Autologous CD34+ enriched peripheral blood progenitor cell (PBPC) transplantation is associated with higher morbidity in patients with lymphoma when compared to unmanipulated PBPC transplantation

High-dose rituximab does not negatively affect peripheral blood stem cell mobilization kinetics in patients with intermediate-grade non-Hodgkin's lymphoma

Rituximab, an anti-CD20 human-mouse chimeric monoclonal antibody has been shown to improve response rates when it is combined with standard salvage chemotherapy in patients with relapsed or refractory intermediate-grade B-cell non-Hodgkin's lymphoma. A vast majority of these patients subsequently undergo high-dose therapy followed by stem cell transplantation. However, the impact of rituximab on stem cell mobilization kinetics is not well characterized. The purpose of this study was to study the effect of high-dose rituximab given with chemotherapy on stem cell mobilization in patients with intermediate-grade B-cell non-Hodgkin's lymphoma. Thirty-six patients received ifosfamide, etoposide, and rituximab followed by filgrastim for stem cell mobilization. The chemotherapy regimen was well tolerated. Thirty-four of 36 patients (94%) were able to mobilize at least 2 x 10(6) CD34+ cells/kg body weight after a median of 2 apheresis procedures. The median CD34+ cell dose collected per kilogram of recipient body weight was 6.5 x 10(6) (range, 4.65-31.15). All patients who subsequently underwent high-dose chemotherapy and stem cell transplantation experienced sustained engraftment. In conclusion, high-dose rituximab given during stem cell mobilization does not negatively affect stem cell mobilization kinetics.

Overnight storage of autologous stem cell apheresis products before cryopreservation does not adversely impact early or long-term engraftment following transplantation

To reduce costs and avoid inconvenient overtime work, our institution changed policy in September 2000 so that autologous stem cell apheresis products were stored overnight before cryopreservation rather than immediately processed. This retrospective review was conducted to evaluate the possible impact of this policy change on hematopoietic engraftment following autologous stem cell transplantation (ASCT). In total, 229 consecutive lymphoma patients who underwent a single, unpurged ASCT in Calgary between January 1995 and November 2003 were evaluated. Of these patients, 131 patients' autografts underwent immediate processing and cryopreservation before September 2000, and 98 patients' autografts underwent next-day cryopreservation after overnight storage following this date. Results of univariate and multivariate analyses demonstrated no adverse effect of overnight storage before cryopreservation on the number of days to initial engraftment of platelets or neutrophils, on the proportion of patients with low blood counts 6 months post-ASCT, or on lymphoma relapse rates or overall survival post-ASCT. These data suggest that overnight storage of the autograft before cryopreservation does not adversely affect graft viability or influence long-term disease status, and support the continued use of overnight storage of stem cells before cryopreservation as a convenient, cost reduction measure.

Infections after CD34-selected or unmanipulated autologous hematopoietic stem cell transplantation

Immune reconstitution may be delayed after CD34-selected compared with unmanipulated autologous peripheral blood stem cell transplantation (PBSCT), resulting in a theoretically increased risk of infections. In a case-control matched study we compared the incidence of infection in 25 recipients of CD34-selected PBSC (CD34 group) and 75 recipients of unmanipulated PBSC (PBSC group) transplants. The population included 52 males and 48 females suffering from non-Hodgkin's lymphoma (n = 32), Hodgkin's disease (n = 8), multiple myeloma (n = 40) or breast cancer (n = 20). Neutrophil engraftment was comparable in the two groups. The actuarial incidence of infection was similar in the two groups (56% vs. 49% at day 30, and 70% vs. 64% at 1 yr respectively). The proportion of patients with 1, 2 or 3 infections, the number of infectious event per patient (1.32 vs. 1.04; NS), the number of infections before day 15 or 30, between days 31 and 100 or after day 100, the risk of varicella-zoster virus or cytomegalovirus infection or disease, or the use of antibiotic or antifungal therapy, were not increased in the CD34 compared with the PBSC group. The main agents responsible for infection were bacteria, particularly gram-positive cocci, in both groups. Bacteremia accounted for 33% of all infectious events in the CD34 group vs. 16% in the PBSC group (P < 0.05). Fungal infections were rare. In conclusion, our results do not support the notion that CD34-selection of the graft is associated with an increased rate of infection after autologous PBSC transplantation. The role of extended infection prophylaxis should be evaluated.

