Cell function studies in long-term bone marrow culture after cell concentration and cryopreservation for autologous transplantation

Abstract: Autologous bone marrow transplantation (ABMT) is frequently used in the treatment of neoplastic diseases. It involves several manipulations in vitro that can damage the stem cells responsible for grafting. Long-term bone marrow cultures (LTBMC) reproduce the bone marrow microenvironment and support haematopoiesis in vitro for several weeks. This technique provides information on the extent of the injury of stem cells during manipulations of bone marrow cells in vitro. We studied the effect of the usual process of bone marrow cells in vitro in autologous transplantation: cell concentration and cell cryopreservation. 28 bone marrows from healthy donors and 45 from patients who had undergone ABMT were assayed in LTBMC. The cultures were initiated after manual or automatic buffy coat cell separation or after density gradient or automatic mononucleated cells suspension. Bone marrows were studied pre- and post-cryopreservation. The results show that several manipulations can disturb normal cell behaviour in LTBMC. Following automatic mononucleated cell separation and after thawing, the development of adherent cell layer in LTBMC is anomalous. These manipulations led to a delay in covering 50% of the flask surface, absence of adypocytes in adherent cell layer and absence of haemopoietic precursors in the supernatant at the 4^th week of culture. The results suggest that LTBMC can be used for control of the manipulations in vitro related with ABMT.     

Immune modulation in autologous bone marrow transplantation: cyclosporine and gamma-interferon trial.

From March 1994 to November 1994, 16 patients with high risk hematological malignancies were entered in a phase I clinical trial, designed to confirm the toxicity of cyclosporine and gamma interferon given to induce autologous graft-versus-host disease (GVHD) after autologous bone marrow transplantation (ABMT). This trial was based on the results in a rodent model, in which cyclosporine given after ABMT induces an autoimmune syndrome (autologous GVHD) identical to allogeneic GVHD. Further, this autologous GVHD is associated with a graft-versus-tumor effect augmented by interferon that upregulates MHC class II expression on normal and tumor cells, the target of the cytolytic T cells in autologous GVHD. In this trial, cyclosporine 1 mg/kg/day was given from the day of bone marrow reinfusion until the completion of the interferon and gamma-interferon. Gamma-interferon at 0.025 mg/m2 every other day was started when the total white cell count was >200 cells/ml for 2 consecutive days and continued for a total of 10 doses after ABMT. The preparative regimens were busulfan and cyclophosphamide, or cyclophosphamide with total body irradiation. All patients received 4HC-purged marrow grafts. Median age was 45 years (range 19-68). The diagnoses included chemo-resistant non-Hodgkin's lymphoma (10), acute lymphoblastic leukemia (two), chemo-resistant Hodgkin's disease (two), acute myeloid leukemia (one), and multiple myeloma (one). Median absolute neutrophil count recovery was 25.5 days (range 19-46 days). Median platelet count recovery was 40.5 days (range 28-279 days). There were nine deaths, two were related to transplant toxicity (infection), while the other seven were due to relapse. Event-free survival with a median of 964 days (range 19-1441 days of follow-up was 44%. In conclusion, treatment with cyclosporine, and gamma-interferon after ABMT was well tolerated and did not impair engraftment. Further studies with a larger number of patients are required to document any beneficial anti-tumor effect of autologous GVHD induction after ABMT.     

Characteristics of engraftment after repeated autologous bone marrow transplantation

