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

Promotive effect of macrophage colony-stimulating factor on long-term engraftment of murine hematopoietic stem cells

Large ex vivo expansion of hematopoietic stem cells (HSCs) sufficient for use in clinical applications has not been achieved, although the influence of some cytokines including SCF, IL-11, Flt3-L, and TPO for this purpose has been reported. We present evidence for an indirect effect of macrophage colony-stimulating factor (M-CSF) on expansion of murine HSCs. Fresh Lin(-/low) cells were isolated from Ly5.1 mouse bone marrow and cultured with or without M-CSF in the presence of SCF + IL-11 + Flt3-L or SCF + IL-11 + TPO for 6 days. The expanded cells were harvested and transplanted into lethally irradiated Ly5.2 recipients with competitor cells. Culture of Lin(-/low) cells with M-CSF significantly enhanced long-term engraftment. When the more enriched HSC populations of Lin(-/low) c-Kit(+) Sca-1(+) cells were used as a source of HSCs, such a promotive effect was not observed, in agreement with negative expression of the M-CSF receptor (c-Fms). However, co-culture with Lin(-/low) c-Fms(+) resulted in a significant increase of long-term engraftment. These results suggested that M-CSF is an indirect stimulator for ex vivo expansion of HSCs in the presence of SCF, IL-11, Flt3-L, and TPO. These observations provide new directions for ex vivo expansion and insight into new engraftment regulation through M-CSF signaling.

Second transplantation with CD34+ blood cells from an HLA-mismatched related donor after engraftment failure of transplanted cord blood cells

Unrelated cord blood transplantation (CBT) has been worldwide for bone marrow reconstitution. CBT is associated with a high frequency of engraftment failure and rejection due to a small dose of graft cells. In cases of engraftment failure or rejection following unrelated CBT, retransplantation from the original donors is impossible. We report a successful transplantation with CD34+ blood cells selected from a 2-loci HLA-mismatched mother to a child with acute monocytic leukemia after engraftment failure of the primary CBT. Selected CD34+ blood cell transplantation is a useful approach for retransplantation in the setting of engraftment failure.

Thrombopoietic factors potentially useful in the treatment of acute leukemia

Thrombocytopenia is a major cause of morbidity following intensive chemotherapy for acute leukemia. Over recent years, there has been an increasing use of platelet transfusions which, although generally efficacious to prevent severe hemorrhage, have associated risks of transmitting blood-borne disease and of alloimmunization. Therefore, there is a clinical requirement for a drug that will reliably alleviate the thrombocytopenia associated with leukemia therapy. The c-mpl ligand thrombopoietin is the most interesting factor for the treatment of thrombocytopenia because of its lineage specificity. Phase I and II studies confirm its biological efficacy to induce rise in platelet count in patients with solid tumors and acute leukemia. Several other pleiotropic hematopoietic growth factors are also currently in clinical trials. These include interleukin-6, interleukin-3, interleukin-11, PIXY321 and stem cell factor. The effects of these cytokines appear to be modest at most and, with the exception of interleukin-11, their side effects are likely to limit their clinical application. Combinations of factors may prove more efficacious approaches to enhance platelet recovery.

Macrophage colony-stimulating factor accelerates wound healing and upregulates TGF-beta1 mRNA levels through tissue macrophages

Macrophage colony-stimulating factor (M-CSF) is produced by many cell types involved in wound repair, yet it acts specifically on monocytes and macrophages. The monocyte-derived cell is thought to be important in wound healing, but the importance of the role of tissue macrophages in wound healing has not been well defined. Dermal ulcers were created in normal and ischemic ears of young rabbits. Either rhM-CSF (17 microg/wound) or buffer was applied to each wound. Wounds were bisected and analyzed histologically at Days 7 and 10 postwounding. The amounts of epithelial growth and granulation tissue deposition were measured in all wounds. The level of increase of TGF-beta1 mRNA level in M-CSF-treated wounds was examined using competitive RT-PCR. M-CSF increased new granulation tissue formation by 37% (N = 21, P < 0.01) and 50% (P < 0.01) after single and multiple treatments, respectively, in nonischemic wounds. TGF-beta1 mRNA levels in rhM-CSF-treated wounds increased 5.01-fold (N = 8) over vehicle-treated wounds under nonischemic conditions. In contrast, no effect could be detected in ischemic wounds treated with rhM-CSF, and these wounds only showed a 1.66-fold increase in TGF-beta1 mRNA levels when compared to ischemic wounds treated with vehicle alone. GAPDH, a housekeeping gene, showed no change. As mesenchymal cells lack receptors for M-CSF, the improved healing of wounds treated with topical rhM-CSF must reflect a generalized enhancement of activation and function of tissue macrophages, as demonstrated by upregulation of TGF-beta. The lack of effect under ischemic conditions suggests that either macrophage activity and/or response to M-CSF is adversely affected under those conditions; this may suggest the pathogenesis of impaired wound healing at the cellular level.

