@article {8405, title = {Incorporating sampling weights into robust estimation of Cox proportional hazards regression model, with illustration in the Multi-Ethnic Study of Atherosclerosis.}, journal = {BMC Med Res Methodol}, volume = {20}, year = {2020}, month = {2020 03 14}, pages = {62}, abstract = {

BACKGROUND: Cox proportional hazards regression models are used to evaluate associations between exposures of interest and time-to-event outcomes in observational data. When exposures are measured on only a sample of participants, as they are in a case-cohort design, the sampling weights must be incorporated into the regression model to obtain unbiased estimating equations.

METHODS: Robust Cox methods have been developed to better estimate associations when there are influential outliers in the exposure of interest, but these robust methods do not incorporate sampling weights. In this paper, we extend these robust methods, which already incorporate influence weights, so that they also accommodate sampling weights.

RESULTS: Simulations illustrate that in the presence of influential outliers, the association estimate from the weighted robust method is closer to the true value than the estimate from traditional weighted Cox regression. As expected, in the absence of outliers, the use of robust methods yields a small loss of efficiency. Using data from a case-cohort study that is nested within the Multi-Ethnic Study of Atherosclerosis (MESA) longitudinal cohort study, we illustrate differences between traditional and robust weighted Cox association estimates for the relationships between immune cell traits and risk of stroke.

CONCLUSIONS: Robust weighted Cox regression methods are a new tool to analyze time-to-event data with sampling, e.g. case-cohort data, when exposures of interest contain outliers.

}, issn = {1471-2288}, doi = {10.1186/s12874-020-00945-9}, author = {Sitlani, Colleen M and Lumley, Thomas and McKnight, Barbara and Rice, Kenneth M and Olson, Nels C and Doyle, Margaret F and Huber, Sally A and Tracy, Russell P and Psaty, Bruce M and C Delaney, Joseph A} } @article {8403, title = {Innate and adaptive immune cell subsets as risk factors for coronary heart disease in two population-based cohorts.}, journal = {Atherosclerosis}, volume = {300}, year = {2020}, month = {2020 05}, pages = {47-53}, abstract = {

BACKGROUND AND AIMS: Cell-mediated immunity is implicated in atherosclerosis. We evaluated whether innate and adaptive immune cell subsets in peripheral blood are risk factors for coronary heart disease.

METHODS: A nested case-cohort study (n~=~2155) was performed within the Multi-Ethnic Study of Atherosclerosis (MESA) and the Cardiovascular Health Study (CHS). Cases of incident myocardial infarction (MI) and incident angina (n~=~880 total cases) were compared with a cohort random sample (n~=~1275). Immune cell phenotypes (n~=~34, including CD14 monocytes, natural killer cells, γδ T cells, CD4, CD8 and CD19 lymphocyte subsets) were measured from cryopreserved cells by flow cytometry. Cox proportional hazards models with adjustment for cardiovascular disease risk factors were used to evaluate associations of cell phenotypes with incident MI and a composite phenotype of incident MI or incident angina (MI-angina) over a median 9.3 years of follow-up. Th1, Th2, Th17, T regulatory (CD4CD25CD127), naive (CD4CD45RA), memory (CD4CD45RO), and CD4CD28 cells were specified as primary hypotheses. In secondary analyses, 27 additional cell phenotypes were investigated.

RESULTS: After correction for multiple testing, there were no statistically significant associations of CD4 naive, memory, CD28, or T helper cell subsets with MI or MI-angina in MESA, CHS, or combined-cohort meta analyses. Null associations were also observed for monocyte subsets, natural killer cells, γδ T cells, CD19 B cell and differentiated CD4 and CD8 cell subsets.

CONCLUSIONS: The proportions of peripheral blood monocyte and lymphocyte subsets are not strongly related to the future occurrence of MI or angina in adults free of autoimmune disease.

