Read more about this disease, some with Classification – Types – Signs and symptoms – Genetics – Pathophysiology – Diagnosis – Screening – Prevention – Treatment and management – Cures and much more, some including pictures and video when available.
Idiopathic thrombocytopenic purpura (ITP) is the condition of having a low platelet count (thrombocytopenia) of no known cause (idiopathic). As most causes appear to be related to antibodies against platelets, it is also known as immune thrombocytopenic purpura or immune-mediated thrombocytopenic purpura. Often ITP is asymptomatic, however a very low platelet count can lead to visible symptoms, such as purpura (bruises), or more seriously, bleeding diathesis.
A normal platelet count is considered to be in the range of 150,000–400,000 per cubic millimeter (mm3) of blood for most healthy individuals. Hence one may be considered thrombocytopenic below that range, although the threshold for a diagnosis of ITP is not tied to any specific number.
The incidence of ITP is estimated at 50–100 new cases per million per year, with children accounting for half of that amount. More than 70 percent of childhood cases end up in remission within six months, whether treated or not.[1][2][3] Moreover, a third of the remaining chronic cases remitted during follow-up observation, and another third ended up with only mild thrombocytopenia (defined as a platelet count above 50,000).[1]
ITP is usually chronic in adults[4] and the probability of durable remission is 20–40 percent.[5] The male to female ratio in the adult group varies from 1:1.2 to 1.7 in most age ranges (childhood cases are roughly equal for both sexes) and the median age of adults at the diagnosis is 56–60.[6] The ratio between male and female adult cases tends to widen with age. In the USA, the adult chronic population is thought to be approximately 60,000 (with women outnumbering men 2:1), which has resulted in ITP being designated an orphan disease.[7]
Symptoms of ITP include the development of bruises (purpura) and petechiae, especially on the extremities, bleeding from the nostrils and bleeding at the gums, any of which may occur if the platelet count is below 20,000 per mm3.[8] A very low count (<10,000 per mm3) may result in the formation of hematomas in the mouth or on other mucous membranes. Serious and possibly fatal complications due to an extremely low count (<5,000 per mm3) may include subarachnoid or intracerebral hemorrhage, lower gastrointestinal bleeding or other internal bleeding. An ITP patient with an extremely low count is also vulnerable to major internal bleeding caused by abdominal trauma, as might be experienced in a motor vehicle crash. Fortunately, these complications are not likely in a patient whose platelet count is above 20,000. In many cases, the cause is not actually idiopathic but autoimmune,[9] with antibodies against platelets being detected in approximately 60 percent of patients. Most often these antibodies are against platelet membrane glycoproteins IIb-IIIa or Ib-IX, and are of the IgG type. The famous Harrington–Hollingsworth experiment established the immune pathogenesis of ITP.[10] [tubepress mode=’tag’, tagValue=’Idiopathic thrombocytopenic purpura’]