Acquired disorders of platelet function

Definition

Acquired platelet function defects are diseases or conditions that cause the platelets (the blood cells essential for clotting) to not work properly. The term "acquired" means these diseases or conditions are not inherited, but rather develop independently in a person.

Alternative Names

Acquired qualitative platelet disorders; Acquired disorders of platelet function

Causes

Platelet disorders can involve an abnormal number of these cells (too many or too few), or abnormal functioning of the platelets. Any platelet disorder affects blood clotting.

Disorders of platelet function can be caused by congenital (present at birth) diseases, or they can be acquired conditions. Acquired platelet function disorders involve abnormal platelet function. These disorders develop as a result of another disease or condition (acquired). In many cases, the platelet count may be normal or even high, but evidence of a bleeding disorder will be present. Bone marrow disorders such as primary thrombocytopenia, polycythemia vera, chronic myelogenous leukemia, and myelofibrosis can produce abnormalities in platelet function.

Other causes include renal failure, multiple myeloma, and medications such as aspirin and other anti-inflammatory drugs, penicillins, phenothiazines, and prednisone (after prolonged use).

Symptoms

Exams and Tests

Treatment

Treatment is directed at the cause of the abnormality. Dialysis reduces the bleeding tendency if the cause is renal failure. Platelet transfusions or plateletpheresis (removal of platelets from the blood and replacement with donated platelets) may be needed in bone marrow disorders. Medication-induced platelet abnormalities require stopping the medication.

Outlook (Prognosis)

Treatment of the cause of the abnormality usually corrects the defect.

Possible Complications

When to Contact a Medical Professional

Call your health care provider:

Prevention

Care in the use of medications can reduce the risk of drug-related acquired platelet function defects. Treatment of other disorders may also reduce risk. Some cases are not preventable.

Hoffman R, Benz Jr. EJ, Shattil SJ, et al.. Hematology: Basic Principles and Practice. 4th ed. Philladelphia, Pa: Churchill Livingston; 2005.

McPherson RA and Pincus MR. Henry's Clinical Diagnosis and Management by Laboratory Methods. 21st ed. Philadelphia, Pa: WB Saunders; 2007:762-64.