Clonal hematopoiesis driven by mutated DNMT3A promotes inflammatory bone loss.

Clonal hematopoiesis of indeterminate potential (CHIP) arises from aging-associated acquired mutations in hematopoietic progenitors, which display clonal expansion and produce phenotypically altered leukocytes. We associated CHIP-DNMT3A mutations with a higher prevalence of periodontitis and gingival inflammation among 4,946 community-dwelling adults. To model DNMT3A-driven CHIP, we used mice with the heterozygous loss-of-function mutation R878H, equivalent to the human hotspot mutation R882H. Partial transplantation with Dnmt3aR878H/+ bone marrow (BM) cells resulted in clonal expansion of mutant cells into both myeloid and lymphoid lineages and an elevated abundance of osteoclast precursors in the BM and osteoclastogenic macrophages in the periphery. DNMT3A-driven clonal hematopoiesis in recipient mice promoted naturally occurring periodontitis and aggravated experimentally induced periodontitis and arthritis, associated with enhanced osteoclastogenesis, IL-17-dependent inflammation and neutrophil responses, and impaired regulatory T cell immunosuppressive activity. DNMT3A-driven clonal hematopoiesis and, subsequently, periodontitis were suppressed by rapamycin treatment. DNMT3A-driven CHIP represents a treatable state of maladaptive hematopoiesis promoting inflammatory bone loss.

The impact of age and number of mutations on the size of clonal hematopoiesis.

Clonal hematopoiesis (CH) represents the clonal expansion of hematopoietic stem cells and their progeny driven by somatic mutations. Accurate risk assessment of CH is critical for disease prevention and clinical decision-making. The size of CH has been showed to associate with higher disease risk, yet, factors influencing the size of CH are unknown. In addition, the characteristics of CH in long-lived individuals are not well documented. Here, we report an in-depth analysis of CH in longevous (≥90 y old) and common (60~89 y old) elderly groups. Utilizing targeted deep sequencing, we found that the development of CH is closely related to age and the expression of aging biomarkers. The longevous elderly group exhibited a significantly higher incidence of CH and significantly higher frequency of TET2 and ASXL1 mutations, suggesting that certain CH could be beneficial to prolong life. Intriguingly, the size of CH neither correlates significantly to age, in the range of 60 to 110 y old, nor to the expression of aging biomarkers. Instead, we identified a strong correlation between large CH size and the number of mutations per individual. These findings provide a risk assessment biomarker for CH and also suggest that the evolution of the CH is influenced by factor(s) in addition to age.

Aging and comprehensive molecular profiling in acute myeloid leukemia.

Acute myeloid leukemia (AML) is an aging-related and heterogeneous hematopoietic malignancy. In this study, a total of 1,474 newly diagnosed AML patients with RNA sequencing data were enrolled, and targeted or whole exome sequencing data were obtained in 94% cases. The correlation of aging-related factors including age and clonal hematopoiesis (CH), gender, and genomic/transcriptomic profiles (gene fusions, genetic mutations, and gene expression networks or pathways) was systematically analyzed. Overall, AML patients aged 60 y and older showed an apparently dismal prognosis. Alongside age, the frequency of gene fusions defined in the World Health Organization classification decreased, while the positive rate of gene mutations, especially CH-related ones, increased. Additionally, the number of genetic mutations was higher in gene fusion-negative (GF-) patients than those with GF. Based on the status of CH- and myelodysplastic syndromes (MDS)-related mutations, three mutant subgroups were identified among the GF- AML cohort, namely, CH-AML, CH-MDS-AML, and other GF- AML. Notably, CH-MDS-AML demonstrated a predominance of elderly and male cases, cytopenia, and significantly adverse clinical outcomes. Besides, gene expression networks including HOXA/B, platelet factors, and inflammatory responses were most striking features associated with aging and poor prognosis in AML. Our work has thus unraveled the intricate regulatory circuitry of interactions among different age, gender, and molecular groups of AML.

