Risk factors for Nocardia infection among allogeneic hematopoietic cell transplant recipients: A case-control study of the Infectious Diseases Working Party of the European Society for Blood and Marrow Transplantation.

OBJECTIVES: Nocardiosis is a rare but life-threatening infection after hematopoietic cell transplantation (HCT). We aimed at identifying risk factors for nocardiosis after allogeneic HCT and clarifying the effect of trimethoprim-sulfamethoxazole prophylaxis on its occurrence. METHODS: We performed a retrospective multicenter case-control study of patients diagnosed with nocardiosis after allogeneic HCT between January 2000 and December 2018. For each case, two controls were matched by center, transplant date, and age group. Multivariable analysis was conducted using conditional logistic regression to identify potential risk factors for nocardiosis. Kaplan-Meier survival curves of cases and controls were compared using log-rank tests. RESULTS: Sixty-four cases and 128 controls were included. Nocardiosis occurred at a median of 9 months after allogeneic HCT (interquartile range: 5-18). After adjustment for potential confounders in a multivariable model, Nocardia infection was associated with tacrolimus use (adjusted odds ratio [aOR] 9.9, 95 % confidence interval [95 % CI]: 1.6-62.7), lymphocyte count < 500/µL (aOR 8.9, 95 % CI: 2.3-34.7), male sex (aOR 8.1, 95 % CI: 2.1-31.5), recent use of systemic corticosteroids (aOR 7.9, 95 % CI: 2.2-28.2), and recent CMV infection (aOR 4.3, 95 % CI: 1.2-15.9). Conversely, use of trimethoprim-sulfamethoxazole prophylaxis was associated with a significantly decreased risk of nocardiosis (aOR 0.2, 95 % CI: 0.1-0.8). HCT recipients who developed nocardiosis had a significantly decreased survival, as compared with controls (12-month survival: 58 % and 90 %, respectively; p < 0.0001). CONCLUSIONS: We identified six factors independently associated with the occurrence of nocardiosis among allogeneic HCT recipients. In particular, trimethoprim-sulfamethoxazole prophylaxis was found to protect against nocardiosis.

A retrospective study of intravenous pentamidine for Pneumocystis jirovecii pneumonia prophylaxis in adult patients with hematologic malignancies-its utility during respiratory virus pandemics.

OBJECTIVES: In hematology, prophylaxis for Pneumocystis jirovecii pneumonia (PCP) is recommended for patients undergoing hematopoietic stem cell transplantation and in selected categories of intensive chemotherapy for hematologic malignancies. Trimethoprim-sulfamethoxazole (TMP-SMX) is the recommended first-line agent; however, its use is not straightforward. Inhaled pentamidine is the recommended second-line agent; however, aerosolized medications were discouraged during respiratory virus outbreaks, especially during the COVID-19 pandemic, in view of potential contamination risks. Intravenous (IV) pentamidine is a potential alternative agent. We evaluated the effectiveness and tolerability of IV pentamidine use for PCP prophylaxis in adult allogeneic hematopoietic stem cell transplantation recipients and patients with hematologic malignancies during COVID-19. RESULTS: A total of 202 unique patients who received 239 courses of IV pentamidine, with a median of three doses received (1-29). The largest group of the patients (49.5%) who received IV pentamidine were undergoing or had received a hematopoietic stem cell transplant. The most common reason for not using TMP-SMX prophylaxis was cytopenia (34.7%). We have no patients who had breakthrough PCP infection while on IV pentamidine. None of the patients developed an infusion reaction or experienced adverse effects from IV pentamidine. CONCLUSIONS: Pentamidine administered IV monthly is safe and effective.

Harmonizing definitions for hematopoietic recovery, graft rejection, graft failure, poor graft function, and donor chimerism in allogeneic hematopoietic cell transplantation: a report on behalf of the EBMT, ASTCT, CIBMTR, and APBMT.

