Biomedical subjects

S D Rowley

Publications and source records attributed to S D Rowley.

At least 55 records · Page 3Linked to original sources

PubMed1991

Selection of normal human hematopoietic stem cells for bone marrow transplantation using immunomagnetic microspheres and CD34 antibody.

Complete yet nontoxic removal of tumor cells from autologous marrow grafts has proved difficult. New methods for separating normal stem cells from tumor cells are needed. The CD34+ cells in bone marrow, 1-2% of the low-density leukocytes, include precursors of all lymphohematopoietic lineages and probably also the primitive cells responsible for engraftment. A nontoxic, inexpensive, reproducible, and clinically applicable method for positive selection of CD34+ cells was developed. Paramagnetic microspheres coated with goat anti-mouse IgG1 are used to partition the cells; brief incubation with chymopapain is used to release them from the beads. Chymopapain exposure does not injury colony-forming cells or delay engraftment in rodents. Clinical volumes of bone marrow can be processed rapidly. In pilot experiments, the resulting grafts have a purity of 85-99% CD34+ cells and 40% median recovery of the assayable colony-forming cells. These studies form the background for a Phase I trial of autologous BMT using CD34+ stem cells.

Animals↗

PubMed1991

Phase I study of combination drug purging for autologous bone marrow transplantation.

In a phase I clinical trial of autologous bone marrow transplantation, we determined the feasibility of ex vivo purging with high concentrations of pharmacologics in combination. Light-density cells isolated from the grafts of 26 patients with acute leukemia or lymphoblastic lymphoma were treated with 4-hydroperoxycyclophosphamide (4-HC; 30 to 60 micrograms/mL), vincristine (Vcr; 1.5 to 3.0 micrograms/mL), and methylprednisolone sodium succinate (MP; 5 mg/mL). All patients received marrow-lethal induction therapy followed by infusion of the treated grafts. Three patients died of transplant-related complications before achieving peripheral blood recovery of greater than 0.5 x 10(9) granulocytes per liter. All other patients achieved this parameter of engraftment at a median of 35 days after marrow infusion. The median time to last platelet transfusion was 45 days. These durations of aplasia were similar to those experienced by other patients receiving density-gradient separated grafts treated with 60 micrograms/mL of 4-HC as a single agent. No patient required infusion of untreated reserve marrow because of engraftment failure. The colony-forming unit-granulocyte macrophage (CFU-GM) content of the grafts after purging predicted these parameters of engraftment. Colony-forming unit-leukemia (CFU-L) cultured from the grafts of 12 of the patients treated for acute lymphoblastic leukemia (ALL) were considerably more sensitive to the combination regimen than to 4-HC alone; the sensitivity of CFU-GM from these patients did not differ between the two regimens. The results of this trial indicate the feasibility of treating autologous bone marrow grafts with high concentrations of pharmacologics in combination. The use of combinations may increase the efficacy of ex vivo purging without increasing the toxicity to normal hematopoietic cells.

Adolescent↗

PubMed1991

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.

Adolescent↗

PubMed1990

Bone marrow graft engineering by counterflow centrifugal elutriation: results of a phase I-II clinical trial.

In an attempt to reduce the incidence and severity of acute graft-versus-host disease (GVHD), we have decreased the number of bone marrow (BM) lymphocytes in the donor marrow graft before bone marrow transplantation (BMT) using counterflow centrifugal elutriation (CCE). In a phase I-II clinical trial, 23 patients received lymphocyte-depleted BM allografts from their HLA-identical, mixed lymphocyte culture (MLC)-nonreactive sibling donors. The patients entered in the study were deemed to be at high risk for treatment failure on the basis of age (greater than 30 years; median, 39 years) and the result of our skin explant assay predictive of acute GVHD. Patients predicted not to develop acute GVHD by this assay were excluded from this study. All patients received a standard lymphocyte dose of 0.5 x 10(6) morphologic lymphocytes per kilogram ideal body weight (IBW) in the marrow graft and were maintained on cyclosporine A (CsA) immunosuppression for 170 days after BMT. Prompt hematopoietic recovery occurred in 22 of 23 patients with a median time to an absolute neutrophil count (ANC) greater than or equal to 500/microL of 21 days. Donor cell engraftment was subsequently verified by cytogenetic and/or DNA analysis in all of 21 evaluable patients. No patient developed systemic acute GVHD. Only five (22%) developed cutaneous GVHD (clinical stage 1) that required steroid treatment, including one patient who failed to engraft. The median follow-up of the patients enrolled in this study is 14 months (range, 5 to 20 months). Actuarial survival 1 year after BMT is 83%. Thus, in two consecutive clinical trials using CCE to deplete donor BM of alloreactive lymphocytes (1.0 x 10(6) versus 0.5 x 10(6) lymphocytes/kg), we have demonstrated that the procedure does not interfere with BM engraftment and is effective in decreasing the incidence and severity of acute GVHD. Furthermore, comparison of these studies has revealed a differential dose response relationship between the number of graft lymphocytes, protection of engraftment, and induction of acute GVHD. Although there appears to be a modest relationship between lymphocyte dose and time to hematopoietic recovery, the 50% reduction in lymphocyte dose from that used in our previous trial resulted in a marked decrease in acute GVHD without compromising engraftment.

