Severe infections after allogeneic peripheral blood stem cell transplantation: a matched-pair comparison of unmanipulated and CD34+ cell-selected transplantation

BACKGROUND AND OBJECTIVES

T-cell depletion of the graft delays immune recovery following allogeneic peripheral blood stem cell transplantation (PBSCT), but it is not clear whether it actually increases the risk of severe infections after the transplant.

DESIGN AND METHODS

We have compared the occurrence of severe infections following 162 CD34+ cell-selected allogeneic PBSCT and 162 unmanipulated PBSCT (CD34+ and UM groups, respectively) from HLA-identical siblings.

RESULTS

The probability of infection-related mortality (IRM) was 22% in the UM group and 31% in the CD34+ group (log-rank, p=0.2). In multivariate analyses only the use of fluconazole prophylaxis showed a protective effect on IRM in the whole set of patients, while in both transplant groups the most significant factor was the development of moderate-to-severe graft-versus-host disease (GVHD). The probability of developing cytomegalovirus (CMV) infection was 42% in the UM group and 59% in the CD34+ group (p=0.002), with no differences in CMV disease (10% and 9%, respectively). Multivariate analysis of CMV infection identified three variables associated with a higher risk in the whole set of patients: CMV positive serostatus, CD34+ transplant group and recipient age above 40 years. The development of moderate-to-severe GVHD was a significant factor only in the UM group. Disseminated varicella-zoster virus infection was more common in the CD34+ group (19% and 12%, p=0.05), as were early (< 30 days post-transplant) severe bacterial infections (28% vs 14%, p=0.002). Invasive fungal infections and pneumonias of unknown origin did not differ between groups.

INTERPRETATION AND CONCLUSIONS

Our results do not show a significant increase in the risk of dying from an opportunistic infection with CD34+-PBSCT, but the risk of CMV infection is increased, with no differences in CMV disease or mortality attributable to CMV. There is an additive effect on IRM of developing moderate-to-severe GVHD (acute or chronic) following CD34+-PBSCT, and in this subset of patients maximum efforts for the prevention and early treatment of opportunistic infections should be pursued.

Gene scanning of VDJH-amplified segments is a clinically relevant technique to detect contaminating tumor cells in the apheresis products of multiple myeloma patients undergoing autologous peripheral blood stem cell transplantation

Contaminating tumour cells in apheresis products have proved to influence the outcome of patients with multiple myeloma (MM) undergoing autologous stem cell transplantation (APBSCT). The gene scanning of clonally rearranged VDJ segments of the heavy chain immunoglobulin gene (VDJH) is a reproducible and easy to perform technique that can be optimised for clinical laboratories. We used it to analyse the aphereses of 27 MM patients undergoing APBSCT with clonally detectable VDJH segments, and 14 of them yielded monoclonal peaks in at least one apheresis product. The presence of positive results was not related to any pre-transplant characteristics, except the age at diagnosis (lower in patients with negative products, P = 0.04). Moreover, a better pre-transplant response trended to associate with a negative result (P = 0.069). Patients with clonally free products were more likely to obtain a better response to transplant (complete remission, 54% vs 28%; >90% reduction in the M-component, 93% vs 43% P = 0.028). In addition, patients transplanted with polyclonal products had longer progression-free survival, (39 vs 19 months, P = 0.037) and overall survival (81% vs 28% at 5 years, P = 0.045) than those transplanted with monoclonal apheresis. In summary, the gene scanning of apheresis products is a useful and clinically relevant technique in MM transplanted patients.