Despite emergence of novel therapies to treat hematologic malignancies, allogeneic hematopoietic cell transplantation (allo-HCT) remains an essential treatment modality capable of curing these diseases. Allo-HCT has been also shown to be curative in benign hematologic disorders such as aplastic anemia, sickle cell disease, and thalassemia, among others. Recently, the American Society for Transplantation and Cellular Therapy (ASTCT) published standardized definitions for hematopoietic recovery, graft rejection, graft failure, poor graft function, and donor chimerism. To attempt broader international consensus, a panel of adult and pediatric physician transplant experts was assembled from European Society for Blood and Marrow Transplantation (EBMT), ASTCT, the Center for International Blood and Marrow Transplant Research (CIBMTR), and Asia-Pacific Blood and Marrow Transplantation (APBMT). Consensus was defined as ≥70% of voting members strongly agreeing or somewhat agreeing with a definition. With few exceptions, there was a consensus to endorse the prior ASTCT definitions. Importantly, we revised existing EBMT and CIBMTR data collection forms to align with these harmonized definitions that will facilitate research and international collaboration among transplant researchers and across transplant registries.

Current perspectives on resistance to chimeric antigen receptor T-cell therapy and strategies to improve efficacy in B-cell lymphoma.

Although chimeric antigen receptor (CAR) T-cell therapy has demonstrated remarkable efficacy in patients with chemo-refractory B-cell lymphoma, a significant portion is refractory or relapse. Resistance is a major barrier to improving treatment efficacy and long-term survival in CAR T-cell therapy, and clinicians have very limited tools to discriminate a priori patients who will or will not respond to treatment. While CD19-negative relapses due to loss of target antigen is well described, it accounts for only about 30% of cases with treatment failure. Recent efforts have shed light on mechanisms of CD19-positive relapse due to tumor intrinsic resistance, T-cell quality/manufacturing, or CAR T-cell exhaustion mediated by hostile tumor microenvironment. Here, we review the latest updates of preclinical and clinical trials to investigate the mechanisms of resistance and relapse post CAR T-cell therapy in B cell lymphoma and discuss novel treatment strategies to overcome resistance as well as advances that are useful for a CAR T therapist to optimize and personalize CAR T-cell therapy.

Report on hematopoietic cell transplantations performed in 2018/2019 focusing on the trends of selection of stem cell sources in the Asia-Pacific region: APBMT Activity Survey.

The number of hematopoietic stem cell transplantations (HCTs) is increasing annually worldwide, and the Asia-Pacific (AP) region is no exception. We report on the absolute number of HCTs in 2018 and 2019 and the trends in graft selection and disease indication in the past few decades. In 2018, 24,292 HCTs were performed in the AP region, of which 8,754 (36.0%) were autologous and 15,538 (64.0%) were allogeneic. Among the allogeneic HCTs, 10,552 (67.9%) of the recipients were related to their donors, whereas 4,986 (32.1%) were unrelated. In 2019, 27,583 HCTs were reported, of which 17,613 (63.9%) were allogeneic and 9,970 (36.1%) were autologous. Although, in 2010, there was a nearly equal number of related and unrelated HCTs, the difference has shown an annual increase, with more than double (2.05) the number of related than unrelated HCTs in 2019. Recent trends in the AP region show that peripheral blood has overwhelmingly surpassed the bone marrow as a graft source for both related and unrelated HCTs, with the haploidentical donor type being preferred; however, their trends in each country/region were quite different among countries/regions. In 2019, the main conditions requiring HCT were acute myelogenous leukemia (n=6,629 [24.0%]), plasma cell disorders (PCD) (n=4,935 [17.9%]), malignant lymphoma (ML) (n=4,106 [14.9%]), acute lymphoblastic leukemia (AML) (n=3,777 [13.7%]), myelodysplastic syndrome or myelodysplastic/myeloproliferative neoplasm (n=1,913 [6.9%]), severe aplastic anemia (n=1,671 [6.1%]), and hemoglobinopathy (n=910 [3.3%]). PCD and ML were the main indications for autologous HCT, and the number of PCD cases has grown more prominent than the corresponding of ML. The increased number of allogeneic transplants for hemoglobinopathy remains prominent, as well as that of AML and acute lymphocytic leukemia for the past 5 years. There was a significant regional variation in the number of facilities performing HCTs, ranging from one in Mongolia and Nepal to 313 in Japan, and differing regional densities varying from 0.1 in Indonesia and Pakistan to 24.7 in Japan. The total transplant density per 10 million population in each country/region also differed (0.2 in Indonesia and 627 in New Zealand). This annual Activity Survey aims to help all participating countries/regions understand the changes in HCT, serve as an asset in promoting HCT activities in the AP region, and be used as a reference for comparison with other registries from Europe and the United States.