Adult↗

PubMed1990

Clinical toxicity of cryopreserved bone marrow graft infusion.

We prospectively evaluated infusion-related toxicities in 82 recipients of autologous bone marrow grafts. The grafts were cryopreserved in 10% dimethylsulfoxide and stored in liquid nitrogen. All grafts were concentrated and buffy-coat cells were collected. Forty-seven grafts were treated ex vivo with 4-hydroperoxycyclophosphamide (4-HC) at 100 micrograms/mL; 26 grafts were further processed using density-gradient separation and treated with 4-HC at 60 micrograms/mL. Nine buffy-coat concentrates were frozen without drug treatment. Before infusion, patients were medicated with mannitol, hydrocortisone, and diphenhydramine. Grafts were rapidly thawed and immediately infused without further manipulation. During the infusions, 33 (70%) recipients of treated buffy-coat, 5 (56%) recipients of untreated buffy-coat, and 6 (23%) recipients of density-gradient separated grafts experienced varying symptoms including nausea, abdominal cramping, and flushing. Forced vital capacities for 83% of the recipients of treated buffy-coat concentrates decreased after the graft infusion; six of these patients complained of dyspnea and one patient experienced an acute episode of respiratory decompensation. Decreased heart rates were observed in 98% of the recipients of treated buffy-coat cells with asymptomatic bradycardia occurring in 45%. Forty-five patients (96%) in this group experienced transient hypertension, with 18 (38%) requiring additional medications within 6 hours after the infusion for control of blood pressure. Similar cardiovascular changes were observed in the recipients of untreated buffy-coat concentrates. One recipient of an untreated buffy-coat concentrate had 2 degrees heart block after the graft infusion. Twenty-three (88%) recipients of density-gradient separated grafts had decreased heart rates and 21 (81%) had increased blood pressure. However, the degrees of change were less than those experienced by the recipients of treated buffy-coat cells (P less than .01). Forced vital capacities were not affected by the infusion of the density-gradient separated grafts. No renal failure or obvious hemolytic episodes occurred for any patient group. Minor to moderate toxicities were associated with cryopreserved graft infusions. Recipients of buffy-coat separated grafts, both treated and untreated, experienced more complications than the recipients of density-gradient separated grafts. These toxicities may relate to the volumes of cryoprotectant and cell lysis products infused, which were less for the more highly purified density-gradient separated grafts.

Blood Chemical Analysis↗

PubMed1990

Ex vivo chemopurging of autologous bone marrow with 4-hydroperoxycyclophosphamide to eliminate occult leukemic cells. Laboratory and clinical observations.

