Medicine and Pharmacology

Abstract:

Ruxolitinib is a JAK1 and JAK2 inhibitor approved in 2011 for the treatment of myelofibrosis., It is unclear if this drug can increase the risk of fungal infections. We present the case of a 67-year-old man with post-polycythemia vera myelofibrosis under treatment with ruxolitinib and azacitidine admitted to the Hematology Department with a history of subacute constitutional syndrome and diarrhea followed by fever. Biopsies of oral and colonic ulcerated lesions revealed Histoplasma; and subsequent bronchoalveolar lavage (BAL) was also positive for Histoplasma and Pneumocystis. Treatment with amphotericin B and isavuconazole was initiated without discontinuing ruxolitinib, resulting in a favourable response, confirmed by PET/CT. This case highlights the potential association of invasive fungal infection (IFI) with ruxolitinib treatment, the risk of endemic opportunistic fungal infections and the usefulness of PET/CT for follow-up of disseminated IFI.

Abstract: Background: Malnutrition is a common and clinically significant complication in patients with haematological malignancies, yet data from sub-Saharan Africa remain scarce. This study assessed the prevalence and determinants of malnutrition, including sarcopenic obesity, and examined the mediating role of symptom burden between clinical exposures and nutritional status among Nigerian patients with haematological cancers.Methods: This cross-sectional study recruited 81 adult patients with haematological malignancies. Nutritional status was assessed using the Patient-Generated Subjective Global Assessment (PG-SGA), alongside anthropometric measures, the ESAS, and SARC-F screening tool. Sarcopenic obesity was defined as the coexistence of obesity (BMI ≥30 kg/m²) and low MUAC (<24 cm). The Chi-square, Spearman correlation analyses, multivariable linear and ordinal logistic regression were statistical methods employed. Results: The mean age was 51 ± 17.19 years, and 50.6% were female. According to PG-SGA, 35.8% were well nourished, 27.2% moderately malnourished, and 37.0% severely malnourished. Sarcopenic obesity was identified in 4.9% of the cohort (4/81), representing 50% of all obese patients. Malnutrition was significantly associated with age (p=0.007), occupation (p=0.044), income (p=0.034), ECOG performance status (p<0.001), blood transfusion (p=0.010), splenomegaly (p=0.034), hepatomegaly (p=0.007), BMI (p=0.006), MUAC (p<0.001), ESAS (p<0.001), and SARC-F (p=0.002). Conclusion: Malnutrition affects nearly two-thirds of Nigerian patients with haematological cancers and is strongly driven by poor performance status and symptom burden. Sarcopenic obesity, though less prevalent, affects half of all obese patients and may mask underlying lean mass depletion. Early nutritional screening and integrated symptom management should be embedded in haematological oncology care in Nigeria.

Abstract: Measurable residual disease (MRD) assessment has transformed response evaluation and prognostic stratification across hematologic malignancies. Advances in flow cytometry, polymerase chain reaction, next-generation sequencing, and circulating tumour DNA analysis have expanded the sensitivity and biological scope of residual disease detection. However, increasing analytical sensitivity does not necessarily translate into improved clinical utility. This narrative review critically examines contemporary MRD technologies, their analytical limitations, and their applications in acute myeloid leukaemia, acute lymphoblastic leukaemia, multiple myeloma, chronic lymphocytic leukaemia, lymphomas, and chronic myeloid leukaemia. Particular em-phasis is placed on MRD-guided treatment intensification, de-escalation, transplanta-tion decisions, treatment discontinuation, and pre-emptive intervention. Although MRD negativity is strongly associated with favourable outcomes, evidence demon-strating that MRD-guided treatment modification improves survival remains heterogeneous across diseases and therapeutic settings. The review also addresses preanalytical variables, assay validation, laboratory harmonization, standardized reporting, and the complementary role of molecular and immunophenotypic methodologies. Emerg-ing approaches involving artificial intelligence, single-cell profiling, spatial analysis, and multimodal predictive models are discussed. The proposed MRD 2.0 framework emphasizes the transition from increasingly sensitive detection toward integrated, longitudinal, biologically informed, and clinically actionable monitoring. Its successful implementation requires validated laboratory measurements and prospective evidence linking MRD-informed decisions to improved patient outcomes.

