Lymphocyte subpopulations during cytomegalovirus disease in renal transplant recipients

Are the Healthy Vulnerable? Cytomegalovirus Seropositivity in Healthy Adults Is Associated With Accelerated Epigenetic Age and Immune Dysregulation

BACKGROUND

Evaluating age as a risk factor for susceptibility to infectious diseases, particularly coronavirus disease 2019 (COVID-19), is critical. Cytomegalovirus (CMV) serologic prevalence increases with age and associates with inflammatory-mediated diseases in the elderly. However, little is known regarding the subclinical impact of CMV and risk it poses to healthy older adults. Prior to the COVID-19 pandemic we conducted a study to determine the association of CMV to biologic age and immune dysregulation.

METHODS

Community-dwelling, healthy adults older than 60 years were evaluated using DNA methylation assays to define epigenetic age (EpiAge) and T-cell immunophenotyping to assess immune dysregulation.

RESULTS

All subjects were healthy and asymptomatic. Those CMV seropositive had more lymphocytes, CD8 T cells, CD28- T cells, decreased CD4:CD8 cell ratios, and had higher average EpiAge (65.34 years) than those CMV seronegative (59.53 years). Decreased percent CD4 (P = .003) and numbers of CD4 T cells (P = .0199) correlated with increased EpiAge.

CONCLUSIONS

Our novel findings distinguish altered immunity in the elderly based on CMV status. Chronic CMV infection in healthy, older adults is associated with indicators of immune dysregulation, both of which correlate to differences in EpiAge.

Choice of Immunosuppression Influences Cytomegalovirus DNAemia in Cynomolgus Monkey (Macaca fascicularis) Islet Allograft Recipients

This retrospective study reviews the results of our experience with the occurrence of CMV DNAemia in islet cell transplanted cynomolgus monkeys subjected to different immunosuppressive protocols, including induction treatment with thymoglobulin (TMG), with a combination of thymoglobulin and fludarabine (FLUD), with cyclophosphamide, or with daclizumab. CMV DNA in the peripheral blood (CMV DNAemia) of 47 monkeys was quantified by real-time PCR on a weekly to biweekly basis. As compared to other immunosuppressive regimens, and in association with greater decreases in WBC, lymphocyte, CD3+CD4+, and CD3+CD8+ lymphocyte counts, frequent CMV DNAemia occurred earlier (within the first month posttransplant), and was of greater severity and duration in recipients of TMG ± FLUD. Treatment of recipients with alternative induction agents that resulted in less dramatic reductions in WBC and lymphocyte counts, however, resulted in occurrence of CMV DNAemia after postoperative day 60. The frequency, average intensity, duration, and area under the curve (AUC) for CMV DNAemia in animals receiving TMG ± FLUD were 75–100%, 4.02 ± 1.75 copies/ng DNA, 23.0 ± 5.3 days, and 367.0 ± 121.1 days x copies/ng DNA, respectively; corresponding values in animals receiving other treatments (0–44%, 0.19 ± 0.10 copies/ng DNA, 0.5 ± 0.3 days, and 75.4 ± 40.2 days x copies/ng DNA, respectively) were significantly different. The value of WBC, T and B cells at the nadir of cell depletion greatly affects the occurrence of CMV DNAemia. No animals developed CMV DNAemia within the next 3 weeks when the lowest value of WBC, lymphocyte, CD3+, CD3+CD4+, CD3+CD8+, or CD20+ cells was above 4500, 1800, 300, 200, 150, or 300 cells/μl, respectively. Oral valganciclovir prophylaxis did not completely prevent the appearance of CMV DNAemia.