}, issn = {1879-1484}, doi = {10.1016/j.atherosclerosis.2020.03.011}, author = {Olson, Nels C and Sitlani, Colleen M and Doyle, Margaret F and Huber, Sally A and Landay, Alan L and Tracy, Russell P and Psaty, Bruce M and Delaney, Joseph A} } @article {8658, title = {Natural killer cells, gamma delta T cells and classical monocytes are associated with systolic blood pressure in the multi-ethnic study of atherosclerosis (MESA).}, journal = {BMC Cardiovasc Disord}, volume = {21}, year = {2021}, month = {2021 Jan 22}, pages = {45}, abstract = {

BACKGROUND: Hypertension is a major source of cardiovascular morbidity and mortality. Recent evidence from mouse models, genetic, and cross-sectional human studies suggest increased proportions of selected immune cell subsets may be associated with levels of systolic blood pressure (SBP).

METHODS: We assayed immune cells from cryopreserved samples collected at the baseline examination (2000-2002) from 1195 participants from the multi-ethnic study of atherosclerosis (MESA). We used linear mixed models, with adjustment for age, sex, race/ethnicity, smoking, exercise, body mass index, education, diabetes, and cytomegalovirus titers, to estimate the associations between 30 immune cell subsets (4 of which were a priori hypotheses) and repeated measures of SBP (baseline and up to four follow-up measures) over 10~years. The analysis provides estimates of the association with blood pressure level.

RESULTS: The mean age of the MESA participants at baseline was 64 {\textpm} 10~years and 53\% were male. A one standard deviation (1-SD) increment in the proportion of γδ T cells was associated with 2.40~mmHg [95\% confidence interval (CI) 1.34-3.42] higher average systolic blood pressure; and for natural killer cells, a 1-SD increment was associated with 1.88~mmHg (95\% CI 0.82-2.94) higher average level of systolic blood pressure. A 1-SD increment in classical monocytes (CD14CD16) was associated with 2.01 mmHG (95\% CI 0.79-3.24) lower average systolic blood pressure. There were no associations of CD4 T helper cell subsets with average systolic blood pressure.

CONCLUSION: These findings suggest that the innate immune system plays a role in levels of SBP whereas there were no associations with adaptive immune cells.

}, issn = {1471-2261}, doi = {10.1186/s12872-021-01857-2}, author = {Delaney, Joseph A C and Olson, Nels C and Sitlani, Colleen M and Fohner, Alison E and Huber, Sally A and Landay, Alan L and Heckbert, Susan R and Tracy, Russell P and Psaty, Bruce M and Feinstein, Matt and Doyle, Margaret F} } @article {9175, title = {Association of immune cell subsets with incident heart failure in two population-based cohorts.}, journal = {ESC Heart Fail}, year = {2022}, month = {2022 Sep 12}, abstract = {

AIMS: Circulating inflammatory markers are associated with incident heart failure (HF), but prospective data on associations of immune cell subsets with incident HF are lacking. We determined the associations of immune cell subsets with incident HF as well as HF subtypes [with reduced ejection fraction (HFrEF) and preserved ejection fraction (HFpEF)].

METHODS AND RESULTS: Peripheral blood immune cell subsets were measured in adults from the Multi-Ethnic Study of Atherosclerosis (MESA) and Cardiovascular Health Study (CHS). Cox proportional hazard models adjusted for demographics, HF risk factors, and cytomegalovirus serostatus were used to evaluate the association of the immune cell subsets with incident HF. The average age of the MESA cohort at the time of immune cell measurements was 63.0~{\textpm}~10.4~years with 51\% women, and in the CHS cohort, it was 79.6~{\textpm}~4.4~years with 62\% women. In the meta-analysis of CHS and MESA, a higher proportion of CD4+ T helper (Th) 1 cells (per one standard deviation) was associated with a lower risk of incident HF [hazard ratio (HR) 0.91, (95\% CI 0.83-0.99), P~=~0.03]. Specifically, higher proportion of CD4+ Th1 cells was significantly associated with a lower risk of HFrEF [HR 0.73, (95\% CI 0.62-0.85), <0.001] after correction for multiple testing. No association was observed with HFpEF. No other cell subsets were associated with incident HF.