The rate of engraftment after autologous bone marrow transplantation (ABMT) is extremely variable and largely unpredictable. To identify factors influencing engraftment, we studied 35 patients with refractory germ cell tumors undergoing high-dose chemotherapy with carboplatin (900-2000 mg/m2) and etoposide (1200 mg/m2) with bone marrow rescue. Prior to the initiation of chemotherapy, bone marrow sufficient for two marrow infusions was harvested (range 0.86-4.82 x 10(8) nucleated cells per kg). All 35 patients received half of the collected bone marrow 3 days after the last dose of chemotherapy; 23 responders received a second round of the same chemotherapy followed by infusion of the second half of the bone marrow. Eighteen patients could be compared for the two transplant episodes. The "rate of engraftment" was defined as the unweighted mean of four parameters: 1) the number of days until the absolute granulocyte count surpassed 0.2 x 10(9)/liter, 2) the number of days until the absolute granulocyte count surpassed 0.5 x 10(9)/liter, 3) the number of days until the last platelet transfusion, and 4) the number of days until the reticulocyte count surpassed 25 x 10(9)/liter. No significant correlation was found between rate of engraftment and such factors as the number of nucleated cells per kg infused, the dose of chemotherapy, extent of prior chemotherapy, tumor response to the high-dose chemotherapy, age of the patient, or the days of granulocytopenic fever (all p greater than 0.20). In contrast, a close correlation was found for the number of units of platelets (p = 0.005) and red blood cells (p = 0.006) transfused following each of the two transplants. There was no significant difference between rate of engraftment after first and second transplantation. Comparison of these data with the results obtained in reported ABMT with separate harvests suggests that the characteristics of the infused marrow determine the rate of engraftment after ABMT. This model of repeated transplantation could provide an important tool for assessing the therapeutic efficacy of hematopoietic growth factors.     

Hematopoietic reconstitution after high-dose chemotherapy and autologous nonfrozen bone marrow rescue

Summary The kinetics of marrow engraftment were analyzed in 50 patient with acute leukemia (21), malignant lymphoma (15), and solid tumors (14) after high-dose multiagent chemotherapy followed by autologous bone marrow transplantation (ABMT) with nonfrozen bone marrow. Unseparated heparinized whole bone marrow was stored in 10% CPDA1 at 4°C for 72 h, then filtered and reinfused. The median number of nucleated cells reinfused was 1.6×10⁸/kg (range 0.5–3.8×10⁸/kg). All patients had a full hematopoietic reconstitution. Median time to achieve a neutrophil count > 500/l was 20 days (range 12–39) and median time to achieve an unsupported platelet count > 20.000/l was 20 days (range 10–55). The main factor associated with delayed engraftment was the number of prior chemotherapy cycles. We conclude that high-dose chemotherapy with nonfrozen ABMT is a safe procedure, without the requirement for costly cryopreservation facilities.     

Low level of gene transfer to and engraftment of murine bone marrow cells from long-term bone marrow cultures

OBJECTIVE: We wanted to determine whether the long-term bone marrow culture (LTBMC) transduction system would lead to efficient gene transfer and engraftment of murine repopulating hematopoietic stem cells (HSC), particularly in nonablated recipients. MATERIALS AND METHODS: Congenic mouse strains expressing Ly 5.1 or Ly 5.2 and the GP+E86 cell line producing the MGirL22Y vector carrying the gene for enhanced GFP were used. Murine LTBMCs were established and demi-depopulated on days 7 and 14 with addition of vector supernatant on days 8 and 15. RESULTS: Cell recovery on day 21 was 21.3%+/-3.8% of input cells and CFU-C recovery was 9.7+/-3.4% as compared with CFU-C of input cells. In vitro transduction efficiency determined by CFU-C expressing GFP was 22.2%+/-1.6%. In irradiated (950 cGy) mice transplanted with 2x10(6) LTBMC cells, 94% of nucleated cells in the blood at week 16 were of donor origin. However, GFP was only detected at low level in a few animals at week 4 and not later. Analysis of bone marrow from these mice at week 20 did not show any GFP expression and semiquantitative PCR revealed a transgene level of <1%. When 3.5-20.8x10(6) LTBMC cells (corresponding to 20-100x10(6) fresh cells) were transplanted to nonablated recipients, no engraftment or GFP expression were detected. Competitive repopulation experiments showed that the long-term repopulation ability (LTRA) of the LTMC cells was only 7% of fresh cells. CONCLUSION: These results indicate that LTBMC transduction of murine cells leads to low-level transduction of progenitors, no gene transfer to repopulating stem cells, and reduction in LTRA in ablated and nonablated recipients.     

Circulating erythropoietin levels after bone marrow transplantation: inappropriate response to anemia in allogeneic transplants.