Abstract: Background / Objectives: Circadian light exposure and rest–activity timing may influence hematologic physiology through pathways involving autonomic regulation, inflammation, and vascular function. However, the relationships between objectively measured circadian exposures and platelet indices remain insufficiently characterized, particularly in young adults with previous SARS-CoV-2 infection. We investigated associations between actigraphy-derived light and activity metrics and platelet indices, and examined whether these associations differed according to previous infection status. Methods: One hundred twelve young adults (mean age 24.4±9.7 years; 74 COVID+, 38 COVID−) from Tyumen, Russia, wore wrist actigraphs with light sensors for 7 consecutive days (October–November 2023). Fasting morning complete blood counts provided platelet count (PLT), mean platelet volume (MPV), platelet distribution width (PDW), and plateletcrit (PCT). Multivariable linear regression tested associations between circadian predictors and platelet indices, adjusted for age and sex. Results: No significant associations were found between circadian metrics and PLT, PDW, PCT, or MPV/PLT ratio after FDR correction. Higher MPV was independently associated with greater normalized amplitude of blue-light exposure, earlier BLE L5 onset, earlier wake time, and earlier 24-h activity acrophase. These associations were stronger in COVID+ participants and non-significant in COVID− participants. Earlier BLE L5 and fair light hygiene were associated with higher MPV in COVID+ only. Conclusions: In this cross-sectional study, MPV, but not the other platelet indices examined, was associated with selected measures of circadian light exposure and rest–activity timing. Associations were more pronounced among participants reporting previous SARS-CoV-2 infection. These findings identify a potential link between environmental circadian patterns and hematologic phenotype that warrants further investigation in relation to vascular physiology. Longitudinal studies incorporating direct measures of platelet function and cardiovascular regulation are needed to determine the underlying mechanisms and clinical significance.

Abstract: Systemic light-chain (AL) amyloidosis and multiple myeloma are two separated but closely related entities. Both are chronic, complex, challenging, heterogeneous, and incurable diseases. Both belong to the broad group of monoclonal gammopathies, with a peak incidence between 60 and 70 years of age. They are characterized by the presence of a bone marrow clonal plasma cell infiltration, and they share similar anti-clonal therapy. Frailty is a dynamic, multidimensional, age-related syndrome, defined by reduced physiological reserve and resistance to stressors, leading to vulnerability and poor outcomes. Therefore, frailty plays a crucial role in clinical decision making to tailor therapy, minimizing toxicity and optimizing outcome. A systematic and comprehensive English PubMed search was undertaken and complemented with other parallel search’ strategies. A growing body of evidence supports including frailty as a standard of care in these diseases, at baseline and dynamically at selected moments through the evolutive course. This narrative review aims to critically analyze the efficiency and prognostic impact of tools and scores used to assess frailty in both clinical scenarios, whether in the context of clinical trials or in real life. Barriers to a widely, dynamic, and standardized use of frailty assessment in the real world are analyzed as well as strategies to overcome them.

Abstract: Circulating histones are increasingly recognised as biologically relevant components of extracellular chromatin, but their composition and treatment-associated dynamics in acute myeloid leukaemia (AML) remain poorly defined. In this prospective single-centre observational study, we profiled 13 histone measures by ImageStream imaging flow cy-tometry in 31 plasma samples from 15 newly diagnosed AML patients at diagnosis/day 7/day 28 (n=15/10/6), with 30 healthy controls and 12 patients with myelodysplastic neoplasms with increased blasts. At diagnosis, nine of 13 measures differed from controls after false discovery rate (FDR) correction, defining a bidirectional profile with higher H2A-, H2B- and macroH2A1-associated measures and lower H3, H4 and H3/H4; the largest differences included in-creased macroH2A1.1 (7.07% vs. 0.47%; δ=0.98) and reduced H4 (0.14% vs. 3.25%; δ=−0.87). By day 7, five measures remained FDR-significant, all decreasing: H4, H3/H4 and the three tetrameric complexes. At day 28, no paired comparison remained FDR-significant; however, H3/H4 showed a significant overall temporal change across the six complete serial trajectories (q = 0.0334). Exploratory day-28 trajectories showed concordant decreases in all three tetrameric complexes in complete remission, with opposite changes in residual disease. MDS with increased blasts showed higher macroH2A1-containing tetrameric complexes than controls and AML. These findings support disease- and treatment-associated redistribution of circulating histone populations across myeloid neoplasia.

