Hematopoietic stem cell transplantation activity worldwide in 2012 and a SWOT analysis of the Worldwide Network for Blood and Marrow Transplantation Group including the global survey

Data on 68 146 hematopoietic stem cell transplants (HSCTs) (53% autologous and 47% allogeneic) gathered by 1566 teams from 77 countries and reported through their regional transplant organizations were analyzed by main indication, donor type and stem cell source for the year 2012. With transplant rates ranging from 0.1 to 1001 per 10 million inhabitants, more HSCTs were registered from unrelated 16 433 donors than related 15 493 donors. Grafts were collected from peripheral blood (66%), bone marrow (24%; mainly non-malignant disorders) and cord blood (10%). Compared with 2006, an increase of 46% total (57% allogeneic and 38% autologous) was observed. Growth was due to an increase in reporting teams (18%) and median transplant activity/team (from 38 to 48 HSCTs/team). An increase of 167% was noted in mismatched/haploidentical family HSCT. A Strengths, Weaknesses, Opportunities, Threats (SWOT) analysis revealed the global perspective of WBMT to be its major strength and identified potential to be the key professional body for patients and authorities. The limited data collection remains its major weakness and threat. In conclusion, global HSCT grows over the years without plateauing (allogeneic>autologous) and at different rates in the four World Health Organization regions. Major increases were observed in allogeneic, haploidentical HSCT and, to a lesser extent, in cord blood transplantation.

Primary graft failure after myeloablative allogeneic hematopoietic cell transplantation for hematologic malignancies

Clinical outcomes after primary graft failure (PGF) remain poor. Here we present a large retrospective analysis (n=23,272) which investigates means to prevent PGF and early detection of patients at high risk. In patients with hematologic malignancies, who underwent their first myeloablative allogeneic hematopoietic cell transplantation, PGF was reported in 1,278 (5.5%), and there was a marked difference in PGFs using peripheral blood stem cell compared to bone marrow grafts (2.5 vs. 7.3%; P<0.001). A 4-fold increase of PGF was observed in myeloproliferative disorders compared to acute leukemia (P<0.001). Other risk factors for PGF included recipient age below 30, HLA-mismatch, male recipients of female donor grafts, ABO-incompatibility, busulfan/cyclophosphamide conditioning, and cryopreservation. In bone marrow transplants, total nucleated cell doses ≤2.4 × 10⁸/kg were associated with PGF (OR 1.39; P<0.001). The use of tacrolimus-based immunosuppression and granulocyte colony-stimulating factor were associated with decreased PGF risk. These data, allow clinicians to do more informed choices with respect to graft source, donor selection, conditioning and immunosuppressive regimens to reduce the risk of PGF. Moreover, a novel risk score determined on day 21 post-transplant may provide the rationale for an early request for additional hematopoietic stem cells.

Effects of spleen status on early outcomes after hematopoietic cell transplantation

To assess the impact of spleen status on engraftment, and early morbidity and mortality after allogeneic hematopoietic cell transplantation (HCT), we analyzed 9,683 myeloablative allograft recipients from 1990 to 2006; 472 had prior splenectomy (SP), 300 splenic irradiation (SI), 1,471 with splenomegaly (SM), and 7,440 with normal spleen (NS). Median times to neutrophil engraftment (NE) and platelet engraftment (PE) were 15 vs 18 days and 22 vs 24 days for the SP and NS groups, respectively (P<0.001). Hematopoietic recovery at day +100 was not different across all groups, however the odds ratio of days +14 and +21 NE and day +28 PE were 3.26, 2.25 and 1.28 for SP, and 0.56, 0.55, and 0.82 for SM groups compared to NS (P<0.001), respectively. Among patients with SM, use of peripheral blood grafts improved NE at day +21, and CD34+ cell dose >5.7 × 10(6)/kg improved PE at day+28. After adjusting variables by Cox regression, the incidence of GVHD and OS were not different among groups. SM is associated with delayed engraftment, whereas SP prior to HCT facilitates early engraftment without having an impact on survival.

Central Venous Catheter-related Complications in Patients with Hematological Malignancies: A Retrospective Analysis of Risk Factors and Prophylactic Measures

We retrospectively analyzed the incidence of thrombotic and infectious complications in relation with the use of central venous catheters (CVCs), in a series of patients with hematological malignancies and low platelet and leucocyte counts.

