Recovery Of CFU-GM Research Articles

Progenitor Cells Purging: Negative Selection

Disease relapse after autologous bone marrow transplantation (ABMT) may arise from residual tumor in the recipient and/or from cancer cells that are reinfused. The aim of purging by negative selection is to remove tumor cells from the marrow without adversely affecting the engraftment potential of the normal cell. We report the results of a study on fifty-six patients (pts) with non Hodgkin's lymphoma or acute leukemia submitted to ABMT after immunomagnetobead (IMB) purging (11 pts), Maphosphamide purging (31 pts) and no purging (14 pts). The IBM procedure involved one incubation of 3 monoclonal antibodies (CD10, CD19 and CD22) and two incubations with magnetic beads (Dynabeads M-450). The median recovery of mononuclear cells and CFU-GM was 40% and 45% after IMB purging and 84% and 5% after Maphosphamide purging respectively. The rate of leukocyte, neutrophils and platelets recovery following ABMT was similar in the three groups of pts, although platelet recovery was slow in patients received graft purged with Maphosphamide. Our study confirms the clinical feasibility of the IMB procedure, but only randomized studies will be able to definitely address the question of the clinical utility of purging.

Effect of stem cell factor (c-kit ligand), granulocyte-macrophage colony stimulating factor and interleukin 3 on hematopoietic progenitors in human long-term bone marrow cultures.

In this paper we attempt to improve upon the methods of hematopoietic stem cell expansion. We evaluate the effects of recombinant human stem cell factor (SCF or c-kit ligand) alone and also in combination with recombinant human granulocyte-macrophage colony stimulating factor (GM-CSF) and interleukin 3 (IL-3), on cell proliferation and differentiation in human long term bone marrow cultures (LTBMC). Weekly addition of 5 ng/ml of SCF with 25% serum containing media resulted in increased recovery of total nonadherent cells, granulocyte-macrophage colony forming units (CFU-GM), and burst-forming units erythroid (BFU-E) at week 1, but the number of bone marrow (BM) progenitor cells fell below the level of untreated control cultures at weeks 3 (BFU-E) and 4 (CFU-GM). At week 8, when the cultures were terminated, the CFU-GM recovery was markedly reduced in flasks supplemented with SCF compared with the controls (p < 0.002). Moreover, SCF treatment induced the early disappearance of BFU-E. When LTBMC were supplemented with the combination of SCF plus GM-CSF (100 U/ml) and IL-3 (5 ng/ml), synergistic activity of the CSFs was observed at week 1. The number of BM colony forming cells (CFC) rapidly declined below the level of growth factor-free controls, leading to the early exhaustion of the culture when SCF was combined with GM-CSF. By comparison, GM-CSF and IL-3 alone induced a statistically significant increase above the controls (no growth factor) in the number of nonadherent cell colonies of CFU-GM and BFU-E. Analysis of adherent layer cells from cultures supplemented with SCF showed increased cellularity, no adipogenesis, and early disappearance of myeloid progenitors while the percentage of CFU-GM in S phase, assessed by cytosine arabinoside (Ara-C) suicide assay, was 9.2 +/- 5% SD versus 27.7 +/- 10% SD in control (no growth factor) samples (p < 0.01). SCF increased the number of fibroblast colony forming units (CFU-F) and also showed a synergistic activity (9.6-fold increase) when combined with IL-3. These findings suggest that SCF, GM-CSF and IL-3 exert their activity on different cell populations within the hematopoietic system. Further investigations are needed to optimize the use of SCF in supporting hematopoiesis.

