Predictors of post traumatic growth in allogeneic hematopoietic stem cell transplantation survivors: a cross-sectional survey.

AIMS: Given the increasing number of Hematopoietic Stem Cell Transplantations (HSCT) performed world-wide, the increasing likelihood of survival following HSCT, and the profound physical, psychosocial, and emotional impact of HSCT on survivors, their carers and families, it is important to identify factors that may contribute to or support post-traumatic growth (PTG) after transplant. In this study, we aimed to investigate the prevalence of PTG in an Australian cohort of long-term allogeneic HSCT survivors and describe associations between PTG and relevant clinical, sociodemographic and psychological variables. METHODS: This was a large, multi-centre, cross sectional survey of Australian HSCT-survivors inviting all those transplanted in New South Wales between 2000 and 2012. Respondents completed the PTG Inventory (PTGI), the Sydney Post-BMT Survey, FACT-BMT, DASS 21, The Chronic Graft versus Host Disease (GVHD) Activity Assessment-Patient Self-Report (Form B), the Lee Chronic GVHD Symptom Scale, and the Fear of Cancer Recurrence Scale. Data was analysed using independent t-tests, one-way analysis of variance, and pearson's correlations, and hierarchical multiple regression adjusted for potential confounders and to ascertain independent associations of explanatory variables with PTG. RESULTS: Of 441 respondents, 99% reported some level of PTG with 67% reporting moderate to high levels of PTG. Female gender, younger age, complementary therapy use, anxiety, psychological distress and psychosocial care, and higher quality of life were associated with higher levels of PTG. Importantly, we also found that PTG was not associated with either chronic GVHD or post-HSCT morbidity. CONCLUSIONS: In this study - the largest study of PTG in long-term allogeneic HSCT survivors - we found that growth appears ubiquitous, with 99% of survivors reporting some degree of PTG and 67% reporting moderate-high levels of PTG. Importantly, we found no association with GVHD or chronic physical post-HSCT morbidity, or adverse financial, occupational or sexual impacts. This suggests that it is the necessity for and experience of, HSCT itself that foments personal growth. Accordingly, healthcare professionals should be alert to the profound and wide-ranging impact of HSCT - and the degree to which survivor's may experience PTG. Identifying interventions that may assist HSCT survivors cope and building their resilience is of utmost importance.

Decisional Regret in Long-Term Australian Allogeneic Hematopoietic Stem Cell Transplantation Survivors: A Cross-Sectional Survey.

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is an intensive but effective treatment for malignant and non-malignant diseases. However, long-term survival often comes at a cost, with survivors experiencing chronic morbidity and are at risk of relapse and secondary malignancy. This study aimed to describe decisional regret in a large cohort of Australian long-term allo-HSCT survivors. A cross-sectional survey was conducted with 441 adults in New South Wales, assessing quality of life (QoL), psychological, social, demographic, and clinical variables. Less than 10% of survivors expressed regret, with chronic graft-versus-host disease being the most important clinical factor. Psycho-socioeconomic factors such as depression, lower QoL scores, lower household income, higher treatment burden, and not resuming sex post-HSCT were also associated with regret. Findings highlight the need for valid informed consent and ongoing follow-up and support for allo-HSCT survivors dealing with life post-transplant. Nurses and healthcare professionals play a critical role in addressing decisional regret in these patients.

Incidence of Sinusoidal Obstruction Syndrome/Veno-Occlusive Disease and Treatment with Defibrotide in Allogeneic Transplantation: A Multicenter Australasian Registry Study.