Reduced-intensity conditioning reduces the risk of severe infections after allogeneic peripheral blood stem cell transplantation

We compared the occurrence of severe infections following 71 reduced-intensity conditioning (RIC) allogeneic peripheral blood stem cell transplants (PBSCT) and 123 standard myeloablative PBSCT (MINI and STAND groups, respectively) from HLA-identical siblings. The probability of 1-year infection-related mortality (IRM) was 19% in the STAND group and 10% in the MINI group (log-rank, P = 0.3). On multivariate analysis the only significant variable associated with a higher risk of IRM was the development of moderate-to-severe GVHD (P = 0.005). The probability of developing CMV infection was 39% in the STAND group and 21% in the MINI group (P = 0.03) (43% and 21%, respectively, in seropositive donor/recipient pairs, P = 0.01), and the probability of developing CMV disease was 9.5% and 1%, respectively (P = 0.05) (11% and 1%, respectively, in seropositive donor/recipient pairs, P = 0.03). Multivariate analysis of CMV infection identified four variables associated with a higher risk: CMV positive serostatus (P = 0.05), STAND transplant group (P = 0.02), the development of moderate-to-severe GVHD (P < 0.001) and a dose of CD34(+) cells infused below 6 x 10(6)/kg (P = 0.01). Invasive fungal infections and pneumonias of unknown origin did not differ between groups, and neither did other severe non-CMV viral infections and bacterial infections. Our results suggest that RIC allogeneic PBSCT may decrease the risk of dying from an opportunistic infection and reduces the occurrence of CMV infection and disease. Overall, the development of GVHD (acute or chronic) is an important risk factor for these complications. Other infections continue to pose a significant threat to recipients of RIC allografts, stressing that prophylactic and supportive measures are an important aspect in their care.

Identification of factors associated with poor peripheral blood progenitor cell mobilization in Hodgkin's disease

BACKGROUND AND OBJECTIVES

Although the use of drugs which damage stem cells is common in patients with Hodgkin's disease (HD), factors affecting peripheral blood progenitor cell (PBPC) mobilization have not been clearly established in this group of patients. The aim of this study was to identify factors associated with poor PBPC mobilization in patients with HD.

DESIGN AND METHODS

In order to address this issue we have evaluated in 54 patients with HD mobilized with G-CSF alone the following factors: sex, age, histologic subtype, B symptoms at diagnosis, status of remission, previous chemotherapy and radiotherapy, interval from diagnosis and last chemotherapy cycle to harvest, and dose of G-CSF. Univariate analysis was performed using Student's t-test, Pearson's correlation and Spearman's correlation. A stepwise regression model was used to determine which of the variables was the most predictive of PBPC mobilization.

RESULTS

In univariate analysis poorer PBPC mobilization was observed in patients who had previously received at least two courses of mini-BEAM (p=0.006), a high number of different chemotherapy regimens (p=0.002), a chemotherapy score >30 (p=0.02) and more than 9 months of alkylating agents (p=0.07). We did not find radiotherapy to be a significant factor affecting progenitor cell yield (p=0.59). In the stepwise regression model, only the previous administration of two or more mini-BEAM cycles predicted a poor PBPC yield (p=0.006).

INTERPRETATION AND CONCLUSIONS

Previous chemotherapy, principally exposure to a mini-BEAM regimen, seems to be the principal factor affecting collection of PBPC in patients with HD mobilized with G-CSF alone. Since mini-BEAM is an effective salvage regimen in relapsed or refractory HD, collection of PBPC should be planned when there has been no or only minimal exposure to a mini-BEAM regimen.

Long-term follow-up in patients treated with Mini-BEAM as salvage therapy for relapsed or refractory Hodgkin's disease