Clonal Hematopoiesis of Indeterminate Potential With Loss of Tet2 Enhances Risk for Atrial Fibrillation Through Nlrp3 Inflammasome Activation.

BACKGROUND: Clonal hematopoiesis of indeterminate potential (CHIP), a common age-associated phenomenon, associates with increased risk of both hematological malignancy and cardiovascular disease. Although CHIP is known to increase the risk of myocardial infarction and heart failure, the influence of CHIP in cardiac arrhythmias, such as atrial fibrillation (AF), is less explored. METHODS: CHIP prevalence was determined in the UK Biobank, and incident AF analysis was stratified by CHIP status and clone size using Cox proportional hazard models. Lethally irradiated mice were transplanted with hematopoietic-specific loss of Tet2, hematopoietic-specific loss of Tet2 and Nlrp3, or wild-type control and fed a Western diet, compounded with or without NLRP3 (NLR [NACHT, LRR {leucine rich repeat}] family pyrin domain containing protein 3) inhibitor, NP3-361, for 6 to 9 weeks. Mice underwent in vivo invasive electrophysiology studies and ex vivo optical mapping. Cardiomyocytes from Ldlr-/- mice with hematopoietic-specific loss of Tet2 or wild-type control and fed a Western diet were isolated to evaluate calcium signaling dynamics and analysis. Cocultures of pluripotent stem cell-derived atrial cardiomyocytes were incubated with Tet2-deficient bone marrow-derived macrophages, wild-type control, or cytokines IL-1ß (interleukin 1ß) or IL-6 (interleukin 6). RESULTS: Analysis of the UK Biobank showed individuals with CHIP, in particular TET2 CHIP, have increased incident AF. Hematopoietic-specific inactivation of Tet2 increases AF propensity in atherogenic and nonatherogenic mouse models and is associated with increased Nlrp3 expression and CaMKII (Ca2+/calmodulin-dependent protein kinase II) activation, with AF susceptibility prevented by inactivation of Nlrp3. Cardiomyocytes isolated from Ldlr-/- mice with hematopoietic inactivation of Tet2 and fed a Western diet have impaired calcium release from the sarcoplasmic reticulum into the cytosol, contributing to atrial arrhythmogenesis. Abnormal sarcoplasmic reticulum calcium release was recapitulated in cocultures of cardiomyocytes with the addition of Tet2-deficient macrophages or cytokines IL-1ß or IL-6. CONCLUSIONS: We identified a modest association between CHIP, particularly TET2 CHIP, and incident AF in the UK Biobank population. In a mouse model of AF resulting from hematopoietic-specific inactivation of Tet2, we propose altered calcium handling as an arrhythmogenic mechanism, dependent on Nlrp3 inflammasome activation. Our data are in keeping with previous studies of CHIP in cardiovascular disease, and further studies into the therapeutic potential of NLRP3 inhibition for individuals with TET2 CHIP may be warranted.

Nonpreferential but Detrimental Accumulation of Macrophages With Clonal Hematopoiesis-Driver Mutations in Cardiovascular Tissues-Brief Report.

BACKGROUND: Clonal hematopoiesis of indeterminate potential (CHIP) is an acquired genetic risk factor for both leukemia and cardiovascular disease. It results in proinflammatory myeloid cells in the bone marrow and blood; however, how these cells behave in the cardiovascular tissue remains unclear. Our study aimed at investigating whether CHIP-mutated macrophages accumulate preferentially in cardiovascular tissues and examining the transcriptome of tissue macrophages from DNMT3A (DNA methyltransferase 3 alpha) or TET2 (Tet methylcytosine dioxygenase 2) mutation carriers. METHODS: We recruited patients undergoing carotid endarterectomy or heart surgeries to screen for CHIP mutation carriers using targeted genomic sequencing. Myeloid and lymphoid cells were isolated from blood and cardiovascular tissue collected during surgeries using flow cytometry. DNA and RNA extracted from these sorted cells were subjected to variant allele frequency measurement using droplet digital polymerase chain reaction and transcriptomic profiling using bulk RNA sequencing, respectively. RESULTS: Using droplet digital polymerase chain reaction, we detected similar variant allele frequency of CHIP in monocytes from blood and macrophages from atheromas and heart tissues, even among heart macrophages with and without CCR2 (C-C motif chemokine receptor 2) expression. Bulk RNA sequencing revealed a proinflammatory gene profile of myeloid cells from DNMT3A or TET2 mutation carriers compared with those from noncarriers. CONCLUSIONS: Quantitatively, CHIP-mutated myeloid cells did not preferentially accumulate in cardiovascular tissues, but qualitatively, they expressed a more disease-prone phenotype.