CONCLUSIONS: We observed that higher proportions of CD4+ Th1 cells were associated with a lower risk of incident HFrEF in two distinct population-based cohorts, with similar effect sizes in both cohorts demonstrating replicability. Although unexpected, the consistency of this finding across cohorts merits further investigation.

}, issn = {2055-5822}, doi = {10.1002/ehf2.14140}, author = {Sinha, Arjun and Sitlani, Colleen M and Doyle, Margaret F and Fohner, Alison E and B{\r u}zkov{\'a}, Petra and Floyd, James S and Huber, Sally A and Olson, Nels C and Njoroge, Joyce N and Kizer, Jorge R and Delaney, Joseph A and Shah, Sanjiv S and Tracy, Russell P and Psaty, Bruce and Feinstein, Matthew} } @article {9247, title = {Immune cell subpopulations as risk factors for atrial fibrillation: The Cardiovascular Health Study and Multi-Ethnic Study of Atherosclerosis.}, journal = {Heart Rhythm}, year = {2022}, month = {2022 Oct 18}, issn = {1556-3871}, doi = {10.1016/j.hrthm.2022.10.012}, author = {Floyd, James S and Sitlani, Colleen M and Doyle, Margaret F and Feinstein, Matthew J and Olson, Nels C and Heckbert, Susan R and Huber, Sally A and Tracy, Russell P and Psaty, Bruce M and Delaney, Joseph A C} } @article {9090, title = {Monocyte subsets, T cell activation profiles, and stroke in men and women: The Multi-Ethnic Study of Atherosclerosis and Cardiovascular Health Study.}, journal = {Atherosclerosis}, volume = {351}, year = {2022}, month = {2022 06}, pages = {18-25}, abstract = {

BACKGROUND AND AIMS: Despite mechanistic data implicating unresolving inflammation in stroke pathogenesis, data regarding circulating immune cell phenotypes - key determinants of inflammation propagation versus resolution - and incident stroke are lacking. Therefore, we aimed to comprehensively define associations of circulating immune phenotypes and activation profiles with incident stroke.

METHODS: We investigated circulating leukocyte phenotypes and activation profiles with incident adjudicated stroke in 2104 diverse adults from the Multi-Ethnic Study of Atherosclerosis (MESA) followed over a median of 16.6 years. Cryopreserved cells from the MESA baseline examination were thawed and myeloid and lymphoid lineage cell subsets were measured using polychromatic flow cytometry and intracellular cytokine activation staining. We analyzed multivariable-adjusted associations of cell phenotypes, as a proportion of parent cell subsets, with incident stroke (overall) and ischemic stroke using Cox regression models.

RESULTS: We observed associations of intermediate monocytes, early-activated CD4 T cells, and both CD4 and CD8 T cells producing interleukin-4 after cytokine stimulation (T and T, respectively) with higher risk for incident stroke; effect sizes ranged from 35\% to 62\% relative increases in risk for stroke. Meanwhile, differentiated and memory T cell phenotypes were associated with lower risk for incident stroke. In sex-stratified analyses, positive and negative associations were especially strong among men but null among women.

CONCLUSIONS: Circulating IL-4 producing T cells and intermediate monocytes were significantly associated with incident stroke over nearly two decades of follow-up. These associations were stronger among men and not among women. Further translational studies are warranted to define more precise targets for prognosis and intervention.

}, keywords = {Atherosclerosis, CD4-Positive T-Lymphocytes, CD8-Positive T-Lymphocytes, Cytokines, Female, Follow-Up Studies, Humans, Incidence, Inflammation, Interleukin-4, Ischemic Stroke, Lymphocyte Activation, Male, Monocytes, Stroke, T-Lymphocyte Subsets}, issn = {1879-1484}, doi = {10.1016/j.atherosclerosis.2022.05.007}, author = {Feinstein, Matthew J and B{\r u}zkov{\'a}, Petra and Olson, Nels C and Doyle, Margaret F and Sitlani, Colleen M and Fohner, Alison E and Huber, Sally A and Floyd, James and Sinha, Arjun and Thorp, Edward B and Landay, Alan and Freiberg, Matthew S and Longstreth, William T and Tracy, Russell P and Psaty, Bruce M and Delaney, Joseph Ac} } @article {9478, title = {Association of Immune Cell Subsets with Incident Hip Fracture: The Cardiovascular Health Study.}, journal = {Calcif Tissue Int}, year = {2023}, month = {2023 Aug 31}, abstract = {

