Myelodysplastic Research Articles

Late onset pancytopenia post chimeric antigen receptor T cell therapy triggered by a COVID-19 vaccination: a case report

Cytopenia is a common side effect after chimeric antigen receptor T cell (CAR-T) therapy but is unusual at late timepoints when it is most commonly due to bone marrow (BM) failure, myelodysplasia (MDS) or other secondary malignancies. In this case report, we describe a patient who developed severe aplastic anaemia 18 months after CD19 CAR-T therapy, and shortly after COVID-19 vaccination. This is the first description of severe aplastic anaemia triggered by COVID-19 vaccination as a cause of post-CAR-T cytopenia. The patient described was treated with a combination of eltrombopag and ciclosporin due to frailty and had a rapid and complete clinical response to this therapy, providing an effective option for the treatment of immune-related cytopenia post-CAR-T in an increasingly elderly and frail population.

Rapid Disease Progression of Myelodysplastic Syndrome is Reflected in Transcriptomic and Functional Abnormalities of Bone Marrow MSCs.

Bone marrow (BM) mesenchymal stromal cells (MSCs) are important regulators of hematopoietic stem and progenitor cells (HSPCs). When transformed to a dysplastic phenotype, MSCs contribute to hematopoietic diseases such as myelodysplastic syndromes (MDS), but it remains unclear if there are specific properties in MDS-MSCs that contribute to the disease course. To understand this, we investigated MDS-MSCs from fast (MDSfast) vs slow (MDSslow) progressing disease groups and discovered differences between these groups. MDSfast-MSCs secrete more inflammatory factors, support myeloid-skewed differentiation of HSPCs, and importantly, show poorer response to hypomethylation as a key differentiator in GSEA analysis. When exposed to long-term in vivo stimulation with primary MDSfast-MSCs-based scaffolds, healthy donor (HD) HSPCs show elevated NF-κB expression, similar to leukemic HSPCs in MDS. Those "MDSfast-MSCs-primed" HD-HSPCs continue to show enhanced engraftment rates in secondary MDS-MSC-based scaffolds, providing evidence for the microenvironmental selection pressures in MDS towards leukemic HSPCs. Together, our data point towards a degree of co-development between MSCs and HSPCs during the progression of MDS, where changes in MDS-MSCs take place mainly at the transcriptomic and functional levels. These unique differences in MDS-MSCs can be utilized to improve disease prognostication and implement targeted therapy for unmet clinical needs.

Clinical and neurophysiological aspects of peripheral neuropathy in patients with myelodysplastic syndromes.

Myelodysplastic syndromes (MDS) are a heterogeneous group of clonal disorders, manifesting multiple clinical autoimmune inflammatory phenomena, including rarely peripheral neuropathy. Twenty-four patients diagnosed with MDS and 29 healthy subjects were enrolled in this prospective study in a 5-year period. Every subject was assessed by symptoms questionnaire and clinical neurological examination followed by nerve conduction studies, quantitative sensory testing and skin biopsy. Peripheral neuropathy was diagnosed in 12 subjects (50%). Our study indicated that peripheral neuropathy involving large and small nerve fibres, with a symmetrical length-dependent pattern, is not uncommon between patients with MDS.

Dissecting the genomic traits and clinical course of secondary myelodysplastic syndrome following aplastic anaemia: A milestone.

Dissecting the genomic traits and clinical course of secondary myelodysplastic syndromefollowing aplastic anaemia is a milestone. The report by Li and colleagues investigates determinants of evolution to myelodysplastic syndrome and acute myeloid leukaemia in patients with aplastic anaemia and paroxysmal nocturnal haemoglobinuria with a specific focus on post-transplant outcomes. Commentary on: Li etal. Clinical and genetic profiles and outcomes of allogeneic haematopoietic stem cell transplantation in secondary myelodysplastic syndrome following aplastic anaemia. Br J Haematol 2024 (Online ahead of print). doi: 10.1111/bjh.19855.

The IL-1β inhibitor canakinumab in previously treated lower-risk myelodysplastic syndromes: a phase 2 clinical trial.