Influence of high versus low intestinal concentration of gram-negative bacteria and endotoxin on the susceptibility of murine myelopoiesis in bone marrow and spleen to cytostatic treatment with Ara-C

The haematopoietic recovery alter i.v. cytarabine was studied in C3H/Law mice as a measure for stem cell susceptibility in relation to the intestinal Gram-negative bacteria (GNB) and endotoxin. Reduction or elevation of GNB and endotoxin was induced by either polymyxin or bacitracin, both non-absorbable antibiotics. Bacitracin caused less suppression of the splenic cellularity after cytarabine, and an advancement of the recovery of femoral nucleated cells. The femoral recovery of CFU-GM exhibited a biphasic pattern. The Speed and height of the rebound increase of CFU-GMs were significantly affected by the antibiotics. Thus, (modulation of) the murine intestinal microflora influences the haematopoietic recovery after cytostatic drugs. The mechanisms involved are complex; intestinal endotoxin seems to play a role.

血液センターにおける造血幹細胞の調製および凍結保存について

We concentrated mononuclear cells (MNCs) containing hematopoietic stem cell from bone marrow (BM) or peripheral blood (PB) of patients and MNCs fraction were cryopreserved in cryoprotectant solution (final concentration: 6% hydroxyethyl starch, 5% dimethyl sulfoxide and 4% human serum albumin) without controlled-rate freezing. In preparation of bone marrow MNCs were concentrated by density gradient centrifugation using the COBE 2991, the recovery of MNCs and granulocytemacrophage colony forming unit (CFU-GM) were 56% and 83%, respectively, of the original BM. On the other hand, in preparation of peripheral MNCs were concentrated by low speed centrifugation of lymphocyte fraction collected using the COBE spectra, the recovery of MNCs and CFU-GM were 89% and 90%, respectively. After thawing of both cryopreserved preparations, the recovery of CFU-GM were 58% of original BM and 68% of original PB fraction. These results indicate that the techniques for the separation and storage of blood components in blood center are applicable for the preparation and storage of hematopoietic stem cells from BM and PB.

Radioprotection mediated by the haemopoietic stimulation conferred by AM5: a protein-associated polysaccharide.

The haemopoietic and radioprotective effects of a protein-associated polysaccharide named AM5, have been studied following i.v. injection in mice. A dose-related accumulation of the splenic granulocyte-macrophage colony-forming units (CFU-GM) and colony-forming units in the spleen (CFU-S) was observed in mice treated with doses ranging from 0.1 to 0.4 mg/kg of AM5. The accumulation of splenic CFU-S, CFU-GM and BFU-e (erythroid burst-forming units) was always maximal 5 days after treatment with 0.4 mg/kg of AM5, with increases over control values between 300% and 500%. When the number of haemopoietic progenitors was quantified in the bone marrow, only slight increases of CFU-S were obtained, corresponding to the administration of low doses of AM5 (0.1 mg/kg). However, significant increases of circulating CFU-S were observed following administration of higher doses of AM5, suggesting a mobilization of haemopoietic progenitors from this organ. A faster recovery of spleen CFU-GM was observed in mice treated with 0.4 mg/kg of AM5 3 days or 1 day prior to a sublethal irradiation, and at this later time AM5 produced a significant survival enhancement from 10% to 90% in mice irradiated with 7.6 Gy X-rays. This effect was correlated with an increase in the nadir of leucocytes, characteristic of the radiation syndrome.

Antiproliferative activity of quercetin on normal bone marrow and leukaemic progenitors

