BACKGROUND: Cytomegalovirus (CMV) infection is the important cause affecting the survival rate and function of the transplanted organ after transplantation. The occurrence of CMV infection after liver transplantation (LT) is associated with many factors. Lots of studies suggest that genetic mutation between hosts and CMV may play a role in the occurrence and development of CMV infection. CMV exists in an incubative state, affect or destroy the expression of human leukocyte antigen (HLA) molecules in the host cell surface, and interfere antigen’s submission. This mechanism is the key of CMV to avoid immune defense mechanism of the host. To detect HLA and CMV antibody (CMV-Ab), CMV antigen (CMV-Ag) of transplantation recipients, we evaluated the association of CMV infection and the particular HLA genotypes in recipients after LT.
METHODS: 277 blood samples were collected from 39 LT recipients. CMV antibody and antigen were detected by ELISA or immunohistochemical methods. The HLA types of the recipients were determined by PCR. To analyze the association of HLA alleles and the occurrence of CMV antigenemia in the patients, relative risk degree (RR) was used as the parameter for the Chi-square test.
RESULTS: The LT recipients were serum CMV IgG positive (100%), but none of them was CMV IgM positive (0%). Thirty-three LT recipients (84.6%) were CMV antigenic positive with 1-50 positive leukocytes per 50 000 leukocytes in extent and 7.2±4.2 positive leukocytes per 50 000 leukocytes on average. Thirteen patients developed CMV pneumonia, with CMV antigenic positive (100%) and 17.7±5.5 positive leukocytes per 50 000 leukocytes on average. Some HLA alleles were associated with the occurrence and extent of CMV antigenemia. HLA-A2 was the higher frequency allele for patients with antigenemia (P<0.05), and 7 patients carrying HLA-DR11 allele developed antigenemia (P<0.05). In the lower antigenemia group, HLA-A11 was higher in frequency than others (P<0.05). Besides, none of the patients carrying HLA-B16 allele developed clinical symptoms of CMV infection (P<0.05).
CONCLUSIONS: The variability of HLA alleles might modulate immune response to CMV infection. HLA examination before transplantation should be made for prevention and treatment of CMV infection after operation.