Bootcongres

Introduction The proportion of geriatric patients (>60 years) suffering from end-stage renal disease (ESRD) has significantly increased over the last decade. ESRD is associated with premature immunological ageing of the T cell system which may explain the increased susceptibility for infections, cancer and cardiovascular diseases in these patients. This may in particular be of importance in geriatric patients but data in this age group are limited. The aim of this study was to assess the concept of immunological ageing of T lymphocytes in geriatric ESRD patients prior to KTx, compared to age-matched healthy controls.

Patients, materials and methods We determined T-cell ageing parameters in circulating T cells of 91 ESRD patients and 73 age- and CMV -matched healthy controls. These parameters included thymic output by T-cell receptor excision circle (TREC) -content and number of CD31+ naive T cells, T-cell differentiation status by assessing the naive/memory, central memory (CM) /effector memory (EM) plus terminally differentiated effector (EMRA) ratios and percentage of CD28null memory T cells, and T cell proliferative history by relative telomere length (RTL).

Results Compared to age-matched healthy controls, geriatric ESRD patients had a lower thymic output according to lower TREC-content and CD31+ naive T cell numbers. Moreover, geriatric ESRD patients had a significantly lower T cell count due to decreased CD4+, but not CD8+, T-cell numbers. This T cell compartment consisted of relatively more memory T cells resulting from significant lower numbers of naive T cells. In addition, the memory T cell compartment contained relatively more differentiated T-cell subsets (EM, EMRA) and CD28null T cells. In addition, the RTL was significant reduced in CD8+, and tended to be shorter in CD4+ T cells in geriatric ESRD patients.

Conclusions Geriatric ESRD patients have an advanced aged T cell compartment when compared to age-matched healthy controls. This advanced aged T cell compartment may impact the clinical course following kidney transplantation.