The role of immune-inflammatory markers in children with complicated and uncomplicated malaria in Enugu, Nigeria

Abstract

Background: There is currently insufficient data regarding immune parameters and relationship with severity of malaria infection in Enugu, Nigeria where the economic and social costs of the disease and its management are extremely high. This study was conducted to determine the relationship between malaria severity and some immune-inflammatory markers among malaria-infected children in Enugu, Nigeria.

Methods: The study adopted a case control design. Eligible children were categorized into three groups - complicated, uncomplicated and healthy children. Pro-inflammatory cytokines -interferon-gamma (IFN-γ) and tumor necrosis factor-alpha (TNF-α); and anti-inflammatory cytokine - interleukin-10 (IL-10) were assayed using enzyme-linked immunosorbent assay (ELISA) technique, while immune cell ratios - neutrophil lymphocyte ratio (NLR) and monocyte lymphocyte ratio (MLR) were calculated from full blood count results.

Results: The overall mean age of the participants was 7.3 ± 3.4 (range: 6 months - 12 years) and the male-female ratio was 1:1. There was no significant difference between the ages of the three groups (P = 0.44). The Mean levels of IFN-γ, TNF-α, and NLR were higher in complicated than uncomplicated malaria (266.9 ± 66.3pg/ml vs. 62.5 ± 6.4pg/ml, p < 0.001; 140.3 ± 30.0pg/ml vs. 42.0 ± 9.0pg/ml, p < 0.001; and 32.9 ± 16.2pg/ml vs. 17.8 ± 6.0pg/ml, p < 0.001, respectively); and higher in uncomplicated malaria than healthy children (62.5 ± 6.4pg/ml vs. 40.6 ± 9.1pg/ml, p < 0.001; 42.0 ± 9.0pg/ml vs. 105.7 ± 32.1, p < 0.001; 17.8 ± 6.0pg/ml vs. 18.7 ± 6.2pg/ml, p < 0.001, respectively). On the other hand, the mean level of IL-10 is higher in uncomplicated than complicated malaria (105.73 ± 32.06pg/ml vs. 40.60 ± 9.11pg/ml, p < 0.001). There was a positive correlation between NLR and IFN-γ (r = 0.815; p = 0.003), as well as NLR and TNF-α (r = 0.745; p = 0.002).

Conclusion: Complicated malaria is associated with higher levels of pro-inflammatory cytokines while uncomplicated malaria is associated with higher levels of anti-inflammatory cytokines. NLR correlates positively with pro-inflammatory cytokines, and could be useful in evaluation for the severity of malaria infection.

Keywords: Complicated malaria; Cytokines; Immune cell ratios; Uncomplicated malaria.