Sinusoidal obstruction syndrome/veno-occlusive disease (SOS/VOD) is an established complication in patients undergoing allogeneic hemopoietic stem cell transplantation (HSCT). Defibrotide is an effective and safe pharmacologic option for treating diagnosed SOS/VOD. By exploring data provided to the Australasian Bone Marrow Transplant Recipient Registry (ABMTRR) by centers in Australia and New Zealand, this study aimed to describe the incidence of SOS/VOD and patterns of defibrotide use from 2016 to 2020. Patients who underwent allogeneic hemopoietic stem cell transplantation between 2016 and 2020 were identified from the ABMTRR. Data were extracted for a total of 3346 patients, 2692 from adult centers and 654 from pediatric centers, with a median follow-up of 21.5 months and 33.3 months, respectively. Descriptive statistics were used to describe the patient population, including the incidence of SOS/VOD and defibrotide use. Comparisons were made between patients without SOS/VOD and those with SOS/VOD, divided into defibrotide and no defibrotide cohorts. Associations with overall survival (OS) and day 100 survival with such variables as sex, age, disease at transplantation, stem cell source, conditioning agents, SOS/VOD diagnosis, and use of defibrotide, were determined. The reported incidence of SOS/VOD was 4.1% in adult centers and 11.5% in pediatric centers. Defibrotide was administered to 74.8% of adult patients and 97.3% of pediatric patients with SOS/VOD. Significant variability in the use, dosage, and duration of defibrotide was seen across the adult centers. The day 100 survival rate and median OS for patients managed with defibrotide was 51.8% and 103 days, respectively, for adult patients and 90.4% and not reached, respectively, for pediatric patients. In adults, older age at transplantation, an HLA-matched nonsibling relative donor, and a diagnosis of SOS/VOD treated with defibrotide were associated with reduced OS. In pediatric patients, the patient and transplantation characteristics associated with reduced OS were a diagnosis of SOS/VOD and a ≥2 HLA-mismatched related donor. A collaborative approach across Australasia to diagnosing and managing SOS/VOD, particularly with respect to consistent defibrotide use, is recommended.

Long-term treatment burden following allogeneic blood and marrow transplantation in NSW, Australia: a cross-sectional survey.

BACKGROUND: Allogenic blood and marrow transplant (allo-BMT) is an arduous treatment used increasingly for many life-threatening conditions. Recognition of the profound impacts of the long term and late effects is ever-growing, as is the healthcare workload (treatment burden) of survivorship. PURPOSE: To quantify the treatment burden of long-term survival following allo-BMT, regarding the range of health services, therapies and investigations accessed by survivors. METHODS: A large, multi-centre cross-sectional survey of adult allo-BMT survivors transplanted between 2000 and 2012 in Sydney, Australia. Participants completed six validated instruments and one purposed designed for the study, the Sydney Post BMT Study (SPBS), answering questions relating to medication use, medical treatments, referrals, assessments and frequency of hospital/clinic attendance. RESULTS: Of the 441 allo-BMT survivors, over a quarter who were more than 2 years post BMT attended the hospital clinic at least monthly, and 26.7% required a number of regular medical procedures (e.g. venesection, extracorpororeal photopheresis). Specialist medical and allied health referral was very common, and compliance with internationally recommended long-term follow-up (LTFU) care was suboptimal and decreased as time from BMT increased. CONCLUSION: Respondents reported a large medication (conventional and complementary), screening, assessment and health care burden. IMPLICATIONS FOR CANCER SURVIVORS: Treatment burden contributes significantly to the 'workload' of survivorship and can have a severe and negative impact on BMT survivors, carers and the healthcare system-making it difficult to comply with optimal care. Clinicians must be primed with skills to identify survivors who are overburdened by the health care required for survival and develop strategies to help ease the burden.

Fear of cancer recurrence following allogeneic haematopoietic stem cell transplantation (HSCT) for haematological malignancy: A cross-sectional study.

