Essential requirements for setting up a stem cell processing laboratory.

The Graft Processing subcommittee of the Worldwide Network for Blood and Marrow Transplantation wrote this guideline to assist physicians and laboratory technologists with the setting up of a cell processing laboratory (CPL) to support a hematopoietic stem cell transplant program, thereby facilitating the start-up of a transplant program in a new location and improving patient access to transplantation worldwide. This guideline describes the minimal essential features of designing such a laboratory and provides a list of equipment and supply needs and staffing recommendations. It describes the typical scope of services that a CPL is expected to perform, including product testing services, and discusses the basic principles behind the most frequent procedures. Quality management (QM) principles specific to a CPL are also discussed. References to additional guidance documents that are available worldwide to assist with QM and regulatory compliance are also provided.

Impact of extracorporeal photopheresis on skin scores and quality of life in patients with steroid-refractory chronic GVHD.

There are few prospective studies evaluating the role of extracorporeal photopheresis (ECP) in chronic GVHD (cGVHD) and only occasional reports of the effect of ECP on patients' quality of life (QoL). We report a single-centre prospective study of patients undergoing fortnightly ECP for moderate or severe cGVHD. Response was assessed after 6 months of treatment using NIH scoring criteria and reduction in immunosuppression. QoL assessments were undertaken at baseline and at 6 months using the chronic GVHD symptom scale (cGVHD SS) and dermatology life quality index (DLQI). An intention-to-treat analysis showed that 19/38 (50%) of patients had a complete or partial response. Twenty-seven out of 38 patients completed 6 months of ECP treatment and 70% (19/27) had a complete or partial response. Eighty per cent of patients who completed 6 months of ECP treatment had a reduction in immunosuppression dose. A subset of patients completed QoL questionnaires. Seventeen out of 18 patients (94%) showed an improvement in scores. The mean cGVHD SS and mean DLQI score were both significantly lower after 6 months of ECP (22 compared with 36, P=0.012 and 3.4 compared with 6.9, P=0.009, respectively). This study confirms that ECP can lead to objective clinical responses and, in addition, may lead to an improvement in QoL in cGVHD.

Retrospective study of alemtuzumab vs ATG-based conditioning without irradiation for unrelated and matched sibling donor transplants in acquired severe aplastic anemia: a study from the British Society for Blood and Marrow Transplantation.

This retrospective national study compared the use of alemtuzumab-based conditioning regimens for hematopoietic SCT (HSCT) in acquired severe aplastic anemia with antithymocyte globulin (ATG)-based regimens. One hundred patients received alemtuzumab and 55 ATG-based regimens. A matched sibling donor (MSD) was used in 87 (56%), matched unrelated donor (MUD) in 60 (39%) and other related or mismatched unrelated donor (UD) in 8 (5%) patients. Engraftment failure occurred in 9% of the alemtuzumab group and 11% of the ATG group. Five-year OS was 90% for the alemtuzumab and 79% for the ATG groups, P=0.11. For UD HSCT, OS of patients was better when using alemtuzumab (88%) compared with ATG (57%), P=0.026, although smaller numbers of patients received ATG. Similar outcomes for MSD HSCT using alemtuzumab or ATG were seen (91% vs 85%, respectively, P=0.562). A lower risk of chronic GVHD (cGVHD) was observed in the alemtuzumab group (11% vs 26%, P=0.031). On multivariate analysis, use of BM as stem cell source was associated with better OS and EFS, and less acute and cGVHD; young age was associated with better EFS and lower risk of graft failure. This large study confirms successful avoidance of irradiation in the conditioning regimens for MUD HSCT patients.

Characterization of hemopoietic engraftment kinetics and development of secondary cytopenia in AML post auto-SCT and its correlation with survival outcome.

We performed a single center retrospective analysis of 84 autologous hemopoietic stem cell transplants done for AML to characterize the pattern of hemopoietic engraftment, post-transplant cytopenia and their impact on survival outcome. Following autologous transplant and engraftment, 30 patients (35.7%) had a transient secondary decline in their plt counts, which was not associated with graft rejection, relapse or infection. The median time to onset of thrombocytopenia was 59 days post transplant, with spontaneous recovery after a median period of 41 days. A secondary decline in ANC also occurred in eight patients. Patients with secondary plt decline had a significantly earlier primary plt engraftment (median 15 days) and a trend towards earlier neutrophil engraftment compared with patients who maintained steady plt counts (median 21 days). There was a trend towards a lower incidence of secondary plt decline in patients who received BM stem cells compared with those who received PBSC. No cause was evident for the occurrence of a secondary cytopenia, and it did not adversely affect survival. We conclude that secondary cytopenia is a common and harmless occurrence after autologous transplant especially from PBSC graft.

Blood transfusion requirements and independent predictors of increased transfusion requirements among adult patients on extracorporeal membrane oxygenation -- a single centre experience.

