Hematopoietic Stem Cell Transplantation Patients Research Articles

Immunogenicity and Tolerance of BNT162b2 mRNA Vaccine in Allogeneic Hematopoietic Stem Cell Transplant Patients.

Allogeneic hematopoietic stem cell transplantation (ASCT) induces acquired immunodeficiency, potentially altering vaccine response. Herein, we aimed to explore the clinical tolerance and the humoral and cellular immune responses following anti-SARS-CoV-2 vaccination in ASCT recipients. A prospective, non-randomized, controlled study that involved 43 ASCT subjects and 31 healthy controls. Humoral response was investigated using the Elecsys® test anti-SARS-CoV-2. Cellular response was assessed using the QFN® SARS-CoV-2 test. The lymphocyte cytokine profile was tested using the LEGENDplex™ HU Th Cytokine Panel Kit (12-plex). Adverse effects (AE) were observed in 69% of patients, encompassing pain at the injection site, fever, asthenia, or headaches. Controls presented more side effects like pain in the injection site and asthenia with no difference in the overall AE frequency. Both groups exhibited robust humoral and cellular responses. Only the vaccine transplant delay impacted the humoral response alongside a previous SARS-CoV-2 infection. Noteworthily, controls displayed a Th1 cytokine profile, while patients showed a mixed Th1/Th2 profile. Pfizer-BioNTech® anti-SARS-CoV-2 vaccination is well tolerated in ASCT patients, inducing robust humoral and cellular responses. Further exploration is warranted to understand the impact of a mixed cytokine profile in ASCT patients.

Haematopoietic stem-cell transplantation for patients with Crohn's disease: primum non nocere

Haematopoietic stem-cell transplantation for patients with Crohn's disease: primum non nocere

Recombinant mannan-binding lectin magnetic beads increase pathogen detection in immunocompromised patients

The microbiological diagnosis of infection for hematological malignancy patients receiving chemotherapy or allogeneic hematopoietic stem cell transplantation (allo-HSCT) patients relies primarily on standard microbial culture, especially blood culture, which has many shortcomings, such as having low positive rates, being time-consuming and having a limited pathogenic spectrum. In this prospective observational self-controlled test accuracy study, blood, cerebrospinal fluid (CSF), and bronchoalveolar lavage fluid (BALF) samples were collected from chemotherapy or allo-HSCT patients with clinical symptoms of infections who were hospitalized at Peking University First Hospital. Possible pathogens were detected by the method based on recombinant mannan-binding lectin (MBL) magnetic bead enrichment (M1 method) and simultaneously by a standard method. The analytical sensitivity of M1 method was close to that of standard culture method. Besides, the turn-around time of M1-method was significantly shorter than that of standard culture method. Moreover, the M1 method also added diagnostic value through the detection of some clinically relevant microbes missed by the standard method. M1 method could significantly increase the detection efficiency of pathogens (including bacteria and fungi) in immunocompromised patients.Key points• The detection results of M1-method had a high coincidence rate with that of standard method• M1 method detected many pathogens which had not been found by standard clinic method

WT1 and TP53 as valuable diagnostic biomarkers for relapse after hematopoietic stem cell transplantation in acute myeloid leukemia.

Relapse following hematopoietic stem cell transplantation (HSCT) occurs relatively frequently and is a significant risk factor for mortality in patients with acute myeloid leukemia (AML). Early diagnosis is, therefore, of utmost importance and can provide valuable guidance for appropriate and timely intervention. Here, the diagnostic value of two molecular markers, Wilms tumor 1 (WT1) and tumor suppressor protein p53 (TP53), were studied. Twenty AML patients undergoing HSCT participated in this investigation. Some had relapsed following HSCT, while others were in remission. Peripheral blood (PB) and bone marrow (BM) samples were collected following relapse and remission. WT1 and TP53 messenger RNA (mRNA) expression was evaluated using reverse transcription-quantitative polymerase chain reaction (RT‒qPCR). The diagnostic value of genes was evaluated by utilizing receiver-operating characteristic (ROC) curve analysis. ROC analysis showed WT1 and TP53 as diagnostic markers for relapse after HSCT in AML patients. The mRNA expression level of WT1 was elevated in individuals who experienced relapse compared to those in a state of remission (p value < 0.01). Conversely, the expression level of TP53 mRNA was lower in individuals who had relapsed compared to those in remission (p value < 0.01). WT1 and TP53 possess the potential to serve as invaluable biomarkers in the identification of molecular relapse after HSCT in patients with AML. Further studies for a definitive conclusion are recommended.