Clonal hematopoiesis in patients with HIV and cancer.

BACKGROUND: Cancer-related deaths for people living with HIV (PWH) are increasing due to longer life expectancies and disparately poor cancer-related outcomes. We hypothesize that advanced biological aging contributes to cancer-related morbidity and mortality for PWH and cancer. We sought to determine the impact of clonal hematopoiesis (CH) on cancer disparities in PWH. METHODS: We conducted a retrospective study to compare the prevalence and clinical outcomes of CH in PWH and people without HIV (PWoH) and cancer. Included in the study were PWH and similar PWoH based on tumor site, age, tumor sequence, and cancer treatment status. Biological aging was also measured using epigenetic methylation clocks. RESULTS: In 136 patients with cancer, PWH had twice the prevalence of CH compared to similar PWoH (23% vs 11%, p=0.07). After adjusting for patient characteristics, PWH were four-times more likely to have CH than PWoH (OR 4.1, 95% CI 1.3-13.9, p=0.02). The effect of CH on survival was most pronounced in PWH, who had a 5-year survival rate of 38% if they had CH (vs 59% if no CH), compared to PWoH who had a 5-year survival rate of 75% if they had CH (vs 83% if no CH). CONCLUSION: This study provides the first evidence that PWH may have a higher prevalence of CH than PWoH with the same cancers. CH may be an independent biological aging risk factor contributing to inferior survival for PWH and cancer.

Association of PARP inhibitor treatment on the prevalence and progression of clonal hematopoiesis in patients with advanced prostate cancer.

BACKGROUND: Poly ADP-ribose polymerase (PARP) inhibitors are approved for the treatment of some men with advanced prostate cancer. Rare but serious side effects include myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). The impact of PARP inhibitors on clonal hematopoiesis (CH), a potential precursor lesion associated with MDS and AML, is incompletely understood in prostate cancer. We hypothesized that PARP inhibitors would increase CH prevalence and abundance. METHODS: We prospectively enrolled participants with advanced prostate cancer treated with PARP inhibitors. The presence of CH was assessed from leukocytes using an ultra-deep error-corrected dual unique molecular identifiers sequencing method targeting 49 genes most commonly mutated in CH and myeloid malignancies. Variant allele frequencies (VAF) of ≥0.5% were considered clinically significant. Blood samples were collected before and after PARP inhibitor treatment. RESULTS: Ten men were enrolled; mean age of 67 years. Six patients had Gleason 7 disease, and four had Gleason ≥8 disease at diagnosis. Nine had localized disease at diagnosis, and eight had prior treatment with radiation. The mean time between pre- and post-treatment blood samples was 11 months (range 2.6-31 months). Six patients (60%) had CH identified prior to PARP inhibitor treatment, three with multiple clones. Of 11 CH clones identified in follow-up, 5 (45%) appeared or increased after treatment. DNMT3A, TET2, and PPM1D were the most common CH alterations observed. The largest post-treatment increase involved the PPM1D gene. CONCLUSION: CH alterations are frequently found after treatment with PARP inhibitors in patients with prostate cancer and this may be one mechanism by which PARP inhibitors lead to increased risk of MDS/AML.

