Platelet aggregation in platelet rich plasma and whole blood in 120 patients with myeloproliferative disorders.

In vitro platelet aggregation in platelet-rich plasma (PRP) and in whole blood (WB) was assessed in 31 patients with idiopathic myelofibrosis, 32 with essential thrombocytosis, 23 with polycythemia vera, and 34 with chronic myelogenous leukemia. In PRP most subjects showed normal or reduced platelet aggregation, whereas in WB the majority of patients showed increased platelet function. Spontaneous platelet aggregation (SPA) was observed frequently in WB, whereas it was seldom observed in PRP. SPA in WB was inhibited by in vitro addition of aspirin and apyrase, and SPA was only partially dependent on high platelet count because it also occurred in samples with normal platelet content (at variance with 13 subjects with reactive thrombocytosis, in which SPA was observed only in samples with high platelet concentration). Platelets from patients with idiopathic myelofibrosis had the highest tendency to undergo SPA

Effects of splenectomy in 45 patients affected by idiopathic thrombocytopenic purpura: Search for prognostic factors

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Risultati della splenenectomia in 45 casi di porpora trombocitopenica idiopatica: ricerca di indici prognostici. [Results of splenectomy in 45 cases of idiopathic thrombocytopenic purpura: search of prognostic indices]

We report on the effects of splenectomy in 45 consecutive patients affected by idiopathic thrombocytopenia who did not obtain lasting remission with prednisone therapy. None of the patients had serious complications after surgery, and only one died a year later from an infectious disease. Two years after surgery, 89% of the patients were in remission; 79% had no therapy after splenectomy, while 10% achieved remission in response to additional medical treatment. A significantly better response to splenectomy was obtained in the subjects under 50 years old (90% remission) and by the younger patients who had had a transient response to initial prednisone therapy (100% remission). All patients with thrombocytosis 15 days after surgery were in remission two years later. We were unable to identify parameters constantly associated with a poor response to splenectomy, since at least 25% of the patients with the worst prognostic features obtained lasting remission