The application of autologous bone marrow transplantation (ABMT) in treating acute leukemias in children has been limited by the presence of residual occult viable leukemic cells in the marrow cell suspension. One approach to this problem is the ex vivo treatment ("purging") of the autograft to eradicate these tumor cells yet spare the normal lymphohematopoietic stem cells. Initial studies of acute myeloid leukemia (AML) in a rodent model demonstrated that incubation with 4-hydroperoxycyclophosphamide (4HC), a congener of cyclophosphamide and an active alkylating agent in aqueous solution, could effectively eliminate viable AML cells from marrow cell suspensions without apparent toxicity to normal stem cells. We have conducted clinical trials of ABMT with 4HC-treated marrow in children with acute leukemia in remission; marrow was collected, treated ex vivo with 4HC (100 micrograms/ml), and cryopreserved in liquid nitrogen until reinfusion. Children received pre-ABMT conditioning with either high-dose cyclophosphamide and total body irradiation (CY-TBI) for acute lymphocytic leukemia (ALL) or high-dose busulfan and cyclophosphamide (BU-CY) for AML. Of nine children who underwent ABMT with 4HC-treated marrow for ALL in second complete remission (CR2), all relapsed (eight in the marrow, one in the central nervous system) at a median of 5 months (range, 2-17) after ABMT and all have died with relapsed ALL or as a consequence of its treatment. Twenty-nine children with AML (five in CR1, 24 in CR2) received autografts with chemopurged marrow at a median remission duration of 3 months (range, 2-15). Three patients died from sepsis during aplasia; 10 children (one in CR1 and nine in CR2) relapsed with AML at a median of 7 months (range, 2-23) after ABMT, for an actuarial relapse rate of 47%. Sixteen patients with AML (four in CR1, 12 in CR2) are in unmaintained remission at a median of 16 months (range, 6-102) after ABMT, for an actuarial disease-free survival of 49%. Although ABMT with 4HC-treated marrow appears to have a limited role in the treatment of children with ALL who lack a suitable related donor, the results in AML are encouraging and compare favorably with both syngeneic and allogeneic BMT in similar groups of patients.

Actuarial Analysis↗

PubMed1990

High-dose cytotoxic therapy and bone marrow transplantation for relapsed Hodgkin's disease.

Patients with Hodgkin's disease who have failed two or more chemotherapy regimens or who have relapsed after an initial chemotherapy-induced remission of less than 12 months are seldom cured with conventional salvage therapies. We studied the effect of high-dose cytoreductive therapy followed by bone marrow transplantation in 50 such patients with relapsed Hodgkin's disease. Twenty-one patients with histocompatibility locus antigen (HLA)-matched donors had allogeneic marrow transplants, one patient received marrow from an identical twin, and 28 patients without a matched donor received autologous grafts purged with 4-hydroperoxycyclophosphamide. Busulfan plus cyclophosphamide was the preparative regimen for the 25 patients who had received extensive prior irradiation, and the other 25 patients received cyclophosphamide plus total body irradiation. The overall actuarial probability of event-free survival at 3 years was 30%, with a median follow-up of 26 months. The event-free survival following transplantation was influenced by the number of chemotherapy failures and the patient's response to conventional salvage therapy prior to transplant. The 16 patients who were transplanted at first relapse, while still responsive to standard therapy, had a 64% actuarial probability of event-free survival at 3 years. Age, presence of extranodal disease, preparative regimen, and type of graft (autologous v allogeneic) were not significant prognostic factors. The majority of transplant-related deaths were from interstitial pneumonitis; inadequate pulmonary function, multiple prior chemotherapy regimens, and prior chest irradiation all appeared to increase the transplant-related mortality. These results suggest a role for marrow transplantation in a subset of patients with relapsed Hodgkin's disease who are unlikely to be otherwise cured but are still responsive to conventional-dose cytoreductive therapy.

Actuarial Analysis↗

PubMed1990

Using elutriation to engineer bone marrow allografts.