Several studies have focused on investigation of the optimal salvage regimen to induce maximum response before autologous stem cell transplantation (ASCT) in patients with relapsed or refractory Hodgkin's disease (HD). However, in most of these studies, the follow-up is relatively short. In the present study, we report on long-term results of 55 consecutive patients with HD who received Mini-BEAM [BCNU (carmustine), etoposide, cytarabine, melphalan] as salvage therapy before ASCT. Eleven patients were refractory to front-line therapy, 17 were partial responders, and 27 patients had relapsed from HD. Twenty-eight patients achieved complete response, and 18 achieved partial response with a median of two cycles of Mini-BEAM, giving a total response rate of 84%. Significant factors predicting poor response (P < 0.05) were: initial treatment with MOPP (mechloroethamine, oncovin, procarbazine, prednisolone), > or = two previous chemotherapy regimens and three disease characteristics at Mini-BEAM treatment: presence of B symptoms, extranodal involvement or low serum albumin. However, only the last two factors retained independent influence on multivariate analysis. In total, 45/55 patients have been transplanted. Median follow-up after Mini-BEAM administration for living patients is 68 months. At the time of reporting, 31 out of 55 patients (56.4%) are still alive, 21 patients (38%) have relapsed, three (5.4%) have developed secondary neoplasias, and five have died of other complications not related to disease progression. The actuarial 7-year overall survival (OS) was 52%, the progression-free survival (PFS) 54% and the event-free survival (EFS) 36%. The response to Mini-BEAM was the most important prognostic factor for predicting the long-term probability of surviving the disease: none of the eight patients who did not respond to Mini-BEAM were alive at 3 years. On multivariate analysis, response to Mini-BEAM and extranodal involvement before Mini-BEAM had a significant influence on OS. Our results show the safety and efficacy of Mini-BEAM before ASCT for refractory or relapsed HD patients.

Autologous stem-cell transplantation for Hodgkin's disease: results and prognostic factors in 494 patients from the Grupo Español de Linfomas/Transplante Autólogo de Médula Osea Spanish Cooperative Group

PURPOSE

To analyze clinical outcome and significant prognostic factors for overall (OS) and time to treatment failure (TTF) in a group of 494 patients with Hodgkin's disease (HD) undergoing autologous stem-cell transplantation (ASCT).

PATIENTS AND METHODS

Detailed records from the Grupo Español de Linfomas/Transplante Autólogo de Médula Osea Spanish Cooperative Group Database on 494 HD patients who received an ASCT between January 1984 and May 1998 were reviewed. Two hundred ninety-eight males and 196 females with a median age of 27 years (range, 1 to 63 years) received autografts while in complete remission (n = 203) or when they had sensitive disease (n = 206) or resistant disease (n = 75) at a median time of 26 months (range, 4 to 259 months) after diagnosis. Most patients received high-dose chemotherapy without radiation for conditioning (n = 443). The graft consisted of bone marrow (n = 244) or peripheral blood (n = 250).

RESULTS

The 100-day mortality rate was 9%. The 5-year actuarial TTF and OS rates were 45.0% (95% confidence interval [CI], 39.5% to 50.5%) and 54.5% (95% CI, 48.4% to 60.6%), respectively. In multivariate analysis, the presence of active disease at transplantation, transplantation before 1992, and two or more lines of therapy before transplantation were adverse prognostic factors for outcome. Sixteen patients developed a secondary malignancy (5-year cumulative incidence of 4.3%) after transplantation. Adjuvant radiotherapy before transplantation, the use of total-body irradiation (TBI) in the conditioning regimen, and age > or = 40 years were found to be predictive factors for the development of second cancers after ASCT.

CONCLUSION

ASCT achieves long-term disease-free survival in HD patients. Disease status before ASCT is the most important prognostic factor for final outcome; thus, transplantation should be considered in early stages of the disease. TBI must be avoided in the conditioning regimen because of a significantly higher rate of late complications, including secondary malignancies.

Autologous stem cell transplantation for clinically aggressive non-Hodgkin's lymphoma: the role of preparative regimens

