Consensus recommendations for optimising the diagnosis and treatment of paroxysmal nocturnal haemoglobinuria in Singapore.

Introduction: Paroxysmal nocturnal haemoglobinuria (PNH) is a rare haematologic disease characterised by intravascular haemolysis, thrombophilia and bone marrow failure. There is a lack of established clinical guidance on the screening, diagnosis and manage-ment of PNH in Singapore. A relatively low level of awareness among healthcare professionals regarding PNH manifestations further contributes to diagnostic delays. Additionally, limited access to complement inhibitors, like eculizumab, may delay treatment and impact patient outcomes. Method: Nine haematologists from different institu-tions in Singapore convened to formulate evidence-based consensus recommendations for optimising the diagnosis and management of patients with PNH and improving access to novel treatments. The experts reviewed the existing literature and international guidelines published from January 2010 to July 2023, focusing on 7 clinical questions spanning PNH screening, diagnostic criteria, investigations, treatment and monitoring of subclinical and classic disease, PNH with underlying bone marrow disorders, and PNH in pregnancy. A total of 181 papers were reviewed to formulate the statements. All experts voted on the statements via 2 rounds of Delphi and convened for an expert panel discussion to finetune the recommendations. Results: Sixteen statements have been formulated for optimising the screening, diagnosis and management of PNH. Upon confirmation of PNH diagnosis, individuals with active haemolysis and/or thrombosis should be considered for anti-complement therapy, with eculizumab being the only approved drug in Singapore. Conclusion: The current recommendations aim to guide the clinicians in optimising the screening, diagnosis and management of PNH in Singapore.

A Traceable Vaccine Supply Management System.

Everyone should be vaccinated, but the eligibility and safety of the vaccine are always overlooked by most people. The outbreak of COVID-19 has led many countries to intensify the development and production of the COVID-19 vaccine. and some countries have even required universal vaccination against this epidemic. However, such popularization of vaccination has also exposed various flaws in vaccine management that existed in the past, and vaccinators have become more concerned about the effectiveness of their vaccinations. In this paper, we propose a blockchain-based traceable vaccine management system. First, the system uses smart contracts to store the records generated during the whole process, from vaccine production to vaccination. Second, the proposed scheme uses the Edwards-curve digital signature algorithm (EdDSA) to guarantee the security and integrity of these data. Third, the system participants can access the corresponding data according to their authority to ensure the transparency of the whole system operation process. Finally, this paper will also conduct a security analysis of the whole system to ensure that the system can resist potential attacks by criminals.

Incentive EMR Sharing System Based on Consortium Blockchain and IPFS.

Electronic medical records (EMRs) are extremely private data in the medical industry. Clinicians use the patient data that the EMR stores to quickly assess a patient's status and save diagnostic information. In the conventional medical model, it is easy for duplicate exams, medical resource waste, or the loss of medical records to happen when a patient is transferred between several medical facilities due to problems with data sharing and exchange, inadequate data privacy, security, confidentiality, and difficulties with data traceability. This paper recommends a Hyperledger Fabric-based strategy to promote the exchange of EMR models. With the use of Hyperledger Fabric, EMR stakeholders can be brought into the channel to facilitate data sharing. Attribute-based access control (ABAC) allows users to design the data access control policy, and the data access control may improve security. Any record stored in the blockchain can be viewed using the Hyperledger Fabric feature and it cannot be altered or destroyed, ensuring data traceability. Through proxy re-encryption, which makes sure that the data is not leaked during data exchange, data secrecy can be ensured. A module for medical tokens has now been added. Many foreign medical institutions currently use the medical token system, and the system described in this paper can use the tokens to pay for some medical expenses. The tokens are obtained by the patient's initiative to share their EMR with the medical institution for research, which is how many foreign medical institutions currently use the medical token mechanism. This paradigm can encourage the growth of medical data by enabling stakeholders to collaborate and share EMR trust.

Pre-transplant achievement of negativity in minimal residual disease and French-American-British L1 morphology predict superior outcome after allogeneic transplant for Philadelphia chromosome positive acute lymphoblastic leukemia: an analysis of Southeast Asian patients.

To better understand predictive factors and improve the clinical outcome of allogeneic transplant for patients with Philadelphia positive acute lymphoblastic leukemia, we analyzed 67 Southeast Asian patients transplanted in our institutions. Multivariate analysis showed that disease status before transplant, year of transplant and, interestingly, French-American-British (FAB) subtype had a significant impact on overall survival (OS) and non-relapse mortality. Patients who were minimal residual disease (MRD) negative at transplant had a 3-year OS of 73% compared to those who were MRD positive (45%) and refractory (0%). The 3-year cumulative incidence of relapse was 18% and 36% for the MRD negative and positive groups, respectively. FAB L1 subtype had a significantly superior 3-year OS of 63% vs. 29% for L2 subtype. Pre-transplant use of a tyrosine kinase inhibitor significantly improved outcomes in univariate but not multivariate analysis, as it served to induce more patients into MRD negativity, which was the factor that directly improved transplant outcome.