Allogeneic Umbilical Cord Plasma Eyedrops for the Treatment of Recalcitrant Dry Eye Disease Patients.

BACKGROUND: Dry eye disease is a significant disease in Singapore. While there have been studies using allogenic cord serum for the treatment of dry eye disease, treatment of dry eyes with allogenic umbilical cord plasma drops has yet to be started in Singapore. PURPOSE: To evaluate the effectiveness of umbilical cord plasma eyedrops for the treatment of recalcitrant dry eyes in a local Singaporean context. METHODS: This is an observational, longitudinal, interventional study for dry eye patients who did not show clear improvement after standard therapy. Patients were recruited from 2020 to 2023 from the dry eye clinic of the Singapore National Eye Center. Umbilical cord plasma was delivered frozen to patients and stored in home freezers. All participants underwent a standardized clinical evaluation for dry eye, and data were collected. RESULTS: There were 40 participants (7 males and 33 females). The duration of follow-up was 5.52 ± 1.57 months. Kerato-epitheliopathy staining score, TBUT (tear breakup time), and SPEED (Standard Patient Evaluation of Eye Dryness Questionnaire) scores significantly improved after treatment. No statistically significant improvement was found in terms of visual acuity, according to Schirmer's score. CONCLUSION: Cord plasma eye drops significantly improved kerato-epitheliopathy staining scores in recalcitrant dry eye patients. Allogeneic plasma is a promising form of treatment for recalcitrant dry eye.

Conjunctival T Cell Profile in Allogeneic Hematopoietic Stem Cell Transplant Patients after Instilling Topical Cyclosporine-A 0.1% Cationic Emulsion.

INTRODUCTION: To profile conjunctival T cell populations in allogeneic hematopoietic stem cell transplant (HSCT) patients after instillation of daily topical cyclosporine-A (CsA) 0.1% cationic emulsion (Ikervis), and to evaluate patients' tolerance to these eye drops. METHODS: Nineteen participants were prescribed Ikervis prophylaxis once daily to both eyes from 3-5 weeks pre-HSCT to 12 months post-HSCT. The outcome measure was conjunctival T cell proportions from flow cytometry after impression cytology. Covariates included visual acuity, intraocular pressure, slit lamp and fundal examination, dry eye (SPEED) and quality of life questionnaires, non-invasive keratograph tear break-up time (NIKBUT), conjunctival redness, meibography, lipid thickness, Schirmer test, tear cytokines, fluorescein staining, tear osmolarity, and meibomian gland expressibility. RESULTS: The conjunctival T cell analysis showed either stable or decreased proportions of conjunctival CD4 T cells at the last visit from baseline in compliant patients. CD4 proportions were increased in non-compliant patients and in the single patient who developed ocular graft-versus-host disease (GVHD). All patients were tolerant to Ikervis but 6/19 were not compliant. In the majority of patients, vision did not affect activities of daily living. Pre- and post-HSCT up to the last study visit, there was no statistically significant change in clinical covariates. Only one participant developed ocular GVHD at 9 months post-HSCT. CONCLUSION: Superficial conjunctival T cell profile reflects compliance to daily topical Ikervis eye drops and clinical ocular surface parameters in allogenic HSCT patients. Tolerance is comparable to other formulations of topical CsA in the first 12 months. GOV IDENTIFIER: NCT04636918. URL: https://clinicaltrials.gov/ct2/show/NCT04636918?cond=ocular+Graft+Versus+Host+Disease&cntry=SG&draw=2&rank=2 .