We used an in vitro clonogenic assay in semi-solid medium to test the sensitivity of normal bone marrow and acute myeloid and lymphoid leukaemia progenitors to the flavonol quercetin. We have studied 14 acute myeloid (AML) and four acute lymphoid (ALL) leukaemias. All ALL and the vast majority of AML (12/14) had a high sensitivity to quercetin with more than 50% growth inhibition at 2 x 10(-6) M quercetin. One M3-AML was partially quercetin-sensitive displaying 60% surviving AML-colony forming units (CFU-AML) at a quercetin concentration of 10(-5) M. One M1-AML was resistant to the growth inhibitory effect of quercetin at a concentration of 2 x 10(-5) M. The clonogenic efficiency of both AML and ALL positively correlated with leukaemic colony-forming unit (CFU-L) sensitivity to quercetin suggesting that this parameter can be useful in predicting quercetin responsiveness of leukaemic cells. We have also studied the effect of various quercetin concentrations on colony formation by normal bone marrow cells. At a quercetin concentration of 10(-5) M, we observed (in five different experiments) a mean recovery of 53% and 65% of erythroid blast-forming units (BFU-E) and granulocyte-macrophage colony-forming units (CFU-GM), respectively. Thus, normal bone marrow appeared partially resistant to quercetin, being inhibited less than 50% by quercetin concentration higher than 2 x 10(-5). When normal bone marrow were deprived in CD34+ haematopoietic progenitors the resultant population became highly sensitive to quercetin, with a mean recovery of BFU-E and CFU-GM of 5% and 12% of controls respectively in the presence of 2 x 10(-5) M quercetin. Furthermore, CD34 progenitors, positively selected, appeared fully resistant to quercetin concentrations as high as 2 x 10(-5) M. Thus, CD34+ progenitors are a quercetin-resistant component in normal bone marrow. In conclusion, our results further provide a biological basis for the therapeutic use of quercetin, considering that this compound could inhibit leukaemic cell growth without suppressing normal haematopoiesis.

STIMULATIVE EFFECTS OF RECOMBINANT HUMAN INTERLEUKIN-3 ON MARROW FIBROBLAST COLONY-FORMATING CELLS AND ITS APPLICATION TO AUTOLOGOUS BONE MARROW TRANSPLANTATION

We investigated the toxic effect of mafosfa-mide on marrow stromal progenitor cells (CFU-F) and compared it with the sensitivity of normal hemopoietic progenitor cells (CFU-GM, BFU-E) . Mafosfamide used in our clinical protocol at a dose individually adjusted prior to ABMT not only diminished the recovery of CFU-GM and BFU-E with a respective median of 1 % and 5 %, but also severely injured marrow F-CFU with a median recovery of 16.7% (P<0.001) . These results were different from data previously reported by others on hemopoietic toxicity of 4-hydroperoxycy-clophosphamide (4-HC) which showed a significantly higher resistance of F-CFU as compared to CFU-GM and BFU-E. In this paper, we also reported the stimulating effect of human recombi-nant Il-3, at doses of 8u/ml, on CFU-F formation either from normal controls, or from mafosfamide treated marrow.. Since a functional hemopoietic stroma might be a prerequisite for an optimal hemopoietic reconstitution, these data suggested, in the context of ABMT, a possible beneficial role of IL-3, either used in vitro or in viro. Key words: Human recombinant IL3; bone marrow fibroblast; ABMT

Influence of hydrocortisone on the survival and cluster and colony forming characteristics of normal human granulocyte‐macrophage progenitors

This study was performed to determine the colony and cluster forming ability of granulocyte-macrophage (CFU-GM) progenitors of normal human blood low density cells cultured in a liquid culture system in the presence and absence of physiological doses of hydrocortisone (Hc). The CFU-GM recovered from the liquid cultures were assayed in soft agar medium. The results of the assays indicated that time-related development of clusters and colonies over 1-16 days, proliferative responsiveness to a source of colony stimulating activity, number of cells developed per colony, and the cellular composition of clusters and colonies produced from CFU-GM recovered from 14-day-old liquid cultures with 1.0 microM Hc, were all similar to those that developed from the normal human blood low density cells. However, a higher fraction of the CFU-GM in day 14 liquid cultures with 1.0 microM Hc were in DNA synthesis phase compared with the CFU-GM from the peripheral blood. This study confirmed the results of previous studies showing lower numbers of recognizable neutrophilic granulocytes and improved survival/proliferation of CFU-GM at day 14 in liquid cultures with 1.0 microM Hc compared with cultures without Hc. The present results suggest that the normal human blood CFU-GM which persists and proliferates under the influence of Hc in a liquid culture system is similar in ontogeny to the blood CFU-GM, and that the recovery of CFU-GM from liquid cultures under the influence of Hc appears to be exerted through stimulation of proliferation and controlled differentiation.