We have used elutriation to deplete lymphocytes from the marrow allografts of 64 patients to date. The first phase I trial (1 x 10(6) lymphocytes/kg IBW) was designed to test the procedure for potential toxicities, most notably, graft failure. Study 2 (1 x 10(6) lymphocytes/kg, no CsA) was expected to reduce potential toxicity incurred from long term immunoprophylaxis while study 3 was aimed at reducing the incidence of GVHD by further reducing lymphocyte dose (5 x 10(5)/kg). Graft lymphocyte dose was based on morphologic determination and was subsequently confirmed by limiting dilution analysis and flow cytometry. Although grafts were standardized solely by lymphocyte dose, the product was more uniform than the original harvested BM with respect to other cell populations. Nearly all study I (n = 40) and study III (n = 20) patients engrafted with a median time to ANC greater than 500/ul of 19 days. Three of the 4 patients consecutively enrolled in study II failed to engraft, thus terminating the trial. While a moderate proportion of study I patients had AGVHD (44%) with attendant morbidity, only 20% of study III patients were found to have mild AGVHD (less than or equal to stage I). To date, this cohort has no organ or chronic GVHD and no GVHD-associated morbidity. Median follow-up times for patients in studies I and III are 27 and 11 months, respectively. Overall actuarial survival (n = 60) is 42% at 38 months (38% study I, 80% study III). Good prognosis study I patients experienced 45% actuarial survival versus 9% in the poor prognostic group. While lymphocyte depletion has been effective in reducing the incidence and severity of AGVHD, new strategies are needed to address the issue of disease relapse. As with other methods, lymphocyte depletion by elutriation caused an increased rate of leukemia relapse. The actuarial probability of remaining in remission for recipients of elutriated marrow containing 1 x 10(6) and 5 x 10(5) lymphocytes/kg, respectively, were 60% and 46% at 16 months. Elutriation provides a rapid, reproducible and flexible methodology for graft manipulation which has been effective in reducing the incidence and severity of AGVHD. However, if lymphocyte depletion is to fulfill its promise as a means of reducing the overall morbidity of allogeneic BMT, new strategies may be needed to address the issue of relapse. These may include changes in marrow ablative therapy and post-graft immunosuppression. Equally as important may be the ability to further manipulate accessory cells and lymphoid populations presently excluded from the graft.

Adult↗

PubMed1990

Density-gradient separation of autologous bone marrow grafts before ex vivo purging with 4-hydroperoxycyclophosphamide.

We found in previous studies that the cytotoxicity of 4-hydroperoxycyclophosphamide (4-HC) toward normal and malignant cells in autologous bone marrow grafts was modulated by the variable erythrocyte content of the incubation mixture. This affected both the kinetics of engraftment and the probability of leukemic relapse. To decrease this variability in 4-HC cytotoxicity, we initiated a trial of density-gradient separation of the autografts to remove erythrocytes and other mature blood cells before the 4-HC treatment. A series of 64 consecutive patients was studied. Light-density (sp. gr. much less than 1.077 g/ml) cells were isolated in a 2-step procedure by Ficoll-diatrizoate separation of previously isolated buffy-coat cells. Overall cell recovery after buffy-coat and gradient separations was 28.9 +/- 11.7% ( +/- SD). These cells were then treated with 60 micrograms/ml of 4-HC. The erythrocyte content of the incubation mixtures averaged 0.8%, and did not predict percent CFU-GM survival after the 4-HC incubation. The variability in CFU-GM survival after the purge was less than for previous patients who received buffy-coat cells (with erythrocyte contents ranging from 4-22%) treated with 100 micrograms/ml of 4-HC, indicating that a more uniform purge was achieved. Although the selected dose of 4-HC (60 micrograms/ml) yielded a lower CFU-GM survival, the kinetics of engraftment did not significantly differ between the recipients of light-density or buffy-coat cells. No patient required use of a 'backup' graft because of engraftment failure.

Adolescent↗

PubMed1990

Toxicity of autologous bone marrow graft infusion.

We prospectively evaluated infusion-related toxicities in 70 patients undergoing autologous bone marrow transplantation. We studied symptoms, vital signs, forced vital capacities, and serum chemistry changes associated with the infusion. The bone marrow grafts were cryopreserved in 10% dimethylsulfoxide (DMSO) and stored in liquid nitrogen. All grafts were concentrated by centrifugation and the buffy-coat cells collected. Additionally, 20 grafts had mononuclear cells collected using density-gradients. Before infusion, the patients were medicated with hydration, mannitol, hydrocortisone, and diphenhydramine. The grafts were rapidly thawed and immediately infused without further manipulation. The mean volume infused to patients who received buffy-coat grafts was 6.3 +/- 1.7 ml/kg containing 0.7 +/- 0.2 gm/kg of DMSO. Patients who received density-gradient separated grafts received a product with a volume of 2.9 +/- 1.3 ml/kg containing 0.3 +/- 0.1 gm/kg DMSO. Symptoms included nausea, abdominal cramping, and flushing; patients who received buffy-coat grafts had more complaints. These patients also had mild increases in AST, ALT, and total bilirubin. Forced vital capacities were decreased in this group after the graft infusion; this change was not associated with the infusion of the density-gradient separated products. There was a significant difference (p less than 0.01) in heart rate and blood pressure changes associated with the infusions. Patients who received the larger product had a minimum heart rate of 63.3 +/- 12.4 BPM as compared to 80.7 +/- 18.0 BPM for the other patients. We found minor to moderate toxicities associated with the graft infusions, which were more severe in patients who received buffy-coat grafts. This could have resulted from the greater amounts of DMSO, cell lysis products, or volumes infused.

