The regulation of platelets by oxidants is critical for vascular health and may explain thrombotic complications in diseases such as diabetes and dementia, but remains poorly understood. Here, we describe a novel technique combining electron paramagnetic resonance spectroscopy and turbidimetry, which has been utilised to monitor simultaneously platelet activation and oxygen radical generation. This technique has been used to investigate the redox-dependence of human and mouse platelets. Using selective peptide inhibitors of NOXs on human platelets and genetically modified mouse platelets (NOX1-/- or NOX2-/-), we discovered that:1) intracellular but not extracellular superoxide anion generated by NADPH oxidases (NOXs) is critical for platelet activation by collagen; 2) superoxide dismutation to hydrogen peroxide is required for thrombin-dependent activation; 3) NOX1 is the main source of oxygen radicals in response to collagen, while NOX2 is critical for activation by thrombin; 4) two platelet modulators, namely oxidised low density lipoproteins (oxLDL) and amyloid peptide β (Aβ), require activation of both NOX1 and NOX2 to pre-activate platelets. This study provides new insights on the redox dependence of platelet activation. It suggests the possibility of selectively inhibiting platelet agonists by targeting either NOX1 (for collagen) or NOX2 (for thrombin). Selective inhibition of either NOX1 or NOX2 impairs the potentiatory effect of tested platelet modulators (oxLDL and Aβ), but does not completely abolish platelet haemostatic function. This information offers new opportunities for the development of disease specific antiplatelet drugs with limited bleeding side effects by selectively targeting one NOX isoenzyme.
Amyloidosis of the gastrointestinal tract, with biopsy-proven disease, is rare. We reviewed a series of patients who presented with biopsy-proven gastrointestinal amyloidosis and report their clinical characteristics, treatments, and survival. This is a retrospective review of data prospectively collected from January 1998 to December 2011 in a tertiary referral center; 2,334 patients with all types of amyloidosis were evaluated during this period. Seventy-six patients (3.2%) had biopsy-proven amyloid involvement of the gastrointestinal tract. Their median age was 61 years (range, 34-79). Systemic amyloidosis with dominant gastrointestinal involvement was present in 60 (79%) patients, whereas the other 16 (21%) patients had amyloidosis localized to the gastrointestinal tract without evidence of an associated plasma cell dyscrasia or other organ involvement. Of the 60 systemic cases, 50 (83%) had immunoglobulin light-chain, five (8%) had familial lysozyme, three (5%) had wild-type transthyretin, and two (3%) had mutant transthyretin amyloidosis. The most frequent symptoms for all patients were weight loss in 33 (45%) and gastrointestinal bleeding in 27 (36%). Incidental identification of amyloidosis on routine endoscopic surveillance played a role in the diagnosis of seven patients with systemic immunoglobulin light-chain, and four patients with immunoglobulin light-chain localized to the gastrointestinal tract. Amyloid protein subtyping was performed in 12 of the cases of localized disease, and all had lambda light chain disease. Of the 50 patients with systemic immunoglobulin light-chain amyloidosis, 45 were treated with anti-plasma cell therapy. The median survival has not been reached for this group. For the 16 patients with localized gastrointestinal amyloidosis, supportive care was the mainstay of treatment; none received anti-plasma cell therapy. All 16 are alive at a median follow-up of 36 months (range, 1-143). Patients with biopsy-proven gastrointestinal amyloidosis often present with weight loss and bleeding. In localized cases, all that underwent typing were due to lambda light chain amyloidosis and none progressed to systemic disease during the period of follow-up. Most patients with systemic disease had immunoglobulin light-chain, and their tolerance of therapy and median survival were excellent. Although a rare manifestation of amyloidosis, staining for amyloid should be considered in patients undergoing gastrointestinal biopsy who have unexplained chronic gastrointestinal symptoms.