PURPOSE: The aim of this study was to quantify the prevalence of Fear of Cancer Recurrence (FCR) in patients with a prior haematology malignancy surviving more than one year post allogeneic haematopoietic stem cell transplantation (HSCT), and to identify the demographic, medical and psychological factors associated with FCR occurrence. METHOD: Participants were adult allogeneic HSCT recipients who had undergone the procedure for acute leukaemia or other haematological malignancy between the years 2000-2012 in Sydney, Australia. They completed a purpose designed survey and six other validated instruments which assessed FCR, psychological functioning, quality of life, demographic, social and clinical variables. RESULTS: Of the 364 respondents, approximately 11% of the sample lived with severe FCR while only 5% of subjects reported having no FCR. Variables significantly associated with higher FCR included unemployment, a shorter time (years) post-transplant, not attending to health screening (PAP smear), a secondary diagnosis of skin cancer, younger age, referral to a psychiatrist and taking psychotropic medication. Higher psychological distress (depression, anxiety, stress) and lower quality of life made a significant contribution to the prediction of FCR. CONCLUSIONS: Post HSCT follow-up care should include an assessment and discussion regarding FCR to balance both realistic and unrealistic cancer recurrence risks. Managing FCR is one of the most ubiquitous unmet needs of survivors of haematological disease and it is important that HSCT nurses are both aware of the fear, and are equipped with knowledge on how to help patients navigate it with realistic expectations.

Targeting CD300f to enhance hematopoietic stem cell transplantation in acute myeloid leukemia.

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) significantly reduces the rate of relapse in acute myeloid leukemia (AML) but comes at the cost of significant treatment-related mortality. Despite the reduction in relapse overall, it remains common, especially in high-risk groups. The outcomes for patients who relapse after transplant remains very poor. A large proportion of the morbidity that prevents most patients from accessing allo-HSCT is due to toxic nonspecific conditioning agents that are required to remove recipient hematopoietic stem and progenitor cells (HSPCs), allowing for successful donor engraftment. CD300f is expressed evenly across HSPC subtypes. CD300f has transcription and protein expression equivalent to CD33 on AML. We have developed an anti-CD300f antibody that efficiently internalizes into target cells. We have generated a highly potent anti-CD300f antibody-drug conjugate (ADC) with a pyrrolobenzodiazepine warhead that selectively depletes AML cell lines and colony forming units in vitro. The ADC synergizes with fludarabine, making it a natural combination to use in a minimal toxicity conditioning regimen. Our ADC prolongs the survival of mice engrafted with human cell lines and depletes primary human AML engrafted with a single injection. In a humanized mouse model, a single injection of the ADC depletes CD34+ HSPCs and CD34+CD38-CD90+ hematopoietic stem cells. This work establishes an anti-CD300f ADC as an attractive potential therapeutic that, if validated in transplant models using a larger cohort of primary AML samples, will reduce relapse rate and toxicity for patients with AML undergoing allo-HSCT.

Clinical experience with new formulation SUBA®-itraconazole for prophylaxis in patients undergoing stem cell transplantation or treatment for haematological malignancies.

BACKGROUND: SUper BioAvailability-itraconazole (SUBA®-itraconazole) was introduced into Australia in April 2014 as a substitute for standard itraconazole on the basis of improved bioavailability, tolerance and interpatient variability. Shortly after its introduction, our centre converted to the novel formulation for mould prophylaxis in patients undergoing allogeneic HSCT, autologous HSCT or treatment for haematological malignancies with an intermediate/high risk of invasive fungal infection (IFI). METHODS: A single-institution, investigator-initiated retrospective cohort study was conducted between June 2016 and April 2018 to assess therapeutic drug concentrations, safety and tolerability of a standard prophylactic dose of SUBA®-itraconazole. RESULTS: A total of 74 patients were assessed across 98 admissions with 178 measured itraconazole trough concentrations. The median duration of prophylaxis was 15.5 (1-59) days. No significant correlation was identified between trough concentrations and patient demographics including gender and weight. Drug concentrations were reduced by gastric acid suppression and diarrhoea. Therapeutic itraconazole trough concentrations (≥0.5 mg/L) were achieved at a median of 7 (95% CI = 6-8) days, with 87% of patients achieving therapeutic concentrations at day 14 (expected steady-state). One (1%) proven/probable IFI and 5 (5%) possible breakthrough IFIs were identified. Although adverse events were experienced by 42% of the cohort, only a single event was directly attributable to SUBA®-itraconazole, resulting in change of prophylactic agent. CONCLUSIONS: SUBA®-itraconazole achieved rapid therapeutic trough concentrations, was associated with low rates of IFI and was well tolerated in the study population. This formulation should be considered a realistic and safe first-line agent for the prevention of IFIs in those undergoing HSCT and intermediate/high-risk therapy for haematological malignancies.