Adolescent↗

PubMed1990

In vitro evaluation of combination drug purging for autologous bone marrow transplantation.

Using an in vitro model, we studied whether combining 4-hydroperoxycyclophosphamide (4HC) with other drugs could improve its effectiveness as an ex vivo purging agent for autologous bone marrow transplantation. 4HC was incubated simultaneously with vincristine and etoposide, and sequentially with methylprednisolone, in various combinations. Compared to 4HC alone, all drug combinations increased the kill of the leukemia cell lines K562 and CEM without increasing the kill of granulocyte-macrophage colony-forming units (CFU-GM). The combination of 4HC, vincristine and methylprednisolone was the most active, and this drug combination was also the only combination which showed improved selective cytotoxicity (compared to 4HC alone) toward REH cells. This combination inhibited at least 8 logs of clonogenic leukemia cells from all three cell lines at doses which spared 1% of CFU-GM. This was an increase of 1.7 to 6.6 logs of clonogenic leukemia cell kill over 4HC alone. This drug combination displayed similar differential activity between fresh clonogenic leukemia cells and CFU-GM cultured from the bone marrows of seven patients about to undergo autologous bone marrow transplantation for acute lymphocytic leukemia.

Antineoplastic Combined Chemotherapy Protocols↗

PubMed1989

Efficacy of ex vivo purging for autologous bone marrow transplantation in the treatment of acute nonlymphoblastic leukemia.

We used an in vitro measure of drug activity to predict the efficacy of ex vivo purging of leukemic cells from autologous bone marrow grafts. We previously found that the myeloid progenitor cell (CFU-GM) content of the marrow grafts after ex vivo purging with 4-hydroperoxycyclophosphamide (4-HC) correlates with time to hematologic recovery after autologous bone marrow transplantation in patients with acute nonlymphoblastic leukemia. We observed that variable red blood cell concentration of the bone marrow incubation mixture results in differential cytotoxic activity of 4-HC. The CFU-GM content of the graft after the ex vivo treatment is a measure of this 4-HC activity. We analyzed the disease-free survival of 45 patients with acute nonlymphoblastic leukemia undergoing autologous bone marrow transplantation with 4-HC purged grafts. Patients who relapsed after transplantation had 4.2 +/- 1.1% of graft CFU-GM surviving the ex vivo purge, compared with 1.1 +/- 0.4% for patients who achieved a sustained remission (P = .06). Twenty-three patients with a CFU-GM content after 4-HC purging of greater than 1% of the pretreatment value had an actuarial disease-free survival of 12%, compared to 36% for 22 patients with a less than or equal to 1% CFU-GM content after purging (P = .006). Therefore, percent CFU-GM survival as a measure of 4-HC cytotoxicity identified a group of patients with insufficient purging. Although no randomized clinical trials have documented the need for ex vivo purging, our results suggest that effective bone marrow purging is important for the optimal application of autologous transplantation in the treatment of acute nonlymphoblastic leukemia.

Age Factors↗

PubMed1989

Correlation of hematologic recovery with CFU-GM content of autologous bone marrow grafts treated with 4-hydroperoxycyclophosphamide. Culture after cryopreservation.

We previously described an exponential correlation of the CFU-GM content of 4-hydroperoxycyclophosphamide-treated autologous bone marrow grafts and the rate of hematologic recovery of the recipients after transplantation. Those grafts were assayed before cryopreservation. We now describe a similar analysis based upon cultures of the thawed bone marrow. In a proportional hazards model, the CFU-GM content of the grafts sampled after thawing predicted time to achieving a peripheral blood count of 1 X 10(9)/l leukocytes, 0.5 X 10(9)/l granulocytes, 2% reticulocytes, and last platelet transfusion (p less than 0.001). Using linear regression analysis, the logarithm of the CFU-GM content/kg of recipient weight also was correlated with the time to achieving 1 X 10(9)/l leukocytes (r = -0.62), and 0.5 X 10(9)/l granulocytes (r = -0.66). The hazard ratios (Cox model) and regression coefficients (linear regression model) for the equations calculated from the post-thaw cultures were usually smaller than the corresponding coefficients based upon the pre-freeze cultures, suggesting that pre-freeze cultures may be more accurate predictors of aplasia duration. However, patients with poor post-freeze survival of CFU-GM were more likely to experience delayed engraftment. Therefore, the correlation of post-thaw cultures with engraftment may permit the analysis of cryopreservation techniques.