PATIENTS AND METHODS

126 patients with hematological malignancies were analyzed. A total of 207 CVCs were implanted: 137 centrally (CICCs) and 70 peripherally (PICCs). The median duration of the CVCs was 19 days for a total of 4051 catheter-days. Antithrombotic prophylaxis was unfractionated heparin (UFH), 2,500 IU daily by 24 h continuous infusion in 169 CVCs, low molecular weight heparin (LMWH), 3,800 IU daily by single bolus intravenous injection (i.v.) in 21 and warfarin in one. No prophylaxis was given in 16 CVCs. Thrombotic complications developed in 15.5% of the CVCs (7.9 events/1000 catheter days), and the frequency of infectious complications was 10.6% (5.2 events/1000 catheter days). On multivariate analysis thromboses were more frequent and earlier with PICCs than CICCs (p = 0.0001), and in patients on UFH (16.6%) than in LMWH prophylaxis (4.7%), but the last difference was not statistically significant. In conclusions the incidence of thrombotic complications in our series was comparable to that observed in non-thrombocytopenic patients and was significantly higher in those carrying PICC than CICC (p = 0.0001). There were fewer thrombotic events in the patients receiving i.v. LMWH prophylaxis than in those receiving i.v. UFH. The use of anticoagulants was safe and not associated with hemorrhages.

Endothelial precursors and mature endothelial cells are increased in the peripheral blood of myelodysplastic syndromes

Increased angiogenesis has been demonstrated to be a significant prognostic factor in many solid tumors. In the oncohematological setting, it has been associated with myelodysplastic syndromes (MDS), chronic myeloid leukemia, acute lymphoid, and myeloid leukemias. Recently, increased circulating endothelial cells (CECs) have been associated with breast cancer and non-Hodgkin lymphoma (NHL). Based on these premises we analysed total and activated CECs, and endothelial precursors (CEPs) in 50 MDS patients and 20 healthy donors. CECs and CEPs were quantified by flow cytometry. CEC levels were compared with bone marrow (BM) microvessel density (MVD). In addition, some angiogenic factors, namely vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF) and soluble VEGF-Receptor2 (VEGFR2), were tested in the sera from 25 MDS patients. Total, activated CECs and CEPs were significantly increased in MDS when compared to control group (p<0.0001); whereas in the MDS cases no association was found with French--American--British (FAB), International Prognostic Scoring System (IPSS) subtypes or survival. Patients with higher CECs also showed higher MVD. Among the cytokines analysed, sVEGFR2 was significantly higher in the lower IPSS risk classes, while the levels of bFGF directly correlated with total and activated CECs. Taken together these data strengthen the hypothesis of a possible role of angiogenesis in MDS pathogenesis.

Cure of multiple myeloma -- more hype, less reality

Randomized studies have firmly established the role of autologous transplant as initial therapy in multiple myeloma (MM). Indeed, MM has emerged as the commonest indication for autologous SCT in North America. The conceptual basis for high-dose therapy is the goal of complete remission (CR) through steep reduction in tumor burden affected by single and tandem transplants. Careful analysis of the data challenges the notion of CR as a surrogate to success. Intrinsically aggressive MM, defined by known unfavorable biologic risk factors, overrides the benefit of CR. In contrast, subgroups of patients with favorable biological risk factors may achieve prolonged survival, often without ever achieving CR. Unfortunately, even with tandem transplants, there is no plateau in survival curves. To this end, sequential autologous followed by nonmyeloablative allotransplants are a novel attempt at 'curing' myeloma, but the results thus far have failed to show a definite plateau in survival. Given the improvements in supportive care and concomitant reduction in transplant-related mortality, conventional myeloablative allogeneic transplants need to be re-examined as an option in high-risk aggressive myeloma. At the same time, novel antimyeloma therapies, newer risk stratification and staging tools are transforming the treatment algorithm. We examine the changing role of transplantation in myeloma in the context of novel drug therapy, biologic risk stratification and improving supportive care while arguing that the current 'one size fits all' transplant approaches are far from a cure.