Abstract: Platelet transfusion is essential in hematology but remains characterized by practice variability, uneven certainty of evidence across clinical settings, short component shelf life and clinically relevant adverse effects. This narrative review integrates evidence on efficacy, thresholds and dosing, safety, and implementation of platelet-specific patient blood management (PBM). In stable non-bleeding therapy-induced thrombocytopenia, a restrictive prophylactic threshold of 10 × 10⁹/L is supported by randomized evidence and contemporary guidelines, whereas higher thresholds increase exposure without consistent clinical benefit. Therapeutic-only strategies reduce utilization but are not equally safe across populations, particularly in acute leukemia. Platelet PBM should therefore combine indication-specific protocols, a single-adult-dose policy with reassessment, audit and feedback, post-transfusion response monitoring, refractoriness management, inventory stewardship and multidisciplinary governance. The objective is not simply fewer transfusions, but fewer unnecessary transfusions with preserved hemostatic safety.

Abstract: Background/Objectives: Primary myelofibrosis (PMF) is a myeloproliferative neoplasm, associated with a somatic mutation in the JAK2, CALR, MPL genes and characterized by progressive bone marrow fibrosis, extramedullary hematopoiesis, splenomegaly, constitutional symptoms, progressive cytopenias, and in a subset of patients, leukemic transformation. The aim of the present study is to review recent studies investigating molecular abnormalities observed in myelofibrosis and showing how these studies have led to the development of new therapeutic strategies for PMF. Methods: An extensive search of the most recent literature was performed, selecting and critically analyzing the most relevant studies. Results: The studies carried out in the last years have provided an extensive molecular characterization of PMF, showing its heterogeneity, characterized by the presence of additional cytogenetic and non-driver gene mutations that contribute to disease evolution. The molecular abnormalities, together with clinical parameters, provided criteria for a risk score stratification of PMF patients. The molecular characterization of PMF has triggered the development of targeted therapeutics represented by JAK inhibitors and antibodies targeting mutant CALR. Conclusions: PMF is a complex and heterogeneous disease that needs to be carefully characterized at molecular and clinical level at diagnosis, to provide a careful risk stratification of individual patients and an adequate personalized treatment.

Abstract: Red blood cell (RBC) transfusion is commonly prescribed in units and assessed through changes in recipient hemoglobin concentration. Unit count leaves the administered hemoglobin mass unspecified, while the concentration increment also reflects recipient blood volume, fluid balance, bleeding and cell persistence. This narrative review examines component hemoglobin content, quality specifications, preparation, storage and clinical studies of content-based allocation. Components meeting the same quality specifications can contain different hemoglobin masses [1]. Anticoagulants, additive solutions, container materials and processing further define the component administered. Hemolysis changes the distribution of hemoglobin between cellular and extracellular compartments; posttransfusion recovery measures subsequent cell persistence. Oxygen affinity and oxygen-release kinetics add functional information that concentration and mass alone do not capture. We propose prospective studies linking representative final-component measurements to delivered volume, recipient physiology and samples collected at defined times. The first test is whether measured administered hemoglobin mass improves prediction of the recipient increment beyond routine component and patient data. A subsequent comparison can assess the additional value of oxygen-release measurements and perfusion variables. Clinical benefit requires independently measured physiological and patient outcomes. This approach would make transfusion exposure more explicit and allow the value of individual component characterization to be tested within established compatibility and patient blood management practice.

