Peripheral IFN-γ and IL-4 responses. Concentrations (ng/mL) of IFN-γ (a) and IL-4 (b) as well as mean IFN-γ/IL-4 ratios (c) segregated by N. caninum antigen-stimulated PMBCs from heifers inoculated with 107 Nc-Spain7 tachyzoites (G1), 107 Nc-Spain8 tachyzoites (G2) or MARC-145 cells as a control group (G3 and G4) (see legend). Results are presented as median + upper quartile value in (a) and (b) or as mean + SE in (c). Filled and empty letters “a” indicate the day on which foetal-death was soon after detected in G1 and G2, respectively. (*) Indicates significant differences (P < 0.05) between infected groups. Data for 49 dpi are not represented.