24th July 2024

Immune thrombocytopenic purpura

The pathophysiology of ITP is not entirely understood, but it is thought that sensitised antibodies destroy platelets.

Clinical features of ITP

ITP typically presents with purpura, bruising and bleeding. Mucocutaneous bleeding is common.

A low platelet count with unaffected haemoglobin and white cell count is suggestive of ITP; a blood film can show that other blood lines are not affected and will demonstrate thrombocytopenia. In difficult cases, bone marrow biopsy may be indicated. ITP is a diagnosis of exclusion and it is important to rule out other causes of thrombocytopenia.

Management of ITP

Most patients are treated conservatively with regular monitoring of platelet count. If bleeding symptoms persist and platelet counts are low (<30 x109), prednisolone can be used. If a quicker increase in platelet count is indicated such as before a procedure or surgery or in active bleeding, then IVIG plus steroids is indicated. Platelet transfusion can also be given in bleeding. Second line treatments involve immunosuppression or novel treatments such as thrombopoietin receptor agonists (e.g. eltrombopag).

ITP can also occur secondary to an underlying condition, for example CLL, HIV, HCV, APLS and H. Pylori infection; the treatment of secondary ITP is that of the underlying disease.