Comparison of five methods for concentrating progenitor cells in human marrow transplantation

Enrichment of bone marrow (BM) aspirates is an important prerequisite prior to in vitro treatment or cryopreservation. In this regard, we have analyzed the results obtained on 190 BM processed by the following 5 techniques: HES sedimentation with centrifugation; COBE 2991 blood cell processor; Ficoll/hypaque (F/H) gradient centrifugation; Continuous flow cell separator (CS 3000 Fenwal); Semicontinuous blood cell separator (Dideco T 90). Each procedure was evaluated by measuring the recovery of nucleated marrow cells (NC), mononuclear cells (MNC), committed progenitor cells (CFU-GM), the reduction of BM volume and the removal of red blood cells (RBC) and polymorphonuclear cells (PMN). The results of this comparative study show that F/H gradient on a COBE 2991 cell washer provides the most efficient system for purifying a MNC fraction (89% recovery) from unwanted cells (RBC less than 2% and PMN less than 2%) in a very small volume (98% reduction) with a good recovery of CFU-GM (80%).

Dose rate and fractionation of total body irradiation in dogs: Short and long term effects

Variations of regimens of total body irradiation (TBI) were investigated in the dog as a preclinical model for bone marrow transplantation. Inactivation of hemopoietic precursor cells (CFU-GM) was studied following irradiation of marrow in vitro, following TBI at sublethal doses in vivo and following autologous transplantation of marrow obtained after sublethal TBI. Inactivation and recovery of CFU-GM as well as restoration of hemopoiesis following autologous transplantation was independent of the dose rate, but nadirs of blood counts were lower following sublethal TBI with the higher dose rate. Acute non-hemopoietic toxicity of TBI depended on the dose, the dose rate and the total treatment time and not on the fractionation regimen. At a total dose of 25 Gy acute mortality was prevented by prophylactic administration of oral, non-absorbable antibiotics. Late mortality was due to degenerative and autoimmune-like disorders with or without infections and to malignant tumors. Evaluation of long-term survival is still preliminary, since surviving dogs of two groups (10 Gy as single dose, 25 Gy as hyperfractionated TBI) have not yet reached the median survival time of their group. So far, long-term survival depended on the total dose (p = 0.05) and, possibly, the fractionation regimen (p = 0.12). The latency period until development of malignant tumors was influenced by the total doses given in the same treatment time (p = 0.05) and by the total treatment time for equal doses (p = 0.04). It was concluded that TBI at a low dose rate may give the best therapeutic ratio of inactivation of hemopoietic precursor cells to acute toxicity. A possible benefit of hyperfractionation on long-term survival due to less toxicity has to be weighed against less effective inactivation of clonogenic hemopoietic precursors and less effective immunosuppression seen in allogeneic transplantation.

Bone marrow processing on the Haemonetics V50 cell separator

We have processed 27 bone marrow (BM) harvests using the Haemonetics V50 cell separator with a paediatric plasmapheresis set and programmed for lymphocyte collection. The mean starting volume of 843 mL was processed in 6–8 cycles to a buffy coat (BC) with a mean volume of 230 mL. The mean starting mononuclear cell (MNC) count was 1.22 × 10 8/kg recipient weight, and recovery was 92%. Clonogenic potential of the BC was assessed using CFU-GM assays and recovery was measured after cryopreservation or purging. On 4 occasions where major ABO incompatibility existed between donor and recipient, both BM and BC were consecutively diluted in compatible blood and processed twice. This achieved a calculated reduction in donor erythrocytes of 98%. The procedure was efficient and yielded a BC fraction suitable for cryopreservation and purging. Adequate stem-cells were retained as verified by CFU-GM assays and documentation of stable engraftment.

