To exclude various viral hepatitis forms, anti-HAV IgM is tested for HAV; anti-HBc IgM and HBV-DNA for HBV; anti-HCV and HCV RNA for hepatitis C virus (HCV); and PCR analyses for viral DNA and titer changes of specific IgM and IgG antibodies for infections by HEV, CMV, Epstein Barr virus (EBV), HSV, and VZV [53,57,58,101]. Here, CD40LG is linked to viral hepatitis.