Objective:To investigate the cytokines pr of ile in the serum of some Nigerian children with Ascaris lumbricoides(A.lumbricoides) infection and relations between the intensity of infection, age and the concentration of these cytokines.Methods:Feacal samples from consenting children were examined using formol ether concentration techniques and Kato-Katz thick smear technique.Sera of 96 children comprising 76 A.lumbricoides infection and 20 controls were subjected to enzymes-linked immunosorbent assay.Results:The mean sera concentration of tumor necrosis factor alpha(TNF-α),interleukin-4(IL-4),interleukin-5(IL-5),interleukin- 10(IL-10) were(16.7±7.6) pg/mL,(4.6±0.8)pg/mL,(391.6±52.0) pg/mL and(181.2±30.4) pg/mL,respectively.The control subjects had the following mean serum cytokines:TNF-α(2.9±1.8) pg/m,IL-4(4.0±0.1) pg/mL,IL-5(125.1±50.1) pg/mL,IL-10(74.5±54.2) pg/ mL,respectively.The difference between the sera cytokines concentration of the A.lumbricoides infected children and their controls were statistically significant for TNF-α,IL- 5 and IL-10(χ~2= 9.99,P< 0.05;χ~2 = 137.24,P < 0.05;χ~2 = 44.30,P < 0.05,respectively). The intensity of infection correlated positively with TNF-α,and IL-5(r = 0.93 and 0.98, respectively) while IL-4 and IL- 10 correlated negatively with the intensity of infection(r = -0.62 and 0.99,respectively).TNF-α,IL-4 and IL-5 correlated positively with age(r = 0.19,0.33 and 0.66,respectively).The mean cytokines between those with mild and moderate infections were statistically significant for TNF-α,IL-5 and IL-10(χ~2 = 3.60,4.52 and 5.30, respectively).The ratio of TNF-α:IL-10 was 0.092.Conclusions:Elevated IL-5,IL-10 and TNF-αfound in the sera of the volunteers with Ascariasis implicates these cytokines as key mediators in the host responses to A.lumbriocoides infection in our studied area. Objective: To investigate the cytokines pr of ile in the serum of some Nigerian children with Ascaris lumbricoides (A.lumbricoides) infection and relations between the intensity of infection, age and the concentration of these cytokines. Methods: Feacal samples from consenting children were examined using formol ether concentration techniques and Kato-Katz thick smear technique. Sera of 96 children comprising 76 A. imbricoides infection and 20 controls were subjected to enzymes-linked immunosorbent assay. Results: The mean sera concentration of tumor necrosis factor alpha , interleukin-4 (IL-4), interleukin-5 (IL-5), interleukin- 10 (16.7 ± 7.6) pg / mL, (4.6 ± 0.8) pg / mL, (391.6 ± Respectively. The control subjects had the following mean serum cytokines: TNF-α (2.9 ± 1.8) pg / m, IL-4 (4.0 ± 0.1) pg / mL , IL-5 (125.1 ± 50.1) pg / mL, IL-10 (74.5 ± 54.2) pg / mL respectively.The difference between the sera cytokines concentration of the A.lumbricoides infected children an (P <0.05); χ ~ 2 = 137.24, P <0.05; χ ~ 2 = 44.30, P <0.05, respectively IL-4 and IL-10 correlated positively with the intensity of infection (r = -0.62 and 0.99, respectively) (R = 0.19, 0.33 and 0.66, respectively). The mean cytokines between those with mild and moderate infections were statistically significant for TNF-α, IL-5 and IL-10 (χ ~ 2 = 3.60, 4.52 and 5.30, respectively). The ratio of TNF-α: IL-10 was 0.092.Conclusions: Elevated IL-5, IL-10 and TNF-α found in the sera of the volunteers with Ascariasis implicates these cytokines as key mediators in the host responses to A. floriocoides infection in our studied area.