Abstract: Objective: To characterize the HBB mutation spectrum in a contemporary Bulgarian pediatric cohort with transfusion-dependent β-thalassemia (TDT) and to explore genotype–phenotype relationships, including organ-specific iron loading by magnetic resonance imaging (MRI) T2*. Materials and Methods: We retrospectively analyzed 37 children and adolescents with TDT receiving regular red-cell transfusions and iron chelation. HBB variants identified by Sanger sequencing and multiplex ligation-dependent probe amplification were classified as β0, β+, or β++. Patients with two identified alleles were grouped by predicted genotype severity. Pretransfusion hemoglobin, serum ferritin, and cardiac, hepatic, and pancreatic MRI T2* were evaluated. All comparisons were exploratory. Results: Molecular characterization was available in 28 of 37 patients: 26 had a complete two-allele genotype and 2 had a single identified allele. Among these 28 genetically informative patients, 54 alleles were identified. IVS-I-110 predominated (18/54; 33.3%), followed by IVS-I-6 (13.0%), IVS-II-745 (13.0%), and FS5 (11.1%). Pretransfusion hemoglobin and serum ferritin did not differ significantly among genotype-severity groups (p=0.208 and p=0.289). Hepatic T2* was <6.3 ms in 9/14 patients and cardiac T2* was <20 ms in 2/19. Pancreatic T2* was ≤2.4 ms in all 7 patients examined, a small and possibly selected subgroup. Conclusion: The mutation spectrum closely reflects the established Bulgarian profile. Under regular transfusion therapy, broad genotype-severity categories were not reflected by pretransfusion hemoglobin or serum ferritin, whereas MRI demonstrated organ-specific heterogeneity. The pancreatic findings are preliminary and require prospective confirmation.

Abstract: Background/Objectives: Iron deficiency may be associated with alterations in systemic inflammatory activity and metabolic parameters. However, whether oral and intravenous (IV) iron replacement have different effects on inflammatory markers and serum uric acid remains unclear. We compared inflammatory and metabolic responses to oral and IV iron in premenopausal women with iron deficiency. Methods: This prospective observational study included 72 oral iron recipients, 77 IV iron recipients, and 76 healthy controls. Patients were reassessed at Day 30. The primary outcome was change in C-reactive protein (CRP); changes in erythrocyte sedimentation rate (ESR) and uric acid were secondary outcomes. Additional regressions used robust standard errors, adjusting for age, baseline hemoglobin, and baseline outcome values; the uric acid model additionally included baseline creatinine. Results: Baseline CRP and ESR were significantly higher in both iron-deficient groups than in controls (all Bonferroni-adjusted p<0.001). The IV iron group had more severe baseline anemia than the oral iron group (median hemoglobin: 8.60 vs. 10.70 g/dL; Bonferroni-adjusted p<0.001). Increases in hemoglobin, ferritin, and transferrin saturation over 30 days were greater with IV iron (all p<0.001). Median CRP changes were −0.22 mg/L with IV iron and 0.07 mg/L with oral iron (unadjusted p=0.041). However, multivariable regression with robust standard errors showed no statistically significant difference in Day 30 CRP after adjustment for age, baseline hemoglobin, and baseline CRP (IV minus oral: −1.585 mg/L; 95% CI, −3.261 to 0.091; p=0.064; n=149). The corresponding adjusted analysis showed lower Day 30 ESR with IV iron (−2.118 mm/h; 95% CI, −3.817 to −0.418; p=0.015; n=91). The adjusted serum uric acid difference, additionally accounting for baseline creatinine, was not statistically significant (0.389 mg/dL; 95% CI, −0.009 to 0.787; p=0.055; n=149). Conclusions: IV iron was associated with greater hematologic and iron-store repletion over 30 days. Adjusted comparisons showed no statistically significant differences in CRP or serum uric acid, whereas ESR was modestly lower with IV iron, with uncertain clinical significance. Nonrandomized treatment allocation and premedication restricted to the IV group preclude attributing these findings solely to iron administration.

