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.