To investigate the effect of colony-stimulating factors (CSFs) on drug metabolism using theophylline as a substrate (phase I), and to evaluate the influence of theophylline on endogenous serum cytokine concentrations (phase II).

Hemopoietic stem cell differentiation represents the primary rule of self-renewal, proliferation, and specialization modulated by several mechanisms, including growth factors, cell interactions, and bioavailability of various ions, especially Ca2+ and Zn2+. Apoptotic death, during normal cell turnover, has been widely studied and is recognized as an important pathway for clonal deletion in the hemopoietic system. Multiparametric analyses have shown that subjects with Down syndrome show low levels of plasmic zinc associated with the presence of immature myeloid cells in the peripheral blood. This arrangement is repaired by in vivo zinc therapy. This study presents morphological and biochemical analyses to show that ZnSO4 therapy induces the disappearance of peripheral myeloid precursor cells by a programmed cell death mechanism. The programmed zinc-therapy-induced cell death presumably provides a simple way to regulate the myeloid differentiation selecting appropriate cells.

One reason for relapse after high-dose tumor therapy with subsequent autologous stem cell transplantation is tumor cell contamination of the graft. Removal of tumor cells from bone marrow grafts by chemopurging with the ether lipid edelfosine has been established as an effective and simple method. When compared with bone marrow derived grafts, progenitor cells from peripheral blood have considerably reduced the haematological recovery times. However, this advantage is put at risk by the nonspecific haematotoxic activity of the purging agent. We therefore compared the in vitro recovery of peripheral blood derived progenitor cells (PBPC) from either non-purged (n = 41) or purged (75 micrograms/ml of ether lipid for 4 h at 37 degrees C, n = 48) leukapheresis products. The recovery of CFU-GM after cryopreservation was 63 +/- 4% without and 48 +/- 3% with purging (P = 0.007). After high-dose therapy, patients (n = 37) received similar amounts of either non-purged (n = 17) or purged (n = 20) autologous PBPC. The median haematological recovery times (non-purged vs purged) to > 500 WBC/microlitres were 9.0 vs 8.5 days after transplantation, to > 2000 PMN/microlitres 10.5 vs 10.0 days, and to > 50,000 PLT/microlitres 15.5 vs 14.0 days. All differences were statistically not significant. We conclude that ether lipid purging of PBPC leads to a significant, however tolerable loss of progenitor cells in vitro, and that haematological recovery times after high-dose therapy are identically short, provided similar amounts of PBPC are reinfused.

Children with GH deficiency have enlarged fat cells but a reduced number of fat cells compared with healthy children. After treatment with human GH (hGH) both fat cell volume and number are shifted toward normal. To clarify the role of hGH in fat cell formation in human adipose tissue, we investigated the effect of hGH on the proliferation and the differentiation of cultured human adipocyte precursor cells obtained from five children and 10 adults. In a chemically defined serum-free medium treatment of adipocyte precursor cells with hGH led to an increase in IGF-I production and a stimulation of cell proliferation, which could be blocked by a MAb raised against human IGF-I. hGH dose-dependently reduced the number of differentiating cells and suppressed the expression of glycerol-3-phosphate dehydrogenase (GPDH), a marker of adipose differentiation. No significant differences in the hGH effects on proliferation and differentiation capacities were seen between cultures obtained from children and adults. In newly differentiated adipocytes, hGH inhibited glucose uptake and lipogenesis, and stimulated lipolysis. Scatchard analysis of hGH competition experiments using 125I-labeled hGH yielded a linear plot with an apparent Kd of 1.08 nM and an estimated number of 7000 hGH receptors per cell. These data suggest that hGH is able to enlarge the human adipocyte precursor pool via induction of IGF-I synthesis but exhibits a direct antiadipogenic activity. hGH is also able to reduce fat cell volume by reducing lipogenesis and increasing lipolysis.