Abstract: The incorporation of myelodysplasia-related gene (MRG) mutations into contemporary classifications of acute myeloid leukemia (AML) reshaped the disease stratification. The 2022 International Consensus Classification (ICC) recognizes nine MRG mutations, whereas the fifth World Health Organization classification (WHO-HAEM5) excludes RUNX1. The 2022 European LeukemiaNet (ELN) recommendations classify these mutations as adverse-risk lesions in intensively treated patients. However, emerging evidence challenges their uniform prognostic significance. Large-scale genomic analyses reveal substantial gene-specific heterogeneity, with ASXL1, RUNX1, SF3B1, and U2AF1 generally associated with adverse outcomes, whereas SRSF2 and STAG2 seem to exhibit a more favorable prognostic profile. Importantly, their clinical impact is influenced by co-mutational architecture and treatment context. Venetoclax-based regimens may attenuate the adverse prognostic impact of MRG mutations, while emerging evidence suggests potential benefits from CPX-351 in molecularly defined AML-MR. Allogeneic hematopoietic stem cell transplantation remains crucial for a curative-intent treatment, while post-transplant maintenance represents an evolving strategy. Furthermore, molecular clearance of MRG mutations during remission may provide prognostic information beyond conventional measurable residual disease assessment. This review critically examines the biological and clinical heterogeneity of MRG-mutated AML, differences across classification systems, and contemporary therapeutic approaches, including intensive chemotherapy, CPX-351, venetoclax-based regimens, transplantation, and maintenance strategies. Particular emphasis is placed on gene-specific prognostic differences, co-mutational patterns, and dynamic molecular response. Collectively, available evidence supports moving beyond a binary MRG-positive versus MRG-negative classification toward an integrated, context-dependent framework incorporating molecular characteristics, treatment exposure, and longitudinal response assessment to refine risk stratification and guide personalized therapeutic decisions.

Abstract: Background/Objectives: Post-thaw washing of cryopreserved hematopoietic progenitor cell (HPC) products is performed to remove dimethyl sulfoxide (DMSO) and reduce infusion-related toxicity. Hydroxyethyl starch (HES) has traditionally been used as an osmotic buffer in washing solutions; however, severe regulatory restrictions and market suspensions by the European Medicines Agency (EMA) have limited its availability in Europe. This pilot study evaluated the technical feasibility of utilizing a 4.0% human serum albumin (HSA)-based washing solution to replace HES without compromising post-thaw product quality parameters. Methods: Sixteen cryopreserved peripheral blood HPC bags from eight patients (cryopreserved between 2006 and 2015) were analyzed using a paired experimental design. For each patient, one bag was thawed and washed using the standard HES-HSA solution, while the paired bag was processed using an HSA-based solution. Total nucleated cell (TNC) recovery, TNC viability, viable CD34+ cell recovery, CD34+ viability, and clonogenic potential (CFU assay) were assessed immediately after washing and after 90 minutes of short-term post-thaw storage. Results: No statistically significant differences were observed between the HES-HSA and HSA washing solutions for any evaluated parameter. TNC recovery rates were 86.6 ± 6.6% and 88.9 ± 7.9% for the HES-HSA and HSA groups, respectively (p = 0.54). Post-thaw viability, viable CD34+ cell recovery, CD34+ viability, and clonogenic potential were stable and comparable between both processing strategies. Conclusions: An albumin-based washing solution provides cellular recovery, viability, and clonogenic performance comparable to conventional HES-containing formulations in a laboratory setting. Given current restrictions on HES due to clinical safety concerns, an albumin-based formulation represents a practical and logistically viable operational alternative for the post-thaw processing of peripheral blood HPC products.

Abstract: Background and Objectives: The use of cryopreserved hematopoietic cells in allogeneic hematopoietic cell transplantation (HCT) has become widespread all over the world and in our country, especially after the SARS-CoV-2 pandemic. This situation has increased the importance of the effect of cryopreservation on engraftment, the incidence of transplantation-related complications, and the survival of patients. This study aimed to compare the transplant results between the patient group receiving peripheral blood-derived cryopreserved cells and the patient group receiving fresh products in patients over the age of 18 who had hematological diseases and underwent allogeneic HCT. Materials and Methods: A total of 222 patients over the age of 18 with hematological diseases who underwent allogeneic HCT were included in the study. Neutrophil engraftment time, platelet engraftment time, disease-free survival, overall survival, graft versus host disease incidence, cytomegalovirus reactivation/infection and transplant-related mortality rates were retrospectively compared between the cryopreserved and fresh product groups. Results: No significant difference was found between the cryopreserved and fresh product groups in terms of median age, gender, body weight, hematological disease subtype, disease status before HCT, Sorror comorbidity index, blood group compatibility, and preparation regimen intensity. On the other hand, the haploidentical HCT count was higher in the fresh cell group. The number of CD34+ stem cells received by patients receiving cryopreserved products was lower than the number of CD34+ stem cells received by patients receiving fresh products. No significant difference was found between the cryopreserved and fresh product groups in terms of platelet and neutrophil engraftment time, engraftment failure rate, cytomegalovirus reactivation/infection rate in the first 100 days after HCT, development of graft versus host disease, transplant-related death, disease-free survival and overall survival. Conclusions: Cryopreservation and cell storage is very important in order to prevent complications such as delays in the patient's transplantation process due to donor-related problems, prolonged hospital stay, and related complications. When done properly, cryopreservation can produce HCT outcomes similar to those obtained with fresh products.