A survey of infectious diseases and vaccination uptake in long-term hematopoietic stem cell transplant survivors in Australia.

BACKGROUND: This cross-sectional survey aimed to establish the prevalence of infectious diseases and vaccination uptake in long-term allogeneic hematopoietic stem cell transplants (HSCT) survivors in New South Wales, in order to reduce long-term post-HSCT morbidity and mortality and enhance long-term care. PATIENTS AND METHODS: Hematopoietic stem cell transplants survivors aged over 18 years and transplanted between 2000-2012 in New South Wales (NSW) were eligible to participate. Survivors self-completed the Sydney Post BMT Study survey, FACT-BMT (V4), Chronic Graft versus Host Disease (cGVHD) Activity Assessment Self Report, Lee Chronic GvHD Symptom Scale, DASS21, Post Traumatic Growth Inventory, and the Fear of Recurrence Scale. RESULTS: Of the 583 HSCT survivors contacted, 441 (78%) completed the survey. Respondents included 250 (57%) males and median age was 54 years (range 19-79 years). The median age at the time of transplant was 49 years (Range: 17-71), the median time since HSCT was 5 years (Range: 1-14) and 69% had cGVHD. Collectively, 41.7% of survivors reported a vaccine preventable disease (VPD) with the most common being influenza-like-illness (38.4%), varicella zoster/shingles (27.9%), pap smear abnormalities (9.8%), pneumococcal disease (5.1%), and varicella zoster (chicken pox) (4.6%). Only 31.8% had received the full post-HSCT vaccination schedule, and the majority (69.8%) of these had received the vaccines via their General Practitioner. cGVHD was not found to be a significant factor on multivariate analysis for those who were vaccinated. There was a trend toward lower vaccination rates in patients in a lower income strata. CONCLUSIONS: Vaccinating post-HSCT survivors to prevent infections and their consequences have an established role in post-HSCT care. Improving rates of post-HSCT vaccination should be a major priority for BMT units.

Invasive Fungal Sinusitis Presenting as Acute Posterior Ischemic Optic Neuropathy.

Invasive fungal sinusitis causes painful orbital apex syndrome with ophthalmoplegia and visual loss; the mechanism is unclear. We report an immunocompromised patient with invasive fungal sinusitis in whom the visual loss was due to posterior ischaemic optic neuropathy, shown on diffusion-weighted MRI, presumably from fungal invasion of small meningeal-based arteries at the orbital apex. After intensive antifungal drugs, orbital exenteration and immune reconstitution, the patient survived, but we were uncertain if the exenteration helped. We suggest that evidence of acute posterior ischaemic optic neuropathy should be a contra-indication to the need for orbital exenteration in invasive fungal sinusitis.

The Analysis of CD83 Expression on Human Immune Cells Identifies a Unique CD83+-Activated T Cell Population.

CD83 is a member of the Ig gene superfamily, first identified in activated lymphocytes. Since then, CD83 has become an important marker for defining activated human dendritic cells (DC). Several potential CD83 mRNA isoforms have been described, including a soluble form detected in human serum, which may have an immunosuppressive function. To further understand the biology of CD83, we examined its expression in different human immune cell types before and after activation using a panel of mouse and human anti-human CD83 mAb. The mouse anti-human CD83 mAbs, HB15a and HB15e, and the human anti-human CD83 mAb, 3C12C, were selected to examine cytoplasmic and surface CD83 expression, based on their different binding characteristics. Glycosylation of CD83, the CD83 mRNA isoforms, and soluble CD83 released differed among blood DC, monocytes, and monocyte-derived DC, and other immune cell types. A small T cell population expressing surface CD83 was identified upon T cell stimulation and during allogeneic MLR. This subpopulation appeared specifically during viral Ag challenge. We did not observe human CD83 on unstimulated human natural regulatory T cells (Treg), in contrast to reports describing expression of CD83 on mouse Treg. CD83 expression was increased on CD4+, CD8+ T, and Treg cells in association with clinical acute graft-versus-host disease in allogeneic hematopoietic cell transplant recipients. The differential expression and function of CD83 on human immune cells reveal potential new roles for this molecule as a target of therapeutic manipulation in transplantation, inflammation, and autoimmune diseases.