Coping with stress styles and the level of perceived stress in hematopoietic cell transplant patients.

Hematopoietic stem cell transplantation (HSCT) is considered an integral part of therapy in many hematological and non-hematological malignancies. The procedure can be highly stressful for patients. The primary objective of this study was to compare stress assessments in HSCT patients, depending on their stress coping style (CS) and type of treatment (autologous vs. allogeneic HSCT). A short longitudinal study was conducted between May 2021 and June 2023 among patients with hematological cancers undergoing HSCT. The study involved four time points: the day of admission to hospital - T1, the day before HSCT - T2, 6days after HSCT - T3, and the day of discharge - T4. Participants completed the Coping Inventory for Stressful Situations (CISS) on T1, and the Distress Thermometer (DT) on T1-T4. Descriptive statistics and a repeated measures ANOVA were conducted. A total of 128 participants completed the study: 54.2% female, mean age 48.7years. They were divided into: (1) five groups based on their CS: task-oriented, emotion-oriented, avoidance-oriented, mix-oriented, differential-oriented; (2) two groups based on treatment type. The analyses showed significant differences in stress between the CS study groups (p=0.001). The emotion-oriented group had the highest stress levels during the hospitalization period. There was also a significant time effect (p<0.001): stress levels increased during the hospitalization period, peaking 6days after HSCT, and decreased at discharge. Stress levels depend on coping styles and time points during the hospitalization period, which should be taken into account in planning psychological interventions for HSCT patients.

Primary Prevention of Clostridium Difficile Infection with Oral Vancomycin in Pediatric Hematopoietic Stem Cell Transplant Patients

Primary Prevention of Clostridium Difficile Infection with Oral Vancomycin in Pediatric Hematopoietic Stem Cell Transplant Patients

Invasive Fungal Infections Are Rare in Pediatric and Young Adult Autologous Hematopoietic Stem Cell Transplant Patients

Invasive Fungal Infections Are Rare in Pediatric and Young Adult Autologous Hematopoietic Stem Cell Transplant Patients

Post-Transplant Cyclophosphamide Combined with Brilliant Blue G Reduces Graft-versus-Host Disease without Compromising Graft-versus-Leukaemia Immunity in Humanised Mice.

Allogeneic haematopoietic stem cell transplantation (HSCT) leads to the establishment of graft-versus-leukaemia (GVL) immunity, but in many cases also results in the development of graft-versus-host disease (GVHD). This study aimed to determine if P2X7 antagonism using Brilliant Blue G (BBG) could improve the beneficial effects of post-transplant cyclophosphamide (PTCy) in a humanised mouse model of GVHD, without comprising GVL immunity. NOD.Cg-Prkdcscid Il2rgtm1Wjl (NSG) mice were injected with human peripheral blood mononuclear cells (PBMCs) (Day 0), then with cyclophosphamide (33 mg/kg) on Days 3 and 4, and with BBG (50 mg/kg) (or saline) on Days 0-10. PTCy with BBG reduced clinical GVHD development like that of PTCy alone. However, histological analysis revealed that the combined treatment reduced liver GVHD to a greater extent than PTCy alone. Flow cytometric analyses revealed that this reduction in liver GVHD by PTCy with BBG corresponded to an increase in human splenic CD39+ Tregs and a decrease in human serum interferon-γ concentrations. In additional experiments, humanised NSG mice, following combined treatment, were injected with human THP-1 acute myeloid leukaemia cells on Day 14. Flow cytometric analyses of liver CD33+ THP-1 cells showed that PTCy with BBG did not mitigate GVL immunity. In summary, PTCy combined with BBG can reduce GVHD without compromising GVL immunity. Future studies investigating P2X7 antagonism in combination with PTCy may lead to the development of novel treatments that more effectively reduce GVHD in allogeneic HSCT patients without promoting leukaemia relapse.