There have been few reports of a response to dasatinib or nilotinib after failure of two prior sequential tyrosine kinase inhibitors. We report the outcome of 82 chronic phase patients who received nilotinib or dasatinib as third-line alternative tyrosine kinase inhibitor therapy. Thirty-four patients failed to respond to nilotinib and were started on dasatinib as third-line tyrosine kinase inhibitor therapy while 48 patients were switched to nilotinib after dasatinib failure. Overall, we obtained a cytogenetic response in 32 of 82 patients and major molecular response in 13 patients; disease progression occurred in 12 patients. At last follow up, 70 patients (85.4%) were alive with a median overall survival of 46 months. Our results show that third-line tyrosine kinase inhibitor therapy in chronic myeloid leukemia patients after failure of two prior sequential tyrosine kinase inhibitors may induce a response that, in some instances, could prolong overall survival and affect event-free survival.
Background. The treatment of choice in steroid-resistant immune thrombocytopenia is still controversial, due to the recent advent of new drugs (anti-CD20 antibodies and thrombopoietin mimetics) which have encouraged a generalized tendency to delay splenectomy. Consequently, the importance to define the efficacy and safety of splenectomy in the long-term is substantial. Patients and Methods. We retrospectively analyzed the data of 233 patients affected by immune thrombocytopenia, who underwent splenectomy between 1959 and 2001, in 6 European hematological Institutions and have now a minimum follow-up of 10 years from surgery. Results. Of the 233 patients, 180 (77%) achieved a complete response and 26 (11%) a response. Sixty-eight out of 206 (33%) responsive patients relapsed, mostly (75%) within 4 years from first response. In 92 patients (39.5%), further treatment was required after splenectomy, which was effective in 76 cases (83%). In 138 patients (59%) response was maintained, free of any treatment, at last contact. No significant association between baseline characteristics and likelihood of stable response was found. Overall, 73 (31%) and 58 (25%) patients experienced at least one infectious or hemorrhagic complication, which were fatal in 2 and 3 patients, respectively. A stable response to splenectomy was associated with a lower rate of infections (p=0.004) and hemorrhages (p<0.0001). Thrombosis developed in 18 patients (8%), fatal in 4. Conclusions. Splenectomy achieved a long-term stable responses in around 60% of cases. Complications mainly affected non-responding patients and were fatal in a minority of the cases.
Dietary iron absorption is regulated by hepcidin, an iron regulatory protein produced by the liver. Hepcidin production is regulated by iron stores, erythropoiesis and inflammation, but its physiology has not been characterized when repeated blood loss occurs. Hepcidin was measured in plasma samples obtained from 114 first-time/reactivated (no blood donations in prior 2 years) female donors and 34 frequent (≥3 red blood cell donations in prior 12 months) male donors as they were phlebotomized ≥4 or more times over 18-24 months. Hepcidin was compared to ferritin and hemoglobin using multivariable repeated measures regression models. Hepcidin, ferritin and hemoglobin declined with increasing frequency of donation in the first-time/reactivated females. Hepcidin and ferritin correlated well with each other (Spearman correlation of 0.74), but on average hepcidin varied more between donations for a given donor relative to ferritin. In a multivariable repeated measures regression model the predicted inter-donation decline in hemoglobin varied as a function of hepcidin and ferritin; hemoglobin was 0.51 g/dL lower for subjects with low (≤45.7 ng/ml) or decreasing hepcidin and low ferritin (≤26 ng/ml), and was essentially zero for other subjects including those with high (>45.7 ng/ml) or increasing hepcidin and low ferritin (≤26 ng/ml) (p<0.001). Hepcidin rapidly changes in response to dietary iron needed for erythropoiesis. The dynamic regulation of hepcidin in the presence of low ferritin suggests that plasma hepcidin may provide clinically useful information about an individual's iron status (and hence capacity to tolerate repeated blood donations) beyond that of ferritin alone.