Mobilization of peripheral-blood cells (PBC) with cytokines alone results in rapid hematopoietic recovery and avoids the potential morbidity associated with mobilization by chemotherapy. PIXY321, a fusion protein that consists of granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-3 (IL-3), has enhanced hematopoietic colony-forming activity as compared with individual or equimolar combinations of the two cytokines. A phase I trial of PIXY321 for mobilization of PBC in patients with malignant lymphoma was performed.

We investigated the risks and benefits of allogeneic bone marrow transplantation in children with complications of sickle cell disease.

In this article, we review neoplastic contamination in the peripheral blood (PB) of patients with multiple myeloma (MM) upon stem cell mobilization. We first evaluated PB samples from pretreated MM patients following administration of high-dose cyclophosphamide (Cy, 7 g/m2 or 4 g/m2) and granulocyte colony-stimulating factor (G-CSF) for the presence of myeloma cells as well as hematopoietic progenitors. Plasma cells containing intracytoplasmic immunoglobulin (cIg) were counted by immunofluorescence microscopy after incubation with appropriate antisera against light and heavy chain Ig. Flow cytometry studies were performed to determine the presence of malignant B lineage elements, using monoclonal antibodies against the CD19 antigen and the monotypic light chain. Prior to PBSC mobilization, circulating plasma cells were detected in all MM patients at 0.1%-1.8% of the mononuclear cell (MNC) fraction (mean value 0.7 +/- 0.4% SD). In these patients, a higher absolute number of PB neoplastic cells was detected after administration of chemotherapy and G-CSF. Kinetic analysis showed a pattern of tumor cell mobilization similar to that of normal hematopoietic progenitors, with the peak coinciding with the optimal period for the collection of PBSC. The absolute number of plasma cells showed a 10-50-fold increase over the baseline value. Apheresis products contained 0.7 +/- 0.2% SD myeloma cells (range 0.2%-2.7%), which demonstrated the capacity of plasma cells to proliferate, differentiate, and mature in response to c-kit ligand (SCF), IL-3, IL-6, and a combination of IL-3 and IL-6. Subsequently, in an attempt to reduce tumor cell contamination prior to autologous transplantation, circulating hematopoietic CD34+ cells were highly enriched by avidin-biotin immunoabsorption, cryopreserved, and used to reconstitute bone marrow (BM) function after myeloablative therapy in 13 patients. The median purity of the enriched CD34+ cell population was 89.5% (range 51%-94%), with a 75-fold enrichment compared with the pretreatment samples. The median overall recovery of CD34+ cells and CFU-GM was 58% (range 33%-95%) and 45% (range 7%-100%), respectively. Positive selection of CD34+ cells resulted in 2.5-3 log depletion of plasma cells and CD 19+ B lineage cells as determined by immunofluorescence studies, although DNA analysis of the CDR III region of the IgH gene demonstrated the persistence of minimal residual disease (MRD) in 5 of 6 patient samples studied. Myeloma patients were reinfused with enriched CD34+ cells after myeloablative therapy consisting of total body irradiation (TBI, 1000 cGy) and high-dose melphalan (140 mg/m2) or melphalan (200 mg/m2) alone. They received a median of 5 x 10(6) CD34+ cells/kg and showed a rapid reconstitution of hematopoiesis. The median time to 0.5 x 10(9) neutrophils, 20 x 10(9) and 50 x 10(9) platelets/L of PB was 10, 11, and 12 days, respectively. These results, as well as other clinically significant parameters, did not significantly differ from those of patients (n = 13) receiving unmanipulated PBSC following the same pretransplant conditioning regimen. Our data demonstrate the concomitant mobilization of tumor cells and hematopoietic progenitors in the PB of MM patients. Positive selection of CD34+ cells reduces the contamination of myeloma cells from the apheresis products up to 3 log and provides a cell suspension capable of restoring normal hematopoiesis following a TBI-containing conditioning regimen.

