TY - JOUR T1 - Age-related differences in T cell subsets and markers of subclinical inflammation in aging are independently associated with type 2 diabetes in the Health and Retirement Study. JF - Canadian Journal of Diabetes Y1 - 2023 A1 - Vivek, Sithara A1 - Crimmins, Eileen M A1 - Prizment, Anna E A1 - Meier, Helen C S A1 - Ramasubramanian, Ramya A1 - Barcelo, Helene A1 - Jessica Faul A1 - Bharat Thyagarajan KW - age-related immune phenotype KW - CMV Seropositivity KW - Inflammation KW - memory T cells AB -

AIMS: Age-related changes in adaptive immunity and subclinical inflammation are both important risk factors for diabetes in older adults. We evaluated the independent association between T cell subsets, subclinical inflammation, and diabetes risk in the Health and Retirement Study (HRS).

METHODS: We measured 11 T cell subsets, five pro-inflammatory markers, and two anti-inflammatory markers from the 2016 wave of HRS (baseline). Diabetes/prediabetes status was estimated at the 2016, 2018, and 2020 waves of HRS based on levels of blood glucose/HbA1C in plasma or self-reported status. We used survey generalized logit models to evaluate the cross-sectional associations and Cox proportional hazard models to evaluate longitudinal associations.

RESULTS: Among 8540 participants (age 56-107), 27.6% had prevalent type 2 diabetes and 31.1% had prediabetes in the 2016 survey. After adjusting for age, sex, race/ethnicity, education, obesity, smoking, comorbidity index and cytomegalovirus (CMV) seropositivity, individuals with type 2 diabetes had lower naïve T cells and higher memory and terminal effector T cells as compared to normoglycemic individuals. Among 3230 normoglycemic participants at the 2016 survey, the incidence of diabetes was 1.8% over four years of follow up. The baseline percentage of CD4+ effector memory T cells was associated with a lower risk of incident diabetes (HR=0.63; 95% CI [0.49, 0.80], p=0.0003) after adjustment for covariates. Baseline levels of Interleukin-6 (IL-6) was associated with risk of incident diabetes (HR=1.52; 95% CI [1.18, 1.97], p=0.002). The associations between age-related changes in CD4+ effector memory T cells and risk of incident diabetes remained unchanged after adjustment for subclinical inflammation, though adjusting for CD4+ effector memory T cells nullified the association between IL-6 and incident diabetes.

CONCLUSIONS: This study showed that the baseline percentage of CD4+ effector memory T cells was inversely associated with incident diabetes independent of subclinical inflammation, though CD4+ effector memory T cell subsets affected the relationship between IL-6 and incident diabetes. Further studies are needed to confirm and investigate mechanisms by which T cell immunity affects diabetes risk.

VL - 47 IS - 7 ER - TY - JOUR T1 - Validation of a hybrid approach to standardize immunophenotyping analysis in large population studies: The Health and Retirement Study JF - Scientific Reports Y1 - 2020 A1 - Hunter-Schlichting, DeVon A1 - Lane, John A1 - Cole, Benjamin A1 - Flaten, Zachary A1 - Barcelo, Helene A1 - Ramasubramanian, Ramya A1 - Cassidy, Erin A1 - Jessica Faul A1 - Eileen M. Crimmins A1 - Pankratz, Nathan A1 - Bharat Thyagarajan KW - Bioinformatics KW - high-throughput screening AB - Traditional manual gating strategies are often time-intensive, place a high burden on the analyzer, and are susceptible to bias between analyzers. Several automated gating methods have shown to exceed performance of manual gating for a limited number of cell subsets. However, many of the automated algorithms still require significant manual interventions or have yet to demonstrate their utility in large datasets. Therefore, we developed an approach that utilizes a previously published automated algorithm (OpenCyto framework) with a manually created hierarchically cell gating template implemented, along with a custom developed visualization software (FlowAnnotator) to rapidly and efficiently analyze immunophenotyping data in large population studies. This approach allows pre-defining populations that can be analyzed solely by automated analysis and incorporating manual refinement for smaller downstream populations. We validated this method with traditional manual gating strategies for 24 subsets of T cells, B cells, NK cells, monocytes and dendritic cells in 931 participants from the Health and Retirement Study (HRS). Our results show a high degree of correlation (r ≥ 0.80) for 18 (78%) of the 24 cell subsets. For the remaining subsets, the correlation was low (<0.80) primarily because of the low numbers of events recorded in these subsets. The mean difference in the absolute counts between the hybrid method and manual gating strategy of these cell subsets showed results that were very similar to the traditional manual gating method. We describe a practical method for standardization of immunophenotyping methods in large scale population studies that provides a rapid, accurate and reproducible alternative to labor intensive manual gating strategies. VL - 10 SN - 2045-2322 IS - 1 ER - TY - JOUR T1 - Effect of delayed cell processing and cryopreservation on immunophenotyping in multicenter population studies. JF - Journal of Immunological Methods Y1 - 2018 A1 - Bharat Thyagarajan A1 - Barcelo, Helene A1 - Eileen M. Crimmins A1 - David R Weir A1 - Minnerath, Sharon A1 - Vivek, Sithara A1 - Jessica Faul KW - Cell Separation KW - Cryopreservation KW - Immunophenotyping KW - Leukocytes KW - Time Factors AB -

