CD40LG and Epstein-Barr virus infection: In general, the anti-Toxoplasma IgG does not pose any significant analytical problems, whereas the search for anti-Toxoplasma IgM is subject to possible cross-reactivity with other acute unrelated infectious processes (e.g. acute CMV or EBV infections) or autoimmune diseases outcoming in false positive results (Roberts et al. 2001; Kodym et al. 2007).