GLOSSARY OF TERMS
Some terms you might find helpful
Here is a glossary of terms associated with ITP and that are used across our website. If you’d like any other words included within this glossary, please head to our contact page and let us know.
ITP is called newly diagnosed within 3 montths of initial diagnosis. In children this usually follows a viral infection and generally recovery to a normal platelet count will occur with or without steroid treatment. In adults, the majority will not recover to a normal platelet count and treatment is needed if the platelet count is less than 20-30 x10^9/l or if bleeding complications occur.
Antinuclear Antibody Test (ANA)
The ANA, or Antinuclear Antibody Test, identifies the presence of antinuclear antibodies (ANA) in the blood. ANA is a group of antibodies produced by the patient’s immune system when it fails to distinguish between ‘self’ and ‘non-self’. These autoantibodies may attack the body’s own cells, causing signs and symptoms such as tissue and organ inflammation, joint and muscle pain, and fatigue. The presence of ANA can be a marker of an autoimmune process and is associated with several autoimmune disorders.
Autoimmune diseases occur when a person’s immune system produces an antibody against its own cells. This results in inflammation and damage. There are many different autoimmune diseases, including lupus, rheumatoid arthritis and ITP. These diseases can be localised to a single organ or tissue, or generalised (systemic), affecting many body organs and tissues.
Removal of tissue from the body for the purpose on making a diagnosis. While the amount of tissue removed varies, in many cases only a tiny sample is required.
Bone marrow is found within the bones and is the place where blood cells (red cells, white cells and platelets) are made.
Bone Marrow Biopsy
A bone marrow biopsy is usually performed from the back of the iliac bone (pelvis). Usually some liquid marrow is drawn out by syringe (aspirate), then a core of bone is taken (trephine) so that the marrow can be examined under the microscope by a haematologist. In suspected ITP, the reason for the biopsy is to make sure that there is no other cause (diagnosis) for low platelets. In most people with ITP a bone marrow biopsy is not needed.
Chronic ITP is diagnosed when patients have ITP continuing for more than 12 months from diagnosis.
Coagulation is the process by which blood changes from a liquid to a gel, forming a blood clot. Coagulation is designed to blocks holes in blood vessels.
1. Biochemistry – any steroid hormone produced by the adrenal cortex that affects carbohydrate, protein, and electrolyte metabolism, gonad function, and immune response.
2. Pharmacology – any similar synthetic substance, used in treating inflammatory and allergic diseases (including prednisolone, dexamethasone and hydrocortisone)
means that the cause of a condition is unknown. Many conditions which used to be idiopathic (including ITP) now have a known cause. ITP used to be short for idiopathic thrombocytopenic purpura but now stands for immune thrombocytopenia.
Idiopathic Thrombocytopenia Purpura
id-iuh-pAth-ik THROM-bo-si-toe-PE-ne-ah pUHR-pyu-ruh
Shortened to ITP and is now formally known as Immune Throbocytopenia.
Immune thrombocytopenia (THROM-bo-si-toe-PE-ne-ah), or ITP, is a bleeding disorder. In ITP, the blood doesn’t clot as it should. This is due to a low number of blood cell fragments called platelets (PLATE-lets) or thrombocytes (THROM-bo-sites).
Formerly idiopathic thrombocytopenia purpura and was shortened to ITP. It is now formally known as Immune Throbocytopenia.
Intravenous immunoglobulin (IVIg) is a solution of human IgG antibodies with a broad spectrum of antibody activity. IVIg is prepared from blood donations collected from several thousand blood donors and contains IgG antibodies found in the normal population.
LDH is blood test which indicates increased cell turnover. It is normal in ITP and if raised can indicate an alternative diagnosis such as myelodysplasia or lymphoma OR may indicate the red blood cells are being destroyed by an immune process as well as platelets. This combined platelet/red cell destruction is called Evans syndrome.
The large cells in the bone marrow which produce platelets. Platelet production from these cells is controlled by the hormone thrombopoietin and this is why eltrombopag or romiplostim can increase platelet count in ITP.
A small red or purple spot caused by bleeding into the skin.
Part peptide and part antibody
A small disc-shaped cell fragment without a nucleus, found in large numbers in blood and involved in clotting. Made by megakaryocytes in the bone marrow and reduced in people with ITP.
A rash of purple spots on the skin caused by internal bleeding from small blood vessels.
The spleen is an organ about the size of an orange which is in the abdomen (belly) under the ribs on the left hand side. It filters blood and removes cells coated with antibodies. This is usually helpful in fighting infections, but in conditions like ITP the platelets coated with antibodies are removed, causing low platelet counts (thrombocytopenia).
An operation that removes the spleen. In ITP two thirds of patients will see a substantial rise in platelet counts following splenectomy. There are some short term and long term risks, including increased risk of serious infections (septicaemia) and blood clots. The risks and benefits need to be carefully weighed up in discussion with your haematologist and the surgeon performing the operation.
Low platelet count. A normal platelet count ranges from 150 to 400. In ITP it is rare to have any bleeding problems with a platelet count over 30.It is important to understand that a normal platelet count is not needed for a normal life and in most cases he aim of treatment in ITP is to get a safe platelet count of 50 or more.
Thrombopoietin is the naturally occuring hormone which controls platelet production from megakaryocytes. It is produced in the liver at a constant rate. Drugs including eltrombopag, romiplostm and avatrombopag perform the same role as thrombopoietin in boosting platelet production.
The thrombopoietin receptor agonists (TPO-RAs) are manufactured drugs which perform the same role as naturally occurring thrombopoietin, increasing platelet production. Two TPORAs, romiplostim and eltrombopag, are currenty available for patients with chronic ITP, provided certain conditions are met. Further TPORAs are under development, including avatrombopag.