In myelodysplastic syndromes (MDS), the IL-1β pathway is upregulated, and previous studies using mouse models of founder MDS mutations demonstrated that it enhances hematopoietic stem and progenitor cells' (HSPCs') aberrant differentiation towards the myeloid lineage at the expense of erythropoiesis. To evaluate whether targeting the IL-1β signaling pathway can rescue ineffective erythropoiesis in patients with MDS, we designed a phase 2 non-randomized single-arm clinical trial (NCT04239157) to assess the safety profile and efficacy of the IL-1β inhibitor canakinumab in previously treated lower-risk MDS patients. We enrolled 25 patients with a median age of 74 years; 60% were male, 16% had lower-risk MDS, 84% had intermediate-1 risk MDS according to the International Prognostic Scoring System score, and 80% failed hypomethylating agent therapy. The study met the primary endpoint of defining the clinical activity of canakinumab, and the secondary objective of determining the safety profile, including the rate of transfusion independence, the duration of response, progression-free survival, leukemia-free survival, and overall survival. The overall response rate was 17.4%, with all responses including hematological improvement. Sequential post-hoc prospective single-cell RNA sequencing analyses of HSPCs and bone marrow mononuclear cells at different time points during therapy showed that canakinumab's on-target effects in hematopoietic populations expressing the IL-1β receptor decreased the TNF-mediated inflammatory signaling pathway but rescued ineffective erythropoiesis only in the context of lower genetic complexity. This study demonstrates that better stratification strategies could target lower-risk MDS patients more effectively.

Early mixed donor chimerism is a strong negative prognostic indicator in allogeneic stem cell transplant for AML and MDS.

Allogeneic bone marrow transplantation remains the most potent curative therapy for acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS) due to the graft-versus-tumor effect provided by donor cells. Donor chimerism is utilized early after transplantation to evaluate engraftment and to monitor the persistence of donor hematopoiesis. Literature is conflicting regarding to the prognostic utility of early mixed donor chimerism, chimerism kinetic patterns as well as factors associated with it and we sought to clarify this uncertainty. In this single-centre retrospective analysis, 141 adults aged 18 years of age or older with AML (n=104) and MDS (n=37) who received their first transplant from HLA matched related, matched unrelated or mismatched related (haploidentical) donors between 2016 and 2022 and had at least day 30 chimerism measured were included. Approximately 30% received post-transplant cyclophosphamide for graft-versus-host disease (GVHD) prophylaxis and 67% of subjects received reduced-intensity conditioning. Chimerism was measured using STR-PCR from unfractionated peripheral blood mononuclear cells (whole blood; WB) and CD3+ (T cell; TC) compartment at each time point. Complete donor chimerism was defined as ≥95% whereas <95% defined as mixed. Competing risk analysis was used to estimate cumulative incidence of relapse with kinetic calculations completed using an increment factor. Kaplan-Meier was used for overall survival (OS) and relapse-free survival (RFS). Cox proportional hazards regression was used to explore prognostic factors for OS and RFS. Both day 30 mixed WB and TC donor chimerism were individually associated with an increased risk of relapse and worse overall and relapse-free survival at days 30, 60 and 90 post-transplant. Day 30 mixed WB was more specific for relapse (86%), while mixed TC was more sensitive (67%). Complete day 30 chimerism had a negative predictive value of 63% and 70% and positive predictive value of 57% and 67% for WB and TC, respectively. Day 30 WB and TC donor chimerism of <88.92% and 89.29% had specificities of 79.17% and 82.19% although sensitivities only approximated 50%. Evaluating the kinetics of chimerism over the first 90 days provided additional information for prognosticating relapse than absolute chimerism values at individual time points in both WB day 30 to 90 [HR, 1.75 (95% CI, 1.04-2.94); p<0.035] and TC day 60 to 90 [HR, 1.32 (95% CI, 1.03, 1.69); p<0.29]. Twice as many patients with complete chimerism developed acute GVHD compared to those with mixed chimerism. Factors that were found to be associated with day 30 mixed TC chimerism were donor source, ATG GVHD prophylaxis, myeloablative conditioning and female sex, while only donor source was associated with mixed WB. Both TC and WB day 30 mixed chimerism were associated with an increased risk of relapse. Early mixed WB and TC chimerism is strongly associated with a worse overall and relapse-free survival. The serial measurement of chimerism early post-transplant for monitoring chimerism kinetics provides additional prognostic information beyond the absolute donor chimerism value at a single time point. Haploidentical stem cell transplants were associated with a lower likelihood of mixed chimerism than other donor sources.