Epidemiology of complementary and alternative medicine therapy use in allogeneic hematopoietic stem cell transplant survivorship patients in Australia.

In addition to prescribed conventional medicines, many allogeneic hematopoietic stem cell transplant (HSCT) survivors also use complementary and alternative medical therapies (CAM), however, the frequency and types of CAMs used by allogeneic HSCT survivors remain unclear. Study participants were adults who had undergone an allogeneic HSCT between 1st January 2000 and 31st December 2012. Participants completed a 402-item questionnaire regarding the use of CAM, medical complications, specialist referrals, medications and therapies, infections, vaccinations, cancer screening, lifestyle, and occupational issues and relationship status following stem cell transplantation. A total of 1475 allogeneic HSCT were performed in the study period. Of the 669 recipients known to be alive at study sampling, 583 were contactable and were sent study packs. Of 432 participants who returned the completed survey (66% of total eligible, 76% of those contacted), 239 (54.1%) HSCT survivors used at least one form of CAM. These included dietary modification (13.6%), vitamin therapy (30%), spiritual or mind-body therapy (17.2%), herbal supplements (13.5%), manipulative and body-based therapies (26%), Chinese medicine (3.5%), reiki (3%), and homeopathy (3%). These results definitively demonstrate that a large proportion of HSCT survivors are using one or more form of CAM therapy. Given the potential benefits demonstrated by small studies of specific CAM therapies in this patient group, as well as clearly documented therapies with no benefit or even toxicity, this result shows there is a large unmet need for additional studies to ascertain efficacy and safety of CAM therapies in this growing population.

Design and rationale of the QUAZAR Lower-Risk MDS (AZA-MDS-003) trial: a randomized phase 3 study of CC-486 (oral azacitidine) plus best supportive care vs placebo plus best supportive care in patients with IPSS lower-risk myelodysplastic syndromes and poor prognosis due to red blood cell transfusion-dependent anemia and thrombocytopenia.

BACKGROUND: CC-486 is an oral formulation of the epigenetic modifier azacitidine. In an expanded phase 1 trial, CC-486 demonstrated clinical and biological activity in patients with International Prognostic Scoring System (IPSS) lower-risk (low- and intermediate-1-risk) myelodysplastic syndromes (MDS) with poor prognostic features including anemia and/or thrombocytopenia who may have required red blood cell or platelet transfusions. The overall response rate was 40 %, including hematologic improvement in 28 % of patients and RBC transfusion independence sustained for 56 days in 47 % of patients with baseline transfusion dependence. Based on the results of this study, the randomized, placebo-controlled phase 3 QUAZAR Lower-Risk MDS trial (AZA-MDS-003) was initiated. The design and rationale for this trial comparing CC-486 with placebo for the treatment of patients with IPSS lower-risk MDS with poor prognostic features are described. METHODS: Patients must have IPSS lower-risk MDS with red blood cell (RBC) transfusion-dependent anemia and thrombocytopenia. Eligible patients are randomized 1:1 to receive 300 mg of CC-486 or placebo once daily for the first 21 days of 28-day treatment cycles. Disease status assessments occur at the end of cycle 6 and patients may continue to receive treatment unless there is evidence of progressive disease, lack of efficacy, or unacceptable toxicity. The primary endpoint is RBC transfusion independence for ≥ 84 days, assessed according to International Working Group 2006 criteria. Secondary endpoints include overall survival, hematologic response including platelet response and erythroid response, RBC transfusion independence for ≥ 56 days, duration of RBC transfusion independence, time to RBC transfusion independence, rate of acute myeloid leukemia (AML) progression, time to AML progression, clinically significant bleeding events, safety, health-related quality of life, and healthcare resource utilization. CONCLUSIONS: This study will provide data on the efficacy and safety of CC-486 in the treatment of IPSS lower-risk MDS with poor prognosis due to the presence of both RBC transfusion-dependent anemia and thrombocytopenia. Positive results of the AZA-MDS-003 study may expand treatment options for patients with IPSS lower-risk MDS. TRIAL REGISTRATION: ClinicalTrials.gov NCT01566695, registered March 27, 2012.