Abstract: Background/Objectives: Immune thrombocytopenia (ITP) is an autoimmune disease characterized by increased platelet destruction and insufficient platelet production. Accurate diagnosis, prognostic assessment, and treatment selection remain challenging. Long non-coding RNAs (lncRNAs) regulate immune responses and may contribute to ITP pathogenesis. This review examines lncRNA expression in ITP and its potential diagnostic, prognostic, and therapeutic relevance. Methods: We reviewed English-language literature published between 1994 and 2026 using PubMed, Scopus, and Google Scholar. We examined studies of specific lncRNAs in ITP, focusing on their expression differences and potential diagnostic and therapeutic implications. Re-sults: The studies examined HCP5, NEAT1, lnc-DC, IFNG-AS1, MEG3, GAS5, MALAT1, and THRIL. Findings suggest these lncRNAs may contribute to ITP pathogenesis and serve as candidate diagnostic and prognostic biomarkers. Some were reported as independent predictors of poor prognosis or were associated with glucocorticoid responsiveness. Potential applications include distinguishing primary from secondary ITP, informing patient selection for splenectomy, and identifying therapeutic targets. These applications remain investigational. Conclusions: Research on lncRNAs provides insight into autoimmune mechanisms underlying ITP and may support improvements in diagnosis, prognostic assessment, and individualized treatment. Although several lncRNAs show promise as biomarkers and therapeutic targets, further research, clinical validation, and methodological standardization are needed before routine clinical implementation.

Abstract: Background/Objectives: Iron replacement and investigation of the underlying disorder are complementary aspects of care. We described diagnoses recorded after intravenous iron treatment and gastrointestinal biopsy findings during follow-up. Methods: This single-center retrospective cohort included 1,164 adults treated during 2015–2025. Linked diagnosis and pathology records were classified relative to the index infusion. Two authors manually reviewed and verified pathology reports. Five age- and sex-adjusted logistic models assessed associations between laboratory values obtained within 30 days before infusion and a gastrointestinal composite, with correction for multiple testing. Results: Among 1,085 adults with observation beyond infusion, median follow-up was 38.2 months. Follow-up diagnosis status was documented in 601 patients; 47 had a diagnosis dated after infusion, including 24 after one year. Across linked sources, 33 patients had post-infusion malignancy records, including 10 with supporting pathology. Post-infusion gastrointestinal biopsies were available for 169 patients. Chronic gastritis was reported in 151 (89.3%), atrophy and/or intestinal metaplasia in 143 (84.6%), and malignant tumors in six (3.6%; 95% confidence interval, 1.6–7.5%). The gastrointestinal composite occurred in 52 patients (30.8%); none of the five laboratory associations met the multiplicity-adjusted threshold. Conclusions: Malignant and nonmalignant diagnoses were documented during follow-up, including beyond the first year after intravenous iron treatment. Linked biopsy reports provided histologic detail in a selected subgroup; the findings do not establish the cause of the original iron deficiency or disease incidence in the treated population.

Abstract: Hemophagocytotic lymphohistiocytosis (HLH) is a rare but often life-threatening hyperinflammatory syndrome which is characterised by pathological macrophage activation and failure of self-regulation in immunity. This review examines the key role in macrophages as both victims of defective cytotoxic control, but instead of staying as passive victims, become overactivated partners in immune-mediated tissue damage and primary executors of end-organ damage in HLH. Here, exploration of the links between the impaired perforin-granzyme cytotoxicity, sustained presentation of antigen, and the ultimate culminating into M1 macrophage polarization which drives the clinical conditions of fever, cytopenia, organomegaly, and coagulopathy has been studied. Understanding the dysfunction of macrophages in HLH provides critical insights for targeted therapeutic interventions in this life-threatening rapidly fatal syndrome. Also, the therapeutic targeting of the macrophage pathways, and the future therapeutic developments that are needed to be taken into consideration are discussed, followed by the immediate clinical relevance of macrophage-centric understanding of HLH.