Case report: VEXAS syndrome and literature review

VEXAS syndrome (Vacuoles, E1 enzyme, X-linked, Autoinflammatory, Somatic) is a novel disorder first described in 2020. Patients are diagnosed by identifying a somatic mutation of the ubiquitin-like modifier-activating enzyme 1 (UBA1) gene. They usually have systemic inflammation and present with a combination of hematologic and rheumatologic abnormalities such as myelodysplastic syndrome and polychondritis. VEXAS syndrome patients are at increased risk of developing hematologic malignancies. We present a case of a 60-year-old male who developed transfusion-dependent macrocytic anemia, was found to have UBA1 mutation in the bone marrow, and was diagnosed with VEXAS syndrome. The patient responded well to steroid treatment and did not require more blood transfusion. The two main goals of treating VEXAS syndrome are eradicating the UBA1 mutated hematopoietic cells and inhibiting the inflammatory process. Early stem cell transplant evaluation is necessary as VEXAS-related complications may limit the efficacy of transplantation. Further research is required to improve the prognosis and quality of life of VEXAS syndrome patients.

Clonal hematopoiesis in patients with autoimmune thrombocytopenia: an international multicenter study.

Diagnostic boundaries between immune thrombocytopenia (ITP) and other thrombocytopenic states such as thrombocytopenic myelodysplastic syndromes, may be difficult to establish, and the detection of somatic mutations by next generation sequencing (NGS) may be of aid. Here we aimed at characterizing the prevalence and clinical significance of clonal hematopoiesis in ITP. In this multicentric retrospective observational study we enrolled 167 adult ITP patients, followed at 13 centers in Italy, UK, and USA. Patients underwent NGS evaluation after a median of 3.6 years from ITP onset and 83% had received at least one therapy line, median 2 (0-9) lines; 51 out of 167 patients had at least one mutation (30%). After exclusion of germline variants and polymorphisms, 18.5% (31/167) were defined as having clonal hemopoiesis. Most commonly mutated genes were TET2, DNMT3A, SRSF2, and ASXL1 (median VAF 29%); 19 of 31 subjects (68%) had high-risk variants, and 8 multiple mutations. Mutated patients were more frequently elderly males and showed a shorter time from first to second line therapy, particularly with TPO-RA. Additionally, clonal hematopoiesis was associated with increased thrombotic risk (26% vs 8% in NGS-negative cases, p=0.01), independently from TPO-RA exposure, though with an age effect. These data demonstrated the prevalence of clonal hematopoiesis in 18% of adult ITP patients, being associated with older age, relapsed/refractory disease, and high risk of thrombotic complications.

Elevated serum direct bilirubin is predictive of a poor prognosis for primary myelodysplastic syndrome.