Eligibility for hematopoietic stem cell transplantation in a cohort of children with sickle cell disease: a single-center report

BackgroundHematopoietic stem cell transplantation (HSCT), is the only currently available curative option for SCD. Yet, the eligibility of SCD patients for HSCT is always limited by the significant associated toxicity and lack of suitable donors. At Cairo University’s pediatric hematology outpatient clinic, we aimed to determine hematopoietic stem cell transplantation (HSCT) candidates among a sickle cell disease (SCD) cohort, estimate the number of possible donors, and analyze the differences between patients with and without an HSCT indication.MethodsThis study was a cross-sectional analytic study including 128 SCD children. Their demographic, clinical, and laboratory profiles, total number, and number of siblings with SCD were obtained from their medical records.ResultsSixty-nine (53.9%) had at least one HSCT indication. Recurrent severe pain episodes despite hydroxyurea were the most common indication. Hemoglobin was lower, while reticulocyte count, serum ferritin, and aspartate aminotransferase were higher in HSCT candidates (p value < 0.001). Additionally, the prevalence of splenomegaly, the dose of hydroxyurea, and the number of transfusions were noticeably higher in HSCT candidates (p value = 0.013, 0.005, and < 0.0001 respectively). Among those indicated for HSCT; 75.3% had at least one healthy sibling who might be a potential donor.ConclusionMore than half were eligible for HSCT which should always be considered to provide a possible cure for the disease. Of the transplantation-eligible cases, about two-thirds had at least one healthy sibling who might potentially serve as a donor. Those meeting the requirements for HSCT eligibility should routinely undergo human leukocyte antigen (HLA) testing of their unaffected siblings.

Comparing between HLA-matched sibling donor allogenic HSCT and non-sibling matched related donor allogenic HSCT outcome in pediatric patients; single center retrospective study.

Extended family donor search other than siblings may yield an HLA matched donor in communities with high rate of consanguinity. The outcome of patients who are transplanted from non-sibling matched related donors (NS-MRD) including engraftment and graft versus host disease (GVHD) are scarce in comparison with matched sibling donor (MSD). We retrospectively reviewed the outcome of all our pediatric hematopoietic stem cell transplantation (HSCT) patients who had non-sibling matched related donor and controlled them with matched sibling donor HSCT (based on age, indication of HSCT, conditioning regimen, GVHD prophylaxis, serotherapy, stem cell source and cytomegalovirus status). A total of 76 patients were reviewed during study period. Thirty patients (39.5%) in NS-MRD arm and 46 patients in MSD (60.5%) were identified after matching in age, disease, and conditioning regimens. All patients had similar approach including stem cell source and GVHD prophylaxis (CNI + 2nd agent). Out of the NS-MRD group, 18 patients (59%) had one of their parents as a donor and the rest as second degree relatives. Both groups were equally distributed and were homogeneous. Both groups had no statistically significant difference in outcome including engraftment, GVHD and Chimerism tests results. GVHD was seen in (13%) NS-MRD patients compared to (11%) in MSD patients. All patients remain alive with median follow up of 1249 days (431-3525). This study showed no significant difference in allogenic HSCT outcomes between matched sibling donors and non-sibling matched related donors and support using the same management approach in terms of conditioning therapy, GVHD prophylaxis, and serotherapy only if indicated.

Loneliness, immunological recovery patterns, and health-related quality of life (HRQOL) outcomes in patients receiving hematopoietic stem cell transplantation.

Loneliness may compromise health-related quality of life (HRQOL) outcomes and the immunological impacts of loneliness via neuroendocrinological mechanisms likely have consequences for patients who have undergone a hematopoietic stem cell transplantation (HSCT). Loneliness (pre-transplant), immunological recovery (Day 30, Day 100, 1-year post-transplant), and HRQOL (Day 100, 1 year) were measured in a sample of 205 patients completing a HSCT (127 autologous, 78 allogenic). Greater levels of pre-transplant loneliness predicted poorer HRQOL at Day 100 and 1-year follow-up. Loneliness also was associated with higher absolute neutrophil to absolute lymphocyte (ANC/ALC) ratios in the entire sample at Day 30, which in turn was associated with Day 100 HRQOL. Findings demonstrate that pretransplant loneliness predicts HRQOL outcomes and associates with inflammatory immunological recovery patterns in HSCT patients. The balance of innate neutrophils to adaptive lymphocytes at Day 30 present a distinct profile in lonely individuals, with this immunity recovery profile predicting reduced HRQOL 100 days after the transplant. Addressing perceptions of loneliness before HSCT may be an important factor in improving immunological recovery and HRQOL outcomes.

A prospective study of the relationship between illness perception, depression, anxiety, and quality of life in hematopoietic stem cell transplant patients.

