ABSTRACT
This study was carried out to evaluate leucocyte functions in children with malaria with a view to determine the level of parasitaemia at which leucocyte functions are altered and also to determine the levels of the cytokine ‛‛TNF” alpha in children with malaria. Samples for the study were collected from Central Hospital and Stella Obasanjo Hospital, Benin City, Edo State, Nigeria. Ethical approval was obtained from the Ethical Committee of the Ministry of Health, Benin City, Edo State, Nigeria. A total of three hundred and fifty two (352) subjects were enrolled for the study. Two hundred and ninety four (294) were malaria infected children while fifty eight (58) were non-infected children. The ages of the children enrolled for the study ranged from four (4) months to fifteen (15) years while their sexes were equally matched. Eight (8) millilitres of venous blood were collected from each subject and the leucocyte functions such as Viability, Chemotactic index, Phagocytic index, Respiratory burst were investigated as well as inflammatory marker - Tumor Necrosis Factor alpha (TNF-α) using Standard Techniques. Full Blood Count was also determined for all subjects while malaria parasite was determined for malaria infected children and confirmed negative in the controls. The results obtained from the study showed that the Viability, Chemotactic index and Respiratory Bust functions of malaria infected children were significantly higher (p<0.05, respectively) than those of non-malaria infected children. However the Phagocytic index of malaria positive children were significantly lower (p<0.05) than those of children without malaria while there was no significant difference in the level of Tumor Necrosis Factor-α in both groups. In addition, there was no significant sex variations amongst the malaria infected children and the controls (p>0.05, respectively) except for Phagocytic index where males had significantly higher values compared to females (p<0.05). With regards to age group, Viability, Chemotactic index and Tumor Necrosis Factor-α were significantly lower(p<0.05, respectively) for age group 0-5 years compared to age group 6-10 years but Phagocytic index and Respiratory Burst activity did not show any significant difference between the two age groups. It was observed further that Parasitaemia (Parasite Density) did not affect Viability, Chemotactic index and Tumor Necrosis Factor-α significantly. Total white blood cells(WBC) absolute lymphocyte, monocyte and neutrophil count and platelet counts were lower in children with malaria compared with controls. MCHC and MCH were higher in malaria cases compared with control (p<0.05, respectively) while PCV and Hb were relatively insignificant in malaria and controls and also at the different age groups (p>0.05, respectively.) A significantly lower monocyte – neutrophil ratio was observed among malaria infected children compared with control due to the activation of malaria parasite. There was a significant (p<0.05) but negative correlation between age and chemotactic index of malaria infected and non-malaria infected children. While the correlation between age and phagocytic index of malaria and non-malaria infected children was positive and highly significant (p<0.05). There was no significant correlation between parasite density and respiratory burst, viability, and chemotactic index (p > 0.05respectively.). Although there was a positive correlation between age and Tumor Necrosis Factor-α of malaria infected children, it was however not significant (p>0.05) whereas, there was a positive and significant (p<0.05) correlation between age and Tumor Necrosis Factor –α of non-malaria infected children. There was also a negative (p<0.05) correlation between age and respiratory burst activity of malaria infected and non-malaria infected children. Also, there was a positive correlation between age and Viability of malaria infected and non-malaria infected children, it was however not significant (p>0.05). In conclusion, there were changes in leucocyte functions in children with malaria but there was no change in TNF- α in children with malaria infection when compared with control.