Recent studies suggest that leukocytes and erythrocytes play a role in coagulation. However, whether leukocytes, erythrocytes and other hematological variables are associated with risk of venous thrombosis is not well known. To study this, we used data from 2473 venous thrombosis patients and 2935 controls. The variables assessed were: total leukocytes, granulocytes, lymphocytes, monocytes, hematocrit, hemoglobin, erythrocytes and red cell indices (mean corpuscular volume, mean hemoglobin volume, mean corpuscular hemoglobin volume and red cell distribution width). We found a strong dose-response relation for higher red cell distribution width and monocytes with risk of venous thrombosis, with odds ratios of 3.1 (95% confidence interval, 2.0-4.8) and 2.8 (95% confidence interval, 1.3-5.8), respectively, after adjustment for age, sex, C-reactive protein, malignancy and co-morbidities. Monocyte count and red cell distribution width were associated with venous thrombosis even within reference ranges. A low monocyte count (< 0.12x109/L) was associated with a lower venous thrombosis risk after full adjustment (odds ratios 0.6; 95% confidence interval, 0.4-0.8). In summary, high red cell distribution width and blood monocytes, two unexpensive and easily obtainable tests were clearly associated with an increased risk of venous thrombosis. Future studies should evaluate the underlying mechanism and the use of these variables in prediction models for first and recurrent thrombosis.
The prognosis for fit patients with mantle cell lymphoma has improved with intensive strategies. Currently, the role of maintenance/consolidation approaches is being tested as relapses continue appearing. In this trial we evaluated the feasibility, safety and efficacy of R-Hyper-CVAD alternating with R-MtxAraC followed by consolidation with 90Y-Ibritumomab-Tiuxetan. Patients received 6 cycles followed by a single dose of 90Y-Ibritumomab-Tiuxetan. Thirty patients were enrolled. Median age was 59 years. Twenty four patients finished the induction treatment, 23 achieved complete remission (77%, 95% confidence interval 60-93) and one patient had progressive disease (3%). Eighteen patients (60%), all in complete remission, received consolidation. In the intent- to- treat population, failure free, progression free and overall survival at 4 years were 40 % (95% confidence interval 20.4-59.6), 52% (95% confidence interval 32.4-71.6) and 81% (95% confidence interval 67.28-94.72), respectively. For patients who received consolidation, failure free and overall survival were 55% (95% confidence interval 31.48&-78.52) and 87% (95% confidence interval 70-100), respectively. Hematological toxicity was significant during induction and responsible for one death (3.3%). After consolidation, grade 3-4 neutropenia and thrombocytopenia were observed in 72% and 83% of patients, with median duration of 5 and 12 weeks, respectively. Six (20%) patients died, 3 due to secondary malignancies (myelodisplastic syndrome and bladder and rectum carcinomas). In conclusion, our experience with R-Hyper-CVAD/R-MtxAraC followed by consolidation with 90Y-Ibritumomab-Tiuxetan is efficacious although less feasible than expected. The unacceptable toxicity observed, specially secondary malignancies, advise against the indication of this strategy. Trial registration: clinical.gov identifier: NCT2005-004400-37.
