Idiopathic thrombocytopenic purpura (ITP)

For those of you who read my blog on a regular basis you know that when I was pregnant with C.J. I had a low blood platelet count. The doctors believed it was Gestational Thrombocytopenia. They said it would go away a soon as I delivered. Well after I had C.J. they never checked my blood platelets again. They just assumed it went away. When I left the hostpital I notice a large deep bruise on my breast I thought it was strange but just ignored it. Over the next few weeks I noticed bruises appearing all over my body. So when I went to my six week check up I asked the doctor about it. They thought I was anemic, But decited to check my blood platelet again. Well it tuned out that I was not anemic. My blood platelets were at 110,000 at the time of delivery of C.J. and had now dropped to 80,000. The doctor refered me to a specialist who ran some tests. Two days later hey dropped down to 70,000. The doctor told me it could be a few different things like A disease called ITP which was the most common or leukemia. I didn't like hearing the word Leukemia even if it wasn't the most likly cause. It was a little scary. Poor Justin was so worried. Well a few days later we got the test results back and it was ITP. It's never good news to find out you have some disease but I was sure glad it was that and not something like Leukemia.
So for now they are treating it with steroids. I'm still a little confused on what it is, but for those of you who are curious below is so infomation about it I found on the internet.

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. Although most cases are asymptomatic, very low platelet counts can lead to bleeding diathesis and purpura.

Epidemiology
The incidence of ITP is estimated at 50–100 new cases per million per year, with children accounting for half of that amount. In the USA, ITP is considered an orphan disease.

More than 70 percent of childhood cases end up in remission within six months, whether treated or not. Moreover, a third of the remaining chronic cases remitted during the follow-up observation, and another third ended up with only mild thrombocytopenia (>50,000 platelets per μL). ITP is usually chronic in adults and the probability of durable remission is 20–40%. The male:female ratio in the adult group is 1:1.2–1.7 (for children it is 1:1) and the median age of adults at the diagnosis is 56–60.


Signs and symptoms
Usually, ITP patients suffer from bruising; petechiae, nosebleeds and bleeding gums may occur if the platelet count is below 20,000, compared to a normal range of 150,000–400,000 per mm3.

Subarachnoid, intracerebral hemorrhage or other internal bleeding are very serious possible complications of this disease. Fortunately, these are unlikely in patients with the platelets count above 20,000.

Pathogenesis
In many cases, the cause is not actually idiopathic but autoimmune,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.

The coating of platelets with IgG renders them susceptible to opsonization and phagocytosis by splenic macrophages. The IgG autoantibodies are also thought to damage megakaryocytes, the precursor cells to platelets, but this is thought to contribute only slightly to the decrease in platelet numbers.

The stimulus for auto-antibody production in ITP is probably abnormal T cell activity.Preliminary findings suggest that these T cells can be influenced by drugs that target B cells, such as rituximab.

Diagnosis
The diagnosis of ITP is a process of exclusion. First, the clinician has to determine that there are no blood abnormalities other than low platelet count, and no physical signs except for signs of bleeding. Then, the secondary causes (usually 5–10 percent of suspected ITP cases) should be excluded. Secondary causes could be leukemia, medications (e.g. quinine, heparin), lupus erythematosus, cirrhosis, HIV, hepatitis C, congenital causes, antiphospholipid syndrome, von Willebrand factor deficiency and others. In approximately one percent of cases, autoimmune hemolytic anemia and immune thrombocytic purpura coexist, which is a condition called Evans syndrome.

Despite the destruction of platelets by splenic macrophages, the spleen is normally not enlarged. In fact, an enlarged spleen should lead a clinician to investigate other possible causes for the thrombocytopenia.

Bleeding time is prolonged in ITP patients. However, the use of bleeding time in diagnosis is discouraged by the American Society of Hematology practice guidelines. A normal bleeding time does not exclude a platelet disorder.

A bone marrow examination may be performed on patients over the age of 60 and those who do not respond to treatment, or when the diagnosis is in doubt. On examination of the bone marrow, an increase in the production of megakaryocytes is seen and can help in determining if it's ITP. The blood analysis for the antiplatelet antibodies is a matter of clinician's preference, as there is a disagreement whether the 80 percent specificity of this test is sufficient.

Steroids/IVIG
A platelet count below 20,000/μL is an indication for treatment. Patients with 20,000–50,000 platelets/μL are considered on a case-by-case basis, and there is generally no need to treat patients with a count above 50,000.[6] Hospitalization is recommended in cases of significant internal or mucocutaneous bleeding.

Treatment usually is initiated with intravenous steroids (methylprednisolone or prednisone), intravenous immunoglobulin (IVIg) or a combination of these drugs. A platelet infusion may be administered in order to quickly raise the count. After the platelet count has stabilized, orally administered prednisone (1–2 mg/kg per day) is usually prescribed. Most cases respond during the first week of treatment. After several weeks of oral prednisone therapy, the dose is gradually reduced. However, 60 to 90 percent of patients relapse after the dose is decreased below 0.25 mg/kg per day and subsequently stopped.

Splenectomy (removal of the spleen) is sometimes undertaken, as platelets targeted for destruction will often meet their fate in the spleen. Splenectomy is said to be successful in 60 to 65 percent of cases, although it is less successful in older people.[