Plasma Lipid Peroxidation and Autohaemolysis Status in Sicklers, Carriers and Normal Individuals

Abstract

Sickle erythrocytes and their membranes are susceptible to endogenous free radical mediated oxidative damage which correlates with the proportion of irreversible sickle cell. Measurement of spontaneous lysis (Autohaemolysis) of redcells in sterile defibrinated blood after 24 or more hours of incubation at body temperature (370C) were found useful in the
investigation of certain hemolytic status.Blood samples from normal haemoglobin genotype, homozygotes (HbAA– Normal), sickle heterozygotes(Hb AS- Carrier) and sickle homozygotes (HbSS– Sickler) of agesbetween 20 and 30 years collectedfrom the University of Nigeria TeachingHospital (UNTH) Enugu,were used for this study. The Autohaemolysis of
the red blood cells of the different haemoglobingenotypes was estimated after incubation for 24 hours at 37oC. Lipid peroxidation estimation was also carried out in all the subjects blood samples.The result of Autohaemolysis estimation showed a mean value of 4.6 ± 0.50, 6.5±0.20 and 8.1 ± 0.21 for haemoglobin genotype AA, haemoglobingenotype ‘AS'andhaemoglobin genotype ‘SS' individual respectively.Thehaemolysis observed in sickle haemoglobin was significantly higher (P <0.05)than that of carriers and normal individuals.The result of the lipid peroxidatin estimation (expressed as concentrationof malondialdehyde (MDA) in ug/L) showed mean value of 0.78± 0.06, 1.25± 0.17 and 1.55 ± 0.29 for Haemoglobin genotype ‘AA', Haemoglobin genotype ‘AS' and Haemoglobin genotype ‘SS' respectively. The lipid peroxidation observed in sicklers was significantly(P< 0.05) higher thanthat of carriers and normal individuals. This study showed that both the Autohaemolysis and Lipid peroxidation product estimated wassignificantly (P< 0.05)
higherinsickle haemoglobin which is in agreement with previous studies done by other researchers.Sicklecellsare prone to spontaneous lysis(autohaemolysis).Conclusively sickle erythrocytes and theirmembrane are susceptible to endogenousfree radical mediated oxidative damagewhich correlateswith the proportion of irreversibly sickled cell.Therefore, peroxidation of membrane may be a possible mechanism of red cell membrane damage in sickle cell patients relative to normal individuals.