In this study, we aimed to evaluate the association of innate and adaptive immune cell subsets in peripheral blood mononuclear cells (PBMCs) with hip fracture. To conduct this study, we used data from the Cardiovascular Health Study (CHS), a U.S. multicenter observational cohort of community-dwelling men and women aged >= 65 years. Twenty-five immune cell phenotypes were measured by flow cytometry from cryopreserved PBMCs of CHS participants collected in 1998-1999. The natural killer (NK), γδ T, T helper 17 (Th17), and differentiated/senescent CD4CD28 T cell subsets were pre-specified as primary subsets of interest. Hip fracture incidence was assessed prospectively by review of hospitalization records. Multivariable Cox hazard models evaluated associations of immune cell phenotypes with incident hip fracture in sex-stratified and combined analyses. Among 1928 persons, 259 hip fractures occurred over a median 9.7 years of follow-up. In women, NK cells were inversely associated with hip fracture [hazard ratio (HR) 0.77, 95\% confidence interval (CI) 0.60-0.99 per one standard deviation higher value] and Th17 cells were positively associated with hip fracture [HR 1.18, 95\% CI 1.01-1.39]. In men, γδ T cells were inversely associated with hip fracture [HR 0.60, 95\% CI 0.37-0.98]. None of the measured immune cell phenotypes were significantly associated with hip fracture incidence in combined analyses. In this large prospective cohort of older adults, potentially important sex differences in the associations of immune cell phenotypes and hip fracture were identified. However, immune cell phenotypes had no association with hip fracture in analyses combining men and women.

}, issn = {1432-0827}, doi = {10.1007/s00223-023-01126-8}, author = {Elam, Rachel E and B{\r u}zkov{\'a}, Petra and Delaney, Joseph A C and Fink, Howard A and Barzilay, Joshua I and Carbone, Laura D and Saha, Rick and Robbins, John A and Mukamal, Kenneth J and Valderr{\'a}bano, Rodrigo J and Psaty, Bruce M and Tracy, Russell P and Olson, Nels C and Huber, Sally A and Doyle, Margaret F and Landay, Alan L and Cauley, Jane A} } @article {9240, title = {Circulating differentiated and senescent lymphocyte subsets and incident diabetes risk in older adults: The Cardiovascular Health Study.}, journal = {Endocrinol Diabetes Metab}, volume = {6}, year = {2023}, month = {2023 Jan}, pages = {e384}, abstract = {

INTRODUCTION: Cellular senescence is a feature of aging implicated in the pathophysiology of diabetes mellitus (DM). Whether senescent lymphocytes are associated with the future occurrence of DM is uncertain.

METHODS: We used cryopreserved peripheral blood mononuclear cells collected from 1860 Cardiovascular Health Study participants (average age 80.2 years) and flow cytometry immunophenotyping to evaluate the longitudinal relationships of naive (CD45RA ), memory (CD45RO ), senescent (CD28 ), and T effector memory RA (TEMRA) (CD28 CD57 CD45RA ) CD4 and CD8 T cells, and memory B cells (CD19 CD27 ), with the risk of incident DM. In exploratory analyses we evaluated the relationships of 13 additional innate lymphocyte and CD4 and CD8 subsets with incident DM risk.

RESULTS: Over a median follow-up time of 8.9 years, 155 cases of incident DM occurred. In Cox models adjusted for demographic variables (age, sex, race, study site and flow cytometry analytical batch) or diabetes risk factors (demographic variables plus education, body mass index, smoking status, alcohol use, systolic blood pressure, hypertension medication use and physical activity), no significant associations were observed for any CD4 , CD8 or CD19 cell phenotypes with incident DM.

CONCLUSIONS: These results suggest the frequencies of naive, memory and senescent T cells and memory B cells are not strongly associated with incident DM risk in older adults.

