An Overview of Hematopoietic Stem Cell Transplantation

Surveillance of Stem Cell Fate and Function: A System for Assessing Cell Survival and Collagen Expression In Situ

Cell-based therapy is an emerging paradigm in skeletal regenerative medicine. However, the primary means by which transplanted cells contribute to bone repair and regeneration remain controversial. To gain an insight into the mechanisms of how both transplanted and endogenous cells mediate skeletal healing, we used a transgenic mouse strain expressing both the topaz variant of green fluorescent protein under the control of the collagen, type I, alpha 1 promoter/enhancer sequence (Col1a1(GFP)) and membrane-bound tomato red fluorescent protein constitutively in all cell types (R26(mTmG)). A comparison of healing in parietal versus frontal calvarial defects in these mice revealed that frontal osteoblasts express Col1a1 to a greater degree than parietal osteoblasts. Furthermore, the scaffold-based application of adipose-derived stromal cells (ASCs), bone marrow-derived mesenchymal stem cells (BM-MSCs), and osteoblasts derived from these mice to critical-sized calvarial defects allowed for investigation of cell survival and function following transplantation. We found that ASCs led to significantly faster rates of bone healing in comparison to BM-MSCs and osteoblasts. ASCs displayed both increased survival and increased Col1a1 expression compared to BM-MSCs and osteoblasts following calvarial defect transplantation, which may explain their superior regenerative capacity in the context of bone healing. Using this novel reporter system, we were able to elucidate how cell-based therapies impact bone healing and identify ASCs as an attractive candidate for cell-based skeletal regenerative therapy. These insights potentially influence stem cell selection in translational clinical trials evaluating cell-based therapeutics for osseous repair and regeneration.

Self-regulatory fatigue, quality of life, health behaviors, and coping in patients with hematologic malignancies

BACKGROUND

Self-regulatory fatigue may play an important role in a complex medical illness.

PURPOSE

Examine associations between self-regulatory fatigue, quality of life, and health behaviors in patients pre- (N = 213) and 1-year post-hematopoietic stem cell transplantation (HSCT; N = 140). Associations between self-regulatory fatigue and coping strategies pre-HSCT were also examined.

METHOD

Pre- and 1-year post-HSCT data collection. Hierarchical linear regression modeling.

RESULTS

Higher self-regulatory fatigue pre-HSCT associated with lower overall, physical, social, emotional, and functional quality of life pre- (p's < .001) and 1-year post-HSCT (p's < .01); lower physical activity pre-HSCT (p < .02) and post-HSCT (p < .03) and less healthy nutritional intake post-HSCT (p < .01); changes (i.e., decrease) in quality of life and healthy nutrition over the follow-up year; and use of avoidance coping strategies pre-HSCT (p's < .001).

CONCLUSION

This is the first study to show self-regulatory fatigue pre-HSCT relating to decreased quality of life and health behaviors, and predicting changes in these variables 1-year post-HSCT.

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.

Effectiveness and toxicity of high-dose cyclophosphamide in obese versus non-obese patients receiving allogeneic hematopoietic stem cell transplant

PURPOSE

To determine if there is a difference in toxicity and effectiveness between obese and non-obese patients who receive high-dose cyclophosphamide (Cy) prior to allogeneic hematopoietic stem cell transplant (allo-HCT).

METHODS

Patients were included in this study if they were at least 18 years of age and received high-dose Cy in combination with total body irradiation (CyTBI) or busulfan (BuCy) prior to allo-HCT between 1 January 2008 and 29 February 2012. The primary endpoint was the difference in overall toxicity between obese and non-obese patients. Secondary objectives examined differences in effectiveness between groups assessed by relapse at day +100, relapse at 1 year, death at 1 year, chimerisms at days +30, +60, and +90, and incidence of acute graft versus host disease (aGVHD).

RESULTS

Sixty-one patients met the inclusion criteria, 28 obese and 33 non-obese. Overall toxicity was greater in obese patients compared to non-obese patients (82% vs. 52%, OR 4.3 [95% CI 1.3-14.1]; p = 0.01), which was driven by a greater incidence of renal dysfunction (79% vs. 48%, OR 3.9 [95% CI 1.3-12.1]; p = 0.02). There were no differences in rates of grade 3 or 4 toxicity, hepatic dysfunction, or any measure of effectiveness between groups.

CONCLUSION

Obese patients receiving high-dose Cy and allo-HCT are at increased risk for toxicity, although there appears to be no difference in the rate of relapse or survival between obese and non-obese patients.

