductase and MDA were also measured
Results: Malondialdhyde showed significantly higher mean plasma level in CLD patients [0.71 +/- 0.20 nmol/ml] than healthy children [0.38 +/- 0.09 nmol/ml] p<0.001, while GSH-reductase showed significantly lower mean plasma level in CLD patients [45.7 +/- 17.4 U/L] than healthy children [125.8 +/- 30.4 U/L] p<0.001. Also, alpha-tocopherol, was significantly lower in diseased children [0.78 +/- 0.44 umol/L] than healthy controls [0.98 +/- 0.28 umol/L] p0.029. There were no significant differences between mean plasma levels of MDA, alpha-tocopherol, and GSH-reductase among CLD patients with different etiologies. alpha-tocopherol showed significantly higher mean plasma level in CLD patients with Child's grade A [1 +/- 0.52 umol/L] than patients with more severe CLD, grades B+C [ 0.57 +/- 0.2 umol/L] p = 0.003, while there were no significant differences in MDA nor in GSH-reductase between Child's grade A and grades B + C. There were no significant correlations between MDA, GSH-reductase, nor alpha-tocopherol and liver function tests in CLD except for alpha-tocopherol which significantly negatively correlated with the bilirubin level [r = -0.33, p 0.49]
Conclusion: Children with CLD, irrespective of the underlying etiology, were having a clear evidence of oxidant stress in the form of significant increase in lipid peroxidation and significant decrease of some antioxidants as alpha-tocopherol and GSH-reductase enzyme. Lipid peroxidation did not reflect the severity of CLD while alpha-tocopherol was lower in grades [B+C]. Thus, it is recommended that efforts to improve the hepatic antioxidant system should be taken eg. optimizing the patient's diet, by supplementation with precursors for antioxidants, or by supplementation with essential metals and/or antioxidants