We studied 24 recipients of autologous bone marrow transplantation (ABMT) or allogeneic BMT (BMT) to determine whether impaired erythropoietin (Epo) response to anemia could delay full erythropoietic recovery. Observed Epo levels were compared with predicted levels based on the relationship between Epo and hematocrit in 125 control subjects. Circulating Epo levels were normal during conditioning and the early posttransplant period. Between days 21 and 180, Epo levels remained normal in ABMT patients but were inappropriately low for the degree of anemia in BMT patients. Median time to full erythropoietic engraftment was longer in BMT than in ABMT recipients. Circulating Epo returned to appropriate levels after day 180, except in patients with active cytomegalovirus infection. We conclude that impaired Epo response to anemia can contribute to delayed erythropoietic recovery after allogenic BMT. Renal toxicity of ciclosporin, interaction between host and donor marrow, and cytomegalovirus infection might play a role. This study could support the use of recombinant human Epo to accelerate erythropoietic engraftment after BMT.     

Long-term culture of aplastic anaemia bone marrow

Long-term bone marrow cultures (LTBMC) were established with marrow from 11 patients with aplastic anaemia (AA). Bone marrow from five patients, with low numbers of committed progenitor cells, exhibited an increase in committed progenitor cell production to normal levels in the first week of LTBMC. None of 44 haematologically normal marrow cultures showed this increase. Mature and committed progenitor cell production in all cultures from aplastic anaemia bone marrow, declined faster than in normal cultures. This study indicates that short-term culture for committed progenitor cells is an underestimate of the proliferative capacity of bone marrow from some patients with AA. LTBMC may provide a useful system for further studies into the mechanisms responsible for this increased growth in some patients with AA.     

Analysis of factors affecting hematopoietic recovery after autologous bone marrow transplantation for lymphoma

Thirty patients with relapsed lymphoma (14 Hodgkin's disease, 16 non-Hodgkin's lymphoma) who underwent autologous bone marrow transplantation (ABMT) were assessed for the effect of different parameters on the rate of hematologic recovery post-ABMT. There was no correlation between nucleated cells count or numbers of CFU-GM or BFU-E in the infused marrow on either neutrophil or platelet recovery times. Patients with lymphoma who received more salvage chemotherapy (greater than six cycles) prior to marrow harvest took significantly longer to recover neutrophils to greater than 0.5 x 10(9)/l (p = 0.0229) and platelets to greater than 20 x 10(9)/l (p = 0.0007) than patients who received less than five cycles of salvage chemotherapy prior to harvest. There was no significant correlation between underlying disease, use of total body irradiation or status of cytomegalovirus serology and recovery times post-ABMT. The results suggest that extensive salvage chemotherapy may result in considerable stem cell damage to marrow, and that potential ABMT candidates with lymphoma should undergo harvest of tumor-free bone marrow as soon as possible following first relapse.     

The effect of macrophage colony-stimulating factor on haemopoietic recovery after autologous bone marrow transplantation

Macrophage colony-stimulating factor (M-CSF) is active in the late stages of monocyte maturation, activates mature monocyte-macrophages and enhances their production of various other cytokines. We have examined the effects of a 21 d course of escalating doses of M-CSF purified from human urine (hM-CSF) on recovery following autologous bone marrow transplantation (ABMT) in 20 patients with malignant lymphomas. Four patients were treated at each dose level of 4, 8, 16, 32 and 64 x 10(6) U/m2/d and results compared to 46 concurrent controls. There was no significant difference in recovery to an absolute neutrophil count (ANC) of 0.5 x 10(9)/l (median 20 d in hM-CSF group versus 22 in controls) or in recovery of platelets to 50 x 10(9)/l (32 d versus 39 d, 0.05 less than P less than 0.1); hM-CSF patients received a median of 81 platelet units following ABMT (controls 112 units, P = NS). hM-CSF patients had a median of 5.5 d with fever greater than 37.5 degrees C (control 8, P = NS), received parenteral antibiotics for 14.5 d (control 17, P = NS) and had a 50% incidence of bacteraemia (control 48%). hM-CSF treated patients were discharged by a median of day 29 following transplantation (control 33, P less than 0.05). Platelet and neutrophil recovery correlated significantly with the number of marrow mononuclear cells (MNC) reinfused in the hM-CSF group (P = 0.05 and P = 0.014 respectively) but not in controls. Subgroup analysis showed that hM-CSF patients receiving greater than 2 x 10(8) MNC/kg body weight reached an ANC of 0.5 x 10(9)/l by a median of day 16.5 (control 18.5, NS), became platelet transfusion independent by day 17 (control 29, P less than 0.05) and reached a platelet count of 50 x 10(9)/l by day 21 (control 40, P less than 0.05). No significant toxicity attributable to hM-CSF treatment was seen. These results suggest that hM-CSF accelerates platelet recovery following ABMT and that relatively large marrow innocula are required to see this effect.     

