What Is Idiopathic Thrombocytopenic Purpura?

Idiopathic thrombocytopenic purpura (ITP) is an acquired bleeding disorder of unknown origin, characterized by thrombocytopenia, normal or increased bone marrow megakaryocytes, and lack of any cause. The incidence of ITP in women of childbearing age is higher than that of men, and there is no difference in the ratio of men and women at other ages. ITP can be divided into new diagnosis, persistent (lasting 3 to 12 months) and chronic (lasting 12 or more months) according to duration. The typical cases of adults are usually concealed, and there is no obvious history of viral infection or other diseases before the disease. The course of the disease is mostly a chronic process. ITP in children is generally self-limiting, with approximately 80% of children resolving spontaneously within 6 months.

Basic Information

Also known as

Autoimmune thrombocytopenic purpura

English name

idiopathicthrombocytopenicpurpura

English alias

immunethrombocytopenicpurpura, autoimmunethrombocytopenicpurpura

Visiting department

Immunology

Common locations

Lower limb, distal upper limb

Common symptoms

Skin bleeding point

Causes of Idiopathic Thrombocytopenic Purpura

At present, ITP is considered to be an organ-specific autoimmune hemorrhagic disease, which is caused by the production of anti-platelet autoantibodies, causing the mononuclear macrophage to destroy excessive platelets and causing thrombocytopenia. The cause of the disease is not completely clear, and the pathogenesis is not clear. Fully clarified. The onset of ITP in children may be closely related to viral infections, including herpes virus, EB virus, cytomegalovirus, parvovirus B19, measles virus, mumps virus, rubella virus, and hepatitis virus. Onset usually occurs 2 to 21 days after infection. The incidence of chronic ITP in women of childbearing age is higher than that in men, and it is easy to relapse during pregnancy, suggesting that estrogen may be involved in the pathogenesis of ITP.

Clinical manifestations of idiopathic thrombocytopenic purpura

The onset is usually insidious, showing scattered skin bleeding points and other mild bleeding symptoms, such as epistaxis and gum bleeding. Purpura and ecchymosis can occur on the skin or mucous membranes of any location, but are commonly found in the lower extremities and distal ends. The bleeding manifestations of ITP patients are related to the platelet count to a certain extent. Mild trauma between platelet counts of 20-50 × 10 / L can cause bleeding. A few are spontaneous bleeding, such as ecchymosis, stasis spots, etc., and platelet count. If it is less than 20 × 10 / L, there is a risk of severe bleeding. If the number of platelets is less than 10 × 10 / L, intracranial hemorrhage may occur. Examination is usually without splenomegaly, and a few patients may have mild splenomegaly, which may be caused by viral infection.

Acute ITP in children may have a history of respiratory infections 1 to 3 weeks before the onset of illness, and a few cases occur after vaccination. Acute onset, a few manifested as fulminant onset, may have mild fever, chills, sudden and extensive skin and mucosal purpura, and even large patches. The skin silts are mostly systemic, and the lower limbs are mostly distributed evenly. Mucosal hemorrhage is more common in the nasal cavity, gums, and blood blisters in the mouth. Gastrointestinal and urinary tract bleeding are not uncommon, and intracranial hemorrhage occurs in less than 1% of children and is life-threatening. If the patient has headache or vomiting, be alert for the possibility of intracranial hemorrhage. Most patients resolve on their own, and a few do not become chronic.

Idiopathic thrombocytopenic purpura test

Blood routine

The blood routine showed only thrombocytopenia and other blood cells in the normal range. Some patients suffered iron deficiency due to blood loss, which may be accompanied by anemia. The ITP reticulocyte count was almost normal.

2. Peripheral blood smear

It is necessary to exclude pseudo thrombocytopenia due to EDTA-dependent platelet aggregation. The presence of broken red blood cells should exclude thrombotic thrombocytopenic purpura and hemolytic uremic syndrome. The presence of giant or microplatelets requires consideration of hereditary thrombocytopenia.

3. Bone marrow smear

Bone marrow hyperplasia is active, and megakaryocytes generally increase significantly and sometimes are normal. The more prominent changes are imbalanced nuclear plasma maturation of megakaryocytes, fewer particles in the cytoplasm, and significant reduction or lack of platelet-producing megakaryocytes.

4. HIV and Hepatitis C Virus (HCV) Testing

Adult patients considering ITP should be tested for HIV and HCV. Thrombocytopenia caused by HIV and HCV infection is sometimes difficult to distinguish clinically from patients with primary ITP.

5. Quantitative immunoglobulin

More serum IgG, IgA, IgM levels were measured. Low levels of immunoglobulin often suggest variant immunodeficiency disease or selective IgA deficiency.

Idiopathic thrombocytopenic purpura diagnosis

The diagnosis of ITP is still clinically excluded. The main points of diagnosis are as follows: The platelet count is reduced and blood cell morphology is normal at least 2 times; The spleen is generally small; The number of megakaryocytes in the bone marrow is normal or increased, with maturity disorders; Other secondary thrombocytopenia needs to be ruled out .

Differential diagnosis of idiopathic thrombocytopenic purpura

The part of the thrombocytopenia caused by the drug is also immune, and it is difficult to identify with ITP, and you should carefully ask the medication history; congenital thrombocytopenic purpura is similar to this disease, you should investigate the family history, if necessary, check other family members to distinguish; connective The early manifestations of tissue disease may only be thrombocytopenia. Patients with thrombocytopenia should undergo relevant laboratory tests; those with thrombosis should pay attention to anticardiolipin syndrome, and should ask for a history of miscarriage and detect antiphospholipid antibodies for identification; with hemolytic Anemia patients should consider Evans syndrome; in addition, it needs to be distinguished from diseases such as hypersplenism, thrombotic microangiopathy, leukemia, lymphoma, and myelodysplastic syndrome.

Idiopathic thrombocytopenic purpura treatment

The treatment of ITP should be individualized. Generally speaking, the platelet count is greater than 50 × 10 / L, and those without a tendency to bleed can be observed and regularly checked; if the platelet count is between (20-50) × 10 / L, the patient's clinical manifestation / degree of bleeding and risk It depends; those with platelets less than 20 × 10 / L should usually be treated. Patients with severe bleeding tendency should stay in bed to avoid trauma and avoid taking drugs that affect platelet function. The purpose of the treatment of this disease is to control bleeding symptoms and reduce platelet destruction, but it is not emphasized to increase the platelet count to normal to ensure that patients are not at risk due to bleeding and do not cause serious adverse reactions due to overtreatment.

1. Initial treatment of ITP

(1) Glucocorticoids.

(2) Severe patients can use large doses of gamma globulin.

(3) Anti-Rh (D) immunoglobulins can be used abroad.

2. Second-line treatment of ITP

(1) Alternative second-line treatment drugs include azathioprine, cyclosporine A, danazol, vinca alkaloids, Xiaoxi and so on.

(2) Splenectomy.

Idiopathic thrombocytopenic purpura prognosis

ITP in children is a benign disease. A small number of patients with severe thrombocytopenia may die of intracranial hemorrhage with a mortality rate of less than 1%. Spontaneous remission of ITP in adults is rare. About one-third of patients are ineffective for hormonal and splenectomy. These patients are often unhealed, and about 5% of patients can die from intracranial hemorrhage.