Comparative Regimens for the ex vivo Chemopurification of B Cell Lymphoma-Contaminated Marrow

The success of autologous bone marrow transplantation for B cell lymphoma may depend on the efficacy of in vitro purification of patients' tumor cell-contaminated marrow. In this study, we tested the toxicity of seven different chemotherapeutic agents against two B cell lymphoma lines (LY-16 and SK-DHL-2) as compared to normal human bone marrow granulocyte-macrophage progenitor cells (CFU-GM). 4-Hydroperoxycyclophosphamide (4-HC), VP-16-213 (VP-16), nitrogen mustard, and vincristine showed a highly selective toxicity against cultured lymphoma cells; i.e., at doses sufficient to induce a 4-log clonogenic tumor cell reduction (4-HC 21 micrograms/ml, VP-16 50 micrograms/ml, nitrogen mustard and vincristine 5 micrograms/ml), 10.0 +/- 6.7, 3.0 +/- 3.2, 23.2 +/- 22.7 and 24.0 +/- 17.0% (mean +/- 1 SD), respectively, of normal bone marrow CFU-GM were preserved. The differential sensitivity of tumor cells and normal hematopoietic precursors was less prominent after exposure of cells to cis-diamminechloroplatinum II (cis-platinum); thus, at a drug dose of 100 micrograms/ml, all detectable lymphoma cells could be eradicated (i.e., greater than or equal to 4 log reduction) while a CFU-GM recovery of only 0.2 +/- 0.2% was observed. In contrast, adriamycin and bleomycin, at the highest tumoricidal concentrations tested (5 and 100 micrograms/ml, respectively) did not exhibit a selective toxicity toward lymphoma cell lines. In summary, our results suggest that nitrogen mustard and vincristine, as well as 4-HC and VP-16, may be useful agents for the ex vivo treatment of bone marrow grafts form B cell lymphoma patients.

The use of the Fenwal CS3000 cell separator to purify a mononuclear cell fraction from pooled buffy coats

Using a modified plateletpheresis program on the Fenwal CS3000, we have studied the recovery of mononuclear cells and clonogenic potential from pooled buffy coats. Recovery of mononuclear cells and CFU-GM was 90% and 67%, respectively. The final volume could easily be adjusted to 100 mL, and erythrocyte contamination was low (2.3%). This method should be readily applicable to bone marrow processing to achieve efficient and rapid separation for subsequent reinfusion, cryopreservation, and treatment with monoclonal antibodies.

Prenatal and Neonatal Irradiation in Dogs: Hematologic and Hematopoietic Responses

Hematologic and hematopoietic responses were evaluated in beagle dogs following a single prenatal (35 days gestation) or neonatal (10 days postpartum) exposure to 1.5 Gy 60Co gamma radiation. Hematopoiesis was studied by the in vitro culture of bone marrow granulocyte-macrophage progenitors (CFU-GM). Prenatally irradiated dogs exhibited a progressive, significant reduction in CFU-GM which was accompanied by decreases in peripheral blood leukocytes up to 24 weeks of age. Dogs which were neonatally irradiated also demonstrated a significant reduction in CFU-GM which was accompanied by significant alterations in peripheral white and red blood cell parameters. This was transient, however, and these dogs showed partial recovery of CFU-GM and hematologic parameter by 24 weeks of age. The persistent CFU-GM deficit in prenatally irradiated dogs suggests a relatively greater sensitivity of fetal marrow as compared to neonatal bone marrow for long-term damage by ionizing radiation.

Variability in 4-Hydroperoxycyclophosphamide Activity During Clinical Purging for Autologous Bone Marrow Transplantation

We examined the effects of varying incubation conditions on the in vitro activity of 4-hydroperoxycyclophosphamide (4HC). 4HC activity against CFU-GM and against the K562 tumor cell line decreased with increasing the RBC concentration of the incubation mixture. Increasing the concentration of nucleated bone marrow cells in the incubation mixture also decreased the 4HC activity. Evaluation of 53 consecutive patients undergoing autologous bone marrow transplantation (BMT) revealed that the incubation RBC concentration during clinical purging showed a similar effect on CFU-GM recovery. Aldehyde dehydrogenase content of RBCs and nucleated marrow cells appears to be the cause of the inhibition of 4HC activity. Although there was no difference in individual CFU-GM sensitivity to 4HC among normals, previously treated patients undergoing autologous BMT showed significant variability in CFU-GM sensitivity to 4HC. The combined effects of incubation RBC concentration and individual patient 4HC sensitivity appear to account for most of the variability in CFU-GM recovery and speed of hematologic recovery after clinical purging with 4HC.