Incidence of cutaneous graft-versus-host disease in a Singapore academic medical centre - A retrospective cohort study.

BACKGROUND: Cutaneous graft-versus-host disease (GVHD) is common in allogeneic haematopoietic stem cell transplantation. HLA mismatch is the most significant determinant of GVHD. Our study aimed to compare the incidence of cutaneous GVHD haploidentical (Haplo) and matched donors in an Asian population. METHODS: Retrospective cohort study of the 2015-2019 bone marrow transplant registry was conducted in a transplant centre. We compared the incidence of cutaneous GVHD in Haplo with allogeneic matched unrelated donor (MUD) and matched-sibling donor (MSD) transplant recipients. Secondary objectives include acute and chronic GVHD incidence, dermatology referrals, and histological findings. RESULTS: One hundred and seventy-nine out of 203 cases were reviewed; 17 (9.5%) Haplo, 80 (44.7%) MUDs and 82 (45.8%) MSDs. The median follow-up for Haplo, MUD and MSD was 15.2, 34.2 and 35.7 months, respectively. Haplo had a higher cumulative incidence of cutaneous GVHD than MUD and MSD (p = 0.053). Chronic GVHD was only reported in MSD. The most common histology was vacuolar interface changes (13 [44.8%]) with a wide range of onset post-transplant (19-456 days). CONCLUSIONS: Haplo donors may have a higher GVHD incidence than MUD and MSD in our predominantly Asian cohort. This information may be helpful when counselling patients pre-transplant. Further prospective studies are required.

Favorable outcomes of COVID-19 in vaccinated hematopoietic stem cell transplant recipients: A single-center experience.

INTRODUCTION: A high incidence of mortality and severe COVID-19 infection was reported in hematopoietic stem cell transplant (HSCT) recipients during the early phases of the COVID-19 pandemic; however, outcomes with subsequent severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants, such as the omicron variant, have yet to be reported. Additionally, rollout of COVID-19 vaccinations in subsequent pandemic waves may modify COVID-19 disease severity and mortality in this immunocompromised population. We describe COVID-19 outcomes among a highly vaccinated population of HSCT recipients at a single center during successive waves of community transmission arising from the SARS-CoV-2 delta and omicron variants. METHODS: We retrospectively reviewed medical records of all HSCT recipients at our institution who tested positive for SARS-CoV-2 from May 2021 to May 2022. Descriptive statistics were reported; the chi-square test was utilized to identify factors associated with 90-day all-cause mortality and severity of COVID-19 infection. RESULTS: Over the 1-year study period, 77 HSCT recipients at our center contracted COVID-19 (43 allogenic; 34 autologous). Twenty-six (33.8%) patients were infected with the SARS-CoV-2 delta variant, while 51 (66.2%) had the SARS-CoV-2 omicron variant. Thirty-nine (50.6%) patients required hospitalization. More than 80% had received prior COVID-19 vaccination (57.1% with two doses, 27.3% with three doses). The majority (90.9%) had mild disease; only one (1.3%) patient required mechanical ventilation. Active hematological disease at time of COVID-19 infection was associated with increased odds of mortality [odds ratio (OR) = 6.90, 95% confidence interval (CI) = 1.20-40]. The 90-day all-cause mortality was 7.8% (six patients). Infection with the omicron variant (vs. delta) was associated with less severe illness (OR = 0.05, 95% CI = 0.01-0.47) and decreased odds of mortality (OR = 0.08, 95% CI = 0.01-0.76). Being on immunosuppression (OR = 5.10, 95% CI = 1.10-23.60) and being unvaccinated at disease onset (OR = 14.76, 95% CI = 2.89-75.4) were associated with greater severity of COVID-19 infection. CONCLUSION: We observed favorable outcomes with COVID-19 infection in a cohort of vaccinated HSCT patients. The SARS-CoV-2 omicron variant was associated with both less severe illness and decreased odds of mortality. As COVID-19 moves toward endemicity, early access to treatment and encouraging vaccination uptake is crucial in mitigating the challenge of COVID-19 management among HSCT recipients. Surveillance and assessment of clinical outcomes with new SARS-CoV-2 variants also remains important in this immunocompromised population.

