No abstract

Toxicity related to autologous PBSC infusion is well known and traditionally attributed to the presence of DMSO as cryoprotectant. But despite DMSO depletion, adverse events continue appearing. We have conducted a retrospective study to determine the incidence of adverse events related to the PBSC infusion in a large series of 144 patients. Adverse effects were observed in 67.36% of patients, although most of them were of grade 1 or 2. The adverse events most frequently reported were allergic reactions, followed by general, gastrointestinal and respiratory symptoms. In the univariate analysis, age (P ¼ 0.01), the volume infused (P ¼ 0.005), the amount of DMSO (P ¼ 0.008), the total nucleated cells (P ¼ 0.002), the total number of granulocytes (P ¼ 0.000001) and clumping (P ¼ 0.000001) were associated with the occurrence of adverse events. In the multivariate analysis, two protective factors, age (P ¼ 0.05) and sex (P ¼ 0.004), and two risk factors, the number of granulocytes, with a relative risk of 1.18 (95% confidence interval, 1.06-1.31) (P ¼ 0.002), and clumping, with an relative risk of 1.94 (95% confidence interval, 1.15-3.29) (P ¼ 0.013), were identified. The best cutoff point for the prediction of the occurrence of adverse events, with a sensitivity of 47% and specificity of 89%, was 6.065 Â 10 9 granulocytes.

The clinical significance of resistance/intolerance to hydroxycarbamide (HC) was assessed in a series of 890 patients with polycythaemia vera (PV). Resistance/intolerance to HC was recorded in 137 patients (15·4%), consisting of: need for phlebotomies (3·3%), uncontrolled myeloproliferation (1·6%), failure to reduce massive splenomegaly (0·8%), development of cytopenia at the lowest dose of HC to achieve a response (1·7%) and extra-haematological toxicity (9%). With a median follow-up of 4·6 years, 99 patients died, resulting in a median survival of 19 years. Fulfilling any of the resistance/intolerance criteria had no impact on survival but when the different criteria were individually assessed, an increased risk of death was observed in patients developing cytopenia [Hazard ratio (HR): 3·5, 95% confidence interval (CI): 1·5-8·3, P = 0·003]. Resistance/intolerance had no impact in the rate of thrombosis or bleeding. Risk of myelofibrotic transformation was significantly higher in those patients developing cytopenia (HR: 5·1, 95% CI: 1·9-13·7, P = 0·001) and massive splenomegaly (HR: 9·1, 95% CI: 2·3-35·9, P = 0·002). Cytopenia at the lowest dose required to achieve a response was also an independent risk factor for transformation to acute leukaemia (HR: 20·3, 95% CI: 5·4-76·5, P < 0·001). In conclusion, the unified definition of resistance/intolerance to HC delineates a heterogeneous group of PV patients, with those developing cytopenia being associated with an adverse outcome.

No abstract

It is unclear whether anticoagulation guidelines intended for the general population are applicable to patients with polycythemia vera (PV) and essential thrombocythemia (ET). In the present study, the risk of thrombotic recurrence was analyzed in 150 patients with PV and ET treated with vitamin K antagonists (VKA) because of an arterial or venous thrombosis. After an observation period of 963 patient-years, the incidence of re-thrombosis was 4.5 and 12 per 100 patient-years under VKA therapy and after stopping it, respectively (P < 0.0005). After a multivariate adjustment for other prognostic factors, VKA treatment was associated with a 2.8-fold reduction in the risk of thrombotic recurrence. Notably, VKA therapy offset the increased risk of re-thrombosis associated with a prior history of remote thrombosis. Both the protective effect of VKA therapy and the predisposing factors for recurrence were independent of the anatomical site involved in the index thrombosis. Treatment periods with VKA did not result in a higher incidence of major bleeding as compared with those without VKA. These findings support the use of long-term anticoagulation for the secondary prevention of thrombosis in patients with PV and ET, particularly in those with history of remote thrombosis.