In a recent Cochrane analysis, pooled results for IgG, IgM, IgA, total antibodies and IgG/IgM all showed low sensitivity during the first week since the onset of symptoms (all less than 30.1%), rising in the second week and reaching their highest values in the third week, with pooled sensitivities of 96% three weeks after infection [14]. Here, CD40LG is linked to infection.