Critical review on non-myeloablative stem cell transplantation (NST)

Modifying the tumour microenvironment and reverting tumour cells: New strategies for treating malignant tumours

The tumour microenvironment (TME) plays a pivotal role in tumour fate determination. The TME acts together with the genetic material of tumour cells to determine their initiation, metastasis and drug resistance. Stromal cells in the TME promote the growth and metastasis of tumour cells by secreting soluble molecules or exosomes. The abnormal microenvironment reduces immune surveillance and tumour killing. The TME causes low anti‐tumour drug penetration and reactivity and high drug resistance. Tumour angiogenesis and microenvironmental hypoxia limit the drug concentration within the TME and enhance the stemness of tumour cells. Therefore, modifying the TME to effectively attack tumour cells could represent a comprehensive and effective anti‐tumour strategy. Normal cells, such as stem cells and immune cells, can penetrate and disrupt the abnormal TME. Reconstruction of the TME with healthy cells is an exciting new direction for tumour treatment. We will elaborate on the mechanism of the TME to support tumours and the current cell therapies for targeting tumours and the TME—such as immune cell therapies, haematopoietic stem cell (HSC) transplantation therapies, mesenchymal stem cell (MSC) transfer and embryonic stem cell‐based microenvironment therapies—to provide novel ideas for producing breakthroughs in tumour therapy strategies.

The impact of hyperglycemia on hematopoietic cell transplantation outcomes: an integrative review

PROBLEM IDENTIFICATION

Many patients undergoing hematopoietic cell transplantation (HCT) for hematologic malignancies experience hyperglycemic events during treatment, leading to adverse outcomes. Understanding how hyperglycemia during the acute HCT treatment phase impacts outcomes is vital for preventing and mitigating adverse events. This integrative review evaluates the impact of hyperglycemia on adult patients undergoing HCT.

LITERATURE SEARCH

PubMed, MEDLINE®, and CINAHL® electronic databases were used to identify relevant articles.Data Evaluation: The final sample for this integrative review included 12 empirical quantitative reports of clinical patient outcomes. Of the 12, 10 are retrospective, 1 is case-control, and 1 is prospective.

DATA ANALYSIS

Content analysis was used to synthesize and summarize findings.Presentation of Findings: A review of published literature found associations between hyperglycemia and infection, time to engraftment, development of acute graft-versus-host disease, length of stay, and overall survival. Patient-related risk factors for hyperglycemia included older age, preexisting diabetes, and insulin resistance (i.e., prediabetes). Patients of normal weight experiencing hyperglycemia had worse outcomes than patients who were overweight or obese. Treatment-related risk factors for hyperglycemia include dose and duration of immunosuppressants, specifically corticosteroids, treatment with antihyperglycemic medications, and use of total parenteral nutrition.

IMPLICATIONS FOR NURSING PRACTICE

HCT is one of the most complex treatments for hematologic disorders. The transplantation nurse, as part of an interdisciplinary team, plays an essential role in glycemic control during the acute phase of HCT. Understanding the effects of hyperglycemia, as well as factors that place the patient at risk for hyperglycemia, allows the nurse to make well-informed, proactive interventions aimed at glycemic control.

Non-myeloablative allogeneic hematopoietic stem cell transplantation

OBJECTIVE

To review the literature related to nonmyeloablative stem cell transplantation (SCT), and the unique characteristics and patient population to which it applies.

DATA SOURCES

Research studies, research and clinical reviews, clinical experience.

CONCLUSION

Nonmyeloablative SCT has demonstrated effective and safe application in a heterogeneous population not otherwise eligible for an allogeneic transplantation. Although many principles are based on those of conventional myeloablative transplantation, the engraftment kinetics, patient selection, and regimen-related complications are distinct.

IMPLICATIONS FOR NURSING PRACTICE

Nurses must be knowledgeable about nonmyeloablative SCT, including the provision of individualized care for a heterogeneous population. This can include non-traditional transplant indications, elderly cancer patients, and those with comorbidities.

