Investigating the relationship between the number and activity of natural killer cells with increased cytomegalovirus and CMV disease after kidney transplantation

Background: Cytomegalovirus (CMV) infections caused by the cytomegalovirus are one of the most common problems in patients after kidney transplant. We examined the association of the relationship between the number and activity of natural killer cells with increased cytomegalovirus and its related disease after kidney transplantation.

Material and methods: In this analytical study, 58 new transplant patients in the Labbafinejad Hospital, who did not have any evidence of CMV infection, were evaluated based on the number and percentage of CD56⁺/16⁺, CD56⁺/16^-, and CD69⁺ Natural Killer (NK) cells.

Results: The results of this study showed that CD16⁺ and CD56⁺ cells in the group of CMV Ag-positive patients are less than negative patients (p = 0.003) and the difference between the two groups are significant (p = 0.01). However, CD69⁺ cells did not differ significantly between the two groups (p = 0.1). Moreover, the absolute number of CD16⁺ and CD56⁺ cells declined significantly after infection with CMV unlike the CMV Ag - group(p = 0.003).

Discussion: These results indicate that kidney transplant patients suffering from CMV infection after transplantation have a significantly reduced total number of NK cells. On the other hand, a slight decrease in the number of NK subgroups was observed with an increase in the peak serum levels of cyclosporine. As a consequence of these findings, it can be assumed that more dosage and a higher level of the drug will result in more severe immunosuppression and, consequently, increased susceptibility to CMV infections. Thus, taking the right dose of the drug would prevent viral infections and immune system from over-activation.