CD40LG and hepatitis A virus infection: CMV immunoglobulin M (IgM) was negative, as were the following studies: Monospot testing, hepatitis panel (including hepatitis C antibody), treponemal antibody, rectal mpox/HSV/varicella zoster virus (VZV) PCRs, repeat gonorrhea/chlamydia (urine/rectal/throat), respiratory viral panel, serum HIV PCR, serum enterovirus and adenovirus PCRs, tick-borne serology panel, and urine mycoplasma/ureaplasma PCR.