Variability in 4-hydroperoxycyclophosphamide activity during clinical purging for autologous bone marrow transplantation

We examined the effects of varying incubation conditions on the in vitro activity of 4-hydroperoxycyclophosphamide (4HC). 4HC activity against CFU-GM and against the K562 tumor cell line decreased with increasing the RBC concentration of the incubation mixture. Increasing the concentration of nucleated bone marrow cells in the incubation mixture also decreased the 4HC activity. Evaluation of 53 consecutive patients undergoing autologous bone marrow transplantation (BMT) revealed that the incubation RBC concentration during clinical purging showed a similar effect on CFU-GM recovery. Aldehyde dehydrogenase content of RBCs and nucleated marrow cells appears to be the cause of the inhibition of 4HC activity. Although there was no difference in individual CFU-GM sensitivity to 4HC among normals, previously treated patients undergoing autologous BMT showed significant variability in CFU-GM sensitivity to 4HC. The combined effects of incubation RBC concentration and individual patient 4HC sensitivity appear to account for most of the variability in CFU-GM recovery and speed of hematologic recovery after clinical purging with 4HC.

Autologous Bone Marrow Transplantation Using Unfractionated Cells Cryopreserved in Dimethylsulfoxide and Hydroxyethyl Starch Without Controlled-Rate Freezing

AbstractTo develop a simplified method of bone marrow (BM) cryopreservation, changes were made in the standard method in three areas: the cryoprotectant, the method of cell freezing, and the storage temperature. Unfractionated BM cells from 60 patients were cryopreserved in 300-mL aliquots in both dimethylsulfoxide (DMSO) and hydroxyethyl starch (HES), a combination known to preserve granulocytes successfully. The cells were frozen without rate-controlled freezing by simple immersion into a –80°C freezer where they remained until the time of reinfusion. The 60 patients underwent 72 autologous transplants after three high-dose chemotherapy regimens: 30 received high-dose carmustine in combination, five received high-dose busulfan and cyclophosphamide, and 37 received high-dose aziridinylbenzoquinone. The BM was infused for more than 30 minutes after rapid thawing at 37°C. The mean postthaw nucleated cell recovery was 96% ± 11.6%, and Trypan blue dye exclusion was 82.2% ± 9.2%. The mean postthaw CFU-GM and BFU-E recoveries were 81.9% ± 39.0% and 90.5% ± 41.2%. Complete count recovery occurred in 68 of 72 transplants. Median times to a WBC count >1,000/μL, a granulocyte count >1,000/μL and a platelet count >20,000/μL were 15, 21, and 15 days, respectively. Risk factors for delayed recovery were not found. Unfractionated BM cells can be successfully cryopreserved in the DMSO/HES mixture rapidly and inexpensively, without rate-controlled freezing or storage at liquid nitrogen temperatures.

Autologous bone marrow transplantation using unfractionated cells cryopreserved in dimethylsulfoxide and hydroxyethyl starch without controlled-rate freezing