Clonality analysis by sequence variation of the latent membrane protein 1 gene in patients with chronic active Epstein-Barr virus infection

Chronic active Epstein-Barr virus (EBV) infection is a severe systemic disease associated with high rates of mortality and morbidity. Recent studies suggest that the clonal expansion of EBV-infected T or natural killer cells plays a crucial role in the pathogenesis of chronic active EBV infection. However, it is not clear whether chronic active EBV infection is truly a monoclonal disorder that originates from one cell. The clonality of EBV was investigated by sequence variation of the latent membrane protein 1 (LMP1) gene, which has a high degree of sequence heterogeneity. Peripheral blood mononuclear cells were obtained from nine Japanese patients with chronic active EBV infection and four with infectious mononucleosis. A carboxyl-terminal region of the LMP1 gene was analyzed by polymerase chain reaction (PCR). The amplified PCR products were subcloned, and 18 clones from each sample were sequenced. Patients with chronic active EBV infection each had two to five different LMP1 nucleotide sequences, whereas patients with infectious mononucleosis each had one to seven different sequences. Patients with chronic active EBV infection and infectious mononucleosis both had one dominant sequence. Longitudinal analysis was performed in four patients with chronic active EBV infection, in whom the dominant strains were found to have remained unchanged for several years. The results suggest that EBV in patients with chronic active EBV infection was polyclonal, although clonal expansion may occur. Collectively, these findings are critical to clarify further the pathogenesis of chronic active EBV infection and aid in the development of effective treatment strategies.

Engraftment syndrome after nonmyeloablative allogeneic hematopoietic stem cell transplantation: incidence and effects on survival

Engraftment syndrome (ES) encompasses a constellation of symptoms that occur during neutrophil recovery after both autologous and allogeneic hematopoietic stem cell transplantation (HCT). Although it is well characterized after conventional myeloablative procedures, limited data exist on this complication after nonmyeloablative allogeneic HCT. The clinical manifestations, incidence, and risk factors associated with ES were investigated in a consecutive series of patients undergoing cyclophosphamide/fludarabine-based nonmyeloablative allogeneic HCT from a related HLA-compatible donor. Fifteen (10%) of 149 patients (median age, 53 years; range, 27-66 years) developed ES; the onset of symptoms occurred at a median of 10 days (range, 3-14 days), and they consisted of fever (100%), cough (53%), diffuse pulmonary infiltrates (100%), rash (13%), and room air hypoxia (87%). ES was more likely to develop in patients who received empiric amphotericin formulations after transplant conditioning (Fisher exact test; P=.007). In a multivariate analysis, older patient age, female sex, and treatment with amphotericin were predictors for the development of ES. Intravenous methylprednisolone led to the rapid resolution of ES; however, transplant-related mortality was significantly higher (cumulative incidence, 49% versus 16%; P=.0005), and median survival was significantly shorter (168 versus 418 days; P=.005) in patients with ES compared with non-ES patients. In conclusion, ES occurs commonly after cyclophosphamide/fludarabine-based nonmyeloablative transplantation and responds rapidly to corticosteroid treatment, but it is associated with a higher risk of nonrelapse mortality and with shorter overall survival.

Reduced-intensity allogeneic stem cell transplantation in adults and children with malignant and nonmalignant diseases: end of the beginning and future challenges

During the last 10 years, multiple studies using reduced-intensity (RI) conditioning followed by allogeneic stem cell transplantation (AlloSCT) have been reported in adult and, less so, pediatric recipients. RI AlloSCT allegedly eradicates malignant cells through a graft-versus-leukemia/graft-versus-tumor effect provided by alloreactive donor T lymphocytes, natural killer cells, or both. Various studies have clearly demonstrated a graft-versus-leukemia/graft-versus-tumor effect in hematologic malignancies and solid tumors. Acute short-term toxicity, including infection and organ decompensation after myeloablative conditioning therapy, can result in a significant incidence of early transplant-related mortality. More importantly, long-term late effects-including growth retardation, infertility, and secondary malignancies-are major complications after myeloablative conditioning therapy, especially in vulnerable children, who are more susceptible to these complications. Recent results comparing RI conditioning with myeloablative conditioning followed by HLA-matched sibling AlloSCT have demonstrated a significant reduction in use of blood products, risk of infections, transplant-related mortality, length of hospitalization, and feasibility of conditioning therapy in outpatient settings. Despite the success of RI AlloSCT, large prospective randomized multicenter studies are necessary to define the appropriate patient population, optimal conditioning regimens and pretransplantation immunosuppression, role of donor lymphocyte infusions, duration of hospitalization, overall survival, cost-benefit ratio, and differences in long-term effects to evaluate the role of RI AlloSCT more fully. We review the recent experience of RI AlloSCT in adults and children with both malignant and nonmalignant diseases and discuss the challenges for the future.