Optimal timing of granulocyte colony-stimulating factor (G-CSF) administration after bone marrow transplantation. A prospective randomized study

The positive role of G-CSF in hastening the myeloid recovery of patients undergoing allogeneic bone marrow transplantation (ALLO-BMT) or autologous bone marrow transplantation (ABMT) has recently been established. Considerable knowledge about adequate doses and route of administration has been accumulated in the past few years. Nonetheless, the optimal time to start growth-factor administration remains undetermined. We have performed a stratified study according to the source of hematopoietic progenitors (ALLO-BMT or ABMT), underlying disease and its stage, and acute graft-versus-host disease (GVHD) prophylaxis regimen and randomized patients in two arms: group A, which started G-CSF on day 0 (36 patients), and group B, which started on day +7 post-BMT (39 patients). The same dose (5 micrograms/kg/day) and route of administration were employed in both groups. We found no significant differences in the time to reach an absolute neutrophil count (ANC) of 0.1, 0.5, and 1 x 10(9)/l and 50 x 10(9) platelets/l (medians: 10 and 11, 14.5 and 14, 17 and 16, 23 and 24 days, respectively, in groups A and B). We did not find differences in the days of fever or days on antibiotic treatment with less than 1 x 10(9)/l ANC, rate of bacteriemia, or days of hospitalization in both groups. In contrast, a considerable saving of G-CSF in B group was found (mean days of infusion in group A, 18, versus 11 in group B) (p < 0.0001). This is equivalent to a saving of 1120 $US per patient.(ABSTRACT TRUNCATED AT 250 WORDS)

Immunotherapy and immunoprophylaxis in bone marrow transplantation

Immunotherapy can be defined as treatment directed at augmenting host immune defence mechanisms. Non-antimicrobial therapies and immunoprophylaxis in bone marrow transplantation (BMT) can be subdivided into three broad categories: passive immunotherapy with intravenous immunoglobulin (IVIG); cytokine therapy; and anti-endotoxin-directed treatments. Most studies using IVIG in BMT are prophylactic and suffer from variability in study design, type of IVIG and dosing regimens. Various effects on viral and bacterial infections and graft-versus-host disease (GVHD) have been reported but few if any have shown benefit in terms of improved patient survival. Moreover the immunomodulatory effect of immunoglobulin G preparations is frequently overlooked. With the exception of cytomegalovirus (CMV) pneumonitis, there is little evidence of benefit in the treatment of established infections and the relative benefits of hyperimmune preparations are poorly established. The development of haemopoietic growth factors has led to the widespread use of cytokines in BMT. The benefits of these agents both in the prevention of fever and infection and as adjuvants to standard antimicrobial therapy in established infection (e.g. invasive mycoses) are rapidly becoming apparent. Both human recombinant granulocyte-macrophage colony-stimulating factor (rhGM-CSF) and granulocyte colony-stimulating factor (rhG-CSF) have been shown to accelerate granulocyte recovery following BMT and reduce fever days, antibiotic usage and hospitalization. RhGM-CSF appears superior in these respects. The roles of interleukin 1 (IL1), IL3, IL6 and interferons are also under evaluation. As with the much publicised studies using anti-endotoxin antibodies as therapy in sepsis, there is little evidence of benefit in the few studies performed in BMT patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Urinary-derived monocyte-colony stimulating factor (P-100) following treatment with carboplatin and etoposide in small cell lung cancer (SCLC)

BACKGROUND

The hematopoietic growth factor P-100 is a monocyte-colony stimulating factor purified from human urine and has been reported to reduce neutropenia following chemotherapy. In this study the effect and toxicity of P-100 was evaluated in 26 patients receiving intensive chemotherapy for SCLC.

STUDY DESIGN

Chemotherapy consisted of four 28 day cycles of carboplatin (C) 600 mg/m2 i.v. on day 1 of cycle 1 + 2 and 300 mg/m2 i.v. on day 1 of cycle 3 + 4 and etoposide (E) 120 mg/m2 i.v. on day 1-3 of each cycle. Patients were randomised to receive P-100 for ten days following chemotherapy during either the first or second cycle. 12 Patients received P-100 with the first and 12 with the second cycle. For each group cycles with P-100 were compared to cycles without P-100.

RESULTS

P-100 was well tolerated but no significant differences between cycles with and without P-100 were seen in the administered chemotherapy dose, depth and duration of neutropenia, number of blood or platelet transfusions, WHO grade 3-4 infection or requirement for intravenous antibiotics. Of 24 evaluable patients 14 (58.3%) achieved CR and 4 (16.6%) PR. Patients achieving CR received radiotherapy. The median time to progression was 169 days (range 38-995+ days) and the median survival time was 305 days (range 42-1052+ days). Three patients are alive after 2 years (11.5%), 2 without relapse (7.7%). Alopecia, nausea and vomiting occurred in all patients but no treatment related deaths occurred.

CONCLUSION

In this study P-100 did not significantly influence the myelotoxicity associated with carboplatin-etoposide chemotherapy in the treatment of SCLC.

The place of high-dose therapy with haemopoietic stem cell transplantation in relapsed and refractory Hodgkin's disease

Conventional salvage therapy in Hodgkin's disease is appropriate in patients who relapse after a first complete remission of greater than one year many of whom who will have good long term survival with no further therapy. Patients who do not achieve CR, who relapse within one year of CR1 or who have a second relapse will have a survival of less than 20% at 5 years and these patients are candidates for high dose therapy (HDT) and Autologous Bone Marrow Transplantation (ABMT) or a second line salvage protocol. Current published and registry data suggests that HDT and ABMT may be superior and there is data from one prospective randomized trial to support this view. The best practice of ABMT to be used in this context must be decided after consideration of; timing, status, source of haematological stem cells, use of haematopoietic growth factors (HGF's) and dose and scheduling of high dose therapy. Confirmatory randomised trials are still urgently required before the optimal strategy for the management of relapsed Hodgkin's disease is defined.