Randomised comparison of two B-cell purging protocols for patients with B-cell non-Hodgkin lymphoma: in vivo purging with rituximab versus ex vivo purging with CliniMACS CD34 cell enrichment device

We investigated the feasibility, safety and efficacy of two B-cell purging methods in patients with CD20+ non-Hodgkin lymphoma (NHL) receiving autologous stsem cell transplantation. Myeloid and immune recoveries between the methods were compared. Twenty-seven patients were randomised to either in vivo purging with rituximab or ex vivo purging by CD34+ cell selection. Both purging methods were efficient at eliminating B-cells in infusates. When compared with in vivo purging, ex vivo purging was associated with CD34+ cell loss and delayed median neutrophil (10 d vs. 11 d) and platelet (12.5 d vs. 17 d) count recoveries. Lymphocyte recovery was similar in both groups, but immunoglobulin recovery was delayed after in vivo purging. Late-infectious complications were few in both arms. At a median follow-up of 27 months, 2-year probabilities of event-free survival (EFS) rates were 81% for in vivo purging and 76% for ex vivo purging (P = 0.66). When compared with 53 unpurged patients, all 27 purged patients had improved 3-year probabilities of overall survival (89% vs. 70%, P = 0.014) and a trend for improved EFS (78% vs. 57%, P = 0.075). In conclusion, although both purging methods were feasible and safe, rituximab purging was superior as it did not impair CD34+ cell mobilisation and was associated with faster myeloid recovery. Further studies are needed to determine whether rituximab purging is more effective than the use of unpurged autografts.

Isolation and transplantation of highly purified autologous peripheral CD34+ progenitor cells: purging efficacy, hematopoietic reconstitution in non-Hodgkin's lymphoma (NHL): results of Japanese phase II study

The purging efficacy of positive selection of autologous CD34+ PBSC with a clinical scale method of magnetic-activated cell sorting system (CliniMACS) was investigated in 48 patients with non-Hodgkin's lymphoma (NHL). The median purity and recovery rate of the CD34+ cells post-selection were 93.3% (range 32.6-99.3) and 72.2% (range 20.5-309.8), respectively. The real-time PCR method to detect the patient-specific monoclonal immunoglobulin heavy chain gene rearrangement (minimal residual tumor; MRT) and CD19 and CD20 positivities were used for the detection of contaminating NHL cells before and after CD34+ selection. After selection, the median (range) depletion rate of MRT was 2.53 (1.52-4.78) log, and that of CD19+ cell and CD20+ cell was 2.46 (0.74-3.64) log and 2.32 (0.40-4.01) log, respectively. In 41 patients, high-dose chemotherapy was performed, followed by the transplantation of the isolated CD34+ cells. Rapid neutrophil recovery as well as platelet recovery was seen with a median time to reach 0.5 x 10(9)/l neutrophils of 10 days (range 8-13) and 20 x 10(9)/l platelets of 14 days (range 10-34), respectively. The present study demonstrated that CliniMACS is a highly effective positive selection method and a high purging efficacy could be obtained without compromising the hematopoietic reconstitution capacity of the graft in NHL patients undergoing high-dose chemotherapy.

