3,4 Prevention and treatment of CMV reactivation and disease significantly contribute to the high cost of transplantation.5 There is currently no clinical test for assessing the degree of immunosuppression, either in

general or with respect to a specific pathogen. As regards CMV, most published studies in transplant patients are focused on the detection of CMV-specific T cells based on interferon-γ (IFN-γ) production (intracellular staining) or MHC-multimer staining and quantitative changes of the identified populations in relation to clinical events. Because CMV is large and complex, published studies are generally focused on one or two CMV proteins, usually pp65, sometimes also IE-1. However, there see more is controversy about how measuring the frequencies of CMV-specific IFN-γ-producing T cells will help to determine CMV-specific immunity. Several studies have linked increasing frequencies of CMV-specific T cells to decreasing ALK assay rates of CMV detection or CMV-related complications after bone marrow or solid organ transplantation.6,7 As T-cell polyfunctionality has been proposed

to be important for protection from viral diseases, this study was designed to assess the effect of post-transplantation immunosuppression on T-cell polyfunctionality. Multi-parameter flow cytometry permits the assessment of response size and‘quality’ (functional composition).8 The use of a ‘qualitative’ approach is supported by results in HIV-positive patients suggesting that progression to AIDS correlates with the loss of HIV-specific CD8+ T cells with several simultaneous functions.9 Here, we considered the CMV-specific production of IFN-γ, tumour necrosis factor-α (TNF-α), interleukin-2 (IL-2) and degranulation of CD8+ and CD8− T-cells at the same time in 23 heart and heart–lung transplant patients and seven healthy controls in response to pp65 and IE-1. This allows us to detect potential differences in functional

profiles relating to different CMV specificities. All heart (n = 16) and lung (n = 7) transplant recipients (eight women, 15 men; Amrubicin mean age 51·2 years, minimum 18 years, maximum: 64 years) were recruited at the German Heart Centre (DHZB) Berlin. All had been CMV-seropositive (IgG) before transplantation. Fourteen patients received a graft from a CMV-positive donor. Immunosuppression consisted of cyclosporin A (22/23 patients), tacrolimus (1/23), everolimus (7/23), mycophenolate mofetil (8/23) and corticosteroids (23/23). Seventeen patients had PCR-proven CMV reactivation and two suffered from clinical disease (duodenitis). Healthy volunteers (three women, four men) known to have T-cell responses to CMV pp65 or IE-1 (n = 7) included hospital personnel and medical students. No significant differences between the groups existed in terms of gender distribution.