To develop a simplified method of bone marrow (BM) cryopreservation, changes were made in the standard method in three areas: the cryoprotectant, the method of cell freezing, and the storage temperature. Unfractionated BM cells from 60 patients were cryopreserved in 300-mL aliquots in both dimethylsulfoxide (DMSO) and hydroxyethyl starch (HES), a combination known to preserve granulocytes successfully. The cells were frozen without rate-controlled freezing by simple immersion into a -80 degrees C freezer where they remained until the time of reinfusion. The 60 patients underwent 72 autologous transplants after three high-dose chemotherapy regimens: 30 received high-dose carmustine in combination, five received high-dose busulfan and cyclophosphamide, and 37 received high-dose aziridinylbenzoquinone. The BM was infused for more than 30 minutes after rapid thawing at 37 degrees C. The mean post-thaw nucleated cell recovery was 96% +/- 11.6%, and Trypan blue dye exclusion was 82.2% +/- 9.2%. The mean postthaw CFU-GM and BFU-E recoveries were 81.9% +/- 39.0% and 90.5% +/- 41.2%. Complete count recovery occurred in 68 of 72 transplants. Median times to a WBC count greater than 1,000/microL, a granulocyte count greater than 1,000/microL and a platelet count greater than 20,000/microL were 15, 21, and 15 days, respectively. Risk factors for delayed recovery were not found. Unfractionated BM cells can be successfully cryopreserved in the DMSO/HES mixture rapidly and inexpensively, without rate-controlled freezing or storage at liquid nitrogen temperatures.

CFU-GM Content of Bone Marrow Graft Correlates With Time to Hematologic Reconstitution Following Autologous Bone Marrow Transplantation With 4-Hydroperoxycyclophosphamide-Purged Bone Marrow

Autologous bone marrow transplants (BMTs) can repopulate the hematologic system of patients treated with marrow-ablative chemotherapy and/or radiotherapy. However, treatment of the bone marrow graft to eliminate residual tumor cells prior to reinfusion can delay the return of peripheral blood elements, presumably from damage to or loss of hematopoietic stem cells responsible for hematologic recovery. To develop a model predictive of hematologic recovery, we studied the progenitor cell contents of 4-hydroperoxycyclophosphamide (100 micrograms/mL)-purged bone marrow grafts of 40 consecutive patients undergoing autologous BMT at this center. Granulocyte-macrophage colonies (CFU-GM) were grown from all grafts after treatment with this chemotherapeutic agent, but erythroid (BFU-E) and mixed (CFU-GEMM) colonies were grown from only 44% and 33% of the grafts respectively. The recovery of CFU-GM after purging ranged from 0.07% to 23%. The logarithm of CFU-GM content of the treated grafts was linearly correlated with the time to recovery of peripheral blood leukocytes (r = -0.80), neutrophils (r = -0.79), reticulocytes (r = -0.60), and platelets (r = -0.66). The CFU-GM content of purged autologous bone marrow grafts may reflect the hematopoietic stem cell content of the grafts and thus predict the rate of hematologic recovery in patients undergoing autologous BMT.

CFU-GM content of bone marrow graft correlates with time to hematologic reconstitution following autologous bone marrow transplantation with 4- hydroperoxycyclophosphamide-purged bone marrow

Autologous bone marrow transplants (BMTs) can repopulate the hematologic system of patients treated with marrow-ablative chemotherapy and/or radiotherapy. However, treatment of the bone marrow graft to eliminate residual tumor cells prior to reinfusion can delay the return of peripheral blood elements, presumably from damage to or loss of hematopoietic stem cells responsible for hematologic recovery. To develop a model predictive of hematologic recovery, we studied the progenitor cell contents of 4-hydroperoxycyclophosphamide (100 micrograms/mL)-purged bone marrow grafts of 40 consecutive patients undergoing autologous BMT at this center. Granulocyte-macrophage colonies (CFU-GM) were grown from all grafts after treatment with this chemotherapeutic agent, but erythroid (BFU-E) and mixed (CFU-GEMM) colonies were grown from only 44% and 33% of the grafts respectively. The recovery of CFU-GM after purging ranged from 0.07% to 23%. The logarithm of CFU-GM content of the treated grafts was linearly correlated with the time to recovery of peripheral blood leukocytes (r = -0.80), neutrophils (r = -0.79), reticulocytes (r = -0.60), and platelets (r = -0.66). The CFU-GM content of purged autologous bone marrow grafts may reflect the hematopoietic stem cell content of the grafts and thus predict the rate of hematologic recovery in patients undergoing autologous BMT.