The aim of this study was to assess the prognostic significance of serum direct bilirubin (DBIL) for patients newly diagnosed with myelodysplastic syndromes (MDS). The clinical, laboratory, and follow-up data of MDS patients were collected, and the associations of DBIL levels with overall survival (OS) and leukemia-free survival (LFS) were analyzed. In total, 262 MDS patients were assigned to the high DBIL level group or the normal DBIL level group in the retrospective study. High DBIL was associated with older age, reduced hemoglobin, higher levels of β2-microglobin, lactate dehydrogenase, and serum ferritin, along with the number of co-mutations (> 1) and a higher frequency of ASXL1, KIT, and KRAS mutations. Multivariate analyses found that high DBIL level was an independent adverse predictor for OS (p = 0.002, hazard ratio = 2.723, 95%CI = 1.442-5.143) but not for LFS (p = 0.057, hazard ratio = 1.678, 95%CI = 0.986-2.857). A novel nomogram based on DBIL, sex, age, β2-microglobulin, lactate dehydrogenase, the Revised International Prognostic Scoring System (IPSS-R) was constructed, which demonstrated superior accuracy compared with the IPSS-R (C-index, 0.790 vs. 0.731, respectively). An elevated DBIL level was identified as an independent adverse prognostic factor for MDS patients. An individualized prediction model was established and validated to improve prediction of OS and LFS.

A Case of Infective Endocarditis Following Bone Marrow Transplantation for Myelodysplastic Syndrome

A Case of Infective Endocarditis Following Bone Marrow Transplantation for Myelodysplastic Syndrome

Hydroxy-wybutosine tRNA modifications as indicators of disease progression and therapeutic targets in leukaemia.

Therapeutic approaches for acute myeloid leukaemia (AML) and myelodysplastic syndromes (MDS) differ due to distinct diagnostic criteria and treatment strengths. However, reliable biomarkers to differentiate AML from MDS are needed. This study investigated transfer RNA (tRNA) modifications, particularly hydroxy-wybutosine (OHyW), in the transition from MDS to AML. We found a significant decrease in OHyW and its biosynthetic enzyme leucine carboxyl methyltransferase 2 (LCMT2, alias symbol is TYW4) levels in AML compared to MDS. Mass spectrometric analysis revealed distinct tRNA modification patterns, with AML showing decreased OHyW and increased precursor levels, indicating a disrupted biosynthetic pathway. Lower LCMT2 expression correlated with reduced drug sensitivity and limited differentiation potential in AML cell lines. The results highlight the pivotal role of tRNA modifications in the progression from MDS to AML and suggest that targeting LCMT2 may enhance therapeutic outcomes in AML. By understanding these molecular mechanisms, we can develop new diagnostic markers and therapeutic strategies, potentially transforming the clinical management of AML and improving patient outcomes.

Role of the CIBMTR biorepository and registry in precision transplantation research.

Observational studies using registry-based data have become indispensable in our management of patients receiving hematopoietic cell transplantation (HCT) or cellular therapies (CT) for hematologic malignancies. These registries support studies that describe the natural history of disease, evaluate clinical effectiveness, or measure safety and quality of patient care. To complement registries, biobanks exist as an essential partner to provide insight on genetic, molecular, and cellular processes. In this review, we discuss and provide examples of several biobank and registry collaborations that have advanced our knowledge in the field of HCT and CT, using the Center for International Blood and Marrow Transplantation Research (CIBMTR) as a highlighted example. The CIBMTR has collected data on over 650,000 patients and has over 60,000 paired donor recipient banked samples available for research. Biospecimens and clinical data from the CIBMTR have led to advancements in our knowledge and care of conditions such as acute myeloid leukemia and myelodysplastic syndrome (MDS), as well as our understanding of the roles of HLA typing and social determinants of health. Despite the utility in advancing research, registries and biobanks do not exist without challenges which are briefly reviewed. Nevertheless, the contributions of these resources in supporting HCT/CT research are noteworthy.

Improvement in quality of life in MDS patients who become transfusion independent after treatment

Myelodysplastic syndromes (MDSs) treatment focuses on improving quality of life (QOL), affected by anemia and transfusion dependence (TD). Using the MDS-CAN registry, we studied how changes in transfusion status – TD to transfusion independence (TI) (group A), or vice versa (group B), and maintaining TD (group C) or TI (group D) – affected OS and QOL in 1120 MDS patients. Analysis showed superior OS for those remaining TI, poorer for those remaining TD, and intermediate for those with changes. Among 656 treated patients, group A (n = 54) showed improved QOL, with trends toward improved physical and social function scores. Group B (n = 151) experienced declines in global QOL measures after switching to TD, particularly in fatigue and physical, role, and social functioning. Group C had notable fatigue worsening, while group D showed milder declines across multiple QOL aspects. Achieving TI in MDS correlates with improved QOL, whereas reverting to TD more significantly worsens overall QOL and function scores.