Adolescent↗

PubMed1987

Dye-mediated photolysis of normal and neoplastic hematopoietic cells.

The purpose of this study was to determine the sensitivity to merocyanine 540 (MC 540)-mediated photolysis of normal human hematopoietic progenitor cells and four leukemia cell lines (Daudi, Raji, K562 and HL-60). Late erythroid progenitors were the most sensitive normal cells. Early erythroid progenitors were of intermediate sensitivity. Granulocyte/macrophage progenitors and multipotent progenitors were the least sensitive normal marrow cells. A combination of dye concentration, serum concentration, and illumination that eliminated 50% of multipotent progenitor cells reduced the concentration of leukemic cells by greater than or equal to 4.5 log. It is conceivable that this difference in photosensitivity can be exploited for the extracorporeal purging of autologous remission marrow grafts.

Bone Marrow Cells↗

PubMed1987

Allogeneic, syngeneic and autologous marrow transplantation in the acute leukemias and lymphomas--Baltimore experiences.

Allogeneic bone marrow transplants (BMT) in acute lymphoblastic leukemia following cyclophosphamide (Cy) and total body irradiation (TBI) has resulted in disease-free survival (DFS) for CR1, CR2, and CR3 of 10/18 (56%), 16/30 (53%) and 4/17 (24%), respectively. Median follow-up of survivors was 25-43 months. One relapse was seen in CR1, 1 in CR2, and 6 in CR3. Allogeneic BMT in acute nonlymphoblastic leukemia (ANLL) following busulfan (Bu) resulted in DFS for CR1, CR2 + CR3 + early relapse of 21/47 (45%) and 13/41 (32%), respectively. Median DFS of survivors of all groups together was 36 months. DFS of all patients 20 years or less was 15/27 (56%) and 19/61 (31%) for ages 21-46. Three relapses of 47 (6%) were seen in CR1 and 6/41 (15%) in subsequent remission and early relapse. BMT of autologous BMT with 4-hydroperoxy-cyclophosphamide (4-HC) purged marrow in ANLL in CR1 (5), CR2 (32) and CR3 (9) following Bu + Cy resulted in DFS of 19/46 (41%) for 1-67 months (median 15 months). Twenty patients with prior risk non-Hodgkin's lymphoma received 4-HC-purged marrow following Cy + TBI. DFS was 10/20 (50%) for 1.4-9.5 years (median 2.9 years).

Acute Disease↗

PubMed1987

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.

Adolescent↗

PubMed1987

Progenitor cell assays predict hematopoietic reconstitution after syngeneic transplantation in mice.

Hematopoietic reconstitution following syngeneic bone marrow transplantation with graded doses of untreated and drug-treated bone marrow was studied in B6D2F1 mice. Granulocyte-macrophage colony-forming units (CFU-GM) and spleen colony-forming units (CFU-S) showed similar in vitro drug sensitivities. Both the speed of hematologic recovery and survival of mice transplanted with untreated or drug-treated bone marrow were directly related to the number of CFU-GM or CFU-S transplanted. Similar hematologic recovery was seen for untreated marrow transplants and treated transplants that had similar CFU-GM or CFU-S content. There is a minimum number of transplanted CFU-GM or CFU-S that allows survival of lethally irradiated mice. This number is present in a marrow transplant containing the equivalent of 5 X 10(3) untreated cells or producing one to two spleen colonies. There also exists a maximum value for the number of hematopoietic progenitors in a marrow graft, above which the rate of hematologic recovery following transplantation is rapid and no detectable increase in the rate is seen with increasing CFU-GM or CFU-S content. The presence of this maximum value for transplanted progenitors and variations in culture techniques are probably the reasons previous studies have not always shown a correlation between CFU-GM content and hematologic recovery after bone marrow transplantation.

Animals↗

PubMed1987

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.

Bone Marrow↗