Primary CNS malignancies are responsible for approximately 12,000 deaths annually in the United States. There has been little change in the outcome for adults with malignant brain tumors over the past few decades, despite improvements in surgical techniques and advances in radiation therapy. These tumors are uniformly fatal one to two years after diagnosis. The morbidity and mortality of this disease arise from the effects of a locally invasive, non-metastasizing lesion. The patients may suffer from seizures, paralysis, incoordination, aphasia, confusion, memory loss, sensory deficits or visual loss, depending on the regions of the brain affected. In addition, they usually require large doses of corticosteroids early and late in their illness, and may experience disabling side effects of this treatment, such as edema, proximal myopathy, diabetes, fungal infections or deep vein thrombosis. Few patients in the older age group are able to work after the diagnosis. Most of the patients are incapable of self-care for several months before death. The localized transfer of new genes into cancer cells potentially permits the expression of proteins with specific biologic functions that may provide a means to alter the biology of tumor growth through a variety of mechanisms including increasing tumor immunogenicity, inducing the local expression of toxic agents, and sensitization of tumors to chemotherapeutic agents. Gene therapy with the transfer of the drug susceptibility gene Herpes virus thymidine kinase (HSV-TK) has shown promise in a number of animal models, including CNS tumors. This study will evaluate the use of adenovirus-mediated transfer of the HSV-TK gene into primary human brain tumors followed by systemic treatment with ganciclovir. The goals of this phase I study are to evaluate the overall safety and efficacy of this treatment and to gain insight into the parameters that may limit the general applicability of this approach. In this phase I study, patients with recurrent gliomas will receive stereotactic-guided injections of the virus into the brain tumor, followed by intravenous ganciclovir for 14 days. Patients eligible to undergo a palliative debulking procedure will receive the same treatment followed by resection on day 7. At the time of resection a second dose of virus will be administered intra-operatively into the residual, unresectable portion of the tumor, and intravenous ganciclovir will be continued for additional 14 days. Tissue removed at the time of resection will be analyzed for evidence of adenovirus infection, thymidine kinase expression and signs of inflammation. The size and metabolic activity of all tumors will be followed by volumetric MRI scans and Position Emission Tomography Scans, respectively. Patients will be enrolled in groups of three, with each group receiving successively larger doses of adenovirus. This study will quantify the toxicity of this therapy, and provide evidence as to the duration of transgene expression and virus induced inflammation.

One of the main obstacles for the use of high-dose chemotherapy with autologous hematopoietic progenitor cell support in the treatment of malignancies is the possibility of reinfusing clonogenic tumor cells with the hematopoietic graft. Purging of the graft with chemicals can reduce the number of tumor cells but can also damage the normal hematopoietic progenitors. Preclinical studies showed that the phosphorylated sulfhydryl compound amifostine (WR-2721) can protect normal hematopoietic progenitors from damage from alkylating agents. We conducted a randomized clinical trial in patients with breast cancer, non-Hodgkin's lymphoma, and Hodgkin's disease undergoing autologous bone marrow transplant. In this study, patients were randomized to have their bone marrow purged with 4-hydroperoxycyclophosphamide (4-HC) with (arm A) or without (arm B) amifostine. The percentage of colony-forming unit granulocyte-macrophages recovered after purging was higher in the amifostine arm, both in patients with breast cancer and in those with lymphoma, although this difference was not statistically significant. In addition, the time to engraftment was significantly shorter in the amifostine arm in both cohorts. We showed that pretreatment of bone marrow with amifostine prior to purging with 4-HC can protect normal hematopoietic progenitors from damage by 4-HC. This resulted in shorter engraftment rates and less need for supportive care.