Enhanced myelopoiesis in long-term cultures of human bone marrow pretreated with recombinant granulocyte-macrophage colony-stimulating factor

Long-term bone marrow culture (LTBMC) for human hemopoiesis supports continuous proliferation and differentiation within the myeloid progenitor population by the formation of an adherent stromal monolayer. LTBMC represents the most suitable in vitro model for the study of regulatory mechanisms in human hemopoiesis. We investigated the effect of recombinant human granulocyte-macrophage colony-stimulating factor (rhuGM-CSF) on bone marrow of normal donors in LTBMC. The cells (2 x 10(6)/ml) were incubated with 100 ng/ml rhuGM-CSF for 24 h in culture medium supplemented with 10% fetal calf serum. After the preincubation, LTBMCs were started and maintained over a period of 10 weeks. After 1 week in culture we observed a statistically significant difference with a 1.5-fold higher number of nonadherent cells in the LTBMCs containing the bone marrow preincubated with rhuGM-CSF (p less than 0.05). This increase was due to an expansion of the mature myeloid cells. At the same time point the number of GM colony-forming units (CFU-GM)/ml in the LTBMCs with rhuGM-CSF-preincubated bone marrow was slightly increased compared to the controls without reaching a statistically significant level. We conclude that rhuGM-CSF at a saturation dose is a potent stimulator of in vitro myelopoiesis stem cell pool. This in vitro result is of relevance for the clinical use of rhuGM-CSF in patients undergoing bone marrow transplantation. The incubation of donor bone marrow prior to transplantation might be a new approach to facilitate the engraftment and to shorten the phase of pancytopenia.     

Addition of peripheral blood stem cells collected without mobilization techniques to transplanted autologous bone marrow did not hasten marrow recovery following myeloablative therapy.

A randomized prospective trial was conducted to determine if the addition of cryopreserved autologous peripheral blood stem cells (PBSC) collected without mobilization techniques to autologous cryopreserved bone marrow for patients receiving an autologous bone marrow transplant (ABMT) affected the time to marrow function recovery. Thirty-five evaluable patients with various malignancies were studied. Sixteen received PBSC + ABMT and 19 received ABMT alone. The PBSC were collected with 4 h leukapheresis procedures on 3 consecutive days. No manipulations to increase the number of circulating stem cells were used during the collections. The median time to recover 0.5 x 10(9)/l circulating granulocytes was 20 days after transplantation in the ABMT group and 27 days in the PBSC + ABMT group (p = 0.12). The median time to recover 20 x 10(9)/l platelets was 22 days after transplantation in the ABMT group and more than 27 days in the PBSC + ABMT group (p = 0.29). The day of discharge from the hospital was earlier for the ABMT group (median 29 days) than the PBSC + ABMT group (median 35 days, p = 0.03). We did not find that the addition of non-mobilized PBSC to infused autologous marrow accelerates marrow recovery.     

Reticulated platelet counts in patients undergoing autologous bone marrow transplantation: An aid in assessing marrow recovery

Thiazole orange (TO) is a fluorescent dye that is commonly used for flow cytometric measurement of erythrocytic reticulocytes. This technique has also been validated for counting “reticulated” platelets, as a measure of bone marrow thrombopoietic activity. Patients with an established diagnosis of idiopathic thrombocytopenic purpura (ITP) have been reported to have a three- to five-fold increase in the percent of circulating reticulated platelets. The current study was conducted to determine if platelet reticulocyte counts predicted recovery of bone marrow thrombopoietic activity following autologous bone marrow transplantation. We found an increase in the percent of circulating reticulated platelets preceding recovery of the platelet count; then, as the patients' platelet counts rose, the percent reticulated platelets fell. In patients with prolonged thrombocytopenia, a persistent increase in the proportion of reticulated platelets suggested a consumptive process, as opposed to failure of engraftment. Moderate transfusion of platelet concentrates did not interfere with the ability of the platelet reticulocyte measurements to detect increased thrombopoietic activity. Platelet transfusions did obscure any decrease in the proportion of reticulated platelets. Our results show that platelet reticulocyte counts could be useful in monitoring the recovery of marrow function following autologous bone marrow transplantation. © 1994 Wiley-Liss, Inc.     