Abstract: Resistance to tyrosine kinase inhibitor therapy in patients with chronic myeloid leukemia remains a clinical challenge of which the underlying mechanisms are not always fully understood. The leukemic bone marrow microenvironment is increasingly recognized as an important factor protecting leukemic cells from therapeutic pressure. However, studying this leukemic bone marrow is complicated by limited accessibility of the bone marrow in vivo and the limited physiological relevance of conventional in vitro disease models. Microfluidic bone-marrow-on-a-chip models provide a platform for reconstructing the cellular, biochemical, and biophysical components of the bone marrow niche under controlled conditions. These models may more accurately recapitulate the in vivo microenvironment while avoiding some of the limitations inherent in animal models. Their ability to mimic the bone marrow niche provides novel opportunities to investigate the complex interactions between leukemic cells and their microenvironment. Moreover, the incorpora-tion of patient-derived cells highlights the potential of personalized chronic myeloid leu-kemia-on-a-chip models to study interpatient heterogeneity in treatment response. This review explores the potential of chronic myeloid leukemia-on-a-chip models as platforms for basic research and clinical translation.

Abstract: Background /Objectives: Longitudinal monitoring after CD19-directed chimeric antigen receptor (CAR)-T-cell therapy primarily focuses on CAR-T cell expansion. However, comprehensive immunophenotypic characterization of both CAR-T and endogenous T-cells remains limited. We investigated longitudinal immune dynamics following tisagen-lecleucel treatment using multiparameter flow cytometry. Methods: Nineteen patients with relapsed or refractory B-cell malignancies (11 diffuse large B-cell lymphoma and 8 B-cell acute lymphoblastic leukemia) receiving tisagenlecleucel were prospectively enrolled. Serial peripheral blood samples collected during the first 28 days after infusion were analyzed for CAR-T-cell kinetics, differentiation status, activation and exhaustion marker expression, longitudinal phenotypic changes, as well as associations with treatment response and immune-related toxicities. Results: CAR-T-cell expansion predominantly peaked on day 7 after infusion. However, in several patients with B-cell acute lymphoblastic leukemia, delayed peak expansion was observed. At peak expansion, CAR-T-cells were enriched for a central memory phenotype and exhibited significantly higher HLA-DR and PD-1 expression than endogenous T-cells. During follow-up, the number of central memory T-cells progressively declined, whereas terminal effector T-cell numbers increased, which was accompanied by reduced expression of HLA-DR, PD-1, and TIGIT. Despite the distinct activation profiles, CAR-T and endogenous T-cells displayed broadly similar differentiation patterns. Exploratory analyses further demonstrated higher absolute CAR-T-cell counts in patients who developed immune effector cell-associated neurotoxicity syndrome. Conclusions: This clinically applicable approach provides immunophenotypic information beyond CAR-T-cell enumeration alone and may facilitate biomarker discovery and longitudinal immune monitoring in patients receiving CAR-T-cell therapy.

Abstract: Relying on the gut-bone marrow bidirectional regulatory axis, the gut microbiota regulates systemic immune homeostasis and the bone marrow hematopoietic microenvironment through signaling molecules such as maintenance of the mucosal barrier, short-chain fatty acids, and tryptophan metabolites, thereby deeply participating in the entire evolution of hematological malignancies. Patients with hematological malignancies universally exhibit characteristic dysbiosis, including decreased gut microbial diversity, depletion of butyrate-producing beneficial bacteria, and overproliferation of opportunistic pathogens. This dysbiosis can drive the origin of malignant hematopoietic clones and disease progression, regulate the response efficiency of chemotherapy and cellular therapy, and determine the risk of fatal complications such as graft-versus-host disease, severe infections, and intestinal mucositis following allogeneic hematopoietic stem cell transplantation. This article systematically reviews the interaction mechanisms between the gut microbiota and hematological malignancies, disease-specific microbiota profiles, therapeutic regulation rules, and bottlenecks in clinical translation, providing a theoretical basis for personalized microbiota-targeted therapy in hematological malignancies.