The results of our study support the need for the continued use of prophylaxis with platelet transfusion and show the benefit of such prophylaxis for reducing bleeding, as compared with no prophylaxis. A significant number of patients had bleeding despite prophylaxis. (Funded by the National Health Service Blood and Transplant Research and Development Committee and the Australian Red Cross Blood Service; TOPPS Controlled-Trials.com number, ISRCTN08758735.).
Hemolysis and hemoglobinemia contribute to serious clinical sequelae in hemolytic disorders. In paroxysmal nocturnal hemoglobinuria (PNH) patients, hemolysis can contribute to thromboembolism (TE), the most feared complication in PNH, and the leading cause of disease-related deaths. We evaluated whether long-term treatment with the complement inhibitor eculizumab reduces the rate of TE in patients with PNH. Clinical trial participants included all patients in the 3 eculizumab PNH clinical studies, which recruited patients between 2002 and 2005 (n ؍ 195); patients from these studies continued treatment in the current multinational open-label extension study. Thromboembolism rate with eculizumab treatment was compared with the pretreatment rate in the same patients. The TE event rate with eculizumab treatment was 1.07 events/100 patient-years compared with 7.37 events/100 patient-years (P < .001) prior to eculizumab treatment (relative reduction, 85%; absolute reduction, 6.3 TE events/100 patient-years). With equalization of the duration of exposure before and during treatment for each patient, TE events were reduced from 39 events before eculizumab to 3 events during eculizumab (P < .001). The TE event rate in antithrombotic-treated patients (n ؍ 103) was reduced from 10.61 to 0.62 events/100 patient-years with eculizumab treatment (P < .001). These results show that eculizumab treatment reduces the risk of clinical thromboembolism in patients with PNH. This study is registered at http://clinicaltrials.gov (study ID no. NCT00122317).
IntroductionIntravascular hemolysis and cell-free plasma hemoglobin have been implicated in the serious clinical sequelae of various hemolytic disorders. 1 Hemolysis is the primary clinical manifestation of the uncommon disease paroxysmal nocturnal hemoglobinuria (PNH) and has been shown to result in chronic disabling morbidities including anemia, severe fatigue, difficulty in functioning, pain, and thrombosis, all of which have a major effect on the patient's quality of life. 1-5 Paroxysmal nocturnal hemoglobinuria is defined by the acquired genetic deficiency of glycosylphosphatidylinositol (GPI)-linked proteins from the surface of blood cells. The absence of GPI-linked complement regulatory proteins on PNH erythrocytes renders them susceptible to terminal complement-mediated hemolysis.Hemolysis most likely contributes to thromboembolism (TE) in PNH, as patients with larger PNH clones have a higher incidence of TE and events have been temporally associated with increased hemolysis. 6-10 Although the mechanism is not fully understood, hemolysis has been implicated in the initiation of platelet activation and aggregation. 1 Additional in vitro studies have suggested that complement may directly activate platelets from PNH patients. 11,12 Thromboembolism is the leading cause of mortality in patients with PNH, 2,3,13-17 and an initial thrombotic event increases the relative risk of death in PNH 5-to 10-fold. 15,17 Retrospective studies suggest that, in non-Asian patients, TE accou...
Context
Hematopoietic stem cell transplantation (HSCT) requires significant infrastructure. Little is known on its use and the factors associated with it on a global level.
Objective
To determine current use of HSCT, to assess differences in its application and to explore associations of macroeconomic factors with transplant rates on a global level.
Design
Structured worldwide collection of numbers of allogeneic and autologous HSCT by main indication, donor type and stem cell source for the year 2006.
Setting
Worldwide Network for Blood and Marrow Transplantation (WBMT), a global non-profit umbrella organization for clinical HSCT.
Patients
All patients with an allogeneic or autologous HSCT for any indication transplanted in 2006 within any of the participating countries.
Interventions
none
Main Outcome measures
Transplant rates (number of HSCT per 10 million inhabitants) by indication, donor type and country; description of main differences in HSCT use; macroeconomic factors of reporting countries associated with transplant rates.
Results
There were 50’417 first HSCT, 21’516 allogeneic (43%), 28’901 autologous (57%) reported from 1’327 centers in 71 countries for leukemia (17’049 (34%; 89% allogeneic)), lymphoma (27’492 (54%; 87% autologous)), solid tumors (2’925 (6%, 95% autologous)), non-malignant disorder (2’593 (5%; 92% allogeneic)) or, “others” 358 (1%). Use of allogeneic or autologous HSCT, use of unrelated or family donors for allogeneic HSCT and proportions of disease indications varied significantly between countries and continental regions. In linear regression analyses, Government Health Care Expenditures (r2 = 77.33), team density (r2 =76.28), Human Development Index (r2 = 74.36) and Gross National Income /Capita (r2 = 74.04) showed the highest association with transplant rates.
Conclusions
HSCT is an accepted therapy today with different use and needs worldwide. Availability of resources, Governmental support and, access for patients to a team were identified as key factors for higher transplant rates.
Paroxysmal nocturnal haemoglobinuria (PNH) is characterized by chronic, uncontrolled complement activation resulting in elevated intravascular haemolysis and morbidities, including fatigue, dyspnoea, abdominal pain, pulmonary hypertension, thrombotic events (TEs) and chronic kidney disease (CKD). The long-term safety and efficacy of eculizumab, a humanized monoclonal antibody that inhibits terminal complement activation, was investigated in 195 patients over 66 months. Four patient deaths were reported, all unrelated to treatment, resulting in a 3-year survival estimate of 97·6%. All patients showed a reduction in lactate dehydrogenase levels, which was sustained over the course of treatment (median reduction of 86·9% at 36 months), reflecting inhibition of chronic haemolysis. TEs decreased by 81·8%, with 96·4% of patients remaining free of TEs. Patients also showed a time-dependent improvement in renal function: 93·1% of patients exhibited improvement or stabilization in CKD score at 36 months. Transfusion independence increased by 90·0% from baseline, with the number of red blood cell units transfused decreasing by 54·7%. Eculizumab was well tolerated, with no evidence of cumulative toxicity and a decreasing occurrence of adverse events over time. Eculizumab has a substantial impact on the symptoms and complications of PNH and results a significant improvement in patient survival.
Advances in hematopoietic cell transplantation (HCT) technology and supportive care techniques have led to improvements in long-term survival after HCT. Emerging indications for transplantation, introduction of newer graft sources (e.g. umbilical cord blood) and transplantation of older patients using less intense conditioning regimens have also contributed to an increase in the number of HCT survivors. These survivors are at risk for developing late complications secondary to pre-, peri- and post-transplant exposures and risk-factors. Guidelines for screening and preventive practices for HCT survivors were published in 2006. An international group of transplant experts was convened in 2011 to review contemporary literature and update the recommendations while considering the changing practice of transplantation and international applicability of these guidelines. This review provides the updated recommendations for screening and preventive practices for pediatric and adult survivors of autologous and allogeneic HCT.
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