Diagnosis of primary immune thrombocytopenia (ITP)
I. Clinical manifestations
Bleeding tendency The clinical picture of ITP is dominated by bleeding from the skin and mucous membranes. In general, the severity of bleeding in patients is negatively correlated with their platelet counts, but using platelet counts alone to evaluate the severity of bleeding in patients is not comprehensive and objective. The Blood Branch of the Chinese Medical Association has introduced the ITP bleeding scale (draft), which is shown in Table 1
Weakness Weakness is one of the clinical symptoms of ITP patients, and some patients show it more obviously.
Thrombotic tendency ITP is not only a bleeding disorder, but also a pre-thrombotic disorder.
II. Diagnostic points.
The diagnosis of ITP is still a clinical exclusion diagnosis and lacks specific laboratory indicators. Its diagnostic points are as follows.
①Diagnosis of ITP requires at least 2 laboratory tests for reduced platelet count, as well as blood smear to check blood cell morphology. Blood cell morphology examination can exclude pseudo-thrombocytopenia (platelet aggregation visible on blood smear), hereditary thrombocytopenia (abnormal platelet morphology), TTP, DIC, leukemia (naïve cells visible on blood smear) or other malignancy-related thrombocytopenia, etc.
② Patients generally do not have an enlarged spleen. Only less than 3% of adult ITP patients have mild splenomegaly, so if patients have splenomegaly, hypersplenism, lymphoproliferative disorders, and autoimmune diseases need to be excluded.
③Exclude secondary thrombocytopenia by detailed history, general physical examination and necessary laboratory tests, such as: autoimmune diseases, thyroid diseases, drug-induced thrombocytopenia, alloimmune thrombocytopenia, proliferative diseases of the lymphatic system, myelodysplasia (aplastic anemia and myelodysplastic syndrome), malignant hematological diseases, hypersplenism in chronic liver disease, and platelet depletion thrombocytopenia in pregnancy, secondary thrombocytopenia due to infection, pseudo-thrombocytopenia, and congenital thrombocytopenia, etc.
④Special laboratory tests for the diagnosis of ITP: These include tests for platelet antibodies and tests for thrombopoietin (TPO). It is not used as a routine test for the diagnosis of ITP, and is generally used for diagnostic reassessment in patients who encounter difficulties in the diagnosis of ITP, or in patients who have failed first- or second-line therapy.
III. Staging and staging.
Newly diagnosed ITP Patients with ITP within 3 months of diagnosis
Persistent ITP Patients with ITP with persistent thrombocytopenia 3 to 12 months after diagnosis
Chronic ITP Patients with ITP whose thrombocytopenia has persisted for more than 12 months
Severe ITP Refers to patients with platelets <10×10^9/L who have bleeding symptoms requiring treatment at the time of presentation or new bleeding symptoms occurring during conventional treatment, requiring treatment with other platelet-elevating drugs or increasing the dose of drugs on existing treatment.
Criteria for refractory ITP: All 3 conditions must be met simultaneously.
① Ineffective or recurrent after splenectomy;
② Treatment is still required to reduce the risk of bleeding;
(iii) The diagnosis of ITP is confirmed except for other causes of thrombocytopenia.