We investigated the impact of the most commonly used preparative regimens on the outcome of 395 patients with diffuse large cell lymphoma (DLCL), consecutively reported to the registry of the Spanish GEL/TAMO. Among them, 139 (35%) were autografted in 1st CR, 86 (22%) in 2nd/3rd CR, 124 (31%) had chemosensitive disease and 46 (12%) had chemoresistant disease. Conditioning consisted of chemotherapy-only in 348 patients (BEAM, 164; BEAC, 145; and CBV, 39) and radiochemotherapy with CY and TBI in 47. Median times to granulocyte, platelet recovery and to discharge were significantly shorter in the chemotherapy-only group. Early transplant-related mortality was significantly higher when using CY-TBI. After a median follow-up of 28 months, overall survival (OS) at 8 years of patients conditioned with BEAM or BEAC (58% (95% CI 50-66%)) was more favorable than with CBV (40% (95% CI 24-56%)), and significantly better than with CY-TBI (31% (95% CI 18-44%)). Multivariate analysis revealed that patients conditioned with chemotherapy-only regimens had improved OS, disease-free (DFS) and relapse-free survival (RFS) when compared to those conditioned with CY-TBI. Status at transplant was also a powerful prognostic indicator. We conclude that preparative regimens consisting of chemotherapy-only seem more efficacious than CY-TBI as conditioning for DLCL, because of faster engraftment and greater anti-lymphoma effect, as indicated by improved OS, DFS and RFS.

Intra-muscular vidarabine therapy for polyomavirus-associated hemorrhagic cystitis following allogeneic hemopoietic stem cell transplantation

Hemorrhagic cystitis (HC) is a common complication following hemopoietic stem cell transplantation (HSCT), its incidence ranging from 7 to 52% of all patients. Late occurring HC frequently results from viral infections. We describe a patient who developed severe polyomavirus-associated HC, which responded dramatically to a single dose of intra-muscular vidarabine. Previous studies show an improvement in HC with vidarabine therapy, but to date only the intravenous route of administration has been described and responses described take from several days to weeks. This report confirms the safety and efficacy of vidarabine administered intramuscularly when used in patients with an adequate platelet count, thereby making its use feasible when intravenous vidarabine is not available.

Pathologic rupture of the spleen during induction with ATRA in a patient with acute promyelocytic leukemia

Pathological rupture of the spleen is a rare but well recognized complication in hematological malignancies. Early clinical recognition of this life-threatening complication is necessary for rapid intervention. Here, we report on the case of a 26-year-old woman with acute promyelocytic leukemia who presented rupture of the spleen on day +2 of treatment with ATRA plus idarrubicin. In patients with acute leukemia, the presence of a painful abdomen and a sudden drop in hemoglobin levels, should alert of a possible splenic rupture, even without additional symptoms. This would facilitate an early treatment intervention with no modification to the chemotherapy schedule.

The detection of contaminating clonal cells in apheresis products is related to response and outcome in multiple myeloma undergoing autologous peripheral blood stem cell transplantation

In the present paper, we report on the use of the heteroduplex PCR technique to detect the presence of clonally rearranged VDJ segments of the heavy chain immunoglobulin gene (VDJH) in the apheresis products of patients with multiple myeloma (MM) undergoing autologous peripheral blood stem cell (APBSC) transplantation. Twenty-three out of 31 MM patients undergoing APBSC transplantation with VDJH segments clonally rearranged detected at diagnosis were included in the study. Samples of the apheresis products were PCR amplified using JH and VH (FRIII and FRII) consensus primers and subsequently analyzed with the heteroduplex technique, and compared with those obtained at diagnosis. 52% of cases yielded positive results (presence of clonally rearranged VDJH segments in at least one apheresis). The presence of positive results in the apheresis products was not related to any pretransplant characteristics with the exception of response status at transplant. Thus, while no one patient with positive apheresis products was in complete remission (CR), negative immunofixation, before the transplant, five cases (46%) with negative apheresis were already in CR at transplant (P = 0.01). The remaining six cases with heteroduplex PCR negative apheresis were in partial remission before transplant. Patients with clonally free products were more likely to obtain CR following transplant (64% vs 17%, P= 0.02) and a longer progression-free survival, (40 months in patients transplanted with polyclonal products vs 20 with monoclonal ones, P = 0.03). These results were consistent when the overall survival was considered, since it was better in those patients with negative apheresis than it was in those with positive (83% vs 36% at 5 years from diagnosis, P= 0.01). These findings indicate that the presence of clonality rearranged VDJH segments is related to the response and outcome in MM transplanted patients.