Self-regulatory fatigue in hematologic malignancies: impact on quality of life, coping, and adherence to medical recommendations

BACKGROUND

Hematopoietic stem cell transplantation (HSCT) is an intensive cancer therapy entailing numerous physical, emotional, cognitive, and practical challenges. Patients' ability to adjust and cope with such challenges may depend on their ability to exert control over cognitive, emotional, and behavioral processes, that is, ability to self-regulate. Self-regulatory capacity is a limited resource that can be depleted or fatigued (i.e., "self-regulatory fatigue"), particularly in the context of stressful life events such as cancer diagnosis and treatment.

PURPOSE

This is one of the first studies to examine self-regulatory fatigue in a cancer population. The current study aimed to (1) extract items for a specific scale of self-regulatory capacity and (2) examine the impact of such capacity on adaptation in patients with hematologic malignancies preparing for HSCT.

METHODS

Factor analysis of four existing scales gauging psychological adjustment and well-being in 314 patients preparing for HSCT (63% male and 89% Caucasian) identified 23 items (α = 0.85) related to self-regulatory control or fatigue. This measure was then examined using existing clinical data obtained from 178 patients (57% male and 91% Caucasian) undergoing treatment for hematologic malignancies in relationship to quality of life, coping, and self-reported adherence to physicians' recommendations.

RESULTS

Controlling for pain severity, physical fatigue, and depression, self-regulatory fatigue scores were incrementally associated with decreased quality of life, use of avoidance coping strategies, and decreased adherence to physicians' recommendations.

CONCLUSION

These results emphasize the potential role of self-regulatory capacity in coping with and adjusting to hematologic cancers and future research is warranted.

Defective pulmonary innate immune responses post-stem cell transplantation; review and results from one model system

Infectious pulmonary complications limit the success of hematopoietic stem cell transplantation (HSCT) as a therapy for malignant and non-malignant disorders. Susceptibility to pathogens in both autologous and allogeneic HSCT recipients persists despite successful immune reconstitution. As studying the causal effects of these immune defects in the human population can be limiting, a bone marrow transplant (BMT) mouse model can be used to understand the defect in mounting a productive innate immune response post-transplantation. When syngeneic BMT is performed, this system allows the study of BMT-induced alterations in innate immune cell function that are independent of the confounding effects of immunosuppressive therapy and graft-versus-host disease. Studies from several laboratories, including our own show that pulmonary susceptibility to bacterial infections post-BMT are largely due to alterations in the lung alveolar macrophages. Changes in these cells post-BMT include cytokine and eicosanoid dysregulations, scavenger receptor alterations, changes in micro RNA profiles, and alterations in intracellular signaling molecules that limit bacterial phagocytosis and killing. The changes that occur highlight mechanisms that promote susceptibility to infections commonly afflicting HSCT recipients and provide insight into therapeutic targets that may improve patient outcomes post-HSCT.

Lung function and late pulmonary complications among survivors of hematopoietic stem cell transplantation during childhood

Hematopoietic stem cell transplantation (HSCT) is used to treat an expanding array of malignant and non-malignant disorders. Pulmonary complications represent a significant source of morbidity and mortality in HSCT recipients. Young children, whose lungs are still developing and growing, may be especially susceptible to the insults of irradiation, drug toxicities, and recurrent infections associated with immunosuppression. Late pulmonary complications, those occurring more than three months after transplantation, are often noninfectious and present with nonspecific symptomatology. Pulmonary function testing (PFT) is a mainstay of monitoring pulmonary health in HSCT recipients. The pulmonologist should be familiar with common patterns seen on PFT in recipients of HSCT during childhood. In this review, we describe the findings in studies which have examined lung function over time in patients who underwent HSCT during childhood. We discuss patterns of PFT abnormalities, associated noninfectious syndromes and their clinical implications, as well as directions for future research.

Glycemic control among older adult hematopoietic cell transplant recipients

Adults age 55 and older with hematological malignancies who require hematopoietic cell transplantation (HCT) for survival are at risk for a number of nonmalignancy-related, potentially life-threatening outcomes, often due to suboptimal immune function. Evidence is emerging regarding how abnormal glycemic levels-newly termed malglycemia-impair cells of the immune system. Further, older adult HCT recipients appear highly susceptible to malglycemic states, particularly hyperglycemia, due to treatment regimens, nutritional imbalances, states of immobility, and stress, all coupled with the natural aging process. Patients with preexisting diabetes may be at further risk for malglycemic states. The growing number of older adults receiving HCT will substantially increase the likelihood nurses will have to provide care to HCT survivors. Therefore, it is important nurses in all practice settings have an understanding of the short-and long-term effects of glycemic status on immune function.

