Review of clonal hematopoiesis, subtypes and its role in neoplasia and different morbidities

CHIPing Away at Proteomics to Find Correlations with Myeloid Neoplasms

Plasma proteomic profiling to identify associations with myeloid neoplasm (MN) risk highlights the potential of integrating proteins and genetic biomarkers for the detection of individuals at high risk of developing MN. These proteins also offer valuable insights into biological pathways and inflammatory mechanisms involved in the progression of clonal hematopoiesis to MN. See related article by Tran et al., p. 3220.

Differences in the mutational landscape of clonal hematopoiesis of indeterminate potential among races and between male and female patients with cancer

Clonal hematopoiesis of indeterminate potential (CHIP) has emerged as a significant precursor to hematological malignancies and is associated with several age-related diseases. We leveraged public data to explore differences in the mutational landscape of CHIP between males (Ms) and females (Fs) and across diverse racial populations. DNA (cytosine-5) methyltransferase 3 alpha (DNMT3A) mutations were substantially more prevalent in Fs than in Ms (38.94% vs. 31.37%, p-value: < 0.001, q-value: < 0.001). Additional sex combs-like 1 (ASXL1) mutations were more frequent in Ms than Fs (5.82% vs. 2.69%, p-value < 0.001, q-value < 0.001). In the racial cohorts with sufficient sample sizes, STAT5B and CSF1R mutations were most frequent in Asian populations (1.40% and 0.84%), followed by Black populations (0.98% and 0.24%) and White populations (0.29% and 0.09%) (p-value: < 0.001 , q-value: 0.023 for both genes). Several other CHIP mutations were enriched in Black: RARA, SMAD2, CDKN1B, CENPA, CTLA4, EIF1AX, ELF3, MSI1, MYC, SOX17, and AURKA. On the other hand, H3C1, H3C4, and MYCL were enriched in the Asian cohort. Our analysis highlights sex and racial differences in CHIP mutations among patients with cancer. As CHIP continues to gain recognition as a critical precursor to malignancies and other diseases, understanding how these differences contribute to CHIP's underlying mechanisms and clinical implications is critical.

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.

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.

Methods for Estimating Personal Disease Risk and Phylogenetic Diversity of Hematopoietic Stem Cells

An individual's chronological age does not always correspond to the health of different tissues in their body, especially in cases of disease. Therefore, estimating and contrasting the physiological age of tissues with an individual's chronological age may be a useful tool to diagnose disease and its progression. In this study, we present novel metrics to quantify the loss of phylogenetic diversity in hematopoietic stem cells (HSCs), which are precursors to most blood cell types and are associated with many blood-related diseases. These metrics showed an excellent correspondence with an age-related increase in blood cancer incidence, enabling a model to estimate the phylogeny-derived age (phyloAge) of HSCs present in an individual. The HSC phyloAge was generally older than the chronological age of patients suffering from myeloproliferative neoplasms (MPNs). We present a model that relates excess HSC aging with increased MPN risk. It predicted an over 200 times greater risk based on the HSC phylogenies of the youngest MPN patients analyzed. Our new metrics are designed to be robust to sampling biases and do not rely on prior knowledge of driver mutations or physiological assessments. Consequently, they complement conventional biomarker-based methods to estimate physiological age and disease risk.