High-sensitive immunophenotyping and DNA ploidy studies for the investigation of minimal residual disease in multiple myeloma

Sensitive techniques for monitoring minimal residual disease (MRD) in multiple myeloma (MM) are needed to evaluate the effectiveness of new intensive treatment strategies. The aim of the present study was to explore the applicability and sensitivity of flow cytometry immunophenotyping and DNA ploidy studies for the investigation of residual myelomatous plasma cells (PC) in MM patients. Bone marrow (BM) samples from 61 untreated MM patients were immunophenotypically analysed with a panel of 21 monoclonal antibodies, using a high-sensitive method based on a two-step acquisition procedure through a SSC/CD38 -CD138+ 'live-gate'. Overall, in 87% of MM cases, PC displayed an aberrant phenotype at diagnosis. The most important aberrant criteria were: antigen over-expression of CD56 (62%), CD28 (16%) and CD33 (6%) and asynchronous expression of CD117 (28%), sIg (21%) and CD20 (10%). DNA aneuploidy was found in 62% of cases. The simultaneous use of these two techniques allowed the detection of aberrant/aneuploid PC in 95% of the cases. Based on dilutional experiments, the detection limit of both techniques ranged from 10(-4) to 10(-5). In 29 stem cells harvests and 19 BM samples obtained 3 months after autologous transplantation, we have investigated the presence of residual myelomatous PC; they were detected in 44% of the stem cell collections and in 61% of the BM samples obtained after transplant. The percentage of pathological PC did not significantly change during the days of harvest. In summary, the present study shows that the combined use of immunophenotyping and DNA ploidy studies is a suitable approach for MRD investigation in MM patients based on their applicability (95% of cases) and sensitivity (up to 10(-5)).

Factors that influence long-term hematopoietic function following autologous stem cell transplantation

The aim of the present study was to assess which factors influence hematopoietic function long term after transplantation. For this purpose, we have analyzed a series of 79 patients who underwent autologous transplantation. None of them received any further chemotherapy or radiotherapy after transplant. All patients were disease-free 1 year after autologous transplantation. Late impairment of hematopoietic function was defined as the presence of non-transient peripheral blood cytopenias, detected 6 and 12 months after autografting. Before transplantation, 38.7% of patients showed peripheral blood cytopenias. Six and 12 months after transplantation, cytopenias presented in 44.2% and 42.4% of patients, respectively. Cases displaying cytopenias 6 months after transplantation had received a significantly lower dose of CFU-GM and CD34+ cells than patients without cytopenias (P = 0.012 and P = 0.04, respectively). The same correlation, with even higher statistical significance, was observed 12 months after transplant (P = 0.007 and P = 0.005). Alkylating agents and radiotherapy administered prior to transplantation and age did not seem to influence the presence of permanent cytopenias. The incidence did not vary significantly according to the stem cell source (bone marrow or peripheral blood). The number of CFU-GM and CD34+ cells infused was the most important factor for maintenance of adequate hematopoiesis.

Hematopoietic damage prior to PBSCT and its influence on hematopoietic recovery

BACKGROUND AND OBJECTIVE

Patients with malignancies receive chemotherapy to induce tumor remission which could damage hematopoiesis and adversely influence hematopoietic reconstitution after transplantation. In the present study we used a long-term culture (LTBMC) system and clonogenic assays to evaluate the marrow damage in patients selected to receive peripheral blood stem cell transplantation (PBSCT).

DESIGN AND METHODS

Thirty-five patients - 20 with breast cancer (BC), 9 with non-Hodgkin's lymphoma (NHL) and 6 with Hodgkin's disease (HD) - were included. Bone marrow aspiration was performed one day prior to the initiation of the conditioning therapy. CFU-GM were cultured in methylcellulose with PHA-LCM. Delta assays of plastic adherent progenitor cells (PD) were performed according to Gordon's method. LTBMC were established for 5 weeks.