We previously reported that bone marrow grafts from matched sibling donors resulted in best graft-versus-host disease-free, relapse-free survival at 1-year post allogeneic hematopoietic cell transplantation. However, pediatric patients comprised the majority of bone marrow graft recipients in that study. To better define this outcome in adults and pediatric patients at 1- and 2-years post- allogeneic hematopoietic cell transplantation, we pooled data from University of Minnesota and Hopital Saint-Louis in Paris, France (n=1901). Graft-versus-host disease-free, relapse-free survival was defined as absence of grade III-IV acute graft-versus-host disease, chronic graft-versus-host disease (requiring systemic therapy or extensive stage), relapse and death. In adults, bone marrow from matched sibling donors (n=123) had best graft-versus-host disease-free, relapse-free survival at 1- and 2-years, compared with peripheral blood stem cell from matched sibling donors (n=540) or other graft/donor types. In multivariate analysis, peripheral blood stem cell from matched sibling donors resulted in a 50% increased risk of events contributing to graft-versus-host disease-free, relapse-free survival at 1- and 2-years than bone marrow from matched sibling donors. With limited numbers of peripheral blood stem cell grafts in pediatric patients (n=12), graft-versus-host disease-free, relapse-free survival did not differ between bone marrow and peripheral blood stem cell graft from any donor. While not all patients have a matched sibling donor, graft-versus-host disease-free, relapse-free survival may be improved by preferential use of bone marrow for adults with malignant diseases. Alternatively, novel graft-versus-host disease prophylaxis regimens are needed to substantially impact graft-versus-host disease-free, relapse-free survival with the use of peripheral blood stem cell.
Evaluation of Xagrid® Efficacy and Long-term Safety, a Phase IV, prospective, non interventional study performed in 13 European countries enrolled high risk essential thrombocythemia patients treated with cytoreductive therapy. Primary objectives were safety and pregnancy outcomes. Of 3721 registered patients, 3649 received cytoreductive therapy. At registration, 3611 were receiving: anagrelide (Xagrid®) (n=804), other cytoreductive therapy (n=2666), anagrelide + other cytoreductive therapy (n=141). Median age was 56 vs 70 years for anagrelide vs other cytoreductive therapy. Event rates (patients with events/100 patient years) were, for total thrombosis 1.62 vs 2.06, venous thrombosis 0.15 vs 0.53. Anagrelide was more commonly associated with hemorrhage (0.89 vs 0.43), especially with anti-aggregatory therapy (1.35 vs 0.33) and myelofibrosis (1.04 vs 0.30). Other cytoreductive therapies were more associated with acute leukemia (AL) (0.28 vs 0.07) and other malignancies (1.29 vs 0.44). Post-hoc multivariate analyses identified increased risk for thrombosis with prior thrombohemorrhagic events, age ≥65, cardiovascular risk factors, or hypertension. Risk factors for transformation were prior thrombohemorrhagic events, age ≥65, time since diagnosis, and platelet count increase. Safety analysis reflected published data and no new safety concerns for anagrelide were found. Live births occurred in 41/54 pregnancies (76%). (ClinicalTrials.gov #NCT00567502).
Autologous transplantation is controversial for older patients with multiple myeloma. The role of age-adjusted high-dose melphalan and the impact of induction chemotherapy cycles is still unclear. A total of 434 patients aged 60-70 years were randomly assigned to 4 cycles of standard anthracycline-based induction chemotherapy or no induction. For all patients, double autologous transplantation after melphalan 140 mg/m(2) (MEL140) was planned. The primary end point was progression-free survival. Of 420 eligible patients, 85% received a first transplant and 69% completed double transplantation. Treatment duration was short with a median of 7.7 months with induction chemotherapy cycles and 4.6 months without induction. On an intention-to-treat basis, median progression-free survival with induction chemotherapy cycles (207 patients) was 21.4 months versus 20.0 months with no induction cycles (213 patients) (hazard ratio 1.04, 95% confidence interval 0.84-1.28; P=0.36). Per protocol, progression-free survival was 23.7 months versus 23.0 months (P=0.28). Patients aged 65 years or over (55%) did not have an inferior outcome. Patients with low-risk cytogenetics [absence of del17p13, t(4;14) and 1q21 gains] showed a favorable overall survival and included the patients with sustained first remission. MEL140 was associated with a low rate of severe mucositis (10%) and treatment-related deaths (1%). Based on hazard ratio, the short treatment arm consisting of mobilization chemotherapy and tandem MEL140 achieved 96% of the progression-free survival, demonstrating its value as an independent component of therapy in older patients with multiple myeloma who are considered fit for autologous transplantation. (clinicaltrials.gov identifier: 02288741).