Association of clonal hematopoiesis and mosaic chromosomal alterations with solid malignancy incidence and mortality.

BACKGROUND: Understanding the impact of clonal hematopoiesis of indeterminate potential (CHIP) and mosaic chromosomal alterations (mCAs) on solid tumor risk and mortality can shed light on novel cancer pathways. METHODS: The authors analyzed whole genome sequencing data from the Trans-Omics for Precision Medicine Women's Health Initiative study (n = 10,866). They investigated the presence of CHIP and mCA and their association with the development and mortality of breast, lung, and colorectal cancers. RESULTS: CHIP was associated with higher risk of breast (hazard ratio [HR], 1.30; 95% confidence interval [CI], 1.03-1.64; p = .02) but not colorectal (p = .77) or lung cancer (p = .32). CHIP carriers who developed colorectal cancer also had a greater risk for advanced-stage (p = .01), but this was not seen in breast or lung cancer. CHIP was associated with increased colorectal cancer mortality both with (HR, 3.99; 95% CI, 2.41-6.62; p < .001) and without adjustment (HR, 2.50; 95% CI, 1.32-4.72; p = .004) for advanced-stage and a borderline higher breast cancer mortality (HR, 1.53; 95% CI, 0.98-2.41; p = .06). Conversely, mCA (cell fraction [CF] >3%) did not correlate with cancer risk. With higher CFs (mCA >5%), autosomal mCA was associated with increased breast cancer risk (HR, 1.39; 95% CI, 1.06-1.83; p = .01). There was no association of mCA (>3%) with breast, colorectal, or lung mortality except higher colon cancer mortality (HR, 2.19; 95% CI, 1.11-4.3; p = .02) with mCA >5%. CONCLUSIONS: CHIP and mCA (CF >5%) were associated with higher breast cancer risk and colorectal cancer mortality individually. These data could inform on novel pathways that impact cancer risk and lead to better risk stratification.

Clinical utility of comprehensive liquid molecular profiling in patients with advanced endometrial cancer.

BACKGROUND: Molecular characterization has significantly improved the management of advanced endometrial cancer (EC). It distinguishes four molecular subclasses associated with prognosis and personalized therapeutic strategies. This study assesses the clinical utility of cell-free DNA (cfDNA) profiling in EC to identify targetable alterations. METHODS: Women with metastatic or recurrent EC were prospectively recruited within the framework of the STING trial (NCT04932525), during which cfDNA was analyzed. Genomic alterations were identified with the FoundationOne CDx assay. Each molecular report underwent review by a molecular tumor board. Alterations were categorized via the European Society of Medical Oncology Scale for Clinical Actionability of Molecular Targets (ESCAT). RESULTS: A total of 61 patients were enrolled. The median age was 66.9 years, with 43% presenting frontline metastatic disease. All histologic subgroups were represented. Notably, 89% of patients yielded informative cfDNA analysis. Six tumors were classified with deficient mismatch repair/microsatellite instability (11%) and 37 as TP53 gene mutant (67%), and 12 had nonspecific molecular profiles (22%). Molecular classification based on liquid biopsy showed 87.5% accuracy in correlating with tissue results. Moreover, 65% of cases exhibited ≥1 actionable alteration, including 25% ESCAT I alterations and 13% ESCAT II alterations. Consequently, 16% of patients received a molecularly matched therapy, and presented with a 56% response rate and median progression-free survival of 7.7 months. CONCLUSIONS: cfDNA sequencing in EC is a feasible approach that produces informative results in 89% of cases and accurately categorizes patients into the main molecular subclasses. It also reveals multiple actionable alterations, which offers the potential for personalized therapeutic strategies.

Emergency myelopoiesis in solid cancers.

