Expression of interleukin-4 in schistosomiasis is influenced by age.

BACKGROUND

Schistosomiasis, a Neglected Tropical Disease (NTD), remains a significant public health issue, particularly in sub-Saharan Africa. Despite various interventions, the disease persists, with a considerable burden on affected populations. This study aimed to characterize the hematological and immunological profiles associated with Schistosoma infection in pediatric and adult populations in Mulobezi district of Zambia.

METHODS

This was a cross-sectional study, which included participants aged 5-55 years, carried out in Mulobezi District in the Western Province of Zambia. The sample size was 143, participants were stratified into children (<15 years) and adults (≥15 years). Schistosomiasis diagnosis was confirmed through urine microscopy using filtration methods, while full blood count and cytokine (IL-4, IL-10) analysis were performed on blood samples. A Multivariate logistic regression was used to identify factors independently associated with infection. Statistical analyses were conducted using two-sided tests to assess the significance of the observed differences between groups.

RESULTS

Out of the 143 participants, 56 (39.2%) had schistosomiasis. In adjusted models, IL-4 showed age-dependent associations: significant in adults (AOR: 1.007, 95% CI: 1.003-1.012, p = 0.001) but not children (AOR: 1.001, 95% CI: 0.999-1.003, p = 0.072). Lymphocyte counts were elevated in both children (AOR: 1.94, 95% CI: 1.07-3.54, p = 0.029) and adults (AOR: 2.96, 95% CI: 1.19-7.36, p = 0.020). Eosinophils (children: AOR: 13.94, 95% CI: 0.24-811.21, p = 0.204; adults: AOR: 12.27, 95% CI: 0.73-207.13, p = 0.082) and IL-10 lost significance after adjustment.

CONCLUSION

This study highlights IL-4 and lymphocyte counts as potential immunomarkers for schistosomiasis infection. The age-specific IL-4 association suggests differential immune activation patterns, while persistent lymphocyte elevation across both groups indicates sustained adaptive immune engagement.