Latency for cytomegalovirus impacts T cell ageing significantly in elderly end-stage renal disease patients

The number of elderly patients with end-stage renal disease (ESRD) has increased significantly during the last decade. Elderly ESRD patients are vulnerable to infectious complications because of an aged immune system. Additional immunological ageing effects may be derived from the uraemic environment and cytomegalovirus (CMV) latency. Elderly patients may be affected by these factors in particular, but data in this age group are limited. To assess the degree of immunological ageing and proliferative capacity of T lymphocytes, 49 elderly ESRD patients (defined as aged ≥ 65 years) on the renal transplantation waiting list were recruited and compared to 44 elderly healthy individuals (HI), matched for age and CMV serostatus. CMV latency was associated with more highly differentiated CD4⁺ and CD8⁺ T cells in both elderly HI and patients. Elderly CMV seropositive ESRD patients showed a substantial reduction in the number of naive CD4⁺ and CD8⁺ T cells compared with age- and CMV serostatus-matched HI. Elderly ESRD patients also showed significantly decreased numbers of central memory CD4⁺ and CD8⁺ T cells compared with HI, independently of CMV serostatus. In addition, thymic output and relative telomere length of both CD4⁺ and CD8⁺ T cells were decreased in CMV seropositive ESRD patients compared with HI. The proliferative capacity of T cells was similar for patients and HI. Elderly ESRD patients have an advanced aged T cell compartment when compared to age-matched healthy controls, which is driven mainly by CMV latency.