Cells of the innate and adaptive immune systems are the progeny of haematopoietic stem and progenitor cells (HSPCs). During steady-state myelopoiesis, HSPC undergo differentiation and proliferation but are called to respond directly and acutely to various signals that lead to emergency myelopoiesis, including bone marrow ablation, infections, and sterile inflammation. There is extensive evidence that many solid tumours have the potential to secrete classical myelopoiesis-promoting growth factors and other products able to mimic emergency haematopoiesis, and to aberrantly re-direct myeloid cell development into immunosuppressive cells with tumour promoting properties. Here, we summarize the current literature regarding the effects of solid cancers on HSPCs function and discuss how these effects might shape antitumour responses via a mechanism initiated at a site distal from the tumour microenvironment.

Clonal hematopoiesis of indeterminate potential and risk of neurodegenerative diseases.

BACKGROUND: Little is known regarding the association between clonal hematopoiesis of indeterminate potential (CHIP) and risk of neurodegenerative diseases. OBJECTIVE: To estimate the risk of neurodegenerative diseases among individuals with CHIP. METHODS: We conducted a community-based cohort study based on UK Biobank and used Cox regression to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for the risk of any neurodegenerative disease, subtypes of neurodegenerative diseases (including primary neurodegenerative diseases, vascular neurodegenerative diseases, and other neurodegenerative diseases), and specific diagnoses of neurodegenerative diseases (i.e., amyotrophic lateral sclerosis [ALS], Alzheimer's disease [AD], and Parkinson's disease [PD]) associated with CHIP. RESULTS: We identified 14,440 individuals with CHIP and 450,907 individuals without CHIP. Individuals with CHIP had an increased risk of any neurodegenerative disease (HR 1.10, 95% CI: 1.01-1.19). We also observed a statistically significantly increased risk for vascular neurodegenerative diseases (HR 1.31, 95% CI 1.05-1.63) and ALS (HR 1.50, 95% CI 1.05-2.15). An increased risk was also noted for other neurodegenerative diseases (HR 1.13, 95% CI 0.97-1.32), although not statistically significant. Null association was noted for primary neurodegenerative diseases (HR 1.06, 95% CI 0.96-1.17), AD (HR 1.04, 95% CI 0.88-1.23), and PD (HR 1.02, 95% CI 0.86-1.21). The risk increase in any neurodegenerative disease was mainly observed for DNMT3A-mutant CHIP, ASXL1-mutant CHIP, or SRSF2-mutant CHIP. CONCLUSION: Individuals with CHIP were at an increased risk of neurodegenerative diseases, primarily vascular neurodegenerative diseases and ALS, but potentially also other neurodegenerative diseases. These findings suggest potential shared mechanisms between CHIP and neurodegenerative diseases.

Red cell distribution width as a bellwether of prognosis.

The red cell distribution width (RDW) is a standard variable reported in the complete blood count. It has been found to have a consistent relationship to life expectancy in older individuals, prognosis in patients with cardiovascular disease, outcome in those with hematological and non-hematological neoplasms and in a variety of medical circumstances such as non-cardiovascular or cancer related critical illness and postoperative outcome from various procedures. This report reviews some of the key medical publications establishing these relationships with RDW. The precise pathobiological processes that explain the predictive value of the RDW in this wide array of circumstances or why an alteration in erythropoiesis (exaggerated red cell size variation) occurs is uncertain. The possible role of inflammation has been one hypothesis considered, but not established.

Clonal Hematopoiesis and Bone Marrow Infiltration in Patients With Follicular Helper T-Cell Lymphoma of Angioimmunoblastic Type.

