CD40LG and hepatitis A virus infection: Liver function, lymphocyte subtypes, immunoglobulin isotypes, serum ferritin, coagulation function test and blood fat level were normal; Serology for human immunodeficiency virus; widal test; bacterial culture of peripheral blood, bone marrow and urine; hepatitis A, B, and C; mycoplasma pneumoniae (IgM and DNA); tests for tuberculosis; cytomegalovirus (IgM, IgG, and DNA); Human Herpes Virus; Toxopasma (IgM); Rubella (IgM); influenza virus A and B; parainfluenza virus; respiratory syncytial virus; adenovirus; legionella; rickettsia; and Epstein Barr Virus (IgM, IgG and DNA) were all negative.