The aim of study was to investigate whether depression and anxiety symptoms and illness perception prior to hematopoietic stem cell transplantation (HSCT) predict health related quality of life (HRQOL) at Day 100 and 1 year following HSCT. A total of 205 patients who underwent HSCT (N = 127 autologous transplants, N = 78 allogeneic transplants) were included in this prospective study. Baseline assessment was assessed prior to transplantation and post HSCT data were collected at Day 100 and 1 year. At baseline we assessed depressive symptoms (Patient Health Questionnaire-9), anxiety symptoms (Generalized Anxiety Disorder-7), illness perception (Brief Illness Perception Questionnaire), and HRQOL (Functional Assessment of Cancer Therapy-BMT). Patients who expressed a greater level of concern about the severity, course, and ability to exert control over one's illness (i.e., illness perception) and who reported a greater level of depression and anxiety symptoms prior to HSCT reported lower HRQOL at both Day 100 and 1 year posttransplant, with a similar degree of association observed at the two follow-up time points. Our findings suggest that pretransplant perceptions about their illness and negative mood are significant predictors of HRQOL following HSCT. Illness perception, depression, and anxiety are potentially modifiable risk factors for less than optimal outcome after HCSCT and intervention strategies should be explored.

Reduced mitochondrial respiration in peripheral T cells after paediatric heamatopoietic stem cell transplantation.

Recovery and functional differentiation of T-cell subsets are central for the development of immune function and complications after allogeneic hematopoietic stem cell transplantation (HSCT), but little is known about the cellular respiration and factors influencing T-cell metabolic fitness during immune maturation after HSCT. We included 20 HSCT patients and analysed mitochondrial oxidative phosphorylation and mitochondrial fitness in peripheral blood mononuclear cell samples collected at days +90 and +180 after HSCT. Phenotypic analysis revealed lower overall T-cell counts, lower CD4+/CD8+ ratio and a skewed distribution of early T-cell subsets at day +90, gradually recovering by day +180. Although ATP turnover in HSCT patients was similar to healthy controls, the spare respiratory capacity (SRC) of T cells, reflecting the available energy reserve, was significantly reduced at day +90 and +180 compared to healthy controls. This reduction in SRC was not correlated with the occurrence of acute graft-versus-host disease (aGVHD), the intensity of conditioning regimens and markers of T-cell exhaustion. We found significantly depressed SRC until six months post-HSCT, but we were not able to identify transplant-related risk factors or associations with the clinical outcome.

Role of Outpatient Physical Medicine and Rehabilitation in a Multidisciplinary Prehabilitation Program for Older Adults Before Allogeneic Hematopoietic Stem Cell Transplant.

Physical rehabilitation is increasingly incorporated throughout the allogeneic hematopoietic stem cell transplant journey for older adults. This study aimed to describe physical medicine and rehabilitation-related diagnoses, exercise barriers, and management recommendations for older adults before allogeneic hematopoietic stem cell transplant. Fifty physical medicine and rehabilitation consults as part of the Enhanced Recovery-Stem Cell Transplant multidisciplinary prehabilitation program at a comprehensive cancer center were retrospectively reviewed. Many physical medicine and rehabilitation-related diagnoses (173), exercise barriers (55), and management recommendations (112) were found. Common diagnoses were musculoskeletal dysfunction (more commonly back, shoulder, then knee) ( n = 39, 23%) and fatigue ( n = 36, 21%). Common exercise barriers were also musculoskeletal dysfunction (more commonly back, knee, then shoulder) (total n = 20, 36%) and fatigue ( n = 20, 36%). Most patients ( n = 32, 64%) had one or more exercise barriers. Common physical medicine and rehabilitation management recommendations were personalized exercise counseling ( n = 37, 33%), personalized nutrition management ( n = 19, 17%), body composition recommendations ( n = 17, 15%), medications ( n = 15, 13%), and orthotics and durable medical equipment ( n = 8, 7%). Routine physical medicine and rehabilitation referral of older allogeneic hematopoietic stem cell transplant patients for prehabilitation resulted in the identification of many rehabilitative needs and substantial additional management recommendations. Increased early, collaborative prehabilitation efforts between physical medicine and rehabilitation and allogeneic hematopoietic stem cell transplant teams to optimize care for these patients is recommended.

A Systematic Review and Metasynthesis of Hematopoietic Stem Cell Transplant (HSCT) Patient's Experiences of Long-Term Monitoring Clinics from the Patient's Perspective.

