Cytomegalovirus contributes partly to uraemia‐associated premature immunological ageing of the T cell compartment

Summary Cytomegalovirus ( CMV ) infection has been implicated in accelerated T cell ageing. End‐stage renal disease ( ESRD ) patients have a severely immunologically aged T cell compartment but also a high prevalence of CMV infection. We investigated whether CMV infection contributes to T cell ageing in ESRD patients. We determined the thymic output by the T cell receptor excision circle ( TREC ) content and percentage of CD 31+ naïve T cells. The proliferative history of the T cell compartment by determination of the relative telomere length ( RTL ) and the T cell differentiation status was determined by immunophenotyping. It appeared that CMV infection did not affect thymic output but reduced RTL of CD 8+ T cells in ESRD patients. Moreover, increased T cell differentiation was observed with higher percentages of CD 57+ and CD 28null CD 4+ and CD 8+ memory T cells. These CD 28null T cells had significantly shorter telomeres compared to CD 28+ T cells. Therefore we concluded that CMV infection does not affect the decreased thymic output but increases T cell differentiation as observed in ESRD ‐related premature T cell ageing.