Abstract
Clonal hematopoiesis (CH) is an age-associated phenomenon that increases the risk of hematologic malignancy and cardiovascular disease. CH is thought to enhance disease risk through inflammation in the peripheral blood.1 Here, we profile peripheral blood gene expression in 66 968 single cells from a cohort of 17 patients with CH and 7 controls. Using a novel mitochondrial DNA barcoding approach, we were able to identify and separately compare mutant Tet methylcytosine dioxygenase 2 (TET2) and DNA methyltransferase 3A (DNMT3A) cells with nonmutant counterparts. We discovered the vast majority of mutated cells were in the myeloid compartment. Additionally, patients harboring DNMT3A and TET2 CH mutations possessed a proinflammatory profile in CD14+ monocytes through previously unrecognized pathways such as galectin and macrophage inhibitory factor. We also found that T cells from patients with CH, although mostly unmutated, had decreased expression of GTPase of the immunity associated protein genes, which are critical to T-cell development, suggesting that CH impairs T-cell function.