gms | German Medical Science

Latent virus infections are the most important factors that adversely affect the success which is provided by immunosuppressive therapy in transplant. For this reason, timely detection of CMV infection disease which causes the loss of the transplanted organ rejection and even patients is extremely important and required. Especially in immunosuppresive patients, the presence of host response or absence of host response play a key role in determining the clinical condition.The cellular immune response has especially a great function in the prevention of viral infections, and memory CD4⁺ and CD8⁺ T lymphocytes are the functional signatures of cellular immunity.

In our study, we have planned the monitoring of cellular immune responses in kidney transplant recipients.We have obtained samples before kidney transplantation (0. month), and post-transplant 1st, 3rd and 6th months from twenty-one patients between the ages of 18 and 66 years whom were planned for live-donor kidney transplantation. The main stages of our procedure are, isolation of peripheral blood mononuclear cells from whole blood, freezing and storing the samples, thawing samples, ex vivo stimulation of lymphocytes with CMV peptides and counting by flow cytometry after functional seperation as a result of CMV-specific IFN-γ-producing T cell surface antigens and intracellular cytokine staining. We showed that post-transplant 3rd month peripheral blood lymphocyte values were significantly lower than post-transplant 1st month peripheral blood lymphocyte values. CMV-specific CD4⁺ lymphocytes were significantly decreased (p=0.003) in post-transplant 3rd month compared to post-transplant 1st month, and no significant difference was observed between other groups. Third month CMV-specific CD4⁺+CD8⁺ T lymphocytes were significantly decreased (p=0.039) compared to 1st month value.We observed that the one case whom had low level of viremia in the 6th month sample had no cellular immune response to CMV and had high level of CMV-specific IFN-γ secretion in six months.

We suggest that, together with CMV blood loads and CMV-specific T cell responses may help to identfy the patients at risk for CMV replication and optimize decisions concerning the duration of immunosuppressive and antiviral therapy.