Variability induced by delayed cell processing and cell cryopreservation presents unique challenges for immunophenotyping in large population studies. We conducted a pilot study to evaluate the effect of delayed cell processing and cryopreservation on cell percentages obtained by immunophenotyping. We collected blood from 20 volunteers and compared the effect of (a) delayed cell processing up to 72 h (b) cryopreservation and (c) the combined effect of delayed cell processing and cryopreservation on immunophenotyping of 31 cell subsets that included several subsets of T, B, Natural Killer (NK) cells, monocytes and dendritic cells using both whole blood collected in EDTA tubes and peripheral blood mononuclear cells collected in CPT tubes. We found the delayed cell processing up to 72 h or cryopreservation alone did not significantly affect the percentages T cells, dendritic cells or monocytes but significantly increased the percentage of B cells and NK cells (p for trend ≤0.01) but. However combination of delayed cell processing up to 72 h and cryopreservation significantly increased the percentage of T cells as compared to cells processed immediately (p for trend <0.0001) while a delayed cell processing followed by cryopreservation decreased the percentage of NK cells (p for trend <0.0001). Total B-cells increased significantly with a 24-48 h delay in cell processing and cryopreservation but not at 72 h. The percentages of monocytes and dendritic cells remained unaffected by the combination of delayed cell processing and cryopreservation. These findings suggest that immunophenotyping of several immune cell subsets can be successfully implemented in large population studies as long as blood is processed within 48 h of biospecimen collection though some cell subsets may be more susceptible to a combination of delayed cell processing and cryopreservation.

VL - 463 ER - TY - JOUR T1 - A Practical Cryopreservation and Staining Protocol for Immunophenotyping in Population Studies. JF - Current Protocols in Cytometry Y1 - 2018 A1 - Barcelo, Helene A1 - Jessica Faul A1 - Eileen M. Crimmins A1 - Bharat Thyagarajan KW - Cryopreservation KW - Quality control KW - Survey Methodology AB - Large population-based cohort studies, through their prospective collection of a broad range of health information, represent an invaluable resource for novel insights into the pathogenesis of human diseases. Collection and cryopreservation of viable cells from blood samples is becoming increasingly common in large cohorts as these cells are a valuable resource for immunophenotyping and functional studies. The cryopreservation of peripheral blood mononuclear cells (PBMCs), thawing, and immunophenotyping protocols used to immunophenotype 9938 participants in the Health and Retirement Study (HRS) are described. The extensive quality control involved in a large-scale immunophenotyping epidemiological study is also outlined. The existing literature on the effect of cryopreservation on various immune cell subsets including T, B, NK cells, monocytes, and dendritic cells is provided. © 2018 by John Wiley & Sons, Inc. VL - 84 IS - 1 U1 - http://www.ncbi.nlm.nih.gov/pubmed/30040214?dopt=Abstract ER -