An Analysis of the Worldwide Utilization of Hematopoietic Stem Cell Transplantation for Acute Myeloid Leukemia.

Acute myeloid leukemia (AML) has an aggressive course and a historically dismal prognosis. For many patients, hematopoietic stem cell transplantation (HSCT) represents the best option for cure, but access, utilization, and health inequities on a global scale remain poorly elucidated. We wanted to describe patterns of global HSCT use in AML for a better understanding of global access, practices, and unmet needs internationally. Estimates of AML incident cases in 2016 were obtained from the Global Burden of Disease 2019 study. HSCT activities were collected from 2009 to 2016 by the Worldwide Network for Blood and Marrow Transplantation through its member organizations. The primary endpoint was global and regional use (number of HSCT) and utilization of HSCT (number of HSCT/number of incident cases) for AML. Secondary outcomes included trends from 2009 to 2016 in donor type, stem cell source, and remission status at time of HSCT. Global AML incidence has steadily increased, from 102,000 (95% uncertainty interval: 90,200-108,000) in 2009 to 118,000 (104,000-126,000) in 2016 (16.2%). Over the same period, a 54.9% increase from 9659 to 14,965 HSCT/yr was observed globally, driven by an increase in allogeneic (64.9%) with a reduction in autologous (-34.9%) HSCT. Although the highest numbers of HSCT continue to be performed in high-resource regions, the largest increases were seen in resource-constrained regions (94.6% in Africa/East Mediterranean Region [AFR/EMR]; 34.7% in America-Nord Region [AMR-N]). HSCT utilization was skewed toward high-resource regions (in 2016: AMR-N 18.4%, Europe [EUR] 17.9%, South-East Asia/Western Pacific Region [SEAR/WPR] 11.7%, America-South Region [AMR-S] 4.5%, and AFR/EMR 2.8%). For patients <70 years of age, this difference in utilization was widened; AMR-N had the highest allogeneic utilization rate, increasing from 2009 to 2016 (30.6% to 39.9%) with continued low utilization observed in AFR/EMR (1.7% to 2.9%) and AMR-S (3.5% to 5.4%). Across all regions, total HSCT for AML in first complete remission (CR1) increased (from 44.1% to 59.0%). Patterns of donor stem cell source from related versus unrelated donors varied widely by geographic region. SEAR/WPR had a 130.2% increase in related donors from 2009 to 2016, and >95% HSCT donors in AFR/EMR were related; in comparison, AMR-N and EUR have a predilection for unrelated HSCT. Globally, the allogeneic HSCT stem cell source was predominantly peripheral blood (69.7% of total HSCT in 2009 increased to 78.6% in 2016). Autologous HSCT decreased in all regions from 2009 to 2016 except in SEAR/WPR (18.9%). HSCT remains a central curative treatment modality in AML. Allogeneic HSCT for AML is rising globally, but there are marked variations in regional utilization and practices, including types of graft source. Resource-constrained regions have the largest growth in HSCT use, but utilization rates remain low, with a predilection for familial-related donor sources and are typically offered in CR1. Further studies are necessary to elucidate the reasons, including economic factors, to understand and address these health inequalities and improve discrepancies in use of HSCT as a potentially curative treatment globally.

AL amyloidosis: Singapore Myeloma Study Group consensus guidelines on diagnosis, treatment and management.