Adherence to cancer screening guidelines in Australian survivors of allogeneic blood and marrow transplantation (BMT).

Allogeneic Blood and Marrow Transplant (BMT) survivors are at high risk of secondary cancers. Although current guidelines endorse survivors following Country-specific general population screening recommendations to mitigate this risk, little is known about cancer screening adherence in Australian BMT survivors. We conducted a cross-sectional survey of 441 BMT survivors who were >1 year post transplant, to explore rates of screening for secondary cancers and to identify barriers to cancer screening recommendations. Survey instruments included the Sydney Post-BMT Survey, FACT-BMT, DASS 21, The Chronic Graft versus Host Disease (GVHD) Activity Assessment-Patient Self-Report (Form B), the Lee Chronic GVHD Symptom Scale, Fear of Cancer Recurrence Scale, and The Post Traumatic Growth Inventory. Fifty-seven percent of respondents were male, median age 54 years, and 40% were >6 years post-BMT. Rates of cancer screening adherence were as follows: cervical 63.4%, breast 53.3%, skin 52.4%, and bowel 32.3%. Older BMT survivors and those >2 years post transplant were more likely to undergo cancer screening. Improved quality of life was associated with screening for skin, breast, and cervical cancer. Fear of cancer recurrence negatively impacted on cervical screening. For those who had not undergone screening, the majority reported not being advised to do so by their treatment team. This study is the largest and most comprehensive to date exploring cancer screening adherence in BMT survivors in Australia. These data provide the basis for health service reform to better meet the needs of BMT survivors and provide evidence to support counseling and education of both patients and professionals.

A survey of fertility and sexual health following allogeneic haematopoietic stem cell transplantation in New South Wales, Australia.

Four hundred and twenty-one adult allogeneic haematopoietic stem cell transplant (HSCT) survivors participated in a cross-sectional study to assess sexual dysfunction and infertility post-transplant. Survey instruments included the Sydney Post-Blood and Marrow Transplant (BMT) Survey, Functional Assessment of Cancer Treatment (FACT) - BMT, the Depression, Anxiety, Stress Scales (DASS 21), the Chronic Graft-versus-Host Disease (cGVHD) Activity Assessment- Patient Self Report (Form B), the Lee cGVHD Symptom Scale and The Post-Traumatic Growth Inventory. Most HSCT survivors reported sexual difficulties (51% of males; 66% of females). Men reported erectile dysfunction (79%) and decreased libido (61·6%) and women reported loss of libido (83%), painful intercourse (73%) and less enjoyment of sex (68%). Women also commonly reported vaginal dryness (73%), vaginal narrowing (34%) and vaginal irritation (26%). Woman had much higher rates of genital cGvHD than men (22% vs. 5%). Age and cGVHD were significantly associated with sexual dysfunction. Few survivors had children following transplant (3·3%). However, for those of reproductive age at HSCT, 22% reported trying to conceive, with 10·3% reporting success. This study is the largest to date exploring sexual function in survivors of allo-HSCT. This data provides the basis for health service reform to better meet the needs of HSCT survivors, including evidence to support counselling and education both pre- and post-transplant.

