Clinical correlates and prognostic impact of clonal hematopoiesis in multiple myeloma patients receiving post-autologous stem cell transplantation lenalidomide maintenance therapy

Epigenetic roles in clonal hematopoiesis and aging kidney-related chronic kidney disease

Accumulation of somatic hematopoietic stem cell mutations with aging has been revealed by the recent genome-wide analysis. Clonal expansion, known as clonal hematopoiesis of indeterminate potential (CHIP), is a premalignant condition of hematological cancers. It is defined as the absence of definitive morphological evidence of a hematological neoplasm and occurrence of ≥2% of mutant allele fraction in the peripheral blood. In CHIP, the most frequently mutated genes are epigenetic regulators such as DNMT3A, TET2, and ASXL1. CHIP induces inflammation. CHIP is shown to be associated with not only hematological malignancy but also non-malignant disorders such as atherosclerosis, cardiovascular diseases and chronic liver disease. In addition, recent several large clinical trials have shown that CHIP is also the risk factor for developing chronic kidney disease (CKD). In this review article, we proposed novel findings about CHIP and CHIP related kidney disease based on the recent basic and clinical research. The possible mechanism of the kidney injury in CHIP is supposed to be due to the clonal expansion in both myeloid and lymphoid cell lines. In myeloid cell lines, the mutated macrophages increase the inflammatory cytokine level and induce chronic inflammation. It leads to epigenetic downregulation of kidney and macrophage klotho level. In lymphoid cell lines, CHIP might be related to monoclonal gammopathy of renal significance (MGRS). It describes any B cell or plasma cell clonal disorder that does not fulfill the criteria for cancer yet produces a nephrotoxic monoclonal immunoglobulin that leads to kidney injury or disease. MGRS causes M-protein related nephropathy frequently observed among aged CKD patients. It is important to consider the CHIP-related complications such as hematological malignancy, cardiovascular diseases and metabolic disorders in managing the elderly CKD patients. There are no established therapies for CHIP and CHIP-related CKD yet. However, recent studies have supported the development of effective CHIP therapies, such as blocking the expansion of aberrant HSCs and inhibiting chronic inflammation. In addition, drugs targeting the epigenetic regulation of Klotho in the kidney and macrophages might be therapeutic targets of CHIP in the kidney.

Understanding DNA Damage Response and DNA Repair in Multiple Myeloma

Multiple myeloma (MM) is a plasma cell malignancy characterized by several genetic abnormalities, including chromosomal translocations, genomic deletions and gains, and point mutations. DNA damage response (DDR) and DNA repair mechanisms are altered in MM to allow for tumor development, progression, and resistance to therapies. Damaged DNA rarely induces an apoptotic response, given the presence of ataxia-telangiectasia mutated (ATM) loss-of-function or mutations, as well as deletions, mutations, or downregulation of tumor protein p53 (TP53) and tumor protein p73 (TP73). Moreover, DNA repair mechanisms are either hyperactive or defective to allow for rapid correction of the damage or permissive survival. Medications used to treat patients with MM can induce DNA damage, by either direct effects (mono-adducts induced by melphalan), or as a result of reactive oxygen species (ROS) production by proteasome inhibitors such as bortezomib. In this review, we will describe the mechanisms of DDR and DNA repair in normal tissues, the contribution of these pathways to MM disease progression and other phenotypes, and the potential therapeutic opportunities for patients with MM.

CHIPing away the progression potential of CHIP: A new reality in the making

Over the past few years, we have gained a deeper understanding of clonal hematopoiesis of indeterminate potential (CHIP), especially with regard to the epidemiology, clinical sequelae, and mechanical aspects. However, interventional strategies to prevent or delay the potential negative consequences of CHIP remain underdeveloped. In this review, we highlight the latest updates on clonal hematopoiesis research, including molecular mechanisms and clinical implications, with a particular focus on the evolving strategies for the interventions that are being evaluated in ongoing observational and interventional trials. There remains an urgent need to formulate standardized and evidence-based recommendations and guidelines for evaluating and managing individuals with clonal hematopoiesis. In addition, patient-centric endpoints must be defined for clinical trials, which will enable us to continue the robust development of effective preventive strategies and improve clinical outcomes.

Game of clones: Diverse implications for clonal hematopoiesis in lymphoma and multiple myeloma

Clonal hematopoiesis (CH) refers to the disproportionate expansion of hematopoietic stem cell clones and their corresponding progeny following the acquisition of somatic mutations. CH is common at the time of diagnosis in patients with blood cancers, including multiple myeloma (MM) and lymphoma. The presence of CH mutations correlates with IL-6 mediated inflammation and may result in lymphoma or MM modulation through microenvironment effects or by manifestations of the mutations themselves within the founding tumor clone. As might be expected with a variety of mutations and multiple potential mechanisms, CH exerts context-dependent effects, being protective in some settings and harmful in others. Though CH is very common in patients with hematologic malignancies, how it intersects with therapy and the natural disease course of these cancers are active areas of investigation. In lymphomas and MM specifically, patients have high rates of CH at diagnosis and are subsequently exposed to therapies, such as cytotoxic chemotherapy, that can cause CH progression to overt hematologic malignancy. The expanding diversity of treatment modalities for these cancers also increases the opportunities for CH to impact clinical outcome and modulate clinical responses. Here we review the basic biology and known health effects of CH, and we focus on the clinical relevance of CH in lymphoma and MM.

Association of clonal hematopoiesis mutations with clinical outcomes: A systematic review and meta-analysis

Clonal hematopoiesis (CH) mutations are common among individuals without known hematologic disease. CH mutations have been associated with numerous adverse clinical outcomes across many different studies. We systematically reviewed the available literature for clinical outcomes associated with CH mutations in patients without hematologic disease. We searched PubMed, EMBASE, and Scopus for eligible studies. Three investigators independently extracted the data, and each study was verified by a second author. Risk of bias was assessed using the Newcastle-Ottawa Scale. We identified 32 studies with 56 cohorts that examine the association between CH mutations and clinical outcomes. We conducted meta-analyses comparing outcomes among individuals with and without detectable CH mutations. We conducted meta-analyses for cardiovascular diseases (nine studies; HR = 1.61, 95% CI = 1.26-2.07, p = .0002), hematologic malignancies (seven studies; HR = 5.59, 95% CI = 3.31-9.45, p < .0001), therapy-related myeloid neoplasms (four studies; HR = 7.55, 95% CI = 4.3-13.57, p < .001), and death (nine studies; HR = 1.34, 95% CI = 1.2-1.5, p < .0001). The cardiovascular disease analysis was further stratified by variant allele fraction (VAF) and gene, which showed a statistically significant association only with a VAF of ≥ 10% (HR = 1.42, 95% CI = 1.24-1.62, p < .0001), as well as statistically significant associations for each gene examined with the largest magnitude of effect found for CH mutations in JAK2 (HR = 3.5, 95% CI = 1.84-6.68, p < .0001). Analysis of the association of CH mutations with hematologic malignancy demonstrated a numeric stepwise increase in risk with increasing VAF thresholds. This analysis strongly supports the association of CH mutations with a clinically meaningful increased risk of adverse clinical outcomes among individuals without hematologic disease, particularly with increasing VAF thresholds.