Screening for viral infections, (HBs-antigen; anti-HCV-IgG/IgM; Anti-HIV-1/2 + p24-Antigen, denguevirus-NS1-Antigen; anti-Dengue virus-IgG; anti-Dengue virus-IgM; anti-HAV-IgM; anti HEV-IgG/IgM all negative), rheumatological disease as well as Syphilis remained negative. Here, CD40LG is linked to viral infectious disease.