CD40LG and infection: According to the ELISA results, the patients were categorized into four groups, negative, with possible acute infection (IgM and IgG positive, IgM positive and IgG negative, IgM positive and IgG borderline, IgM borderline and IgG negative), with possible past infection (IgM negative and IgG positive, IgM borderline and IgG positive), and indeterminate (IgM negative and IgG borderline) [19].