Beneficial effects of cellular immunotherapy in the prevention and treatment of posttransplant hematologic relapse of myelodysplastic neoplasms.

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is the only curative option for myelodysplastic syndrome (MDS). However, relapse remains the primary cause of transplantation failure. This single-center study aimed to evaluate factors influencing therapeutic interventions to prevent overt relapse of MDS and to identify treatment approaches that ensure optimal response and safety. We enrolled 149 patients with relapsed MDS who had undergone allo-HSCT between May 2009 and December 2017, among whom 87 patients had hematologic relapse (HemRel; marrow blasts ≥ 5%, blasts in peripheral blood or dysplasia fulfilling MDS diagnostic criteria) and 62 patients had pre-HemRel; pre-HemRel included imminent (n = 28; donor chimerism ≤ 95%), WT1-based molecular (n = 17; WT1 transcript > 250 copies/104ABL1), and cytogenetic (n = 17; recurrence of chromosomal aberrations) relapses. The estimated 4-year overall survival (OS) rate from the time of relapse was 44.1% among 62 pre-HemRel patients. However, the OS rate was significantly lower in 87 HemRel patients. In a multivariate analysis, preemptive use of cellular immunotherapy (cIMTx, either donor lymphocyte infusion, second allo-HSCT, or both) emerged as an independent factor in preventing HemRel and was more effective, particularly in the presence of other unfavorable factors, such as the absence of chronic graft-versus-host disease and a higher-risk group based on the MDS-transplantation prognostic scoring system. In HemRel, using cIMTx demonstrated a significantly superior OS rate compared to non-cIMTx modalities (25.8% vs. 6.1% vs. 0%, P < .001). In summary, cIMTx demonstrated superior outcomes in both pre-HemRel and HemRel groups, proving particularly advantageous in pre-HemRel cases with progression risk factors, while its benefits remained consistent in HemRel cases.

COVID-19 infection in children with blood cancer: A systematic review.

Blood cancer is the most common type of cancer and the leading cause of death by disease past infancy among children. Children with blood cancer are vulnerable population to viral infections such as coronavirus disease 2019 (COVID-19). To estimate the incidence of COVID-19 in children with blood cancer and analyse the demographic parameters, clinical characteristics and treatment outcomes in children with blood cancer with COVID-19 illness. We adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline and searched ProQuest, Medline, Embase, PubMed, CINAHL, Wiley online library, Scopus and Nature for studies on the development of COVID-19 in children with blood cancer, published from December 1, 2019 to April 30, 2023, with English language restriction. Of the 3077 papers that were identified, 155 articles were included in the systematic review (83 case report, 54 cohort and 18 case-series studies). Studies involving 1289 children with blood cancer with confirmed COVID-19 were analysed. Leukaemias (1141 cases) were the most frequent types of blood cancer observed in children who developed COVID-19, followed by non-Hodgkin's lymphomas (59 cases), Hodgkin's lymphomas (36 cases), Langerhans cell histiocytosis (7 cases), myelodysplastic syndrome (7 cases) and myeloid neoplasm (1 case). Among all 1289 blood cancer paediatric cases who transmitted severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), some children were documented to be admitted to the intensive care unit (ICU) (n = 175, 13.6%), intubated and placed on mechanical ventilation (MV) (n = 111, 8.6%), suffered acute respiratory distress syndrome (ARDS) (n = 144, 11.2%) or died (n = 111, 8.6%). Overall, COVID-19 in children with different types of blood cancer resulted in no or low severity of disease in 78.6% of all included cases (COVID-19 severity: asymptomatic = 238, mild = 601, or moderate = 171). Treatment for COVID-19 was not necessary in a small number of children with blood cancer (n = 94, 7.3%). Fatality in children with blood cancer with COVID-19 was reported in any of the included blood cancer categories for leukaemias (n = 99/1141, 8.7%), non-Hodgkin's lymphomas (n = 7/59, 11.9%), Hodgkin's lymphomas (n = 2/36, 5.5%), myelodysplastic syndrome (n = 1/7, 14.3%) or myeloid neoplasm (n = 1/1, 100%). Fatality rate in children with blood cancer infected with SARS-CoV-2 was the highest in patients with Hispanic ethnicity (n = 44/111, 39.6%) and COVID-19-related fatality was highest in male patients (76.5% of deceased patients). Most studies reported to alter the intensity and regimen of anticancer treatment in children with blood cancer during course of SARS-CoV-2 infection, however, many studies have reported to successfully treat COVID-19 without any changes to the anticancer treatment. Globally, leukaemias were the most prevalent and myeloid neoplasms were the least prevalent blood cancer types in children who developed SARS-CoV-2 infection. Children with blood cancer infected with SARS-CoV-2 may experience higher rates of ICU admission and mortality in comparison with the healthy pediatric populations. Mortality in children with blood cancer and infected with SARS-CoV-2 was highest in cases belonging to male gender and Hispanic ethnicity. However, children with blood cancer tend to have milder COVID-19 symptoms and are less likely to be hospitalized and have better prognosis when compared to adults. Continuation of anticancer treatment in individual paediatric blood cancer patients with COVID-19 seems to be possible.