Isolation and transplantation of highly purified autologous peripheral CD34+ progenitor cells: purging efficacy, hematopoietic reconstitution following high dose chemotherapy in patients with breast cancer: results of a feasibility study in Japan

BACKGROUND

High-dose chemotherapy with autologous stem cell support may have some therapeutic impact on certain groups of the patients with advanced breast cancer(BRCA). Since stem cell contamination by tumor cells might contribute to relapse, development of a tumor cell purging technique would improve the clinical outcome. The present study was undertaken to evaluate the purging efficacy of autologous mobilized CD34+peripheral stem cells in patients with breast cancer (BRCA) in an advanced stage or relapse.

METHODS

CD34+cells were selected from autologous peripheral blood stem cells (PBSC) using a clinical scale of magnetic-activated cell sorting system (CliniMACS), followed by high-dose chemotherapy with transplantation of CD34+ selected cells. Amplification of cytokeratin 19 (CK19) and 20 (CK20) gene in leukapheresis products were measured to evaluate the performance of tumor cell elimination.

RESULTS

Seven patients were entered into this study. After leukopheresis, 1 patient was dropped form this study due to poor mobilization. Among 6 patient, a total of 8 CD34+ selection was performed. The median purity and recovery rate of the CD34+ cells post selection was 85.1% (range 62.5-98.1%) and 74.2% (range 50.2-90.2%), respectively. After isolation of CD34+cells, the elimination rate in the logarithmic transformation of CK19 was 2.77 log, and that of CK20 were 2.43 log and 2.53 log. In 4 patients, high-dose chemotherapy was performed, followed by the transplantation of the isolated CD34+cells. Rapid neutrophil recovery, as well as platelet recovery was seen with a median time to reach 0.5 x 109/l neutrophils of 9 days(range 8-9), and 20 x 109/l platelets of 12 days (range 10-13). There was no treatment related death and no serious adverse events directly associated with the selection procedure or infusion of selected cells.

CONCLUSIONS

The present study demonstrated that the CliniMACS system is a highly effective positive selection method and that a high purging efficacy could be obtained without compromising the hematopoietic reconstitution capacity of the graft in BRCA patients undergoing high-dose chemotherapy.

Evaluation of potential risk factors for early infectious complications after autologous peripheral blood stem cell transplantation in patients with lymphoproliferative diseases

A number of risk factors for the occurrence of neutropaenic fever after haematopoietic stem cell transplantation (HSCT) have been proposed. We were interested in whether these factors remain valid for several early infection-related outcomes when applied to a homogeneous group of patients in uni- and multivariate analyses. Therefore, we analysed 144 consecutive patients with lymphoproliferative disorders receiving autologous peripheral blood HSCT. Variables tested as potential risk factors for the occurrence of fever, documented infection (DI), microbiologically documented infection (MDI) or failure of first-line antimicrobial therapy were sex, conditioning regimen, prolonged neutropaenia, low number of CD34+ cells transplanted, purging, lack of selective gut decontamination, higher age and increased body mass index. In uni- and multivariate analyses, conditioning including total body irradiation was the only risk factor for the occurrence of fever, and neutropaenia >or=10 days was the only factor associated with failure of first-line antimicrobial therapy. None of the variables tested was associated with an increased risk for DI or MDI. This analysis suggests that a number of previously proposed risk factors actually are of minor clinical relevance for early infections in the majority of patients receiving autologous HSCT.

A preliminary analysis of the balance between Th1 and Th2 cells after CD34+ cell-selected autologous PBSC transplantation

BACKGROUND

CD34+ cell-selected autologous PBSC transplantation (CD34+ APBSCT) is a procedure used for the treatment of patients with malignant disease that is intended to eliminate residual tumor cells from autologous grafts. However, frequent infectious complications after CD34+ APBSCT can occur. A delay of recovery of the absolute number of CD4+ T cells after transplantation was reported to be one disadvantageous factor. As data on T-cell function after CD34+ APBSCT are scanty, we analyzed changes in T-helper cell 1 (Th1) and T-helper cell 2 (Th2) after CD34+ APBSCT to evaluate immune reconstitution.