This study aimed to synthesize all qualitative evidence on the experiences of hematopoietic stem cell transplant (HSCT) patients attending long-term monitoring clinics from their perspective. A systematic search of the literature was undertaken across 8 databases. The Critical Appraisal Skills Program was used to evaluate each study's quality. Confidence in the Evidence from Reviews of Qualitative Research was employed to assess confidence in each finding. Three themes from 4 qualitative studies were identified relating to patients' experiences, "[It's] important to maintain a good relationship with the nurses and doctors," "There's always the thing about the logistics," and "Once you have cancer, you're always thinking do I have it again?". The findings suggest that HSCT patients' experiences of long-term follow-up care clinics are influenced by the patient-provider relationship and the logistical set-up of monitoring practices, and weakly connected with fear of cancer recurrence. Future research is needed to understand the impact of each finding of this review, specifically in relation to patients' country of residence to gain a greater understanding of their monitoring support needs.

Effectiveness of oral vancomycin as prophylaxis against Clostridioides difficile infection in hematopoietic stem cell transplant patients

Abstract Objective: Patients receiving hematopoietic stem cell transplants (HSCT) are at increased risk for Clostridioides difficile infection (CDI). The purpose of this study was to assess the effectiveness of oral vancomycin prophylaxis (OVP) for CDI in HSCT patients. Design: Single-center, retrospective cohort. Setting: Tertiary care academic medical center in New Jersey. Patients: Patients ≥18 years old during admission for the HSCT were included. Patients who were admitted &lt;72 hours or who had an active CDI prior to HSCT day 0 were excluded. Methods: Medical records of patients admitted between January 2015 and August 2022 to undergo an allogeneic or autologous HSCT were reviewed. The primary end point was the incidence of in-hospital CDI. Secondary end points included the incidence of vancomycin-resistant enterococci (VRE) bloodstream infections, VRE isolated from any clinical culture, gram-negative bloodstream infections, hospital survival, and hospital length of stay. Exploratory end points, including 1-year survival, relapse, and incidence of graft-versus-host disease, were also collected. Results: A total of 156 HSCT patients were included. There was 1 case of CDI (1 of 81, 1.23%) in the OVP group compared to 8 CDI cases (8 of 75, 10.67%) in the no OVP group (P = .0147). There were no significant (P &gt; .05) between-group differences in incidence of gram-negative bloodstream infections, hospital survival, and length of stay. There were zero clinical cultures positive for VRE. Conclusions: In-hospital incidence of CDI in HSCT patients was significantly decreased with OVP. Randomized controlled trials are needed in this high-risk population to assess the efficacy and risks of OVP for CDI.

Analysis of laboratory parameters before the occurrence of hepatic sinusoidal obstruction syndrome in children, adolescents, and young adults after hematopoietic stem cell transplantation

PurposeHepatic sinusoidal obstruction syndrome (SOS) is a serious complication following hematopoietic stem cell transplantation (HSCT) in which early diagnosis improves patient outcome. The aim of our study was to detect laboratory parameters following HSCT that can predict the occurrence of SOS.MethodsThis retrospective study included 182 children, adolescents, and young adults who underwent allogeneic or autologous HSCT for the first time (median age 7.2 years). The diagnosis of SOS was based on the pediatric criteria of European Society for Blood and Marrow Transplantation (EBMT). We investigated 15 laboratory parameters after HSCT before the onset of SOS.ResultsThe overall incidence of SOS was 14.8%. SOS developed in 24 of 126 allogeneic (19.1%) and in 3 of 56 autologous (5.4%) HSCT patients at a median time of 13 days after HSCT. We observed a low SOS mortality rate of 11.1% within 100 days after HSCT. International normalized ratio (INR) ≥ 1.3, activated partial thromboplastin time (aPTT) ≥ 40 s, reptilase time ≥ 18.3 s, factor VIII ≤ 80%, antithrombin III ≤ 75%, protein C ≤ 48%, D-dimer ≥ 315 µg/L, bilirubin ≥ 9 µmol/L, and ferritin ≥ 3100 µg/L showed significant associations with the onset of SOS in the univariate analyses. In the multivariate analysis, INR ≥ 1.3 [odds ratio (OR) = 8.104, p = 0.006], aPTT ≥ 40 s (OR = 10.174, p = 0.001), protein C ≤ 48% (OR = 5.215, p = 0.014), and ferritin ≥ 3100 µg/L (OR = 7.472, p = 0.004) could be confirmed as independent risk factors after HSCT before SOS. If three of the four significant cut-off values were present, the probability of developing SOS was more than 70%. The probability of SOS was 96%, if all four laboratory parameters were changed according to the cut-off values. The values of factor XIII, von Willebrand factor (vWF), von Willebrand factor activity (vWF activity), protein S, fibrinogen, and alanine aminotransferase (ALT) were not relevant for the occurrence of SOS.ConclusionIn summary, the laboratory parameters INR, aPTT, protein C, and ferritin were very useful to predict the occurrence of SOS. In addition, this is the first report on a significant association between SOS and high values of INR and aPTT after HSCT before SOS.

