CD40LG and infection: The infection work-up was negative: urine cultures revealed no growth; pneumococcal and legionella urinary antigen tests were negative; tests for mycoplasma pneumoniae, chlamydia pneumoniae, HIV, hepatitis B virus (HBV), hepatitis C virus (HCV), and cytomegalovirus (CMV) were negative; Epstein-Barr virus (EBV): IgG positive and IgM negative; and parvovirus: IgG positive and IgM negative.