AL amyloidosis is the most common form of systemic amyloidosis. However, the non-specific nature of presenting symptoms requires the need for a heightened clinical suspicion to detect unexplained manifestations in the appropriate clinical setting. Early detection and treatment are crucial as the degree of cardiac involvement emerges as a primary prognostic predictor of survival in a patient with AL amyloidosis. Following the diagnosis of AL amyloidosis with appropriate tissue biopsies, prompt treatment with a bortezomib, cyclophosphamide and dexamethasone-based first-line induction with or without daratumumab should be initiated. The goal of treatment is to achieve the best haematologic response possible, ideally with involved free light chain <20 mg/L, as it offers the best chance of organ function improvement. Treatment should be changed if patients do not achieve a partial response within 2 cycles of treatment or very good partial response after 4 cycles or after autologous stem cell transplant, as achievement of profound and prolonged clonal responses translates to better organ response and long-term outcomes. Early involvement of multidisciplinary subspecialists such as renal physicians, cardiologists, neurologists, and gastroenterologists for optimal maintenance and support of involved organs is recommended for optimal management of patients with AL amyloidosis.

Nocardia Infections in Hematopoietic Cell Transplant Recipients: A Multicenter International Retrospective Study of the Infectious Diseases Working Party of the European Society for Blood and Marrow Transplantation.

BACKGROUND: Nocardiosis is rare after hematopoietic cell transplantation (HCT). Little is known regarding its presentation, management, and outcome in this population. METHODS: This retrospective international study reviewed nocardiosis episodes in HCT recipients (1/1/2000-31/12/2018; 135 transplant centers; 33 countries) and described their clinical, microbiological, radiological, and outcome characteristics. RESULTS: We identified 81 nocardiosis episodes in 74 allo- and 7 auto-HCT recipients. Nocardiosis occurred a median of 8 (IQR: 4-18) months post-HCT. The most frequently involved organs were lungs (70/81; 86%) and brain (30/81; 37%); 29 (36%) patients were afebrile; 46/81 (57%) had disseminated infections. The most common lung imaging findings were consolidations (33/68; 49%) or nodules (32/68; 47%); brain imaging findings were multiple brain abscesses (19/30; 63%). Ten of 30 (33%) patients with brain involvement lacked neurological symptoms. Fourteen of 48 (29%) patients were bacteremic. Nocardia farcinica was the most common among molecularly identified species (27%; 12/44). Highest susceptibility rates were reported to linezolid (45/45; 100%), amikacin (56/57; 98%), trimethoprim-sulfamethoxazole (57/63; 90%), and imipenem (49/57; 86%). One-year and last follow-up (IQR: 4-42.5 months) all-cause mortality were 40% (32/81) and 52% (42/81), respectively. In the multivariable analysis, underlying disease not in complete remission (HR: 2.81; 95% CI: 1.32-5.95) and prior bacterial infection (HR: 3.42; 95% CI: 1.62-7.22) were associated with higher 1-year all-cause mortality. CONCLUSIONS: Nocardiosis is a late post-HCT infection usually manifesting as a pulmonary disease with frequent dissemination, brain infection, and bacteremia. Brain imaging should be performed in HCT recipients with nocardiosis regardless of neurological symptoms. Overall mortality is high.

One and a half million hematopoietic stem cell transplants: continuous and differential improvement in worldwide access with the use of non-identical family donors.

The Worldwide Network of Blood and Marrow Transplantation (WBMT) pursues the mission of promoting hematopoietic cell transplantation (HCT) for instance by evaluating activities through member societies, national registries and individual centers. In 2016, 82,718 first HCT were reported by 1,662 HCT teams in 86 of the 195 World Health Organization member states representing a global increase of 6.2% in autologous HCT and 7.0% in allogeneic HCT and bringing the total to 1,298,897 procedures. Assuming a frequency of 84,000/year, 1.5 million HCT were performed by 2019 since 1957. Slightly more autologous (53.5%) than allogeneic and more related (53.6%) than unrelated HCT were reported. A remarkable increase was noted in haploidentical related HCT for leukemias and lymphoproliferative diseases, but even more in non-malignant diseases. Transplant rates (TR; HCT/10 million population) varied according to region reaching 560.8 in North America, 438.5 in Europe, 76.7 in Latin America, 53.6 in South East Asia/Western Pacific (SEA/WPR) and 27.8 in African/East Mediterranean (AFR/EMR). Interestingly, haploidentical TR amounted to 32% in SEA/WPR and 26% in Latin America, but only 14% in Europe and EMR and 4.9% in North America of all allogeneic HCT. HCT team density (teams/10 million population) was highest in Europe (7.7) followed by North America (6.0), SEA/WPR (1.9), Latin America (1.6) and AFR/EMR (0.4). HCT are increasing steadily worldwide with narrowing gaps between regions and greater increase in allogeneic compared to autologous activity. While related HCT is rising, largely due to increase in haploidentical HCT, unrelated HCT is plateauing and cord blood HCT is in decline.