Clinical Relevance of Therapeutic Drug Monitoring of Busulfan-Based Regimens in Adult Hematopoietic Stem Cell Transplant Patients

Clinical Relevance of Therapeutic Drug Monitoring of Busulfan-Based Regimens in Adult Hematopoietic Stem Cell Transplant Patients

Common mental disorders in hematopoietic stem cell transplant patients: a scoping review

RESUMO Objetivo: mapear os transtornos mentais comuns recorrentes em pacientes submetidos ao transplante de células-tronco hematopoéticas. Métodos: trata-se de revisão de escopo realizada em janeiro de 2022 em bases de dados eletrônicas e repositórios de dissertações e tese. Foram incluídas publicações que respondessem à questão de pesquisa, atendessem ao objetivo do estudo e que estivessem disponíveis na íntegra em meio eletrônico, em qualquer idioma. Resultados: a amostra foi composta por 28 estudos, dos quais 14 foram publicados nos Estados Unidos da América. Os transtornos mentais comuns encontrados foram os transtornos depressivos, de ansiedade, estresse pós-traumático e de humor. Foram citados 20 sintomas, entre os mais prevalentes estão a fadiga e distúrbios do sono/insônia. Conclusões: evidenciaram-se a dificuldade e a importância de realizar o diagnóstico diferencial desses transtornos, uma vez que seus sintomas podem ser confundidos com outros problemas de saúde e têm forte potencial para interferir na evolução do paciente.

Thrombopoietin mimetic therapy alleviates radiation-induced bone marrow vascular injury in a bone marrow transplant mouse model.

There is a need for therapies that can mitigate bone marrow dysfunction and organ toxicity that occur following myeloablative injury and reduced intensity conditioning regimens used in patients undergoing bone marrow transplantation (BMT). The pathogenesis of adverse effects from BMT conditioning has been linked to injury to the vascular endothelium, bone marrow (BM), and other organs. To evaluate the impact of the thrombopoietin mimetic drug JNJ-26366821 (TPOm) on BM vascular recovery in mice undergoing myeloablative radiation conditioning followed by BMT. TPOm (doses: 0 µg, 300 µg, 1000 µg per Kg body weight) was administered on Days 0 and 7 after BMT, in mice receiving a total body irradiation (TBI) conditioning regimen (5.5 Gy x 2) before congenic BMT. BM donner cell engraftment was analyzed using flow cytometry on Days 7, 14, and 30 post-BMT. The morphological and biophysical properties of the BM vasculature were evaluated by intravital multiphoton microscopy (MPM) and immunofluorescence confocal imaging. Herein, morphological properties involve microvascular density (MVD), vessel diameter, and vascular area, while biophysical properties include transfer rate (Ktrans) of contrast within the BM vascular niche, as well as the fractional volume (vec ) of extracellular extravascular tissue (EES). No significant difference in donor chimerism was observed at days 7, 14, and 30 post-BMT, between TPOm and PBS-treated mice. TPOm intervention improved BM vasculature regeneration in transplanted mice. The MVD, Ktrans, and BM vasculature as well as vascular endothelial growth factor receptor-2 (VEGFR2) in the BM, showed a dose dependent improvement in mice treated with TPOm. On day 14 post-BMT, the group receiving 1000 µg/Kg TPOm showed significant shifts (p-value < 0.05) in MVD, Ktrans, and VEGFR2 expression from their corresponding control types (TPOm dose 0 µg) towards levels comparable to healthy controls. TPOm intervention augments BM vascular structure and function, which may be important for hematopoietic recovery and bone marrow function in radiation conditioned hematopoietic stem cell transplant patients, in addition to enhancing platelet recovery.