Monoclonal antibodies with anti-D-like activity in the amelioration of murine immune thrombocytopenia (ITP)

Anti-D is a therapeutic blood product which is purchased and provided to Canadians by The Canadian Blood Services. Anti-D is an antibody preparation pooled from the liquid component of blood. It binds to red blood cells and can help treat an autoimmune disease called immune thrombocytopenia (ITP). ITP patients have low platelet numbers in their blood. Because platelets are important in controlling bleeding, many of these patients bleed for a long period of time when they have an injury or can have critical problems when they need surgery or have a tooth extracted. Many patients with ITP have purple marks on their skin because of their bleeding. A small percentage of patients (both children and adults) actually die from ITP. Anti-D carries a small theoretical risk of infection and we are trying to help lay a foundation towards an even safer substitute for anti-D. Work in our laboratory has discovered several antibodies that, like anti-D, bind to red blood cells and can increase platelet counts in mice with ITP. The exact mechanism of these antibodies is not precisely understood (like anti-D) and this grant attempts to understand how these antibodies make the mice better (increase their platelet numbers in blood). We hypothesize that antibodies which bind red blood cells stop the destruction of platelets by inactivating or inhibiting the cells that destroy platelets in ITP. When this grant is finished we will know more about how antibodies with anti-D-like activity can make mice with ITP better. This information will be used as a basis to design a laboratory-made (monoclonal) antibody that can be used to treat human patients with ITP and other diseases.

LAZARUS, Alan

St. Michael's Hospital

Intramural Research Grant Program

Ontario

$400,000