Person:

Green, Robert

The burden of mosaic chromosomal alterations in blood-derived DNA, a type of clonal hematopoiesis, is associated with an increased risk for diverse types of infections, including sepsis and pneumonia. Age is the dominant risk factor for infectious diseases, but the mechanisms linking age to infectious disease risk are incompletely understood. Age-related mosaic chromosomal alterations (mCAs) detected from genotyping of blood-derived DNA, are structural somatic variants indicative of clonal hematopoiesis, and are associated with aberrant leukocyte cell counts, hematological malignancy, and mortality. Here, we show that mCAs predispose to diverse types of infections. We analyzed mCAs from 768,762 individuals without hematological cancer at the time of DNA acquisition across five biobanks. Expanded autosomal mCAs were associated with diverse incident infections (hazard ratio (HR) 1.25; 95% confidence interval (CI) = 1.15-1.36; P = 1.8 x 10(-7)), including sepsis (HR 2.68; 95% CI = 2.25-3.19; P = 3.1 x 10(-28)), pneumonia (HR 1.76; 95% CI = 1.53-2.03; P = 2.3 x 10(-15)), digestive system infections (HR 1.51; 95% CI = 1.32-1.73; P = 2.2 x 10(-9)) and genitourinary infections (HR 1.25; 95% CI = 1.11-1.41; P = 3.7 x 10(-4)). A genome-wide association study of expanded mCAs identified 63 loci, which were enriched at transcriptional regulatory sites for immune cells. These results suggest that mCAs are a marker of impaired immunity and confer increased predisposition to infections.

CYP2C19 genotyping to guide antiplatelet therapy after patients develop acute coronary syndromes (ACS) or require percutaneous coronary interventions (PCIs) reduces the likelihood of major adverse cardiovascular events (MACE). Evidence about the impact of preemptive testing, where genotyping occurs while patients are healthy, is lacking. In patients initiating antiplatelet therapy for ACS or PCI, we compared medical records data from 67 patients who received CYP2C19 genotyping preemptively (results >7 days before need) against medical records data from 67 propensity score-matched patients who received early genotyping (results within 7 days of need). We also examined data from 141 patients who received late genotyping (results >7 days after need). We compared the impact of genotyping approaches on medication selections, specialty visits, MACE and bleeding events over one year. Patients with CYP2C19 loss-of-function alleles were less likely to be initiated on clopidogrel if they received preemptive rather than early or late genotyping (18.2%, 66.7%, and 73.2% respectively, p=0.001). No differences were observed by genotyping approach in the number of specialty visits or likelihood of MACE or bleeding events (all p>0.21). Preemptive genotyping had a strong impact on initial antiplatelet selection and a comparable impact on patient outcomes and healthcare utilization, compared to genotyping ordered after a need for antiplatelet therapy had been identified.