Follicular helper T-cell (TFH) lymphoma harbors recurrent mutations of RHOAG17V, IDH2R172, TET2, and DNMT3A. TET2 and DNMT3A mutations are the most frequently affected genes in clonal hematopoiesis (CH). The aim of our study was to investigate the frequency of CH in bone marrow biopsies (BMB) of TFH/angioimmunoblastic T-cell lymphoma (TFH-AITL) patients and its association with myeloid neoplasms. A total of 29 BMB from 22 patients with a diagnosis of TFH-AITL were analyzed by next-generation sequencing (NGS) with a custom panel. Morphologically, 5 BMB revealed that TFH-AITL infiltrates of >5% of bone marrow (BM) cellularity confirmed in 4 cases by NGS-based T-cell clonality. IDH2R172 was demonstrated only in 1 (3%) of 29, and RHOAG17V in 2 (7%) of 29 samples. TET2 and DNMT3A were identified in 24 (83%) of 29 and 17 (59%) of 29 BMB, respectively. In the parallel lymph node the frequencies of mutations were 27% (IDH2R172), 64% (RHOAG17V), 86% (TET2), and 50% (DNMT3A). TET2 and/or DNMT3A mutations identical in lymph node and BMB were present in 18 (82%) of 22 patients, regardless of BM infiltration. In 3 cases the CH mutations were detected 13, 41, and 145 months before TFH-AITL diagnosis. Cases with TET2/DNMT3A mutations and BM variant allele frequencies >40% (7/18, 39%) showed lower blood counts. However, only low platelet count was statistically significant (P = .024). Myeloid neoplasms and/or myelodysplastic syndrome-related mutations were identified in 4 cases (4/22; 18%); all with high TET2 variant allele frequencies (>40%; P = .0114). In conclusion, CH is present in 82% of TFH-AITL and can be demonstrated up to 145 months before TFH-AITL diagnosis. NGS T-cell clonality analysis is an excellent tool to confirm TFH-AITL BM infiltration. Concurrent myeloid neoplasms were identified in 18% of the cases and were associated with TET2 mutations with high allelic burden (>40%). We demonstrated that myeloid neoplasms might occur simultaneously or precede the diagnosis of TFH lymphoma.

Clonal Hematopoiesis of Indeterminate Potential and Long-term Outcomes in Heart Transplantation.

BACKGROUND: Clonal hematopoiesis of indeterminate potential (CHIP) mutations, a trait of aging, has been associated with the progression of cardiovascular disease and the development of malignancy. Uncertainty prevails regarding a robust association between CHIP and heart-transplantation (HT) outcomes. OBJECTIVES: To determine the prevalence of CHIP mutations in HT and their association with long-term outcomes, including cardiac allograft vasculopathy (CAV), graft failure, malignancy, and all-cause mortality. METHODS: We conducted a mixed retrospective-prospective observational study of HT recipients with targeted sequencing for CHIP mutations (variant allele frequency [VAF] of ≥ 2%). The primary composite outcome was the first occurrence of CAV grade ≥ 2, graft failure, malignancy, cardiac retransplantation, or all-cause death. Secondary outcomes were the individual components of the composite primary outcome. Sensitivity analyses with base-case and extreme scenarios were performed. RESULTS: Among 95 HT recipients, 30 had CHIP mutations (31.6%). DNMT3A mutations were most common (44.7%), followed by PPM1D (13.2%), SF3B1 (10.5%), TET2 (7.9%), and TP53 (7.9%). The only significant independent predictor of CHIP was age at enrollment or age at transplantation. After multivariable adjustment, CHIP mutations were not associated with the primary outcome, which occurred in 44 (46.3%) patients (HR = 0.487; 95% CI:0.197-1.204; P = 0.119), nor were they associated with mlalignancy alone, or death. CONCLUSION: We demonstrated no association between CHIP mutations and post-transplant outcomes, including CAV, graft failure, malignancy, and all-cause mortality. In line with previously published data, our analysis provides additional evidence about the lack of clinical value of using CHIP mutations as a biomarker for surveillance in outcomes after HT.

Incipient clonal hematopoiesis is accelerated following CD30.CAR-T therapy.