A large cohort from an immunology reference center and an algorithm for the follow-up of chronic neutropenia.

Chronic neutropenia causes involve nutritional deficiencies and inborn errors of immunity(IEI), such as severe congenital neutropenia. To classify common chronic neutropenia causes in a pediatric immunology unit. We enrolled 109 chronic neutropenia patients admitted to a pediatric immunology department between 2002-2022. We recorded clinical/laboratory features and genetic characteristics. The male/female ratio was 63/46. Fifty-eight patients had parental consanguinity(57.4%). 26.6% (n = 29) patients had at least one individual in their family with neutropenia. Common symtpoms at presentation were upper respiratory tract infections(URTI)(31.1%), oral aphthae(23.6%), skin infections(23.6%), pneumonia(20.8%), and recurrent abscesses(12.3%). Common infections during follow-up were URTI(56.8%), pneumonia(33%), skin infections(25.6%), gastroenteritis(18.3%), and recurrent abscesses(14,6%). Common long-term complications were dental problems(n = 51), osteoporosis(n = 22), growth retardation(n = 14), malignancy(n = 16)[myelodysplastic syndrome(n = 10), large granulocytic leukemia(n = 1), acute lymphoblastic leukemia(n = 1), Hodgkin lymphoma(n = 1), EBV-related lymphoma(n = 1), leiomyosarcoma(n = 1), and thyroid neoplasm(n = 1)]. We performed a genetic study in 86 patients, and 69(71%) got a genetic diagnosis. Common gene defects were HAX-1(n = 26), ELA-2 (ELANE)(n = 10), AP3B1(n = 4), and ADA-2(n = 4) gene defects. The IEI ratio(70.6%) was high. GCSF treatment(93.4%), immunoglobulin replacement therapy(18.7%), and HSCT(15.9%) were the treatment options. The mortality rate was 12.9%(n = 14). The most common long term complications were dental problems that is three times more common in patients with known genetic mutations. We prepared an algorithm for chronic neutropenia depending on the present cohort. An important rate of inborn errors of immunity, especially combined immunodeficiency(11.9%) was presented in addition to congenital phagocytic cell defects. Early diagnosis will allow us tailor the disease-specific treatment options sooner, preventing irreversible consequences.

How did DAT happen? A Coombs Negative Delayed Hemolytic Transfusion Reaction in a Patient with Myelodysplastic Syndrome: A Case Report

How did DAT happen? A Coombs Negative Delayed Hemolytic Transfusion Reaction in a Patient with Myelodysplastic Syndrome: A Case Report

Extent of iron induced organ damage in patients with hematological disorders.

