Diagnostic Performance of Serum IL-10 and IL-17 and Their Association with Disease Severity in Entamoeba Histolytica Infection
Background: Entamoeba histolytica is the etiologic agent of amoebiasis, a prevalent parasitic disease and a major public health problem worldwide, especially in developing countries. The severity of the disease depends on the parasite's virulence and the host's immune response. Interleukin-10 (IL-10) is a well-known immunoregulatory cytokine. IL-17 is a well-known pro-inflammatory cytokine. Therefore, their concurrent elevation during E. histolytica could be diagnostically useful and have important immunological implications. Methods: A case-control study was conducted in 45 laboratory-confirmed patients diagnosed with E. histolytica infection and 45 healthy controls. Patients were classified into mild (n = 9), moderate (n = 10), and severe (n = 26) groups based on disease severity. The serum levels of IL-10 and IL-17 were measured by a quantitative sandwich enzyme-linked immunosorbent assay (ELISA) kit. Differences between severity groups were analyzed using a one-way analysis of variance (ANOVA) followed by Duncan's multiple range test. The diagnostic performance of both cytokines was assessed by receiver operating characteristic (ROC) curve analysis. Statistical significance was set at P < 0.05. Results: Serum levels of IL-10 and IL-17 were markedly elevated in patients with E. histolytica infections compared to healthy controls. The cytokine levels gradually increased with the severity of the disease, and the highest levels were observed in patients with more severe clinical symptoms (P < 0.001). ROC curve analysis revealed excellent diagnostic performance for both cytokines: IL-10 showed remarkable discriminative ability (AUC = 0.995, sensitivity 95.5%, specificity 95.5%), and IL-17 showed excellent discriminative ability (AUC = 0.935, sensitivity 93.2%, specificity 82.6%). Conclusion: Serum levels of IL-10 and IL-17 were significantly associated with disease severity and showed an excellent diagnostic performance in patients with E. histolytica infection. The simultaneous increase of these functionally distinct cytokines may reflect the simultaneous activation of inflammatory and immunoregulatory immune responses during acute amoebic infection. These findings indicate the possibility to use the two cytokines as additional immunological biomarkers for evaluation of disease severity and diagnostic assessment of amoebiasis. Further investigation into the biological significance of the co-elevated levels of both cytokines is required.