Unidirectional association of clonal hematopoiesis with atherosclerosis development.

Clonal hematopoiesis, a condition in which acquired somatic mutations in hematopoietic stem cells lead to the outgrowth of a mutant hematopoietic clone, is associated with a higher risk of hematological cancer and a growing list of nonhematological disorders, most notably atherosclerosis and associated cardiovascular disease. However, whether accelerated atherosclerosis is a cause or a consequence of clonal hematopoiesis remains a matter of debate. Some studies support a direct contribution of certain clonal hematopoiesis-related mutations to atherosclerosis via exacerbation of inflammatory responses, whereas others suggest that clonal hematopoiesis is a symptom rather than a cause of atherosclerosis, as atherosclerosis or related traits may accelerate the expansion of mutant hematopoietic clones. Here we combine high-sensitivity DNA sequencing in blood and noninvasive vascular imaging to investigate the interplay between clonal hematopoiesis and atherosclerosis in a longitudinal cohort of healthy middle-aged individuals. We found that the presence of a clonal hematopoiesis-related mutation confers an increased risk of developing de novo femoral atherosclerosis over a 6-year period, whereas neither the presence nor the extent of atherosclerosis affects mutant cell expansion during this timeframe. These findings indicate that clonal hematopoiesis unidirectionally promotes atherosclerosis, which should help translate the growing understanding of this condition into strategies for the prevention of atherosclerotic cardiovascular disease in individuals exhibiting clonal hematopoiesis.

Clonal hematopoiesis is not prevalent in Hutchinson-Gilford progeria syndrome.

Clonal hematopoiesis of indeterminate potential (CHIP), defined as the presence of somatic mutations in cancer-related genes in blood cells in the absence of hematological cancer, has recently emerged as an important risk factor for several age-related conditions, especially cardiovascular disease. CHIP is strongly associated with normal aging, but its role in premature aging syndromes is unknown. Hutchinson-Gilford progeria syndrome (HGPS) is an ultra-rare genetic condition driven by the accumulation of a truncated form of the lamin A protein called progerin. HGPS patients exhibit several features of accelerated aging and typically die from cardiovascular complications in their early teens. Previous studies have shown normal hematological parameters in HGPS patients, except for elevated platelets, and low levels of lamin A expression in hematopoietic cells relative to other cell types in solid tissues, but the prevalence of CHIP in HGPS remains unexplored. To investigate the potential role of CHIP in HGPS, we performed high-sensitivity targeted sequencing of CHIP-related genes in blood DNA samples from a cohort of 47 HGPS patients. As a control, the same sequencing strategy was applied to blood DNA samples from middle-aged and elderly individuals, expected to exhibit a biological age and cardiovascular risk profile similar to HGPS patients. We found that CHIP is not prevalent in HGPS patients, in marked contrast to our observations in individuals who age normally. Thus, our study unveils a major difference between HGPS and normal aging and provides conclusive evidence that CHIP is not frequent in HGPS and, therefore, is unlikely to contribute to the pathophysiology of this accelerated aging syndrome.

Genetic biomarkers identify a subgroup of high-risk patients within low-risk NPM1-mutated acute myeloid leukemia.

Although acute myeloid leukemia (AML) with NPM1mut/FLT3-ITDneg is a low-risk entity, its relapse rate remains high. Out of 333 AML patients, 27 were NPM1mut, and were analyzed in greater detail in order to find associations between clinical and molecular features and cumulative incidence of relapse. Next-generation sequencing (NGS) was performed on diagnosis and remission samples using two capture-based panels. The presence of the FLT3D835 variant at diagnosis and a qPCR value of NPM1mut ≥0.1% after induction chemotherapy were associated with an increased probability of relapse, especially if both conditions are present together. By contrast, patients in which the main clone found at diagnosis harbored NPM1 variant had a lower risk of relapse. Nineteen of the 85 variants found at diagnosis were detected by NGS in remission. AML Subgroup with NPM1mut/FLT3-ITDneg is a heterogeneous entity, which can be further risk-stratified based on molecular biomarkers.

Clonal Hematopoiesis and Risk of Progression of Heart Failure With Reduced Left Ventricular Ejection Fraction.

BACKGROUND: Clonal hematopoiesis driven by somatic mutations in hematopoietic cells, frequently called clonal hematopoiesis of indeterminate potential (CHIP), has been associated with adverse cardiovascular outcomes in population-based studies and in patients with ischemic heart failure (HF) and reduced left ventricular ejection fraction (LVEF). Yet, the impact of CHIP on HF progression, including nonischemic etiology, is unknown. OBJECTIVES: The purpose of this study was to assess the clinical impact of clonal hematopoiesis on HF progression irrespective of its etiology. METHODS: The study cohort comprised 62 patients with HF and LVEF <45% (age 74 ± 7 years, 74% men, 52% nonischemic, and LVEF 30 ± 8%). Deep sequencing was used to detect CHIP mutations with a variant allelic fraction >2% in 54 genes. Patients were followed for at least 3.5 years for various adverse events including death, HF-related death, and HF hospitalization. RESULTS: CHIP mutations were detected in 24 (38.7%) patients, without significant differences in all-cause mortality (p = 0.151). After adjusting for risk factors, patients with mutations in either DNA methyltransferase 3 alpha (DNMT3A) or Tet methylcytosine dioxygenase 2 (TET2) exhibited accelerated HF progression in terms of death (hazard ratio [HR]: 2.79; 95% confidence interval [CI]: 1.31 to 5.92; p = 0.008), death or HF hospitalization (HR: 3.84; 95% CI: 1.84 to 8.04; p < 0.001) and HF-related death or HF hospitalization (HR: 4.41; 95% CI: 2.15 to 9.03; p < 0.001). In single gene-specific analyses, somatic mutations in DNMT3A or TET2 retained prognostic significance with regard to HF-related death or HF hospitalization (HR: 4.50; 95% CI: 2.07 to 9.74; p < 0.001, for DNMT3A mutations; HR: 3.18; 95% CI: 1.52 to 6.66; p = 0.002, for TET2 mutations). This association remained significant irrespective of ischemic/nonischemic etiology. CONCLUSIONS: Somatic mutations that drive clonal hematopoiesis are common among HF patients with reduced LVEF and are associated with accelerated HF progression regardless of etiology.