The effects of pegylated recombinant human megakaryocyte growth and development factor (PEG-rHuMGDF) on platelet recovery in breast cancer patients undergoing autologous bone marrow transplantation

OBJECTIVE: To assess the safety and efficacy of pegylated recombinant human megakaryocyte growth and development factor (PEG-rHuMGDF) administered after autologous bone marrow transplantation (ABMT). PATIENTS AND METHODS: Two randomized, double-blind, placebo-controlled studies were done. In the phase 1/2 study, 75 breast cancer patients underwent a bone marrow harvest and myeloablative STAMP V chemotherapy and were randomized to receive placebo or one of three doses of PEG-rHuMGDF. In the phase 3 study, 64 patients were randomized to receive placebo or the minimally effective dose of PEG-rHuMGDF. The study drug was administered daily starting on the day of bone marrow infusion until the platelet count was greater than or equal to 50 x 10(9)/L (without transfusion) or for a maximum of 28 days. All patients received 10 microg/kg/day filgrastim starting on day 2 until neutrophil count recovery. RESULTS: PEG-rHuMGDF appeared to be safe and well tolerated. No significant differences were noted in mortality or disease progression rates. Antibodies to MGDF were not observed. In the phase 1/2 study, the time to platelet recovery to greater than or equal to 20 x 10(9)/L and platelet transfusion requirements were significantly reduced for patients treated with PEG-rHuMGDF compared with placebo (p < 0.05). In the phase 3 study, no significant differences in the kinetics of early thrombopoiesis or platelet transfusions after ABMT were observed. CONCLUSIONS: PEG-rHuMGDF was not consistently efficacious in reducing the duration of severe thrombocytopenia. The maximum platelet counts for PEG-rHuMGDF-treated patients occurred a median of 2 weeks after the last dose of drug, suggesting that the biologic effects of this hematopoietic cytokine are delayed compared with other hematopoietic cytokines.     

Successful autografting in chronic myeloid leukaemia after maintenance of marrow in culture

We have previously shown that Philadelphia chromosome (Ph1)-positive cells rapidly disappear when marrow from patients with chronic myeloid leukaemia (CML) is cultured under conditions that maintain normal haematopoiesis for many weeks. The ability of marrow maintained in culture for 10 days to serve as an autograft has now been tested in three patients treated with intensive chemoradiotherapy. Two weeks after transplantation, marrow samples from all patients showed trilineage haematopoiesis. Neutrophil counts greater than 1.0 x 10(9)/l were achieved in all patients within 4 weeks, and platelet counts greater than 20 x 10(9)/l were achieved in two patients within 5 weeks. During this period of haematopoietic recovery, marrow cells were exclusively Ph1-negative in two patients and predominantly so in the third. These results suggest that engraftment can occur from Ph1-negative haematopoietic stem cells selected by maintenance of autologous CML marrow in culture for 10 days. Thus, the feasibility of using this approach to allow intensive and potentially curative therapy for CML has been established.     

Autologous bone marrow transplantation using marrow incubated with Asta Z 7557 in adult acute leukemia