METHODS

Twelve patients underwent APBSCT (CD34+APBSCT group, n=4, and unselected APBSCT, n=8). Peripheral blood (PB) samples were obtained at 2, 4, 8, 12 and 16 weeks after the transplantation. The dynamics of the Th1 and Th2 were analyzed at a single-cell level, using flow cytometry.

RESULTS

In the CD34+ APBSCT group, not only the absolute count of CD4+ T cells but also the proportion of Th1 cells in CD4+ T cells and the ratio of Th1 to Th2 after transplantation were significantly decreased at 2 and 4 weeks after transplantation compared with findings in the unselected APBSCT group.

DISCUSSION

We suggest that higher rates of infectious complications after CD34+ APBSCT may be due to the inability of residual T cells from the CD34+ cell selection to generate mature T cells that function adequately against infection. Although further study would be required, our preliminary data provide some information on the immune reconstitution after CD34+ APBSCT and differentiation of T lymphocytes into Th1 and Th2 in vivo.

Peripheral blood stem cell mobilization following CHOP plus rituximab therapy combined with G-CSF in patients with B-cell non-Hodgkin's lymphoma

We mobilized peripheral blood stem cells (PBSC) following CHOP plus rituximab (CHOP-R) therapy, and compared with the findings following CHOP therapy without rituximab. All patients were given G-CSF starting from day 11 after CHOP therapy. Patients in the CHOP-R group (n=8) were given rituximab on day 12. Target CD34(+) cells number was collected in a single leukapheresis on day 14, from all the eight patients in the CHOP-R group. PBSC mobilization kinetics, CD34(+) cells yield and colony-forming ability in the graft collection, toxicity during mobilization, and engraftment after transplantation of CHOP-R group were not significantly different from those in the CHOP group (n=8). In all patients given CHOP-R therapy, CD20(+) cells and immunoglobulin heavy chain (IgH) rearrangement in the graft collection were undetectable by flow-cytometric analysis and Southern blot analysis, respectively, but with PCR analysis two of eight grafts were positive for IgH rearrangement. While further studies are needed to evaluate the efficacy of purging and the outcome of patients undergoing autologous transplantation, CHOP-R therapy can be safely and effectively used in the mobilization phase of PBSC collection, without excess clinical toxicity or deleterious effect on PBSC mobilization kinetics or engraftment time.

Hemopoietic Recovery and Infectious Complications in Breast Cancer and Multiple Myeloma after Autologous CD34+ Cell-Selected Peripheral Blood Progenitor Cell Transplantation

Autografting with CD34+ cell-selected peripheral blood progenitor cells (PBPC) is often associated with a prolonged recovery time and a higher incidence of infections. The aim of our study was to evaluate whether underlying disease influences hemopoietic recovery and the infectious complications occurring after transplantation. We studied 19 breast cancer (BC) patients and 17 multiple myeloma (MM) patients entered in a high-dose chemotherapy (HDC) program of tandem autografting with CD34+ cell-selected PBPC. PBPC were collected after mobilizing chemotherapy plus granulocyte colony-stimulating factor and were processed for selection of CD34+ cells. After selection, a median of 53% CD34+ cells was recovered with a median final purity of 92% with no significant differences between the MM (52% and 92%, respectively) and BC (53% and 89%, respectively) patients. Medians of 4.5 x 10(6)/kg CD34+ cells (BC, 4.4 x 10(6)/kg; MM, 5.4 x 10(6)/kg) and 18 x 10(4)/kg colony-forming units-granulocyte-macrophage (BC, 21 x 10(4)/kg: MM, 16 x 10(4)/kg) were reinfused after each HDC. Twenty-six patients (10 MM and 16 BC) underwent tandem autografting, and 10 patients received only 1 autograft because of inadequate collection (5 patients), clinical condition (3 patients), and refusal (2 patients). In the BC patients, the HDC regimen included a high-dose melphalan course followed by an ICE (ifosfamide, carboplatin, and etoposide) course. In the MM patients, the regimen consisted of a course of high-dose melphalan therapy and a course of ICBV (idarubicin, cyclophosphamide [Cytoxan], BCNU, and etoposide) or total body irradiation, etoposide, and Cytoxan. We found a significantly prolonged time for neutrophil recovery to > 500/microL in the MM patients (13 days versus 10 days; P < .002), whereas the times for platelet recovery to > 20,000/microL in the two groups were not different (13 days versus 12 days; not significant). No late engraftment failures and no toxic deaths were observed. The incidences of extrahematologic toxicity were similar for the two patient groups. All patients received similar anti-infection prophylaxis for 3 months after transplantation. After 12 months of observation, we found a statistically significant higher incidence of bacterial infections in MM patients in both the early (77.8% versus 48.6%; P < .034) and the late (41.1% versus 0%; P < .014) posttransplantation periods, whereas the incidences of fungal infections were similar in the two groups. Viral infections consisted of herpes zoster virus infection in 2 patients of each group, and cytomegalovirus infection was observed in 3 MM patients and no BC patients. Our experience demonstrates a prolonged neutrophil recovery time and higher incidences of bacterial and viral infections in MM patients compared with BC patients. These observations, although limited by the small sample size, suggest that the underlying disease may influence the incidence of infections after CD34- cell-selected transplantation and should be considered in the planning of appropriate antimicrobial prophylaxis in the autologous transplantation setting.