Chimeric antigen receptor (CAR) T-cells are an emerging therapy for refractory lymphomas. Clonal hematopoiesis (CH), the preferential outgrowth of mutated bone marrow progenitors, is enriched in lymphoma patients receiving CAR-T cells. CAR-T therapy requires conditioning chemotherapy and often induces systemic inflammatory reactions, both of which have been shown to promote expansion of CH clones. Thus, we hypothesized that pre-existing CH clones could expand during CAR-T cell treatment. We measured CH at 154 timepoints longitudinally sampled from 26 patients receiving CD30.CAR-T therapy for CD30+ lymphomas on an investigational protocol (NCT02917083). Pre-treatment CH was present in 54% of individuals and did not correlate with survival outcomes or inflammatory toxicities. Longitudinal tracking of single clones in individual patients revealed distinct clone growth dynamics. Initially small clones, defined as VAF <1%, expanded following CAR-T administration, compared with relatively muted expansions of larger clones (3.37-fold vs. 1.20-fold, P = 0.0014). Matched clones were present at low magnitude in the infused CD30.CAR-T product for all CH cases but did not affect the product's immunophenotype or transduction efficiency. As cellular immunotherapies expand to become frontline treatments for hematological malignancies, our data indicates CAR-T recipients could be enriched for CH, and further longitudinal studies centered on CH complications in this population are warranted.

The role of clonal progression leading to the development of therapy-related myeloid neoplasms.

Therapy-related myeloid neoplasms (t-MN) are characterized by aggressive features and a dismal prognosis. Recent evidence suggests a higher incidence of t-MN in individuals harboring clonal hematopoiesis of indeterminate potential (CHIP). In order to gain insight into CHIP-driven malignant progression, we gathered data from ten published reports with available detailed patient characteristics at the time of primary malignancy and t-MN development. Detailed clinical and molecular information on primary malignancy and t-MN were available for 109 patients: 43% harbored at least one somatic mutation at the time of the primary malignancy. TET2 and TP53 mutations showed an increasing variant allele frequency from CHIP to t-MN. ASXL1-associated CHIP significantly correlated with the emergence of TET2 and CEBPA mutations at t-MN, as well as U2AF1-driven CHIP with EZH2 mutation and both IDH2 and SRSF2-driven CHIP with FLT3 mutation. DNMT3A-driven CHIP correlated with a lower incidence of TP53 mutation at t-MN. In contrast, TP53-driven CHIP correlated with a complex karyotype and a lower tendency to acquire new mutations at t-MN. Patients with multiple myeloma as their first malignancy presented a significantly higher rate of TP53 mutations at t-MN. The progression from CHIP to t-MN shows different scenarios depending on the genes involved. A deeper knowledge of CHIP progression mechanisms will allow a more reliable definition of t-MN risk.

Minimal residual disease monitoring in acute myeloid leukemia: Focus on MFC-MRD and treatment guidance for elderly patients.

Acute myeloid leukemia (AML) is distinguished by clonal growth of myeloid precursor cells, which impairs normal hematopoiesis. Minimal residual disease (MRD) refers to the residual leukemia cells that persist after chemotherapy. Patients who test positive for MRD have a higher likelihood of experiencing a recurrence, regardless of the specific chemotherapy approach used. Multi-parameter flow cytometry (MFC), polymerase chain reaction (PCR), and next-generation sequencing (NGS) are commonly employed techniques for identifying MRD. In the context of AML, patients are frequently monitored for measurable residual disease via multi-parameter flow cytometry (MFC-MRD). In order to explore recent advancements in AML and MRD diagnosis, an extensive search of the PubMed database was conducted, focusing on relevant research in the past 20 years. This review aims to examine various MRD monitoring methods, the optimal time points for assessment, as well as different specimen types used. Additionally, it underscores the significance of MFC-MRD assessment in guiding the treatment of elderly AML.

Clinical relevance of clonal hematopoiesis and its interference in cell-free DNA profiling of patients with gastric cancer.

