CD40LG and infection: Infections with cytomegalovirus and Helicobacter pylori were ruled out by serological tests (anti-CMV-IgG positive and anti-CMV-IgM negative, anti-HP-IgG and anti-HP-IgM negative) and by immunohistochemistry (IHC) performed on the biopsies (no staining of inclusions or Helicobacter pylori bacteria).