STORAGE POOL DISEASE IN CHRONIC LYMPHOCYTIC-LEUKEMIA - ABNORMAL AGGREGATION AND SECRETION WITHOUT BLEEDING

Although bleeding complications are relatively common in patients with chronic lymphocytic leukemia, they tend to be related to thrombocytop enia or an acquired clotting factor inhibitor. Chronic lymphocytic leu kemia-associated thrombocytopenia, which may also contribute to the he morrhagic risk, is generally caused by decreased production and immune -mediated destruction. This is the case of a 56-year-old man with long standing chronic lymphocytic leukemia who developed thrombocytopenia ( platelet counts of approximately 50,000/mu L) with an associated abnor mal platelet morphology. Although the patient did not suffer clinicall y significant bleeding, several tests of platelet function were grossl y abnormal. Electron microscopic examination of the platelets revealed virtually complete absence of dense granules. Platelet aggregation di d not occur with adenosine diphosphate (10 mu M), collagen (2 mu g/mL) , or ristocetin (1 mg/mL). Doubling the agonist concentrations produce d only minimal agglutination with ristocetin. The bleeding time was mi ldly prolonged at 9.0 and 10.5 minutes. Von Willebrand antigen and ris tocetin cofactor levels were normal. Collagen-induced adenosine tripho sphate secretion was less than 10% that of a matched normal control. I n contrast, platelet force development was virtually normal, reaching 4,800 dynes at 1,200 seconds compared with 5,800 dynes for the healthy control. The patient's clots demonstrated enhanced clot modulus 44,00 0 dynes/cm(2) versus 22,400 dynes/cm(2) for the healthy control. The l atter finding was primarily because of high fibrinogen concentration. This third report of storage pool disease in a patient with chronic ly mphocytic leukemia demonstrates that dense granule release is not requ ired for normal platelet-mediated force development.