WPSS is a strong prognostic indicator for clinical outcome of allogeneic transplant for myelodysplastic syndrome in Southeast Asian patients.

To better understand the predictive factors and improve clinical outcome of allogeneic transplant for patients with myelodysplastic syndrome (MDS), we retrospectively analyzed the post-transplant outcome of 60 Southeast Asian patients with MDS. Multivariate analysis showed that WHO classification-based Prognostic Scoring System (WPSS) significantly affect overall survival (OS), progression-free survival (PFS), cumulative incidence of relapse (CIR), and cumulative incidence of non-relapse mortality (CINRM). Stratified by WPSS into very low/low, intermediate, high, and very high-risk categories, 3-year OS was 100, 61, 37, and 18% (p = 0.02); PFS was 100, 55, 32, and 18% (p = 0.014); CIR was 12, 24, 38, and 59% (p = 0.024); CINRM was 0, 6, 12, and 26% (p = 0.037), respectively. WHO classification, Revised International Prognostic Scoring System (IPSS-R), IPSS-R-defined cytogenetic risk groups, donor gender, and acute and chronic graft vs host disease (GVHD) also influenced different aspects of transplant outcome. We found that WPSS is a powerful predictor of post-transplant outcome. WPSS provides an important model not only for prognostication but also for exploration of further post-transplant measures such as immunological maneuvers or novel therapy to improve the poor outcome of high-risk patients.

Outcome of donor lymphocyte infusion after T cell-depleted allogeneic hematopoietic stem cell transplantation for acute myelogenous leukemia and myelodysplastic syndromes.

Relapse occurs in 30%-50% of recipients of T cell-depleted (TCD) reduced-intensity conditioned (RIC) hematopoietic stem cell transplantation (HSCT) for acute myelogenous leukemia (AML) and myelodysplastic syndromes (MDS). Despite limited published supportive data, donor lymphocyte infusion (DLI) is used preemptively (pDLI) to improve donor chimerism and prevent relapse, and therapeutically (tDLI) after disease recurrence. We evaluated the efficacy and toxicity of pDLI and tDLI in 113 patients after TCD (alemtuzumab, n = 99; antithymocyte globulin, n = 14) RIC HSCT for AML or MDS. Recipients of pDLI (n = 62) had an estimated 5-year overall survival (OS) of 80% and an event-free survival of 65%. More than one-half (52%; n = 32) of the patients received pDLI within 6 months post-HSCT; despite this, the 5-year incidence of graft-versus-host disease was only 31% (95% confidence interval [CI], 19%-43%). Recipients of tDLI (n = 51) had an estimated 5-year OS of 40% and a 5-year relapse/progression rate of 69% (95% CI, 54%-81%). Recipients of tDLI at >6 months post-HSCT had a significantly superior 5-year OS after tDLI compared with those treated earlier (P = .008). The cumulative incidence of graft-versus-host disease at 5 years after tDLI was 45% (95% CI, 23%-65%). We demonstrate that pDLI safely promotes durable remission after TCD RIC HSCT for AML or MDS, and that tDLI salvages patients after late relapse with greater efficacy.

Allogeneic stem cell transplantation for myelodysplastic syndromes with bone marrow fibrosis.

BACKGROUND: Bone marrow fibrosis in patients with myelodysplastic syndrome is associated with a poor outcome, but whether the outcome after allogeneic stem cell transplantation is related to the degree of bone marrow fibrosis is unknown. DESIGN AND METHODS: Patients with myelodysplastic syndrome and known bone marrow histology (n=721) who underwent hematopoietic stem cell transplantation were classified according to the degree of bone marrow fibrosis into those without fibrosis (n=483), those with mild or moderate fibrosis (n=199) and those with severe fibrosis (n=39) and analyzed regarding engraftment, treatment-related mortality, relapse and survival. RESULTS: The degree of fibrosis was not associated with disease status or abnormal cytogenetics. The cumulative incidence of engraftment achieved at day +30 in non-fibrotic patients was 93% and was significantly lower in those with mild or moderate fibrosis (89%) and severe fibrosis (75%) (P=0.009). Neutrophil engraftment occurred later in patients with mild or moderate fibrosis and severe fibrosis than in patients without fibrosis (median 17 versus 20 versus 16 days, respectively; P=0.002). The cumulative incidence of relapse at 3 years was significantly higher in patients with severe fibrosis than in those with a lesser degree of fibrosis or no fibrosis (47% versus 28% versus 27%, respectively; P=0.04), resulting in comparable 3-year disease-free survival rates in patients without fibrosis and in those with mild or moderate fibrosis (42% versus 38%, respectively) but a lower disease-free survival rate in those with severe fibrosis (18%; P=0.002). Severe fibrosis remained an independent factor for reduced survival (hazard ratio, 1.9; P=0.006). CONCLUSIONS: Among patients with myelodysplastic syndromes, only severe fibrosis affects survival after hematopoietic stem cell transplantation while patients with mild or moderate fibrosis have an outcome comparable to that of patients without bone marrow fibrosis.