CD34+-selected versus unmanipulated autologous stem cell transplantation in multiple myeloma: impact on dendritic and immune recovery and on complications due to infection

BACKGROUND

Large-scale CD34+ enrichment has been demonstrated a safe method in autologous transplantation for multiple myeloma. However, the high CD34+ enrichment and the consequent plasma cell purging result in concomitant T-cell and dendritic-cell (DC) depletion, theoretically increasing the risk of life-threatening infections.

PATIENTS AND METHODS

We evaluated immunological and dendritic reconstitution in 72 myeloma patients who had undergone CD34+-selected (n = 45) and unmanipulated (n = 27) stem cell transplant, and its correlation with infections.

RESULTS

Haematological recovery occurred promptly in all patients. Only a slight delay in platelet recovery to >50 x 10(9)/l was observed in patients receiving CD34+-enriched graft. Natural killer (NK) cell count recovered in all patients within 2 months and B-cell count had recovered by 6 months post-transplant in both groups. CD3 cells remained lower than normal in both groups. CD8 cells increased above the normal level, reaching a peak at day 90, and lowered to normal level within 1 year post-transplant. CD4 lymphocytes remained <50% of normal, especially in selected patients. In both groups, both DC1 and DC2 counts were already significantly lower than in normal individuals before conditioning therapy. Pre-conditioning levels of DC1 were reached in unmanipulated patients at day 30 and became normal at 6 months. In selected patients, DC1 pre-transplant level was observed at day 60 and was maintained thereafter. DC2 recovery showed a similar trend. In unselected patients, DC2 count increased to pre-conditioning level at haematological recovery and was normal after 1 year. In selected transplants, DC2 increased more slowly than DC1 in the same patients: pre-transplant level was detected at day 90 but was still significantly lower than normal 1 year after transplant. The incidence of infection was similar in both groups. Sepsis had Gram+ aetiology in the majority of cases. After engraftment only viral infections were recorded, mostly due to herpes reactivation, with no difference between groups.

DISCUSSION

In spite of a delay in immune recovery, CD34 enrichment is not associated with a significant increase of complications due to infection. Relatively fast NK cell recovery to pre-transplant levels and the presence of functionally efficient DCs can justify the low incidence of infections.

CD34+-enriched-CD19+-depleted autologous peripheral blood stem cell transplantation for chronic lymphoproliferative disorders: high purging efficiency but increased risk of severe infections

OBJECTIVE

The main objective of this work was to decrease the incidence of relapse after autologous stem cell transplantation with a "double purging" procedure.