OBJECTIVES: Clonal hematopoiesis (CH) is a condition in which healthy individuals have somatic mutations in hematopoietic stem cells. It has been reported with increased risk of hematologic malignancy and cardiovascular disease in the general population, but studies of Korean populations with comorbid disease entities are scarce. METHODS: White blood cells (WBCs) from patients with gastric cancer (GC) (n=121) were analyzed using a DNA-based targeted (531 genes) panel with customized pipeline designed to detect single nucleotide variants and small indels with low-allele-frequency of ≥0.2 %. We defined significant CH variants as having variant allele frequency (VAF) ≥2 % among variants found in WBCs. Matched cell-free DNA (cfDNA) samples were also analyzed with the same pipeline to investigate the false-positive results caused by WBC variants in cfDNA profiling. RESULTS: Significant CH variants were detected in 29.8 % of patients and were associated with age and male sex. The number of CH variants was associated with a history of anti-cancer therapy and age. DNMT3A and TET2 were recurrently mutated. Overall survival rate of treatment-naïve patients with stage IV GC was higher in those with CH, but Cox regression showed no significant association after adjustment for age, sex, anti-cancer therapy, and smoking history. In addition, we analyzed the potential interference of WBC variants in plasma cell-free DNA testing, which has attracted interest as a complementary method for tissue biopsy. Results showed that 37.0 % (47/127) of plasma specimens harbored at least one WBC variant. VAFs of interfering WBC variants in the plasma and WBC were correlated, and WBC variants with VAF ≥4 % in WBC were frequently detected in plasma with the same VAF. CONCLUSIONS: This study revealed the clinical impact of CH in Korean patients and suggests the potential for its interference in cfDNA tests.

Pathophysiology of Acute Myeloid Leukemia.

BACKGROUND: Acute myeloid leukemia (AML) is a biologically heterogenous disease arising in clonally proliferating hematopoietic stem cells. Sequential acquisition of mutations leads to expanded proliferation of clonal myeloid progenitors and failure of differentiation, leading to fulminant AML. SUMMARY: Here, we review the pathophysiology of AML with a focus on factors predisposing to AML development, including prior chemo- and radiation therapy, environmental factors, and germline predisposition. KEY MESSAGE: Increasing genomic characterization of AML and insight into mechanisms of its development will be critical to improvement in AML prognostication and therapy.

Association Between Rheumatoid Arthritis and Clonal Hematopoiesis: A Mendelian Randomization Study.

Immunity activation and inflammation are the main characteristics of rheumatoid arthritis and clonal hematopoiesis. However, it remains unclear whether rheumatoid arthritis increase the risk of clonal hematopoiesis. Here, a Mendelian randomization (MR) analysis was conduct to explore the causal effects of rheumatoid arthritis on clonal hematopoiesis. Summary statistics data of rheumatoid arthritis (13,838 cases and 33,742 controls) and clonal hematopoiesis (10,203 cases and 173,918 controls) derived from a genomewide association study were selected to analyze. We selected inverse-variance weighted, MR-Egger, weighted median, simple mode, and weighted mode to evaluate the causal effect of rheumatoid arthritis on clonal hematopoiesis. The two-sample MR analysis suggested a strong causal relationship between rheumatoid arthritis and clonal hematopoiesis by inverse-variance weighted (OR = 1.002311673, 95% CI [1.000110757, 1.004517433], p = .039706) and weighted median (OR = 1.002311673, 95% CI [1.000110757, 1.004517433], p = .039518447) methods. No significant pleiotropy or heterogeneity was found in the sensitivity analysis. These results supported a potentially causal relationship between rheumatoid arthritis and clonal hematopoiesis, and the exposure of rheumatoid arthritis increased the risks of clonal hematopoiesis. Our findings highlight the importance of how chronic inflammation and immune activation induced rheumatoid arthritis enhances the risks of clonal hematopoiesis, and that early intervention with rheumatoid arthritis patients might reduce the clonal hematopoiesis risks in rheumatoid arthritis patients. Moreover, our study provides clues for prediction of risk factors and potential mechanisms of clonal hematopoiesis.