Delayed attainment of full donor chimaerism following alemtuzumab-based reduced-intensity conditioning haematopoeitic stem cell transplantation for acute myeloid leukaemia and myelodysplastic syndromes is associated with improved outcomes.

This prospective study evaluated the kinetics of lymphoid (CD3) engraftment in 110 patients with acute myeloid leukaemia (AML) and myelodysplastic syndromes (MDS) after allogeneic transplantation and conditioning with fludarabine, busulphan and alemtuzumab, using ciclosporin for post-transplant immunosuppression. Declining donor CD3 chimaerism beyond day+100 was treated with pre-emptive donor lymphocyte infusion (pDLI). The median age of patients was 53.0 years (range: 19-72 years), and the median follow-up was 690 d (range:168-1470 d). Patients achieving full CD3 donor chimaerism (FDC, n = 46) by day+100 had a significantly inferior disease-free survival (DFS) and overall survival (OS) compared to patients with mixed donor chimaerism (MDC, n = 59). Twenty patients had stable MDC and did not require pDLI. Patients attaining early FDC had a higher transplant-related mortality compared to those who maintained stable levels of MDC (P = 0.02), with no difference between the FDC and pDLI groups (P = 0.07). There was no difference in relapse between all three groups (P = 0.21). On multivariate analysis, only CD3 chimaerism status at day+100 and disease status at transplantation had a significant effect on DFS and OS. In patients with AML/MDS undergoing alemetuzumab based-RIC HSCT, prolonged MDC beyond day+100 is associated with an improved OS. Future studies need to be directed towards establishing the underlying factors that dictate T-cell engraftment, expansion and homing post-transplantation.

Allogeneic transplantation for myelodysplastic syndrome (MDS).

Haematopoietic stem cell transplantation (HSCT) remains the only curative option for patients with myelodysplastic syndrome (MDS). Developing conditioning regimens with low toxicity, at the same time as preserving an effective graft versus tumour response, is pivotal to expanding the scope for allogeneic transplantation in older patients with MDS. With the introduction of reduced intensity conditioned regimens, transplant centres worldwide are able to offer allogeneic HSCT to a much larger cohort of patients. Graft versus host disease (GvHD) remains a significant cause of morbidity and mortality, however with the use of T-cell depletion, centres have been able to utilise volunteer unrelated donors with an increasing degree of HLA disparity. The graft versus dysplasia effect resulting from allogeneic HSCT and the infusion of donor leukocytes has led to a greater understanding of the immunological mechanisms that govern outcome following transplantation in MDS.

Outcomes of alemtuzumab-based reduced intensity conditioning stem cell transplantation using unrelated donors for myelodysplastic syndromes.

This prospective study evaluated the outcomes of 75 successive patients receiving a FBC (fludarabine, busulphan, alemtuzumab) reduced-intensity conditioning (RIC) regimen for myelodysplastic syndromes (MDS) using volunteer unrelated donors(VUD). The prognostic significance of a variety of clinical variables including the recently described haematopoietic cell transplantation co-morbidity index (HCT-CI) was assessed. The median age of the cohort was 52.0 years (range: 19-68 years) with a median follow-up of 1038.5 d. Forty-nine patients (65%) had an International Prognostic Scoring System stage of > or = Intermediate-2, 35 (46%) had intermediate or poor risk cytogenetics, and 23 patients(31%) were human leucocyte antigen-mismatched. The actuarial 3-year overall survival (OS) and disease-free survival (DFS) was 43% [95% confidence interval (CI): 37-49] and 41% (95%CI: 35-47) respectively, and the cumulative incidence of extensive chronic graft-versus-host disease was 22%. On multivariate analysis, presence of either one class II mismatch or a two-antigen mismatch adversely influenced transplant-related mortality, DFS and OS. In addition, disease status at transplantation and the haematopoietic cell transplantation-specific comorbidity index were independent variables for overall survival. In contrast, both advanced age and pre-transplant cytogenetic status did not significantly affect overall outcomes. RIC regimens using VUD was associated with durable long-term survival even in older patients with MDS, and the use of a pre-transplant comorbidity index may help to improve patient selection for transplantation.