METHODS

We used a "positive" (CD34) and "negative" (CD19) double selection method to improve the efficacy of "single purging" of hematopoietic harvests in poor-prognosis lymphoproliferative disorders. All patients included in the study had a positive molecular marker of their disease. Minimal residual disease (MRD) was studied by flow cytometry and PCR techniques during the purging procedure and after transplantation.

RESULTS

Twenty-six patients fulfilled entry criteria. Median age of patients was 50 years (range: 33-66); 17 were male and 9 female. Thirteen (50%) of the patients mobilized an adequate number of CD34+ cells (>or=3 x 10(6)/kg) to proceed with the double-selection protocol. Twelve of the 13 harvests became PCR negative after purging. Ten patients were grafted with the selected products and all but one engrafted without delay. After a median follow-up of 30 months, 2 of 10 patients suffered a molecular relapse at 7 and 19 months respectively. The earlier relapse was observed in the patient who received a MRD+ product. Only one patient experienced a clinical relapse. Three patients died due to obliterans bronchiolitis, pneumococcal sepsis, and septic shock of unknown origin, respectively, and three others presented life-threatening infections.

CONCLUSION

Therefore, CD34+/CD19+ positive/negative selection is an effective purging approach in patients with chronic lymphoproliferative disorders. This favorable effect is, however, counterbalanced by the high frequency of life-threatening infections.

Combined isolation of CD34+ progenitor cells and reduction of B cells from peripheral blood by use of immunomagnetic methods

BACKGROUND

Malignant cells may contribute to relapse after autologous hematopoietic cell transplantation The effectiveness of a double immunomagnetic purging strategy combining CD34-positive with B-negative cell selection to purge peripheral blood progenitor cells (PBPCs) from patients with chronic lymphoproliferative disorders has been analyzed.

STUDY DESIGN AND METHODS

Twenty-two CD34+ cell selections from patients with follicular lymphoma (n = 14), chronic lymphocytic leukemia (n = 6), mantle cell lymphoma (n = 1), and splenic marginal zone lymphoma (n = 1) were performed by use of a magnetic cell selector followed by a negative cell selection step with anti-CD19 monoclonal antibody bound to immunomagnetic beads.

RESULTS

The PBPC components contained median CD34+ cells of 1.24 percent (range, 0.38-3.92%) and CD19+ cells of 1.83 percent (range, 0.06-69.7%). After positive selection (n = 22), 49 percent (range, 16-72%) of CD34+ cells were recovered with a purity of 93 percent (range, 24-99%). The double-positive and -negative selections (n = 20) yielded 57.5 percent of CD34+ cells (range, 33.4-79.4%) with a purity of 95 percent (range, 63-99%). Logarithms of B-cell reduction in the CD34+-cell-enriched B-cell-depleted component had a median value of 3.63 (range, 2.74-4.84 log) and CD19+ and CD5+ cells for chronic lymphocytic leukemia patients with more than 4.56 log (>3.6-5.6 log). Of 13 PBPC components that had a tumor-specific clonal signal, 10 became PCR negative after the double-selection procedure.

CONCLUSION

Combined positive and negative magnetic cell selection achieves a high grade of tumor cell reduction with up to 77 percent of the grafts being negative for tumor-specific clonal signal by PCR analysis. This technique preserves an adequate recovery of progenitor cells able to engraft.

Tumor cell depletion of peripheral blood progenitor cells using positive and positive/negative selection in metastatic breast cancer

BACKGROUND

The clinical relevance of tumor cell purging of hematopoietic progenitor cell grafts has yet to be conclusively determined. Therefore, in addition to the demonstration that a method for graft purification is capable of removing an adequate number of tumor cells, it is critical that the procedure has as benign an impact upon the hematopoietic repopulating potential of the graft as possible. We evaluated tumor cell depletion, recovery of CD34(+) cells and post transplant engraftment kinetics as accepted measures of the effectiveness of an immunomagnetic bead (positive and positive/negative) purging methodology.