Development of macrophages of cyprinid fish

The innate immune responses of early vertebrates, such as bony fishes, play a central role in host defence against infectious diseases and one of the most important effector cells of innate immunity are macrophages. In order for macrophages to be effective in host defence they must be present at all times in the tissues of their host and importantly, the host must be capable of rapidly increasing macrophage numbers during times of need. Hematopoiesis is a process of formation and development of mature blood cells, including macrophages. Hematopoiesis is controlled by soluble factors known as cytokines, that influence changes in transcription factors within the target cells, resulting in cell fate changes and the final development of specific effector cells. The processes involved in macrophage development have been largely derived from mammalian model organisms. However, recent advancements have been made in the understanding of macrophage development in bony fish, a group of organisms that rely heavily on their innate immune defences. Our understanding of the growth factors involved in teleost macrophage development, as well as the receptors and regulatory mechanisms in place to control them has increased substantially. Furthermore, model organisms such as the zebrafish have emerged as important instruments in furthering our understanding of the transcriptional control of cell development in fish as well as in mammals. This review highlights the recent advancements in our understanding of teleost macrophage development. We focused on the growth factors identified to be important in the regulation of macrophage development from a progenitor cell into a functional macrophage and discuss the important transcription factors that have been identified to function in teleost hematopoiesis. We also describe the findings of in vivo studies that have reinforced observations made in vitro and have greatly improved the relevance and importance of using teleost fish as model organisms for studying developmental processes.

Corticosteroids for preventing graft-versus-host disease after allogeneic myeloablative stem cell transplantation

BACKGROUND

Despite ongoing progress, acute and chronic GvHD still represent major drawbacks in the context of allogeneic myeloablative haematopoietic stem cell transplantation (HSCT) due to their high morbidity and mortality. Corticosteroids are used as first-line treatment of acute and chronic GvHD. However, their role for preventing GvHD is unclear as the published study results are controversial.

OBJECTIVES

To determine the effectiveness of corticosteroids used for the prophylaxis of GvHD in adults following allogeneic myeloablative HSCT. in improving overall survival, disease-free survival, relapse incidence, non-relapse mortality, acute GvHD grade I to IV, II to IV and III to IV, chronic GvHD, incidence of infectious complications, other adverse effects and cause of deaths.

SEARCH STRATEGY

We searched the Cochrane Haematological Malignancies Group trials register, CENTRAL (The Cochrane Library Issue 2, 2004), MEDLINE (January 1999 to February 2006), EMBASE (January 1999 to 2004), LILACS covering publications until 2004, as well as handsearched conference proceedings, including citations until 2005.

SELECTION CRITERIA

Randomised controlled trials (RCT) comparing the addition of corticosteroids to a GvHD prophylaxis regimen in adult patients having undergone allogeneic myeloablative HSCT were included into the review. All types and stages of the underlying disease as well as all types of possible HLA-matching were considered.

DATA COLLECTION AND ANALYSIS

Trial eligibility and quality assessment, data extraction and analysis were done in duplicate.

MAIN RESULTS

Five RCTs involving 604 people were included. The pooled results revealed that the addition of corticosteroids reduces statistically significant the risk for acute GvHD grade I to IV (HR 0.58; 95% CI 0.45 to 0.76) and II to IV (HR 0.69; 95% CI 0.51 to 0.92). No evidence was found that it has any clinical relevance on overall survival (HR 0.99; 95% CI 0.79 to 1.25) or disease-free survival (HR 0.95; 95% CI 0.74 to 1.23). As well, no statistically significant influence was found for acute GvHD grade III to IV (HR 0.78; 95% CI 0.52 to 1.15), chronic GvHD (HR 1.21;95% CI 0.89 to 1.65]), relapse incidence (HR 0.82; 95% CI 0.57 to 1.18) or non-relapse mortality (HR 0.88;95% CI 0.61 to 1.26). No clear evidence was found that the rate of infectious complications (under the concomitant use of antiviral or antibacterial medication or both) increases with the addition of corticosteroids. With respect to the other outcomes no significant differences could be detected.