RESULTS

There were fewer CFU-GM from all patient groups than from normal BM (p<0.05). In contrast, the number of immature progenitor cells (PD) was not decreased. The total number of CFU-GM produced by LTBMC patients was significantly reduced (p<0.05). The adherent layer from patients was often qualitatively different. In order to know whether the hematopoietic damage could affect hematopoietic reconstitution, we correlated culture data with time taken to reach peripheral cell counts. A negative correlation (r= - 0.71) was found between percentage of stromal layer and time taken to reach 20x10(9) platelets/L (tplat= 20x3-0.08% stromal layer).

INTERPRETATION AND CONCLUSIONS

We can conclude that prior to PBSCT, hematopoietic function is impaired at both the level of committed progenitor cells and that of BM stroma. This damage could influence platelet recovery.

Diagnosis of secondary myelodysplastic syndromes (MDS) following autologous transplantation should not be based only on morphological criteria used for diagnosis of de novo MDS

Secondary myelodysplastic syndromes (MDS) are increasingly being reported after autologous transplantation. Transient dysplastic changes have also been observed after this type of treatment. However, to the best of our knowledge no systematic morphological analysis has been performed to determine the influence of stem cell transplantation on bone marrow morphology. In 53 patients undergoing autologous transplantation, we evaluated the bone marrow, before and 6 and 12 months after the transplant, in order to analyze the appearance of dyshemopoietic changes, assessed according to a pre-established score. We also studied 25 bone marrow samples obtained at the time of diagnosis, prior to treatment, but we did not find morphological atypia. Six months after transplant, cellularity and thrombopoiesis had decreased in 38% and 49% of patients respectively, although 1 year after the process they were normal in most cases. Myelodysplasia was already present in bone marrow before transplantation and continued to be in evidence for a long time afterwards. This suggests that chemotherapy and radiotherapy used prior to transplantation are responsible for dysplastic changes. The myeloid line was the most affected with 100% of patients showing dysgranulopoiesis 1 year after autografting. Cytopenias were observed in 51% and 44% of patients 6 and 12 months after transplantation. Moreover, concomitant presence of cytopenia and myelodysplasia was observed in 37.7% of patients at 6 months after transplantation and 25% at 12 months, and therefore they could be diagnosed with MDS. These data contrast with the incidence of secondary MDS reported in earlier publications. According to these findings, the value of the French-American-British Co-operative Group criteria for the diagnosis of MDS following autologous transplantation is questionable. Moreover, since dyshemopoietic features are almost always present after autologous transplant, morphological criteria are not useful for early recognition of patients with secondary MDS after transplantation.

An abnormal CD34+ myeloid/CD34+ lymphoid ratio at the end of chemotherapy predicts relapse in patients with acute myeloid leukemia

During conventional follow-up of patients with acute myeloid leukemia (AML), the emergence of cytopenias is considered to be a sign of impending relapse, and it represents an example of how leukemic hematopoiesis affects normal hemopoietic differentiation. In the present study, we have explored the possible value of the analysis of the distribution of CD34+ myeloid and CD34+ lymphoid progenitor cells in follow-up complete remission bone marrow samples from de novo AML patients as a prognostic parameter for predicting relapse. A total of 213 bone marrow samples from 36 AML patients in morphological complete remission, obtained at the end of induction, consolidation, and intensification therapy and every six months thereafter were analyzed. The normal CD34+ myeloid/CD34+ lymphoid ratio ranged between 2.4 and 8.9. In contrast, in most AML cases an abnormally high ratio (> or =10) was observed at the end of induction and consolidation therapy: 96% and 75% of cases, respectively. On the other hand, at the end of intensification, 70% of the patients displayed a normal CD34+ ratio. Patients with a myeloid/lymphoid CD34+ ratio higher than 10 at the end of intensification showed a significantly lower overall survival (median survival of 19 months versus median not reached, P = 0.05), as well as a lower disease-free survival (median of 7 months versus 30 months, P = 0.0001). Regarding sequential studies, 67% of the relapses were preceded by the re-appearance of an abnormal CD34 ratio, whereas relapse was not predicted in four patient with leukemia classified as M3 undergoing maintenance therapy. From the remaining 18 patients who are still in continuous complete remission, all except 3 cases (17%) displayed a normal CD34 myeloid/lymphoid ratio. In summary, the present study shows that the persistence at the end of chemotherapy of an abnormally high (> or =10) ratio between CD34+ myeloid and CD34+ lymphoid progenitors in the bone marrow of AML patients is associated with high risk of relapse and a shorter overall survival.