METHODS

The patients received either positive selection (CD34 selection alone) or a combination of positive and negative (CD34 selection followed by breast cancer cell depletion) using the Isolex 300 (automated and semiautomated) devices. Immunocytochemistry was used to determine the degree of breast cancer cell contamination before and after the selection procedures to determine the efficacy of the procedure. CD34 enumeration was employed to evaluate the recovery and purity of the CD34-selected cellular products and engraftment indices (days to absolute neutrophil count (ANC) recovery and platelet count (Plt) recovery and transfusion requirements) were evaluated to determine the safety of the procedure.

RESULTS

A total of 130 aphereses was performed on 101 patients. Ten pairs of collections were pooled before selection to increase the likelihood of achieving CD34 dose goals after selection. In all, 100 positive selections and 20 positive/negative selections were performed. Of the 10 (10.4%) ICC-positive preselection samples, 2 products showed persistent contamination after processing. The majority of patients (85.4%) required one selection procedure to achieve an adequate CD34(+) selected cell dose. Median CD34(+) cell recovery was > 50% for positive selection procedures and > 60% for the positive/negative procedures. The dose of CD34(+) cells infused ranged from 0.76 x 10(6) CD34(+) cells/kg to 27.7 x 106 CD34(+) cells/kg. There were no significant delays in neutrophil or platelet recovery or infections between any of the treatment groups.

DISCUSSION

CD34 selection alone or in combination with negative selection can result in a significant reduction of contaminating tumor cells in the peripheral blood progenitor cell autograft. Although there was one engraftment failure with the CD34-positive selected cells, transplantation of the selected products after high-dose chemotherapy for metastatic breast cancer did not result in a clinically significant delay in the hematopoietic reconstitutive capacity of the autografts.

Recent publications in hematological oncology

In order to keep subscribers up-to-date with the latest developments in their field, John Wiley & Sons are providing a current awareness service in each issue of the journal. The bibliography contains newly published material in the field of hematological oncology. Each bibliography is divided into 14 sections: 1 Books, Reviews & Symposia; 2 General; Leukemias: 3 Lymphoblastic; 4 Myeloid & Myelodysplastic Syndromes; 5 Chronic; 6 Others; Lymphomas: 7 Hodgkin's; 8 Non-Hodgkin's; 9 Plasmacytomas/Multiple Myelomas; 10 Others; 11 Bone Marrow Transplantation; 12 Cytokines; 13 Diagnosis; 14 Cytogenetics. Within each section, articles are listed in alphabetical order with respect to author. If, in the preceding period, no publications are located relevant to any one of these headings, that section will be omitted.

European Group for Blood and Marrow Transplantation Registry studies in multiple myeloma

The European Group for Blood and Marrow Transplantation (EBMT) Myeloma Registry, established in 1987, contains data on 1,368 allogeneic and more than 8,000 autologous stem cell transplants performed since 1983. Among autologous transplant patients, the median survival after transplantation is 50 months, and the actuarial survival at 10 years is 30%, with a plateau appearing at about 8 years. Factors of importance for a more favorable prognosis are lower age, response to chemotherapy, only one course of primary chemotherapy, stage I or II disease, and low beta(2)-microglobulin at diagnosis. Beneficial procedural factors associated with better outcome are a preparative regimen without total body irradiation (TBI), posttransplant interferon alfa maintenance treatment, and possibly tandem transplantation. In vitro graft purging, using CD34(+) selection, does not have any impact on survival. A case-matched analysis comparing autologous and allogeneic transplantation demonstrated significantly better survival in the former group, with median posttransplant survival times of 36 months and 18 months in the autologous and allogeneic groups, respectively. This result was in turn due to a markedly lower incidence of transplant-related death among the autotransplant patients: 13%, versus 41% for the allogeneic group. However, recent data on allogeneic transplants performed from 1994 to 1998 has demonstrated a decrease in treatment-mortality to 30%, and this has resulted in a prolongation of survival; in this analysis, the results are similar irrespective of the type of graft used, allogeneic bone marrow or blood stem cells. In a small case-matched analysis, transplantation with an identical twin donor was superior to both allogeneic and autologous transplantation with respect to survival and freedom from progression.

