CCL18 and onchocerciasis: In onchocerciasis patients at baseline, the OvAg-induced cytokine IL-10 production correlated positively with IFN-γ (R = 0.371, P = 0.0022), with CCL17 (R = 0.471, P < 0.0001) and with CCL18 (R = 0.322, P = 0.008) (Table 3).