What does platelet antibody mean

When examining platelets, platelet antibody testing can be performed, which is an important condition for diagnosing some bleeding diseases. Investigations have found that about 90% of primary thrombocytopenia is related to increased platelet-related antibodies, especially idiopathic thrombocytopenic purpura, which is an immune hemorrhagic disease. It is of great clinical significance.

What does platelet antibodies mean?

Idiopathic thrombocytopenic purpura (ITP) is an autoimmune hemorrhagic disease caused by the body's production of anti-platelet autoantibodies (PAIgG), which leads to excessive platelet destruction by the mononuclear macrophage system. Its clinical features include thrombocytopenia, normal or increased bone marrow megakaryocytes, and skin and mucous membrane bleeding.

The platelet surface of most ITP patients is coated with IgG autoantibodies, so the detection of PAIgG is of great significance for the diagnosis and treatment of ITP. PAIgG exists in two forms in the body, namely antibodies in the serum that can bind to platelets and antibodies associated with the platelet surface. There are two main methods for PAIgG detection: indirect method and direct method. The indirect method is used to detect PAIgG in serum, and the direct method mainly detects PAIgG on the surface of platelets. Commonly used clinical methods include solid-phase platelet immunoserological test, simplified sensitized red blood cell platelet serological technique, enzyme-linked immunosorbent assay and monoclonal antibody solid-phase method.

Clinical significance

1.PAIgG as one of the diagnostic indicators of ITP

More than 90% of ITP patients have elevated PAIgG. If PAIgM, PAIgA and PAC are measured simultaneously, the positive rate can reach 100%. But autoimmune diseases such as SLE also test positive.

2. PAIgG as an indicator for observing therapeutic efficacy

PAIgG decreased in ITP after treatment with adrenocortical hormones, while it increased in recurrent patients.

3. PAIgG as a prognostic indicator

Patients with reduced ITP and PAIgG after treatment and no recurrence have a better prognosis, otherwise the prognosis is poor.

4. PAIgG as an indicator of splenectomy indication

Patients whose PAIgG does not decrease after treatment with adrenocortical hormones are all candidates for splenectomy.

5. PAIgG as an indicator for predicting fetal platelet status

If the level of free antiplatelet antibodies in the serum of pregnant women with ITP increases, the antibodies can enter the fetal blood circulation through the placenta and cause fetal thrombocytopenia.