Allogeneic Peripheral Blood Stem Cell Transplantation Using Reduced Intensity Versus Myeloablative Conditioning Regimens for the Treatment of Leukemia

Reduced intensity conditioning (RIC) have allowed the application of transplantation to older patients and to patients with underlying medical problems. Between October, 1999, and June, 2003, 61 patients with acute leukemia or chronic myeloid leukemia received allogeneic peripheral blood hematopoietic stem cell transplantation (HSCT) from HLA-identical siblings. Thirty-four were conditioned with myeloablative protocols and twenty-seven with RIC regimens. The patients in the myeloablative group were younger (29 vs. 37 years; p < 0.0003), most of them were transplanted in complete remission (74% vs. 59%; p < 0.03), had a shorter interval between diagnosis and HSCT (12 vs. 21 months; p < 0.02) and a greater proportion belonged to standard-risk prognosis (68% vs. 48%; p < 0.1). The median times to neutrophil, platelet and red blood cell engraftment for the myeloablative and RIC groups were 14 versus 11 days (p < 0.009), 17 versus 9 days (p < 0.0001), and 19 versus 12 days (p < 0.007), respectively. Transfusion requirements were lower in the RIC group. Severe mucositis was present in 32% and 7%, respectively (p < 0.01). The proportion of patients having acute graft versus-disease (GVHD), chronic GVHD, and infections was the same, as well as early and late mortality, disease-free survival, and overall survival. Analyzing all the patients together, three factors significantly influenced overall survival: standard risk patients, complete remission at transplant, and the absence of severe acute GVHD. In conclusion, our data suggest that even in high-risk patients, RIC transplantation seems to be as useful as ablative HSCT.

Minimal GVHD following in-vitro Tcell–depleted allogeneic stem cell transplantation with reduced-intensity conditioning allowing subsequent infusions of donor lymphocytes in patients with hematological malignancies and solid tumors

OBJECTIVE

Allogeneic stem cell transplantation (alloSCT) following reduced-intensity conditioning offers a relatively nontoxic regimen while preserving rapid and sustained engraftment. Acute and chronic graft-vs-host disease (GVHD) is, however, a significant cause of severe morbidity. To reduce the incidence of GVHD, we treated a group of high-risk patients with a reduced-intensity conditioning regimen followed by in vitro T-cell-depleted alloSCT using Campath 1-H incubation.

PATIENTS AND METHODS

Eighteen patients were treated with fludarabine (6 x 30 mg/m(2)), busulphan (2 x 3.2 mg/kg), and ATG (4 x 10 mg/kg) followed by the infusion of high-dose T-cell-depleted peripheral stem cells from sibling donors. No posttransplant GVHD prophylaxis was administered. At 6 months after alloSCT, low-dose donor lymphocyte infusion (DLI) was administered.

RESULTS

All patients had sustained engraftment of donor cells with a median of 95% donor cells at 3 months after alloSCT. Minimal acute and no chronic GVHD was observed after alloSCT. A high incidence of cytomegalovirus (CMV) reactivation but no CMV disease was observed. Eleven patients received DLI at a median of 6.5 months after alloSCT. Acute GVHD grade II-III developed in 6 patients. All patients showed improvement of donor chimerism after DLI. With a median follow-up of 211 days, 11 patients are alive. Particular in patients with chronic lymphocytic leukemia and acute myeloid leukemia, a significant graft-vs-tumor effect was observed.

CONCLUSIONS

In vitro T-cell-depleted alloSCT following reduced-intensity conditioning leads to durable donor engraftment without GVHD. The high levels of donor chimerism allow the subsequent use of cellular immunotherapy to treat residual disease.