High-dose methylprednisolone (HDMP) treatment has been shown to induce the differentiation of myeloid leukemic cells to mature granulocytes in patients with acute promyelocytic leukemia and other subtypes of acute myeloblastic leukemia (AML). HDMP administration has also been shown to accelerate the recovery of leukocytes and increase bone marrow hematopoietic CD34+ progenitor cells in patients with acute lymphoblastic leukemia (ALL). In the present study, we evaluated the effect of short-course (4-day) HDMP treatment on peripheral blood (PB) CD34+ cells in patients with acute leukemia (AL). Fourteen children with AL who were receiving maintenance therapy were enrolled in this study. Methyl-prednisolone was given orally as a single daily dose of 30 mg/kg for only 4 days to nine children (three AML, six ALL) in whom chemotherapy-induced leukopenia (< 2 x 10(9)/L) was observed. Circulating CD34+ progenitor cells were determined by flow cytometry before (day 0) and 4 and 7 days after HDMP treatment. On days 4 and 7 after initiation of HDMP treatment, the number of PB CD34+ cells increased significantly (p < 0.05). Hematopoietic CD34+ progenitor cells were also determined in five patients with AL (two AML, three ALL) and chemotherapy-induced leukopenia who did not receive HDMP. The number of CD34+ cells was found to be significantly (p < 0.05) higher in the patients who received HDMP than in those who did not. Along with PB CD34+ progenitor cells, white blood cells (WBC), polymorphonuclear cells (PMN), and monocytes also increased significantly (p < 0.05) in patients treated with short-course HDMP. In conclusion, short-course HDMP treatment can be used to shorten the chemotherapy-induced leukopenic period in patients with AL, possibly by increasing the number of hematopoietic progenitor cells. Further studies are needed to evaluate the effect of this treatment on leukopenic patients with other malignancies.

The objective of this study was to characterize CD34+ cell grafts, obtained using a novel technique, from children undergoing autologous bone marrow transplantation (BMT) for cancer therapy. In particular, we wanted to determine if the CD34+ marrow cell grafts generated hematopoietic reconstitution, since a positive result would motivate further development and use of this methodology.

To reduce the morbidity and mortality associated with unrelated donor bone marrow (BM) transplantation and potentially extend the pool of suitable donors, cryopreserved unrelated donor umbilical cord blood was considered as an alternate source of hematopoietic stem cells for transplantation. Patients with leukemia, BM failure syndrome, or inborn error of metabolism were eligible for a phase I clinical trial designed to estimate the risk of graft failure and severe acute graft-versus-host disease after transplantation of umbilical cord blood from unrelated donors. As of December 21, 1995, unrelated donor umbilical cord blood was used to reconstitute hematopoiesis in eighteen patients aged 0.1 to 21.3 years weighing 3.3 to 78.8 kg with acquired or congenital lympho-hematopoietic disorders or metabolic disease. Patients received either HLA-matched (n = 7) or HLA-1 to 3 antigen disparate (n = 11) grafts collected and evaluated by the New York Blood Center (New York, NY). The probability of engraftment after unrelated donor umbilical cord blood transplantation was 100% with no patient having late graft failure to date. The probability of grade III-IV acute graft-versus-host disease at 100 days was 11%. With a median follow-up of 6 months (range, 1.6 to 17 months); the probability of survival at 6 months is 65% in this high risk patient population. We conclude that cryopreserved umbilical cord blood from HLA-matched and mismatched unrelated donors is a sufficient source of transplantable hematopoietic stem cells with high probability of donor derived engraftment and low risk of refractory severe acute graft-versus-host disease. Limitations with regard to recipient size and degree of donor HLA disparity remain to be determined.

Transplantation of bone marrow from unrelated donors is limited by a lack of HLA-matched donors and the risk of graft-versus-host disease (GVHD). Placental blood from sibling donors can reconstitute hematopoiesis. We report preliminary results of transplantation using partially HLA-mismatched placental blood from unrelated donors.

