- Platelets Play a Role in Immune Response
- Recovery in Three ITP Patients Treated with Etanercept
- MMR Vaccinations Can Trigger ITP
- Platelet Antibodies May Inhibit Platelet Production
- New Site Lists Household Health Perils
- Clinical Trial to Evaluate Rituximab in Children
- Calendar Helps Families Plan and Helps PDSA
PLATELETS PLAY A ROLE IN IMMUNE RESPONSE
Platelets do more than help blood clot when they rush to a wound site. They can release proteins that kill bacteria directly. They also help the body protect against illness by making CD154, a surface protein that stimulates dentritic cells which then stimulate T and B cell growth. The B cells make antibodies that bind to the surface of the offending microbe and promote its destruction.
Speaking about the importance of this work for ITP, John Semple of the University of Toronto said, “Platelet-derived CD154 may be the link that stimulates these pathogenic antibody responses.”
From: “Platelets in blood may guide immune response” Science News, July 26, 2003
Immunity, July, 2003 http://www.immunity.com/content/article/abstract?uid=PIIS1074761303001778
(We are pleased to have John Semple, PhD as one of our medical advisors. To view slides of his presentation at our recent ITP Conference 2003 see: http://www.pdsa.org/conference2003/confprog03.htm
RECOVERY IN THREE ITP PATIENTS TREATED WITH ETANERCEPT
Three ITP patients who previously failed at least six and as many as eleven therapies were given etanercept, an inhibitor of tumor necrosis factor-alpha approved for the treatment of rheumatoid arthritis. All three patients responded promptly to the treatment reported the authors in the American Journal of Hematology. Although etanercept appeared to be effective in these patients, it is important to remember that it is an experimental treatment for ITP. An ITP clinical trial has been established to gather further information about using this drug.
From: American Journal of Hematology, 2003 Jun; 73(2): 135-40
See: www.itppeople.com/clinical.htm for clinical trail information
See: www.enbrel.com for more information about etanercept
(Note: please consider the side-effects of this and any medication before making a treatment decision)
MMR VACCINATIONS MAY TRIGGER ITP
The risk of developing ITP within six weeks of an MMR vaccination is estimated to be 1 in 25,000 vaccinations according to a new study by the Department of Public Health, Aberdeen University, UK. The study confirms the increased risk of ITP within six weeks after MMR vaccination.
From: “MMR vaccine and idiopathic thrombocytopaenic purpura” British Journal of Clinical Pharmacology, 2003 Jan: 55 (1): 107-11
PLATELET ANTIBODIES MAY INHIBIT PLATELET PRODUCTION
Megakaryocytes in the bone marrow produce platelets. To determine if anti-platelet antibodies inhibit megacaryocyte development and influence platelet production, researchers at the Children’s Hospital of Orange County mixed the blood from ITP patients and controls plus other factors in test tubes and measured the number of megacaryocytes produced. The test tubes with ITP patients’ blood produced fewer megacaryoctytes indicating that antibodies in the ITP plasma may also inhibit platelet production.
“Immune thrombocytopenic purpura (ITP) plasma and purified ITP monoclonal autoantibodies inhibit megakaryocytopoiesis in vitro” Blood, 1 August, 2003, Vol. 102, No. 3
NEW SITE LISTS HOUSEHOLD HEALTH PERILS
Is your deodorant making you ill? Should you avoid dry cleaned clothes? The National Library of Medicine published a new web site, http://householdproducts.nlm.nih.gov that provides information about the potential health effects of more than 4,000 common household products. On an associated site, http://www.toxtown.nlm.nih.gov you can click around various locations such as a school or a home and find the lurking environmental hazards.
NEW CLINICAL TRIAL TO EVALUATE RITUXIMAB IN CHILDREN
The purpose is to formally evaluate the safety and effectiveness of Rituximab in children and adolescents with severe or refractory ITP. For very general information or a reference guide for parents, see http://www.itpkids.org.
More specific inquiries (from MDs) may be addressed to Pamela Boardman, Study Coordinator, Children's Hospital Boston 617-355-2901; email@example.com (Her info is also on the www.itpkids.org site