Hypersplenic thrombocytopenia differentiated from increased peripheral destruction by platelet volume

Platelet volume distribution was examined in 16 patients with hepatosplenomegaly and platelet counts of 45 000 to 90 000/mm; 12 patients with autoimmune thrombocytopenia and randomly matched platelet counts; and 20 normal subjects. Five platelet volume variables of increasing platelet size were defined from the averages of 20 normal curves. Patients with hypersplenism had decreased volume values of 78% to 87% (mean, 83%) of the average normal population (P less than 0.001). Patients with autoimmune thrombocytopenic purpura had values significantly greater than normal by 124% to 149% (mean, 134%) (P less than 0.001). Patients with autoimmune thrombocytopenic purpura, when compared with hypersplenic patients, had significantly greater platelet volume values ranging from 154% to 174% (mean, 161%), P less than 0.001. We concluded that patients with hepatosplenomegaly have smaller platelets in their peripheral blood and a platelet volume distribution that can be distinguished easily from patients with autoimmune thrombocytopenic purpura, despite comparable platelet counts.