Trends in disease indications for hematopoietic stem cell transplantation in the Asia-Pacific region: A report of the Activity Survey 2017 from APBMT.

The Asia-Pacific Blood and Marrow Transplantation Group (APBMT) has been conducting annual surveys on the activity of hematopoietic stem cell transplants since 2007. The APBMT Data Center collected the following data in 2017. A total of 21,504 transplants were registered from 733 transplant centers of 20 countries/regions in the Asia-Pacific (AP) region. Five countries/regions comprised 89.4% of all transplants - China (6,979), Japan (5,794), South Korea (2,626), India (2,034), and Australia (1,789). The number of centers in these five countries/regions also comprised 88.9% of all centers: Japan (373), China (123), India (66), Australia (45), and South Korea (44). The overall ratio between autologous and allogeneic transplants was 37.0% and 63.0%, respectively, but the ratios varied significantly among countries/regions. Autologous transplants have surpassed allogeneic transplants in Thailand, Australia, Vietnam, New Zealand, Singapore, and Iran. In contrast, the proportion of allogeneic transplants comprised over 70% of all transplants in Pakistan, China, and Hong Kong. These ratios were compared by the Data Center among countries/regions that performed more than 50 transplants. The proportion of related and unrelated transplants also differed among countries/regions. The number of unrelated transplants was more than related ones in Japan (2,551 vs. 1,202) and Australia (329 vs. 291), whereas more than 80% of all transplants were related transplants in Malaysia (90.9%), India (89.5%), Iran (87.2%), Vietnam (85.7%), China (80.9%), and Thailand (80.6%). All transplant activities were related transplants in Pakistan, the Philippines, Myanmar, and Nepal, and no allogeneic transplants were performed in Bangladesh and Mongolia. Regarding the indications for transplants, acute myeloid leukemia (AML) was the most common disease for allogeneic transplant (4,759, 35.1% of allogeneic transplants), while plasma cell disorder (PCD) was the most common disease for autologous transplant (3,701, 27.3% of all autologous transplants). Furthermore, the number of transplants for hemoglobinopathy has steeply increased in this region compared with the rest of disease indications (677, 3.1% of all transplants). APBMT covers a broad area globally, including countries/regions with diverse disease distribution, development of HSCT programs, population, and economic power. Consistent and continuous activity surveys considering those elements in each country/region revealed the HSCT field's diverse characteristics and background factors in this region.

Human leukocyte antigen allele and haplotype frequencies in Singapore bone marrow donors and cord blood units.