Immune reconstitution after autologous selected peripheral blood progenitor cell transplantation: comparison of two CD34+ cell-selection systems

BACKGROUND

Selection of CD34+ PBPCs has been applied as a method of reducing graft contamination from neoplastic cells. This procedure seems to delay lymphocyte recovery, while myeloid engraftment is no different from that with unselected PBPC transplants.

STUDY DESIGN AND METHODS

Lymphocyte recovery was studied in two groups of patients who underwent autologous CD34+ PBPC transplant with two different technologies (Ceprate SC, Cellpro [n = 17]; CliniMACS, Miltenyi Biotech [n = 13]). The median number of CD34+ cells transfused was 3.88 x 10(6) per kg and 3.32 x 10(6) per kg, respectively. Residual CD3 cells x 10(6) per kg were 4.97 and 0.58, respectively (p = 0.041). Residual CD19 cells x 10(6) per kg were 1.33 and 0.73, respectively (NS).

RESULTS

No differences were found between the two groups in total lymphocyte recovery to >0.5 x 10(9) per L, which achieved a stable count by Day 30. During the study period, the CD4+ cell count remained below 0.2 x 10(9) per L, and the B-cell subset showed a trend toward normalization. CD3/HLA-DR+ and CD16/56 increased markedly in both groups by Day 30. An increase in CMV (13%) and adenovirus (17.4%) infection was found in both groups.

CONCLUSION

Both CD34+ cell selection technologies used here determined an excellent CD34+ cell purity and an optimal depletion of T cells. The high rate of viral complications is probably due to the inability of residual T cells left from the CD34+ cell selection to generate, immediately after transplant, an adequate number of virus-specific lymphocytes.

High-dose therapy in patients with Hodgkin's disease: the use of selected CD34(+) cells is as safe as unmanipulated peripheral blood progenitor cells

Register data suggest that patients with Hodgkin's disease (HD) given high-dose therapy (HDT) with peripheral blood progenitor cells (PBPC) have a less favourable prognosis as compared to those given bone marrow as stem cell support. Since this can be due to infusion of tumour cells contaminating the PBPC grafts, we initiated a feasibility study in which PBPC grafts from HD patients were purged by CD34(+) cell enrichment. Controversy exists about whether the use of CD34(+) enriched stem cells leads to a delayed haematological and immune reconstitution. We compared these parameters, including risk of infections and clinical outcome after HDT, in patients with HD given either selected CD34(+) cells or unmanipulated PBPC as stem cell support. From October 1994 to May 2000, 40 HD patients with primary refractory disease or relapse were treated with HDT and supported with either selected CD34(+) cells (n = 21) or unmanipulated PBPC (n = 19) as stem cell support. All patients had chemosensitive disease at the time of transplantation. A median of 5.8 (range 2.7-20.0) vs 4.5 (range 2.3-17.6) x 10(6) CD34(+) cells per kilo were reinfused in the CD34(+) group and PBPC group, respectively. No difference was observed between the two groups with regard to time to haematological engraftment, reconstitution of B cells, CD56(+) cells and T cells at 3 and 12 months and infectious episodes after HDT. Two (5%) treatment-related deaths, one in each group, were observed. The overall survival at 4 years was 86% for the CD34(+)group and 74% for the PBPC group with a median follow-up of 37 months (range 1-61) and 46 months (range 4-82), respectively (P = 0.9). The results of this study demonstrate that the use of CD34(+) cells is safe and has no adverse effects either with respect to haematological, immune reconstitution or to infections after HDT.