Prognostic value of immunophenotypic detection of minimal residual disease in acute lymphoblastic leukemia

PURPOSE

The identification of immunophenotypic aberrancies through multiparametric flow cytometry makes the differentiation between normal and leukemic cells relatively simple and quick, and is therefore an attractive method for the investigation of minimal residual disease (MRD). In this report, we have analyzed the impact on relapse and relapse-free survival (RFS) of detecting immunophenotypical aberrant cells in acute lymphoblastic leukemia (ALL) patients in cytomorphologic complete remission (CR).

MATERIALS AND METHODS

Two hundred eleven bone marrow (BM) samples from 53 consecutive ALL (37 precursor B-ALL and 16 T-ALL) patients were analyzed. The only selection criteria were to have at least one aberrant immunophenotypic feature at diagosis and to have achieved cytomorphologic CR after induction therapy. For MRD detection, all follow-up samples were analyzed with triple labelings using a two-step acquisition procedure, in which 106 cells were screened for the possible persistence of residual leukemic cells with the same phenotypic aberrancy as that identified diagnosis.

RESULTS

Patients who displayed a gradual increase in MRD levels showed a higher relapse rate (90% v22%; P < .00001) and shorter median RFS (12 months v not reached; P < .0001) than those with stable or decreasing MRD levels. This adverse prognostic influence also was observed when children and adults, as well as B-ALL and T-ALL patients, were analyzed separately. An MRD level > or = or greater than 10(-3) discriminated two risk groups of ALL patients with significantly different relapse rates and RFS at all treatment phases (end of induction, consolidation, maintenance, and out of treatment).

CONCLUSION

Multiparametric flow cytometry of MRD in ALL patients is a valuable tool for relapse prediction and for the identification of a cohort of patients with very poor prognosis.

[Immune reconstitution after autologous progenitor hemopoietic cell transplantation. A study comparing autologous bone marrow and autologous peripheral blood transplantation]

BACKGROUND

In order to find out the effect of peripheral blood (PB) hematopoietic progenitor cells on immune reconstitution the present study compares, through a randomized trial, some lymphoid subsets after peripheral blood (PBT) or bone marrow (BMT) autologous transplantation.

MATERIAL AND METHODS

Twelve patients suffering from malignant hematological disorders were included (6 BMT and 6 PBT). From these patients 14 lymphoid and natural killer (NK) subsets were sequentially analyzed using appropriate dual staining. NK activity was analyzed by measuring Cr51 release from the K562 cell line. Studies were done in days and -6, +10, +17, +24, +31, +38, +52, +66, +90, +120, +180 and +360 after transplantation.

RESULTS

The CD8+ cell regeneration was produced mainly by activated cells (CD38+), and no differences were observed between BMT and PBT, but CD8+ HLADR+ cells were higher in the PBT group. During the first year after transplantation CD4+ lymphoid cells were never within normal range, and its recovery was due to the memory subset (CD4+/CD45RO+). The CD19+ lymphocytes began their regeneration after the first month and it was produced mainly by by the CD19+/CD5+ subset. NK cells recovered faster in patients who underwent PBT, but NK activity was similar in both subgroups of patients and it was within normal range from day +17 until the end of the study.

CONCLUSION

T, B and NK lymphoid reconstitution do not differ significantly between patients that receive BM or PB as hemathopoietic rescue, but PB seems influence a faster reconstitution of cytotoxic subsets (CD8+/HLADR+ and NK lymphoid cells).