Consecutive patients with non-Hodgkin's lymphoma (NHL, n = 133) or Hodgkin's disease (HD, n = 20) were treated with 12.0 Gy of fractionated total body irradiation, etoposide 60 mg/kg, and CY 100 mg/kg followed by infusion of autologous hematopoietic stem cells. Seventy-nine patients received purged (n = 62) or unpurged BM (n = 17), and 74 received unpurged PBSCs alone (n = 56) or with BM (n = 18). The median day for achieving a sustained granulocyte count of 0.5 x 10(9)/I was 14 range (7-66) for BM recipients and 10 (7-30) for PBSC +/- BM recipients (P = 0.03). A platelet count of 20 x 10(9)/I was achieved at a median of day 24 (6-145) in BM recipients and day 11 (range, 7-56) in PBSC +/- BM recipients (P = 0.007). The median number of platelet units transfused was 86 (0-1432) for BM recipients and 30 (6-786) for PBSC +/- BM recipients (P = 0.001). The median number of hospital days was 36 (10-88) for BM recipients and 27 (14-76) for PBSC +/- BM recipients (P = 0.0001). The unadjusted Kaplan-Meier (KM) estimates of survival, event-free survival (EFS) and relapse at 2 years were 0.57, 0.45 and 0.43 for patients receiving BM and 0.55, 0.36 and 0.59 for patients receiving PBSC +/- BM. After adjusting for confounding variables, the estimated relative risk (RR) of death from any cause was 0.92 (P = 0.75), of relapse was 1.25 (P = 0.39), of non-relapse mortality was 0.71 (P = 0.42) and of mortality and/or relapse was 1.17 (P = 0.48) for patients receiving PBSC +/- BM as compared to BM. For 46 patients with NHL receiving unpurged PBSC alone, the unadjusted KM estimate of relapse was 0.61 compared with 0.48 for 52 comparable patients receiving purged BM, while the RR for relapse for patients receiving unpurged PBSCs was 1.37 (P = 0.33) after adjusting for other significant covariates. These data confirm previous observations that patients who receive PBSC +/- BM have faster engraftment, fewer transfusions and shorter hospital stays than patients who receive only BM. There were no statistically significant differences between the two groups in survival, relapse, death from causes other than relapse and event-free survival.

The characteristics of PBSC mobilized with GM-CSF, which has been shown to augment monocyte/macrophage (Mo/Mx) antitumor and accessory activities, were evaluated. Patients with metastatic cancers were treated with GM-CSF at 5 micrograms/kg sc, days 1 to 7; leukaphereses were performed on days 6 and 7. A mean of 3.3 x 10(10) mononuclear cells were collected, 59% of which were lymphoid and 32%, monocytoid. Spontaneous Mo/Mx tumor cell cytotoxicity was not detectable in the leukapheresis product, either before or after cryopreservation; Mo/Mx tumor cell cytotoxicity, however, was inducible in vitro with IFN-gamma. Likewise, spontaneous lymphocyte cytotoxicity was not detectable in the leukapheresis product; lymphokine-activated killer cell activity was inducible in vitro with IL-2. Whereas lymphoproliferative responses to tetanus toxoid of cryopreserved PBSC were less than that of freshly collected PBSC, the capacity of Mo/Mx from cryopreserved PBSC to function as accessory cells in the lymphoproliferative response was maintained. These results indicate that significant numbers of immune cells can be mobilized with GM-CSF alone. Cryopreserved, GM-CSF-mobilized PBSC do not demonstrate spontaneous antitumor cytolytic activity; however, accessory activity is present and antitumor cytolytic activity mediated by both monocytoid and lymphoid cells is inducible.

Peripheral blood stem cell (PBSC) transplantation gives rapid recovery of neutrophils and platelets and sustained haemopoiesis. However in patients with acute myeloid leukaemia (AML) platelet recovery has a distinctive rapid rise and then secondary fall between 3 to 8 weeks post-transplant. This study compares platelet and neutrophil recovery after PBSC transplantation in 15 patients with AML and 29 patients with other diseases consecutively transplanted in a single unit. PBSC were collected during recovery from consolidation chemotherapy in AML patients and after cyclophosphamide or cytokine administration in the other patient groups. Mononuclear cell numbers collected were similar but CFU-GM numbers were greater from the AML patients. A significant secondary fall occurred only in the platelet count and only in AML patients. Long-term recovery of the platelet count was the same in AML as in the other patients. In AML patients, the fall was the same in the long term remitters as in those who eventually relapsed. Previous studies have not, demonstrated a difference in type of precursors mobilized by differing methods, but have not included AML patients. Megakaryocyte precursors were assayed in this study and showed no consistent differences in number between patient groups however pre-progenitor assays are not yet established especially in the megakaryocytic lineage. The possible explanation for this secondary fall in AML patients is discussed.

