Serum Levels of Proinflammatory Cytokines, Haptoglobin in Children of Various ABO Blood Group and Heamoglobin-Genotype with P. Falciparaum Malaria in Nnewi, Nigeria

Abstract

Malaria is characterized by marked changes in cytokine production from immune responses to infection (Jurgen, 2007). Genetics influences these variations in cytokine expression and ABO blood group and haemoglobin phenotype are genetic expressions (Deepa et al, 2011). Acute phase proteins may also be involved in cytokine induced replication of inflammatory processes (Warren (2010). This case controlled study involving children with plasmodium falciparum malaria (PFM) in Nnewi, Nigeria, sought to examine pro-inflammatory cytokine production in severe and uncomplicated PFM compared with healthy control group, to assess the influence of ABO blood group and haemoglobin phenotype in cytokine expression in malaria and to determine whether differences in serum cytokine levels correlated with severity. The study group comprised of 158 children between the ages of 3 months and 12 years who were attending Paediatrics units of Nnamdi Azikiwe University Teaching Hospital, Nnewi, between the months of March and December, 2011. The study protocol involved screening children with febrile illness for possible malaria parasiteamia employing microscopic examination of Giemsa stained blood smear. A slide is considered negative after examining 100 fields with high power objective without seeing a P. falciparum (PF). Those who had positive smear were recruited as subjects. Patients who had malaria in addition to other infections were excluded. 56 healthy children who attended child welfare clinics or who came for medical examinations and tested negative to malaria were used as control subjects. The following parameters were assessed; serum cytokine (TNFα, IL-1, IL-6) and haptoglobin testing, using ELISA test kits (Abcam company U.K), complete blood count (using Sysmex KX-21N machine), haemoglobin electrophoresis (using Shandon electrophoresis machine) and blood grouping (of Dacie and Lewis) and parasite density were determined for each patient. We identified 15 cases of severe malaria and 143 cases of uncomplicated malaria. The mean levels of the cytokines tested (in picograms/milliliter) were for the uncomplicated malaria category: IL- value was 177.9 ±316.31 when compared with the control value of 45.6 ±37.04; (p< 0.05); IL-6 value was 492.3± 596.84 when compared with the control value of 48.0±35.27; (p<0.05), TNFα was 132.2± 229.42 when compared with the control value 48.9±58.98; (p< 0.05). In severe forms: IL-1 gave a value of 315.8±233.71 when compared with the control value 45.6±37.04; (p<0.05) IL-6 value was 1275.3±605.37 when compared with the control value 48.0 ± 35.27; (p<0.05) and TNFα value was 369.0 ± 453.45 when compared with the control value 48.9 ± 58.98; (p < 0.05). The percentage frequency of malaria in the AA phenotype was 82.3% in severe forms while 86.7% was seen in the uncomplicated category. Also the frequency of malaria in the AS phenotype was 17.7% in severe category and 13.3% recorded in uncomplicated. In the same vein, the percentage frequency in blood group O for the uncomplicated form was 66.9% while that of severe form was 60%. Lower frequency of 33.1% and 40% were seen in uncomplicated and severe forms respectivel). An association was observed between malaria and AA phenotype ((X2 = 8.06; p < 0.05) while no association was observed between malaria and ABO blood group(X2 = 15.9; p < 0.05). IL-6 and TNFα levels correlates with parasite density and platelet count (p < 0.05). IL-1 has no correlation with parasite density (p > 0.05). IL-6 and TNFα show a negative correlation with haemoglobin and haptoglobin levels (p < 0.05) but not with IL-1 (p> 0.05). This study observed an elevation in the levels of Ll-1, IL-6 and TNFα and these increase correlates with severity. Anaemia, thrombocytopenia, PCT, RDW, MPV, % monocytes and % lymphocytes could be considered as prognostic variables.