BACKGROUND/OBJECTIVES: More adults undergo extracorporeal membrane oxygenation (ECMO) now. They have high transfusion requirements. This study described transfusion requirements of adults during ECMO in a single institution, and determined factors associated with high transfusion requirements. MATERIALS/METHODS: Retrospective analysis was done on the amount of blood products received by adults during ECMO. Predictors of increased average daily transfusion requirements during ECMO and increased ECMO duration (which correlated positively with total transfusion requirements) were determined. RESULTS: Forty-one patients (median age 50 years) underwent 42 ECMO sessions for respiratory failure (16.7%), cardiogenic shock (76.2%) or massive pulmonary embolism (7.1%). They received 569 red blood cells, 852 platelets, 126 fresh-frozen plasma (FFP) and 220 cryoprecipitate in total during median ECMO duration of 5 (1-15) days. On multivariate analysis, average daily red blood cell transfusion increased with nadir haemoglobin (Hb) during ECMO (Hb(nadir)) of < 7.5 g/dl (P < 0.001). Average daily platelet transfusion increased with recent antiplatelet agents (P = 0.015) and maximum Hb decline of > 5.5 g/dl during ECMO (P = 0.011). Average daily platelet transfusion > 3 units was also associated with increased ECMO duration (P = 0.024). Average daily FFP transfusion was increased in patients with hypertension (P = 0.007) and Hb(nadir) < 7.5 g/dl (P = 0.050). Patients with sepsis (P = 0.009) or without surgery (P = 0.009) had increased ECMO duration, which correlated positively with total transfusion requirements during the entire ECMO session. ECMO improved mortality of patients with fulminant myocarditis, respiratory failure and massive pulmonary embolism. CONCLUSION: Adult ECMO patients with lower Hb(nadir) require more daily red blood cell and FFP. Hypertension increases daily FFP requirements. Recent antiplatelet agents, larger Hb decline and longer ECMO duration increase daily platelet requirements. Patients with sepsis or on ECMO for medical reasons have longer ECMO duration, which is associated with total transfusion requirements. Some of these factors may be identified early to optimize blood product support.

The management of perioperative bleeding.

Excess perioperative bleeding remains a major complication following surgery, resulting in increased morbidity and mortality. The principal causes of non-surgical haemostatic perioperative bleeding are a pre-existing undetected bleeding disorder, related to the nature of the operation itself or from coagulation abnormalities arising from massive blood loss. Very often, it is a combination and coexistence of various pathologies. Identifying patients at risk remains a major component of preventing excessive blood loss. Understanding the haemostatic changes occurring in the perioperative period, especially in complex procedures like cardiopulmonary bypass and orthotopic liver transplantation is crucial in developing new strategies for the management of perioperative bleeding. Pharmacological interventions, especially aprotinin, tranexamic acid, desmopressin and increasingly, recombinant VIIa are being used both in prophylaxis and therapeutically to stop bleeding. The use of near patient testing like thromboelastography and platelet function analyser has allowed for more detailed assessment of the various steps of haemostasis. One of the main goals is to reduce the usage of allogeneic blood transfusion and its attendant risks.

Cytomegalovirus-specific cellular immune responses and viremia in recipients of allogeneic stem cell transplants.

The immune suppression inherent in allogeneic stem cell transplantation (SCT) offers a favorable environment for infection by opportunistic agents, such as human cytomegalovirus (CMV). Despite the application of potent antiviral prophylaxis, patients remain at risk for CMV infection until adequate immunity is restored. CMV-specific CD8(+) T cell counts were monitored, using HLA-A2 tetrameric complexes, to establish the level of immune response to the viral phosphoprotein UL83 in patients after allogeneic SCT. Correlating this with viral replication and clinical status shows that the level of tetramer-positive T cells provides an assessment of CMV immune reconstitution after stem cell transplantation. Most patients with seropositive donors did reconstitute long-term CMV immunity, unless prolonged immunosuppression to control graft-versus-host disease was induced. Together with polymerase chain reaction testing, this technique provides measurable parameters that can be a guide to therapeutic decision making and can form the basis of CMV immunotherapy.

Immunotherapy of AML: future directions.

Immunotherapy in the form of allogeneic GvL has been curing AML patients for nearly 30 years but our understanding of the mechanisms has been poor. Our rapidly evolving understanding of the human immune system and the concomitant technical developments in ex vivo cell manipulation, the vision of funding bodies, the dedication of clinical and research staff, and above all the commitment of our patients, promise substantial progress in the treatment of this disease in the year 2000 and beyond.

Selective removal of alloreactive cells from haematopoietic stem cell grafts: graft engineering for GVHD prophylaxis.

One of the main goals in allogeneic bone marrow transplantation is the abrogation of graft-versus-host disease with the preservation of antileukaemia and antiviral activity. We have established a novel system for the selective removal of alloreactive lymphocytes from donor grafts while retaining an effective allogeneic response to third-party stimulator cells. Initial feasibility studies were done with unrelated HLA-mismatched pairs and then extended into the matched setting. Mononuclear cells from HLA-matched donors were cocultured with irradiated recipient cells prestimulated with cytokines (gamma-IFN and TNF-alpha) in a modified mixed lymphocyte culture (MLC). Alloreactive donor lymphocytes were identified by expression of CD69, an early activation marker and selectively removed by paramagnetic bead sorting. The remaining 'non-alloreactive' lymphocytes were tested in proliferative assays against the original matched recipient and to a third-party donor. A mean depletion of proliferative capacity to 11.5 +/- 9.9% of the original matched recipient response was achieved while the residual third-party response was largely preserved at 77.8 +/- 20.9% which should translate into improved immune reconstitution and preservation of antiviral activity. The non-alloreactive lymphocytes could also possess functional antileukaemia activity. Moreover, the alloreactive cells are easily recoverable in this selective T cell depletion strategy for cryopreservation and ready for immediate access as therapeutic donor lymphocyte infusions in cases of frank relapse post transplant.