}, keywords = {CD28 Antigens, CD8-Positive T-Lymphocytes, Cellular Senescence, Diabetes Mellitus, Leukocytes, Mononuclear, Lymphocyte Subsets}, issn = {2398-9238}, doi = {10.1002/edm2.384}, author = {Olson, Nels C and Doyle, Margaret F and B{\r u}zkov{\'a}, Petra and Huber, Sally A and de Boer, Ian H and Sitlani, Colleen M and Tracy, Russell P and Psaty, Bruce M and Mukamal, Kenneth J and Delaney, Joseph A} } @article {9588, title = {Determinants of mosaic chromosomal alteration fitness.}, journal = {medRxiv}, year = {2023}, month = {2023 Oct 21}, abstract = {

Clonal hematopoiesis (CH) is characterized by the acquisition of a somatic mutation in a hematopoietic stem cell that results in a clonal expansion. These driver mutations can be single nucleotide variants in cancer driver genes or larger structural rearrangements called mosaic chromosomal alterations (mCAs). The factors that influence the variations in mCA fitness and ultimately result in different clonal expansion rates are not well-understood. We used the Passenger-Approximated Clonal Expansion Rate (PACER) method to estimate clonal expansion rate for 6,381 individuals in the NHLBI TOPMed cohort with gain, loss, and copy-neutral loss of heterozygosity mCAs. Our estimates of mCA fitness were correlated (R = 0.49) with an alternative approach that estimated fitness of mCAs in the UK Biobank using a theoretical probability distribution. Individuals with lymphoid-associated mCAs had a significantly higher white blood cell count and faster clonal expansion rate. In a cross-sectional analysis, genome-wide association study of estimates of mCA expansion rate identified , , and locus variants as modulators of mCA clonal expansion rate.

}, doi = {10.1101/2023.10.20.23297280}, author = {Pershad, Yash and Mack, Taralynn and Poisner, Hannah and Jakubek, Yasminka A and Stilp, Adrienne M and Mitchell, Braxton D and Lewis, Joshua P and Boerwinkle, Eric and Loos, Ruth J and Chami, Nathalie and Wang, Zhe and Barnes, Kathleen and Pankratz, Nathan and Fornage, Myriam and Redline, Susan and Psaty, Bruce M and Bis, Joshua C and Shojaie, Ali and Silverman, Edwin K and Cho, Michael H and Yun, Jeong and DeMeo, Dawn and Levy, Daniel and Johnson, Andrew and Mathias, Rasika and Taub, Margaret and Arnett, Donna and North, Kari and Raffield, Laura M and Carson, April and Doyle, Margaret F and Rich, Stephen S and Rotter, Jerome I and Guo, Xiuqing and Cox, Nancy and Roden, Dan M and Franceschini, Nora and Desai, Pinkal and Reiner, Alex and Auer, Paul L and Scheet, Paul and Jaiswal, Siddhartha and Weinstock, Joshua S and Bick, Alexander G} } @article {9538, title = {Mosaic chromosomal alterations in blood across ancestries using whole-genome sequencing.}, journal = {Nat Genet}, volume = {55}, year = {2023}, month = {2023 Nov}, pages = {1912-1919}, abstract = {

Megabase-scale mosaic chromosomal alterations (mCAs) in blood are prognostic markers for a host of human diseases. Here, to gain a better understanding of mCA rates in genetically diverse populations, we analyzed whole-genome sequencing data from 67,390 individuals from the National Heart, Lung, and Blood Institute Trans-Omics for Precision Medicine program. We observed higher sensitivity with whole-genome sequencing data, compared with array-based data, in uncovering mCAs at low mutant cell fractions and found that individuals of European ancestry have the highest rates of autosomal mCAs and the lowest rates of chromosome X mCAs, compared with individuals of African or Hispanic ancestry. Although further studies in diverse populations will be needed to replicate our findings, we report three loci associated with loss of chromosome X, associations between autosomal mCAs and rare variants in DCPS, ADM17, PPP1R16B and TET2 and ancestry-specific variants in ATM and MPL with mCAs in cis.