We describe the allele and haplotype frequencies seen in a volunteer unrelated bone marrow donor registry, a public cord blood bank, and donor/recipient samples processed by the Health Sciences Authority (HSA) in Singapore. Historical human leukocyte antigen (HLA) typing reports were anonymized and combined. They were checked for HLA typing nomenclature discrepancies or ambiguities using the HLA-net UNIFORMATE tool, and for analysis, the validated data were subsequently separated into Chinese, Malay, Indian, and "Others," according to the race classification system used in Singapore. Individual ethnic allele and haplotype frequencies were calculated with the HLA-net GENE[RATE] pipeline using basic statistics. The Basic Statistics Tool of HLA-net was used to estimate haplotype frequency using an expectation maximization algorithm, given a set of multi-allelic data pairs for a given HLA locus. The outputs downloaded from the site comprised plain text files with haplotype frequency estimates, results of a global linkage disequilibrium test, and standardized residuals (stdres) corresponding to deviations from expected frequencies. HLA typing results from 59,186 individuals met the inclusion criteria, yielding 118,372 analyzable alleles. In our study population, the haplotype A*33:03-B*58:01-C*03:02-DRB1*03:01～DQB1*02:01:01G with a frequency of 4.91% was the most common. This haplotype was also the most common among Singaporean Chinese donors. Consistent with the predominant Chinese population, haplotypes with a frequency greater than 1% were also the most frequently observed haplotypes in the Singaporean population. In the Malay donor population, the most common haplotype was A*33:03～B*44:03～C*07:01:01G～ DRB1*07:01-DQB1*02:01:01G, with a frequency of 3.41%, whereas within the Indian donor population, the most common haplotype was A*01:01-B*57:01-C*06:02～DRB1*07:01-DQB1*03:03, with a frequency of 3.42%. Haplotype diversity and composition statistics within donor pools provide HLA background data required for the targeted recruitment of donors to support the hematopoietic stem cell donor requirements of the country. These data may be used in the future to devise donor recruitment strategies for optimizing the donor pool through targeted publicity and accruals.

High risk of relapse with intermediate dose cytarabine for consolidation in young favourable-risk acute myeloid leukaemia patients following induction with 7+3: a retrospective multicentre analysis and critical review of the literature.

Following the 2017 European LeukemiaNet (ELN) guidelines, we changed our practice from using high-dose cytarabine (HIDAC-3 g/m2 q12h-D1,3,5) to intermediate-dose cytarabine (IDAC-1·5 g/m2 q12h-D1,3,5/D1-3) for consolidation in young(<60 years) favourable-risk acute myeloid leukaemia (AML) patients. We assessed the clinical impact of this practice change. Of 80 patients, 51 received HIDAC prior to the protocol change, and subsequently, 29 received IDAC. The three-year risk of relapse was significantly higher with IDAC [61%; 95% confidence interval (CI) 40-82] compared with HIDAC (22%; 10-34), P < 0·01. Our findings suggest HIDAC, rather than IDAC, is the preferred dose for single-agent cytarabine consolidation in young, favourable-risk AML following 7+3 induction.

Higher Starting Dose of Ciclosporin Optimized Therapeutic Levels in Patients Receiving Phenytoin for Busulfan-induced Seizure Prophylaxis.

Background: Despite understanding the drug-drug interaction between phenytoin and ciclosporin (CsA), there is no recommended CsA dosing in patients receiving phenytoin as seizure prophylaxis in busulfan-based conditioning regimens. This drug-drug interaction has resulted in patients with sub-therapeutic levels at day 0 (D0) of allogeneic hematopoietic stem cell transplantation (alloHSCT) and at risk for acute graft-versus-host disease (aGVHD). Objective/Methods: A single-center historical-control study was conducted at Singapore General Hospital between March 2010 and July 2019 to evaluate a new dosing strategy. Patients with phenytoin received a higher starting dose of intravenous CsA (4 mg/kg/dose twice daily instead of 3 mg/kg/dose twice daily). The primary endpoint of this study was to determine the proportion of patients with therapeutic CsA levels at D0. Secondary endpoints included median CsA level on D-1 and D0, time to the therapeutic target, incidence and severity of aGVHD, and safety profile. Results: A total of 91 patients were included in this study. Patients with therapeutic CsA at D0 was higher (66.7%) in the study arm than in the control arm (24.7 %) (p = 0.006). The median CsA concentration at D0 in the study arm was 284 ng/mL (range, 144-441 ng/mL) as compared to the control arm, 255 ng/mL (range, 104-580). There was no difference in the time to therapeutic range and the cumulative incidence of aGVHD. There were no significant differences in the safety outcomes. Conclusion: The new strategy with higher dosing based on the actual body weight should be adopted as it resulted in a higher proportion of patients with therapeutic CsA at D0, without an increase in CsA-related adverse events.