ABSTRACT
Coronavirus disease 2019 (COVID-19) is associated with significant morbidity and mortality, albeit with considerable heterogeneity among affected individuals. It remains unclear which factors determine severity of illness and long-term outcomes. Emerging evidence points towards an important role of preexisting host factors, such as a deregulated inflammatory response at the time of infection. Here, we demonstrate the negative impact of clonal hematopoiesis, a prevalent clonal disorder of ageing individuals, on COVID-19-related cytokine release severity and mortality. We show that mutations in the gene coding for the methylcytosine dioxygenase TET2 promotes amplification of classical and intermediate monocyte subsets. Using single cell multiomic sequencing approaches, we identify cell-specific gene expression changes associated with the loss of TET2 and significant epigenomic deregulation affecting enhancer accessibility of a subset of transcription factors involved in monocyte differentiation. We further identify EGR1 down-regulation secondary to TET2-mediated hypermethylation, resulting in overexpression of MALAT1, a lncRNA that plays a role in hematopoietic stem cell differentiation and monocyte lineage commitment. Together, these data provide a mechanistic insight to the poor prognostic value of clonal hematopoiesis in patients infected with Sars-COV2.
ABSTRACT
SARS-CoV-2 has had an unprecedented impact on human health and highlights the need for genomic epidemiology studies to increase our understanding of the evolution and spread of pathogens and to inform policy decisions. Most efforts have focused on international or country-wide transmission, which are unable to highlight state-wide trends. We sequenced virus genomes from over 22,000 patients tested at Mayo Clinic Laboratories between 2020-2022 and leveraged detailed patient metadata to describe county-to-county spread in Minnesota. Our findings indicate that spread in the state was mostly dominated by viruses from Hennepin County, which contains the largest metropolis. For many counties, we found that state government restrictions eventually led to a decrease in the diversity of circulating viruses from other counties and that their complete removal in May of 2021 saw a drastic revert to levels at or greater than those observed during the months before. We also linked over 14,000 genomes with patient risk characteristics and infection-related phenotypes from the Mayo Clinic electronic health record. We found that the genetic relationship of Omicron viruses was structured by clinical outcomes when stratifying by patient risk factor and variant of concern. However, we were unable to identify nucleotide variants that drove this association.
