Pseudo gray platelet syndrome

Presentation

Bleeding time, activated partial thromboplastin time, prothrombin time, and euglobulin lysis time were within normal limits. There were no platelet antibodies detected. The patient's mother and two sisters had histories of easy bruising and heavy menstrual periods. A brother had no reported bleeding tendencies. Platelets from the mother, sisters, and a daughter were normal in number and appearance under the light microscope. Platelets in blood collected into EDTA tubes appeared gray and agranular compared with platelets from blood in citrate or heparin. The key finding is under electron microscopy, EDTA-exposed platelets showed extensive activation, with loss of storage granule contents and pseudopod formation. Platelet aggregation studies were normal.

The abnormal platelet reaction following EDTA exposure is thought to be caused by a plasma factor, although not an immunoglobulin. The mechanism by which platelet activation occurs remains unknown. Few cases have been reported in the literature.

Diagnosis

Comparison to gray platelet syndrome

Pseudo-gray platelet syndrome differs from gray platelet syndrome (GPS), one of the giant platelet syndromes. GPS is characterized by "thrombocytopenia, abnormally large agranular platelets in peripheral blood smears, and almost total absence of platelet alpha-granules and their constituents." The defect in GPS is the failure of megakaryocytes to package secretory proteins into alpha-granules. Patients with the GPS are affected by mild to moderate bleeding tendencies.

References

References

1. (October 1988). "Pseudo grey platelet syndrome--grey platelets due to degranulation in blood collected into EDTA". Eur. J. Haematol..
2. (November 2002). "Pseudo gray platelet syndrome in a patient with acute myocardial infarction". Int. J. Hematol..
3. Jantunen E. (October 1994). "Inherited giant platelet disorders". Eur. J. Haematol..
4. (July 1994). "Gray platelet syndrome with splenomegaly and signs of extramedullary hematopoiesis: a case report with review of the literature". Am. J. Hematol..