CD40LG and hepatitis A virus infection: Extensive serological work-up was negative including hepatitis A IgM, hepatitis B surface antigen, hepatitis B core antibody, hepatitis C antibody, hepatitis C RNA, Cytomegalovirus IgM, Epstein-Barr virus IgM, hepatitis E antibody, antinuclear antibody, anti-cytoplasmic antibody, anti-liver kidney microsomal antibody, and soluble liver antigen.