In a phase I-II study, we evaluated toxicities, tolerability, pace of engraftment, and tumor responses to high-dose bulsulfan and cyclophosphamide followed by autologous peripheral blood stem cell transplantation in patients with hematological malignancies. We treated 51 patients with various hematological malignancies involving the bone marrow with busulfan (16 mg/kg) and cyclophosphamide (120 mg/kg) followed by reinfusion of autologous peripheral blood stem cells. Stem cells were previously collected during hematopoietic recovery after cyclophosphamide (100 mg/kg) and etoposide (600 mg/m2) followed by G-CSF (5 micrograms/kg/day). Neutrophil recovery (>0.5 x 10(9)/I) was rapid in the majority of patients (median 10 days after transplant, range 7-91 days), resulting in a low number of days with severe neutropenia (median 7 days, range 5-85 days) and with fever (median 5 days, range 1-13 days). Platelet recovery, however, was delayed in 60% of patients. There was one acute transplant-related death (2%). Four patients died of late, presumed infections, pulmonary complications (interstitial pneumonia). Tumor responses were documented in a significant proportion of these patients with high-risk hematological malignancies. We conclude that peripheral blood stem cell transplantation results in rapid recovery of neutrophils but variable recovery of platelets after high-dose busulfan and cyclophosphamide, when stem cells are harvested following priming with cyclophosphamide/etoposide and G-CSF. The regimen is well-tolerated with limited non-hematological toxicities and transplant-related mortality. While significant tumor responses were documented in this trial, the ultimate efficacy of the regimen needs to be further defined.

Fifteen consecutive patients with multiple myeloma (MM) scheduled for peripheral blood progenitor cell (PBPC) transplantation, were randomly selected to receive cyclophosphamide (CY) (4 g/m2) alone (group I) or associated with recombinant human granulocyte-macrophage colony stimulating factor (rhGM-CSF) (5 micrograms/kg/day) (group II). The mean time of neutropenia after CY administration was 9.8 +/- 4.3 days in group I and 6.4 +/- 1.2 days in group II (P = 0.0228). One hundred and eight aphereses were performed (7.1 +/- 1.8 aphereses per patient in group I and 6.4 +/- 2.8 aphereses per patient in group II). rhGM-CSF administration after CY allowed a higher collection of CD34+ cells in apheresis products (1.42 +/- 1.68 x 10(6) CD34+ cells/kg) in comparison to without factor administration (0.47 +/- 0.52 x 10(6) CD34+ cells/kg) (P = 0.0165). The mean number of cells infused per patient was 6.56 +/- 4.02 x 10(8) MNC/kg and 7.64 +/- 3.00 x 10(4) CFU-GM/kg in group I and 6.25 +/- 4.03 x 10(8) MNC/kg and 8.16 +/- 9.73 x 10(4) CFU-GM/kg in group II. The mean time to recover 0.5 x 10(9) granulocytes/I, 20 and 50 x 10(9) platelets/I in peripheral blood (PB) was 17.2 +/- 7.4, 13.4 +/- 3.7 and 16.5 +/- 6.9 days respectively, in group I and 13.3 +/- 1.7, 11.6 +/- 1.6 and 15 +/- 6.3 days, in group II. rhGM-CSF administration after CY treatment for PBPC mobilization in MM patients reduces the neutropenic period after CY and enhances apheresis CD34+ cell collection.

