Several studies used the same cut-off for IgG and IgM, despite the differences in immunity dynamics of the different antibody isotypes–this should be taken into consideration when interpreting results of such tests [15, 24, 27, 28], as generally, upon infection a spike in IgM is seen, followed by increased levels of IgG, which also confers long-term protection. Here, CD40LG is linked to infection.