GvHD; graft versus recipient response. The donor’s immune system transplanted with a foreign donation (e.g. stem cells) can recognise the recipient’s body cells as foreign and attack them. A distinction is made between acute GvHD (grades 1-4) and chronic GvHD (limited and extensive form). The acute form is observed in the first 2-3 months after transplantation, later the chronic form. The chronic form often develops from the acute form, but it can also occur anew. Symptoms can be: reddening of the skin, itching, peeling of the skin, inflammation of the mucous membranes, jaundice, diarrhoea, abdominal pain, organ failure. Immunosuppressive medications are administered for therapy (including ciclosporin, ATG, cortisone).