AUTHORS' CONCLUSIONS

The addition of corticosteroids reduces the incidences of acute GvHD grade I to IV and II to IV. This reduction, however, did not show any effect on overall survival and disease-free survival. Further randomised controlled studies are needed to evaluate if the timing of steroid administration has a significant influence on the outcome; data on quality of life should be assessed systematically.

Lifetime probabilities of hematopoietic stem cell transplantation in the U.S

Healthcare policies regarding hematopoietic stem cell transplantation (HSCT) must address the need for the procedure as well as the availability of stem cell sources: bone marrow, peripheral blood, or umbilical cord blood (UCB). However, data with respect to the lifetime probability of undergoing HSCT are lacking. This study was undertaken to estimate the latter probability in the United States (U.S.), depending on age, sex, and race. We used data from the Center for International Blood and Marrow Transplant Research, the U.S. Surveillance, Epidemiology and End Results Program, and the U.S. Census Bureau and calculated probabilities as cumulative incidences. Several scenarios were considered: assuming current indications for autologous and allogeneic HSCT, assuming universal donor availability, and assuming broadening of HSCT use in hematologic malignancies. Incidences of diseases treated with HSCT and of HSCTs performed increase with age, rising strongly after age 40. Among individuals older than 40, incidences are higher for men than for women. The lifetime probabilities of undergoing HSCT range from 0.23% to 0.98% under the various scenarios. We conclude that, given current indications, the lifetime probability of undergoing autologous or allogeneic HSCT is much higher than previously reported by others and could rise even higher with increases in donor availability and HSCT applicability.

Vancomycin-resistant enterococcal colonization appears associated with increased mortality among allogeneic hematopoietic stem cell transplant recipients

There are no cohort studies describing outcomes of patients colonized with vancomycin-resistant enterococci (VRE) undergoing allogeneic hematopoietic stem cell transplantation (AHSCT). We therefore conducted a retrospective cohort study of 217 consecutive adults undergoing AHSCT at the Mayo Clinic (Rochester, MN, USA) from 1998 to 2004. We analyzed the association between VRE colonization prior to transplant and 100-day post transplant mortality and morbidity. We identified 22 pretransplant VRE colonized patients and 195 non-colonized patients. Both groups had similar baseline characteristics with the following six exceptions. Colonized patients were more likely to have had pretransplant Clostridium difficile-associated diarrhea, pretransplant acute renal failure, AML, Cy/TBI conditioning, decreased platelet count at time of transplantation and myeloablative conditioning regimens. Overall, patients colonized with VRE were twice as likely to die by day 100 post transplant compared to non-colonized patients (hazard ratio: 2.1, P=0.028). This association persisted even after adjusting for differences in baseline characteristics. Increased mortality in the colonized group correlated with the presence of VRE bacteremia. Overall, pretransplant VRE colonization appears to be an independent risk factor for increased mortality post-AHSCT.

Viral pneumonia after hematopoietic stem cell transplantation: high-resolution CT findings

Hematopoietic stem cell transplantation (HSCT) is the treatment of choice for many hematologic malignancies and nonmalignant disorders of bone marrow function. Pulmonary infections from bacterial, fungal, and viral organisms are a major cause of morbidity and mortality in patients after HSCT. The radiographic and high-resolution computed tomography (HRCT) findings of the different lower respiratory tract viral infections are quite similar. Findings of viral pneumonia on HRCT include small poorly defined centrilobular nodules and patchy, often bilateral, areas of peribronchial ground-glass opacity and consolidation. Air trapping may be present because of associated bronchiolitis. Interlobular septal thickening, bronchial wall thickening, and tree-in-bud opacities may also be present. Advanced viral pneumonia with diffuse alveolar damage is characterized by patchy or confluent consolidation and ground-glass opacities. Although nonspecific, in the correct clinical setting, these HRCT findings can help suggest the diagnosis of viral pneumonia in recipients of HSCT.

Dental management of patients with bone marrow and solid organ transplantation

With advances in transplant science, an increasing number of people are undergoing and surviving hematopoietic stem cell and solid organ transplantation. Those transplant recipients are also living longer. This means that many dentists nowadays will occasionally treat patients who are anticipating or who have received a transplant. Dentists thus should be knowledgeable about issues related to this population. The dentist's role is important because transplant patients are especially vulnerable to infection, which can stem from poor oral and dental hygiene. This article provides dentists with an overview of transplant science and guidance for dentists treating transplant patients.