Objective: To determine the extent of iron induced organ damage in patients of Haematological disorders who are transfusion dependent, presenting in the emergency department of SZH, Lahore. Study Design: Cross Sectional study. Setting: Department of Emergency, Shaikh Zayed Hospital, Lahore. Period: December 25, 2020 to June 24, 2021. Methods: A total of 100 patients aged 10-60 years, of both genders, diagnosed with haematological disorders, and receiving multiple blood transfusions were included in this study. Demographic details were noted including name, age, sex, diagnosis, duration of receiving transfusions and number of transfusions received per month. Patients were evaluated clinically for organ damage including pulmonary, hepatic, renal, and cardiac organs using Denver MOF score. Results: Mean age of patients was 35.33±14.27 years. Mean duration of receiving transfusion was 6.69±2.71 months. There were 67 (67%) males and 33 (33%) female patients. Primary diagnosis was Autoimmune Haemolytic Anemia (AIHA) in 18 (18.00%) patients, Aplastic anemia in 34 (34%) patients, Thalassemia in 37 (37%) patients and Myelodysplastic syndrome (MDS) in 11 (11%) patients. Multiple organ damage was found in 23 (23%) patients. Pulmonary damage was diagnosed in 21 (21%) patients, hepatic damage in 21 (21 %) patients, renal damage in 20 (20%) patients and cardiac damage in 15 (15%) patients. Conclusion: There is a high frequency of multi-organ damage in patients of Haematological disorders requiring chronic blood transfusions. In this study, multi-organ damage was diagnosed in 23% patients requiring chronic blood transfusion.

Development of iPSC-derived human bone marrow organoid for autonomous hematopoiesis and patient-derived HSPC engraftment

Current efforts in translational studies in hematology often rely on immunodeficient mouse models for engrafting patient-derived hematopoietic stem and progenitor cells (HSPCs), yet these models often face challenges in effectively engrafting cells from patients with various diseases, such as myelodysplastic syndromes (MDS). In this study, we developed an induced pluripotent stem cell (iPSC)-derived human bone marrow organoid model that closely replicates the bone marrow microenvironment, facilitating the engraftment of MDS patient-derived HSPCs, thereby mirroring the patients' distinct disease characteristics. Specifically, through advanced microscopy, we verified the development of a complex three-dimensional network of endothelial, stromal, and hematopoietic cells within the organoids, resembling the autonomous human marrow microenvironment. Furthermore, we showed that HSPCs derived from the donor bone marrow of normal individuals or patients with MDS can migrate to and proliferate within the organoid’s vascular niche while maintaining self-renewal and original genetic profiles. Within the organoids, the differentiation patterns from MDS HSPCs were significantly distinct compared to the multilineage hematopoiesis from normal HSPCs, which can be correlated with the clinical manifestations of the disease. These findings underscore the significance of the organoid model in studying human hematopoiesis and the pathophysiology of hematologic diseases, offering new avenues for personalized medicine and therapeutic interventions.