The sensitivity of human myeloblastic leukemic (CFU-L) and normal hemopoietic stem cells (CFU-GM and BFU-e) to Asta Z 7557 (INN Mafosfamide) was studied with regard to autologous bone marrow transplantation (ABMT) with cleansed marrow for consolidation therapy in adult patients with acute leukemia (AL) in remission. Establishment of the dose-response curves for CFU-GM (n = 37), BFUe (n = 11), and myeloblastic CFU-L (n = 9) demonstrated a wide range of sensitivity from patient to patient for all three progenitors. Whereas CFU-L, CFU- GM, and BFU-e grown in semisolid cultures disclosed similar sensitivities to Asta Z 7557, long-term culture (LTC) studies (n = 41) indicated a higher resistance of early progenitors. In an effort to achieve a maximum tumor cell kill and yet spare a sufficient amount of normal stem cells to ensure consistent engraftment, we defined the optimal dose for marrow cleansing as the dose sparing 5% CFU-GM (LD95). This dose was established from a preincubation test (PIT) realized on a 10-mL marrow aspirate taken 15 days before marrow collection in each individual patient. Twenty-four adult patients while in remission of AL (20 in complete remission, four in partial remission) were consolidated by cyclophosphamide 60 mg/kg X 2 and total body irradiation at 10 Gy followed by ABMT with marrow cleansed by Asta Z 7557 according to the specification described above. Patients were divided in two groups: group 1, unfavorable prognosis (11 patients); group 2, standard prognosis [13 patients in first complete remission (CR)]. All patients engrafted on leukocytes (median day for recovery to 10(9)/L: day 30), patients with ALL recovered faster than patients with ANL (median day 19 v 34). Similarly, recovery of platelets to 50.10(9)/L occurred sooner in patients with ALL (median day 67, range day 23 through 90) whereas three patients with acute nonlymphoblastic leukemia (ANLL) in group 2 had to be supported with platelet transfusions for more than one year. In group 1, six patients had recurrent tumor within six months; three patients died from toxicity with no evidence of tumor. Two patients are still disease-free with a short follow-up (nine and ten months). In group 2, two patients died from toxicity with no evidence of leukemia three and 16 months post-ABMT. One patient with a M5 ANLL and one patient with ALL relapsed at six and 15 months, respectively. Nine patients have remained in CR or are disease-free with a median follow-up of 22 months.(ABSTRACT TRUNCATED AT 400 WORDS)     

A phase II study of continuous infusion recombinant human granulocyte- macrophage colony-stimulating factor as an adjunct to autologous bone marrow transplantation for patients with non-Hodgkin's lymphoma in first remission

Recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) clearly hastens myeloid recovery in patients with relapsed hematologic malignancies undergoing autologous bone marrow transplantation (ABMT). In efforts to further improve neutrophil engraftment and shorten hospital stay in ABMT patients, rhGM-CSF was administered by a potentially more potent route (continuous infusion) to non-Hodgkin's lymphoma (NHL) patients with better BM reserve (first remission). Time to myeloid engraftment was compared with that of NHL patients treated in first remission at our institution on a similar ABMT protocol but without growth factor support (controls). Median neutrophil engraftment (absolute neutrophil count, 500 cells/microL) in first remission patients treated with rhGM-CSF was 14 days, compared with 22 days in controls (P = .0001). Hospital stays were also significantly reduced for rhGM-CSF patients (P = .0003). Platelet engraftment did not differ between the two groups. Persistent fever and generalized serositis were the primary toxicities. rhGM-CSF, delivered by this route, was efficacious but more toxic than 2-hour rhGM-CSF infusions previously reported by other investigators. Future alterations in both dose and schedule may retain comparable efficacy yet diminish toxicity.     

Analysis of factors predicting speed of hematologic recovery after transplantation with 4-hydroperoxycyclophosphamide-purged autologous bone marrow grafts

We previously described the predictive value of graft colony-forming units granulocyte macrophage (CFU-GM) content after 4-hydroperoxycyclophosphamide (4-HC) purging for the duration of aplasia after autologous bone marrow transplantation. Despite the uniform 4-HC concentration, we observed heterogeneity in CFU-GM survival and the kinetics of engraftment. We have now analysed patient and graft characteristics for 154 patients undergoing autologous transplantation with 4-HC purged grafts to further define this heterogeneity. Patients transplanted for the treatment of malignant lymphoma reached a peripheral blood granulocyte count of greater than 0.5 x 10(9)/l (median, 20 versus 40 days; p less than 0.001) and platelet transfusion independence (median, 30 versus 70 days; p less than 0.001) significantly faster than patients transplanted for acute non-lymphoblastic leukemia. Other diagnostic groups were intermediate. These differences were independent of graft CFU-GM content. Multiple other patient and graft factors including patient age, peripheral blood counts on day of harvest, and amounts of other hematopoietic progenitors also predicted the kinetics of engraftment in univariate and multivariate analysis. Cytomegalovirus infection during the aplastic period predicted a delay in granulocyte (p = 0.024) but not platelet recovery (p = 0.174). This analysis demonstrates that multiple patient, graft, and post-transplant factors predict the engraftment capacity of autografts, and the kinetics of engraftment with 4-HC purged grafts. The multiple predictive factors explain a significant portion of the variability in engraftment kinetics observed after transplantation with 4-HC purged autografts.     