}, keywords = {Black People, Genome, Human, Genome-Wide Association Study, Hispanic or Latino, Humans, Mosaicism, Precision Medicine}, issn = {1546-1718}, doi = {10.1038/s41588-023-01553-1}, author = {Jakubek, Yasminka A and Zhou, Ying and Stilp, Adrienne and Bacon, Jason and Wong, Justin W and Ozcan, Zuhal and Arnett, Donna and Barnes, Kathleen and Bis, Joshua C and Boerwinkle, Eric and Brody, Jennifer A and Carson, April P and Chasman, Daniel I and Chen, Jiawen and Cho, Michael and Conomos, Matthew P and Cox, Nancy and Doyle, Margaret F and Fornage, Myriam and Guo, Xiuqing and Kardia, Sharon L R and Lewis, Joshua P and Loos, Ruth J F and Ma, Xiaolong and Machiela, Mitchell J and Mack, Taralynn M and Mathias, Rasika A and Mitchell, Braxton D and Mychaleckyj, Josyf C and North, Kari and Pankratz, Nathan and Peyser, Patricia A and Preuss, Michael H and Psaty, Bruce and Raffield, Laura M and Vasan, Ramachandran S and Redline, Susan and Rich, Stephen S and Rotter, Jerome I and Silverman, Edwin K and Smith, Jennifer A and Smith, Aaron P and Taub, Margaret and Taylor, Kent D and Yun, Jeong and Li, Yun and Desai, Pinkal and Bick, Alexander G and Reiner, Alexander P and Scheet, Paul and Auer, Paul L} } @article {9981, title = {Association of Immune Cell Subsets With Longevity: The Cardiovascular Health Study.}, journal = {J Gerontol A Biol Sci Med Sci}, volume = {80}, year = {2025}, month = {2025 Jun 10}, abstract = {

BACKGROUND: Changes in the immune system are a potential biological mechanism of aging. We investigated the association of circulating immune cell subsets with age at death and survival to age 90.

METHODS: Immune cell phenotypes were measured at baseline in 1 625 adults, aged 70-85 years, in the Cardiovascular Health Study. We selected 5 primary immune cell subsets: gamma-delta T-cells, natural killer cells, CD8+ T effector memory CD45RA expressing cells(TEMRA) cells, ratio of CD4+ to CD8+ cells, and ratio of na{\"\i}ve to memory CD8+ cells. We used linear regression and Poisson models, adjusting for demographics and clinical factors; and tested for effect modification by sex and race. In a secondary analysis, we investigated 23 additional immune cell subsets, using the Holm-Bonferroni method to adjust for multiple comparisons.

RESULTS: No primary immune cell subsets were significantly associated with longevity. Two secondary subsets were significantly associated with age at death. Each SD higher proportion of CD4+CD57+ cells was associated with a 0.64-year earlier death (95\% CI: -0.99, -0.30) and each SD higher proportion of CD4+CD28-CD57+ cells was associated with a 0.54-year earlier death (95\% CI: -0.87, -0.21). Several subsets had significant interactions with sex and race in the fully adjusted model of age at death. A higher proportion of CD4+CD57+ T-cells was significantly associated with lower likelihood of survival to age 90 (relative risk: 0.79) and 1.07-year earlier age at death in males, but not in females.

CONCLUSIONS: Our results suggest that CD4+CD57+ cells are associated with earlier death and this relationship was stronger in males than females.

}, keywords = {Aged, Aged, 80 and over, Aging, Cardiovascular Diseases, CD4-Positive T-Lymphocytes, CD8-Positive T-Lymphocytes, Female, Humans, Killer Cells, Natural, Longevity, Male}, issn = {1758-535X}, doi = {10.1093/gerona/glaf094}, author = {Dobrota Lai, Sylvie and B{\r u}zkov{\'a}, Petra and Delaney, Joseph A and Olson, Nels C and Psaty, Bruce M and Huber, Sally A and Doyle, Margaret F and Tracy, Russell P and Odden, Michelle C} }