Correlation of interleukin-4 levels with Plasmodium falciparum malaria parasitaemia in Sudanese children.

Objectives: This study aimed to measure the level of interleukin-4 (IL-4) in the serum of children patients with falciparum malaria and to correlate the production of this cytokine with the severity of malaria parasitaemia.

Methods: One hundred ten patients with malaria participated in this study (53 males and 57 females) and their results were compared with that of 60 healthy control subjects. Their ages ranged between 6 months and 15 years. For the detection of parasitaemia, a calibrated thick-smear technique was used with standard Giemsa staining. For designation of the relative parasite count, a simple code from one to four crosses is used according to the criteria mentioned by Gilles and Warrell. The blood samples were assessed for IL-4 using enzyme-linked immunosorbent assay (ELISA) technique.

Results: Thirty-three malaria patients (30.27%) had one cross (+) parasitaemia, 13 patients (11.93%) had (++) parasitaemia, 24 patients (22.02%) had (+++) parasitaemia and 39 patients (35.78%) had (++++) parasitaemia. There was a significant difference (P<0.009) in the concentration of IL-4 between malaria patients (160.74±25.5 pg/ml) and control group (62.136±18.16 pg/ml). Uncomplicated malaria patients showed the highest record of IL-4 level followed by cerebral malaria (CM) group and then severe malaria anaemia group (SMA) (255.8±54.13, 102.7±34.88 and 90.95±20.90 pg/ml respectively, P>0.0001).

Conclusion: It was concluded that elevation of serum IL-4 in Sudanese children suffering from Plasmodium falciparum malaria is correlated with the severity of malaria hyperparasitaemia rather than with the severity of the disease.