Serum inflammatory cytokine IL-4 and IL-18 Levels in Patients with Typhoid Fever in Baghdad

Abstract

Background: Gram-negative Salmonella enterica serotype typhi, or S. typhi, is intracellular bacteria belong to Enterobacteriaceae family that infect humans and cause Salmonellosis (typhoid fever), or (enteric fever), this disease is a major public health problem and a life-threatening bacterial infection in developing countries. Every year, there are thought to be between 12 and 33 million cases of typhoid fever, which leads to over 600,000 deaths. Specific immunity both humoral and cellular specific immune response activated to control Salmonella infection. This study aimed evaluate the function of IL-4 and IL18 levels as a diagnostic aid for this infection. Material and methods: Ninety suspected patients with typhoid fever diagnosed by specialist according to sign and symptom and thirty apparently healthy control where enrolled during the study period from September 2023 to February 2024. Blood was taken from both groups (5ml) and serum were gathered using centrifugation (3000 rpm for 5 min) and kept frozen in three Eppendorf for detection of serum IgM, IgG, IL-4 and IL-18 levels. Results: the result showed that out of 90 blood samples only 60 samples were positive to salmonella infection (confirmed by detecting specific salmonella IgM and IgG antibodies using ELIZA kits Sunlong biotech\China). Serum levels of IL-4, and IL18 (pg/ml) was measured in positive samples using ELIZA kits (Cloud-clone corp \USA). There is a significant increase in the level of IgM (0.33 ± 0.13) (mg\dl) and IgG (0.27 ± 0.1) (mg\dl) as compared to the control group in patients (0.16±0.03 and 0.12±0.03) (mg\dl) respectively with P < 0.01, and there was a significant increase in the average IL-4 (334.00 ± 87.49) (pg/ml) and IL-18 level in patients (380.44 ± 68.95) (pg/ml) compared to the control group (83.40 ± 17.44 and 189.66 ± 70.40) (pg/ml)  respectively with P < 0.001. The results indicated a direct correlation between IL-4 and IL-18 serum levels with high level of serum IgM antibody compared to their levels in control group.