What They Want: Inclusion of Blood and Marrow Transplantation Survivor Preference in the Development of Models of Care for Long-Term Health in Sydney, Australia.

Four hundred forty-one adult allogeneic blood and marrow transplantation (BMT) survivors participated in a cross-sectional survey to assess long-term follow-up (LTFU) model of care preference. Survey instruments included the Sydney Post BMT Survey, Functional Assessment of Cancer Therapy-BMT, Depression Anxiety Stress Scales 21, the Chronic GVHD Activity Assessment-Patient Self Report (Form B), the Lee Chronic GVHD Symptom Scale and the Post-Traumatic Growth Inventory. We found most BMT survivors (74%) would prefer LTFU with their transplantation physicians alone or in combination with transplantation center-linked services (satellite clinics or telemedicine) Over one-quarter indicated a preference for receiving comprehensive post-transplantation care in a "satellite" clinic staffed by their BMT team situated closer to their place of residence, with higher income, higher educational level, and sexual morbidity being significant social factors influencing this preference. Regular exercise was reported less often in those who preferred telemedicine, which may reflect reduced mobility. The factor most strongly associated with a preference for transplantation center follow-up was the severity of chronic graft-versus-host disease. Full- and part-time work were negatively associated with transplantation center follow-up, possibly implying decreased dependency on the center and some return to normalcy. This study is the first to explore the preferences of BMT survivors for long-term post-transplantation care. These data provides the basis for LTFU model of care development and health service reform consistent with the preferences of BMT survivors.

Gene therapy for hemophilia: clinical trials and technical tribulations.

As monogenic disorders, hemophilia A and B are compelling candidates for treatment with gene therapy. In hemophilia, a therapeutic benefit achieved by gene therapy should only require a modest increase in the endogenous factor level; response to treatment can be monitored easily; and there are relevant small and large animal models. The two main approaches aiming to restore factor VIII or factor IX production are based on genetically modified cells or direct in vivo gene delivery using viral or plasmid vectors. The progress toward gene therapy for hemophilia A and B in both preclinical and clinical models will be evaluated in this review. Various viral and nonviral vectors are discussed in the context of current hurdles arising from preclinical and clinical trials. Despite disappointing clinical results to date, there are favorable indications that the near future should deliver on the long-sought promise of a cure for hemophilia.

Improved granulocyte colony-stimulating factor mobilization of hemopoietic progenitors using cytokine combinations in primates.

Peripheral blood stem cells (PBSCs), usually mobilized with granulocyte colony-stimulating factor (G-CSF) alone or in combination with chemotherapy, are the preferred source of cells for hemopoietic stem cell transplantation. Up to 25% of otherwise eligible transplant recipients fail to harvest adequate PBSCs. Therefore it is important to investigate existing and novel reagents to improve PBSC mobilization. Because of marked interindividual variation in humans, we developed a robust nonhuman primate model that allows the direct comparison of the efficacy of two PBSC mobilization regimens within the same animal. Using this model, we compared pegylated G-CSF (pegG-CSF) with standard G-CSF and compared the combination of G-CSF and pegylated megakaryocyte growth and development factor (pegMGDF) with G-CSF plus stem cell factor (SCF) by measuring the levels of CD34(+) cells, colony-forming cells (CFCs), and SCID repopulating cells (SRCs) before and after cytokine administration. Mobilization of CD34(+) cells, CFCs and SRCs using pegG-CSF achieved similar levels to those resulting from 5 days of standard G-CSF. The combination of G-CSF+pegMGDF mobilized progenitors to levels similar to G-CSF+SCF but greater than standard G-CSF for CD34(+) cells and CFC. This first direct comparison of PBSC mobilization in individual primates demonstrates that peg-G-CSF is equivalent to daily G-CSF and that the addition of pegMGDF to G-CSF improves mobilization. In light of the development of new thrombopoietin agonists, these data offer the potential for improved stem cell mobilization strategies. Disclosure of potential conflicts of interest is found at the end of this article.