P04 A vexing case of polymyalgia rheumatica

Abstract Introduction VEXAS (Vacuoles, E1 enzyme, X-linked, Autoinflammatory, Somatic) syndrome is a recently described autoinflammatory condition characterised by somatic mutations in the UBA1 gene, resulting in significant morbidity. Disease presentation can mimic several rheumatological conditions, delaying diagnosis and appropriate management. This case report presents the clinical course of a patient with a complex history of musculoskeletal symptoms and systemic inflammation, first diagnosed with polymyalgia rheumatica (PMR), who was later identified as having VEXAS syndrome almost six years after first referral to the rheumatology clinic. It illustrates the importance of considering rare autoinflammatory conditions in patients with atypical presentations of common rheumatological disorders. Case description A 76-year-old gentleman was referred from the haematology clinic where he had undergone investigation for pancytopenia and raised inflammatory markers. Initial investigations under the haematology team revealed normal CT chest, abdomen and pelvis, unremarkable bone marrow biopsy and cytogenetics. He presented with muscle stiffness and proximal limb girdle pain. Additional symptoms included fatigue and a diffuse non-specific erythematous rash. There was no significant past medical history and he was previously very fit and active. Rheumatology investigations were normal, apart from persistently elevated inflammatory markers (ESR 86 mm/h and CRP 70 mg/L). A diagnosis of polymyalgia rheumatica was made and prednisolone 15 mg was started. Although he initially had a good response to this, he continued to experience significant inflammatory and constitutional symptoms. These included small joint polyarthritis, night sweats and weight loss. He was pancytopenic with associated reduced exercise tolerance, requiring transfusions and erythropoietin. To exclude other differentials, a repeat bone marrow biopsy was performed. This revealed dysplasia likely secondary to underlying inflammation, although no clonal abnormalities or vacuoles were detected. MRI right hand showed synovitis, and he was therefore treated for myalgic-onset rheumatoid arthritis. Prednisolone dose was increased temporarily and methotrexate was added, resulting in temporary improvement of his ESR 16 mm/h and CRP 25 mg/L. The patient continued to have ongoing constitutional symptoms and developed new ataxia. Further investigations, including MRI head, gastroscopy and Whipple’s PCR were all normal. Repeat CT chest, abdomen and pelvis and PET-CT were unremarkable. His symptoms and inflammatory markers were responsive to steroids. Given his symptoms and macrocytosis, he was tested for ubiquitin-activating enzyme UBA1 gene which was positive, confirming the diagnosis of VEXAS syndrome. Methotrexate was stopped due to worsening cytopenia, prednisolone continued and tocilizumab started. He showed significant improvement in pancytopenia and symptoms following initiation of tocilizumab. Discussion VEXAS is characterised by somatic mutations in the UBA1 gene; its pathogenesis leads to malfunctioning methionine-41, an enzyme that initiates ubiquitylation. This leads to increased activation of innate immune pathways and induces systemic inflammation, manifesting in a variable clinical presentation. This variability makes the diagnosis challenging and leads to a median diagnostic delay of 5.5 years, similar to our patient’s six-year delay. Our patient was initially managed as PMR due to his clinical presentation and lack of an obvious alternative diagnosis. This misdiagnosis is not unique. Often, patients later diagnosed with VEXAS are first managed as either inflammatory conditions, notably polychondritis, vasculitis or Sweet’s syndrome, or myelodysplastic syndrome (MDS). VEXAS is hallmarked by haematological dysfunction as much as it is by inflammatory features. In fact, our patient’s first signs included a mild cytopenia which later developed into a progressive macrocytic anaemia. This is classical of VEXAS. Other haematological manifestations include thrombotic events and MDS, with minimal response to EPO-stimulating agents as seen here. His ongoing deterioration triggered an alternative diagnosis to be sought. VEXAS is unusual as an autoinflammatory disease: its causative mechanism is a somatic mutation acquired later in life. Its diagnosis can be confirmed by inactivation of the x-linked UBA1 gene. This case highlights the need for UBA1 testing when dealing with an unexplained inflammatory phenotype, especially in men with cytopenia, multiorgan autoinflammation or MDS-like features. VEXAS presents a management challenge. The term ‘haeamatoinflammatory’ has been created to reflect its unique nature, warranting input from both specialist teams as well as the wider MDT. Key learning points • VEXAS should be considered as a differential when dealing with unexplained inflammatory symptoms, especially in men, multiorgan autoinflammation, vasculitis and/or MDS-like features. • VEXAS is often progressive and transfusion-dependence is associated with a poorer prognosis. A macrocytic anaemia is a prominent feature of the condition. • The absence or low proportion of vacuoles in bone marrow should not prevent us from testing for VEXAS if clinically indicated. • No established protocols for VEXAS yet exist. Haematological management is supportive. Anti-inflammatory treatment is based on collective observed evidence, including the use of tocilizumbab (anti-IL6) and janus kinase (JAK) inhibitors. Allogenic haemopoietic stem cell transplantation has been successful in few patients and may represent an option for patients with severe disease.