Randomized study of filgrastim versus molgramostim after peripheral stem cell transplant in breast cancer

BACKGROUND AND OBJECTIVE

The aim of this study was to compare the efficacy and toxicity of Filgrastrim (granulocyte colony-stimulating factor-G-CSF) versus molgramostim (granulomonocyte colony-stimulating factor-GM-CSF) after autologous peripheral blood stem cell transplant (PBSCT) in patients with breast cancer. To the best of our knowledge no randomized studies comparing filgrastrim and molgramostim have been published.

DESIGN AND METHODS

Forty-two patients with breast cancer were randomized to receive filgrastrim versus molgramostim subcutaneous at a dose of 5 mcgr/kg starting on day 6 after PBSCT. PBSC were collected in all patients after stimulation with filgrastrim and infused following conditioning with cyclophosphamide, cisplatin and carmustine (n = 25) or cyclophosphamide, carboplatin and thiotepa (n = 17).

RESULTS

The median days to reach > 0.5 x 10(9)/L granulocytes was similar for patients receiving filgrastrim (10.5 +/- 0.8 days) and molgramostim (10.2 +/- 0.9 days). No significant differences were observed in time taken to reach 20 x 10(9)/L platelets 10.8 +/- 2.2 vs 12 +/- 2.9 for filgrastrim and molgramostim, respectively, but in time to reach 50 x 10(9)/L was slightly lower in the filgrastrim arm (15.1 +/- 2.9 vs 18.9 +/- 8.4, p = 0.03). Nevertheless there were no differences in the number of platelets transfused. Time of discharge was two days earlier in the filgrastrim arm (15 +/- 4.2 vs 17.4 +/- 4.7, p = 0.04). Finally, the incidence of adverse side effects attributable to the cytokines (filgrastrim or molgramostim) was equivalent and only present in 19% of the patients.

INTERPRETATION AND CONCLUSIONS

This randomized study shows that filgrastrim and molgramostim yield quite similar toxicity and efficacy for early hematopoietic reconstitution after PBSCT in breast cancer patients.

Minimal number of circulating CD34+ cells to ensure successful leukapheresis and engraftment in autologous peripheral blood progenitor cell transplantation

BACKGROUND

The number of peripheral blood (PB) CD34+ cells has been widely used to monitor the timing of leukapheresis for autologous transplantation. However, no cutoff value for CD34+ cells in PB has been defined as a guideline for the identification of patients in whom the harvest would be effective and those in whom there was a high probability of failure.

STUDY DESIGN AND METHODS

The present study investigated the best threshold of CD34+ cells in PB for successful harvesting and engraftment, using 263 PB samples with their corresponding leukapheresis components. In addition, that measure has been compared to other commonly used criteria such as the white cell count, the number of mononuclear cells, and the number of colony-forming units-granulocyte macrophage in PB.

RESULTS

Time to engraftment of both granulocytes and platelets was significantly influenced by the number of CD34+ cells transfused, but all patients receiving > or = 0.75 x 10(6) CD34+ cells per kg achieved engraftment within a reasonable number of days (> 0.5 x 10(9)/L granulocytes by Day 11 and > 20 x 10(9)/L platelets by Day 13). A clear correlation between the number of CD34+ cells per microL in PB and of CD34+ cells per kg collected was found at each apheresis (r = 0.9, p < 0.0001). Moreover, the number of CD34+ cells per microL measured in PB the day the first leukapheresis was initiated displayed an excellent correlation with the total amount of CD34+ cells per kg finally collected (r = 0.81, p < 0.0001). On the basis of the regression curve obtained and the clinical engraftment results, it was found that the presence of > 5 CD34+ cells per microL in PB ensured a good yield from the harvest in 95 percent of patients and would avoid an unsuccessful harvest in 81 percent of cases.

CONCLUSION

A dose of only 0.75 x 10(6) CD34+ cells per kg guarantees hematopoietic recovery within a reasonable number of days. To initiate a leukapheresis from which enough progenitor cells may confidently be obtained, a minimum of 5 CD34+ cells per microL in PB is required.