Bone marrow transplantation with interleukin-2-activated bone marrow followed by interleukin-2 therapy for acute myeloid leukemia in mice

We have investigated approaches to induce graft-versus-leukemia (GVL) effect in autologous bone marrow transplantation (ABMT) without graft-versus-host disease to improve survival and cure in leukemia. The present study shows that bone marrow transplantation (BMT) using syngeneic bone marrow activated with interleukin-2 (ABM) for 24 hours in vitro, followed by interleukin-2 (IL-2) therapy, was superior to BMT with fresh, syngeneic bone marrow (FBM) in terms of survival and cure in mice with acute myeloid leukemia (P less than .001) and led to normal hematopoietic reconstitution. Addition of IL-2 therapy after BMT with FBM did not improve the results over BMT with FBM alone (P = .98). These results suggest that the GVL effect of ABMT can be enhanced by using ABM for BMT followed by IL-2 therapy without compromising engraftment.     

Increased levels of soluble flt-3 ligand in serum and long-term bone marrow culture supernatants in patients with chronic idiopathic neutropenia

The levels of serum and long-term bone marrow culture supernatant soluble flt-3 ligand (sFL) were determined in 54 patients with chronic idiopathic neutropenia (CIN) and 16 normal controls. Both serum and supernatant sFL levels were significantly increased in the patients compared with controls. Individual sFL values inversely correlated with the number of circulating neutrophils and the proportion of bone marrow CD34+ cells. Supernatant sFL values positively correlated with the levels of supernatant G-CSF. These findings suggest that the impaired myelopoiesis in CIN patients is accompanied by a compensatory mechanism attempting to increase the neutrophil production at the myeloid progenitor cell level.     

Loss of marrow reserve from dose-intensified chemotherapy results in impaired hematopoietic reconstitution after autologous transplantation: CD34(+), CD34(+)38(-), and week-6 CAFC assays predict poor engraftment

Autologous hematopoietic stem cell transplantation (HSCT) is an increasingly successful modality for treating a variety of malignant disorders in the clinic. Experimental and clinical data suggest that prior exposure to cytotoxic agents that damage primitive stem cells results in impaired hematopoiesis after autologous HSCT. To further investigate the ability to predict for impaired hematopoiesis, we measured different stem/progenitor cell populations transplanted and time to engraftment. Patients with previously untreated, advanced-stage follicular lymphoma were treated in sequential prospective protocols with 6-8 cycles of standard-dose (SD) cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP), or four cycles of a higher-dose (HD) CHOP and granulocyte colony-stimulating factor, to induce remission prior to high-dose cyclophosphamide, total body irradiation, and autologous bone marrow transplantation (ABMT). Cryopreserved marrow samples obtained prior to ABMT were assayed for CD34(+), CD34(+)38(-), and cobblestone area-forming cell (CAFC) frequencies.Despite receiving similar numbers of nucleated cells at ABMT, HD-CHOP patients took significantly longer to attain platelet engraftment than the SD-CHOP patients. Marrow from the HD-CHOP patients contained significantly lower CD34(+), CD34(+)38(-), and week 6-8 CAFC frequencies than marrow from SD-CHOP-treated patients. Time to platelet engraftment was plotted against progenitor/stem cell numbers transplanted for each patient and threshold values were developed for all three stem/progenitor cell populations. These values were 0.5 x 10(6) CD34(+) cells/kg, 0.14 x 10(6) CD34(+)38(-) cells/kg, and 9500 week-6 CAFC/kg transplanted. Approximately 50% of patients received marrow progenitor/stem cell numbers above the threshold values and all engrafted without delay. However, transplantation of stem/progenitor cell numbers below threshold values did not uniformly predict for delayed platelet engraftment.These data provide further evidence for the association of low marrow reserve at ABMT, low numbers of stem/progenitor cells transplanted, and delayed hematopoietic recovery. However, there remains a group of patients who have rapid platelet engraftment after ABMT despite low numbers of progenitor/stem cells transplanted. These data suggest the presence of a crucial stem cell population not represented by the stem/progenitor cell populations studied in these experiments.