Thirty-one patients (median age, 44 years) with advanced hematologic malignancies were given thiotepa 15 mg/kg, and cyclophosphamide 120 (n = 14) or 150 (n = 17) mg/kg followed by unfractionated peripheral blood stem cell transplants (PBSCT) from genotypically identical siblings (n = 28) or one antigen mismatched family donor (n = 3). Donors were mobilized with granulocyte colony-stimulating factor 5 to 10 microgram/kg/d for 6 days and underwent two to three leukapheresis on days +5, +6, +7. The median cell yield per donor expressed/kg of recipients body weight was as follows: nucleated cells 13 x 10(8)/kg; CD34+ cells 6 x 10(6)/kg; colony-forming unit-granulocyte macrophage 38 x 10(4)/kg, and CD3+ cells 449 x 10(6)/kg. The diagnoses were chronic myeloid leukemia (n = 4), acute myeloid (n = 9) or lymphoid leukemia (n = 2), acute myelofibrosis (n = 2), multiple myeloma (n = 1), lymphoma (n = 6), chronic lymphocytic leukemia (n = 1) myelodysplasia (n = 6). Twenty-eight patients had advanced disease, 29 patients were first grafts, and 2 were second transplants 3 and 9 years after the first. Neutrophil counts of 0.5 x 10(9)/L and platelet counts of 30 x 10(9)/L platelets were both achieved on day +14 (median). Engraftment could be proven by sex markers or DNA polymorphism in 29 of 31 patients: one had early leukemia relapse and one patient was unevaluable because of early death. Acute graft-versus-host disease (GVHD) was scored as minimal or absent (grade 0 to 1) in 14 patients, moderate (grade II) in 13, and severe (grade III to IV) in four. Causes of death were leukemia (n = 4), acute GVHD (n = 4, with associated cytomegalovirus infections in three), sepsis (n = 1), liver failure (n = 1), multiorgan failure (n = 1), and hemorrhage (n = 1). The actuarial transplant mortality is 29%, the actuarial relapse rate 22%. Nineteen patients survive with a median follow up of 288 days (100-690). The actuarial 2-year survival is 57%. Three patients received PBSCT from family donors mismatched for one class II antigen: all engrafted, one developed grade I aGVHD; one died of leukemia on day +155; two are alive disease free 267 to 290 days postgraft. This study suggests that thiotepa cyclophosphamide followed by unfractionated PBSC allograft may be an alternative form of transplant for adults with advanced leukemia, also in the setting of one antigen mismatched donor. The engraftment is rapid with acceptable GVHD and relatively low transplant-related mortality.

Retinoids can inhibit the spontaneous in vitro growth of CFU-GM observed in juvenile chronic myeloid leukemia (JCML) and, when administered in vivo, have shown some clinical benefit in this disease. Because adult chronic myelomonocytic leukemia (CMML) has many features in common with JCML, we treated 10 cases of advanced adult CMML with ATRA (45 mg/m2/day). Five of them were also tested in vitro. After two patients had a rapid increase in WBC counts and clinical signs reminiscent of the 'ATRA syndrome' seen in acute promyelocytic leukemia, with fatal outcome in one of them, it was decided to add hydroxyurea (HY) to ATRA to patients with high WBC at inclusion or during ATRA treatment, and no more cases of ATRA syndrome were seen. Overall, six patients received ATRA + HY and four ATRA alone. Four patients had a minor but significant response with reduction of transfusion requirement (two cases) or increase in platelet counts (two cases). Apart from the ATRA syndrome, no other side-effect of ATRA was seen. Bone marrow mononuclear cells showed spontaneous growth of CFU-C in methylcellulose in the five patients tested in vitro, with a predominance of CFU-M. ATRA (10(-7) M) inhibited CFU-M growth in all cases, but increased CFU-G growth in one patient who developed the ATRA syndrome. No differentiation of bone marrow myeloid cells after short-term liquid culture with ATRA was observed. A decrease of CFU-C growth was observed in the four patients reevaluated during follow-up. In some cases of CMML, ATRA can improve anemia or thrombocytopenia but not other parameters. Furthermore, it can also induce hyperleukocytosis and ATRA syndrome in some patients, requiring the rapid addition of cytoreductive agents such as HY.