[Cytomegalovirus active infection after kidney transplantation affecting the expression of activation receptor CD226 on NKT cell].

Objective: To investigate the effect of active cytomegalovirus infection post kidney transplant on the expressing of receptor CD226 on NKT cell. Methods: Case controlled study. From December 2013 to December 2014, 43 cases of kidney transplant recipient with CMV infection were collected in the Organ Transplantation Research Institute of the former 309th Hospital of PLA. The healthy control group included 15 cases. 15 cases of recipients who were stable after operation and followed up in our hospital at the same time were also collected as control. Peripheral blood specimen with EDTA as anticoagulant were used and analyzed by flow cytometry. Results: The population of NKT in CMV infection recipients were 5.19(1.18, 25.92)%, while in the remission stage the population were 4.89(0.68, 25.33)%, Compared with normal healthy controls and the stable recipients, the percentage of CD3(+)CD56(+) NKT cells in periphery blood mononuclear cells did not vary among these groups(P>0.05). The CD226(+) NKT population during the active CMV infection was (70±13)%, which was significantly lower than the health control [(87±10)%] and stable recipients [(80±9)%](P<0.001). Whereas in the CMV infection remission stage, the CD226(+)NKT population was (81±16)%, which was significantly higher than that of CMV active infection group (P<0.05), and showed no difference with the health control group and stable recipients (P>0.05). The CD226 MFI expressed on NKT in CMV infection group was 101±49, which showed no difference with health controls and stable recipients (P>0.05). However, significantly up regulation of CD226 MFI on NKT was observed in the samples obtained from the same recipients in CMV active infection (91±40) and in CMV regression stage(173±73)(P<0.001). Conclusions: The CD226(+) NKT cells population was down during the active CMV infection post kidney transplantation, while the expression of CD226 and the population of CD226(+)NKT could regression when the CMV infection regressed, which indicates the involvement of CD226 in the process of NKT cells anti-CMV infection.