Akademik Veri Yönetim Sistemi
MIKROBIYOLOJI BULTENI, cilt.46, ss.594-606, 2012 (SCI-Expanded)
Epstein-Barr virus (EBV), a herpesvirus leading to latent infections, is principally responsible for infectious mononucleosis, and also plays role in the etiology of various lymphomas and post-transplantation lymphoproliferative disease (PTLD). Laboratory diagnosis of EBV infections depends on the detection of atypical lymphocytes, heterophile antibodies, specific antibodies against viral capsid (VCA), nuclear (EBNA) and early (EA) antigens, and of the viral DNA. Since the seropositivity rate in adult population is very high (80-95%) in our country, routine serologic tests may be insufficient to characterize EBV reactivation in immunosuppressive subjects, such as transplant recipients or oncology patients. In those cases VCA IgG avidity test and molecular methods are more useful. This study was conducted to determine the role of viral DNA levels detected by real-time polymerase chain reaction (Rt-PCR) and serological tests for the diagnosis and follow up of EBV infections in renal transplant recipients and pediatric oncology patients. A total of 62 adult renal transplant recipients, 37 children with oncological diseases, and 50 EBV-seropositive immunocompetent healthy subjects (28 children, 22 adults) as controls, were included in the study. Four blood samples, once before transplantation and three times thereafter (at first week, first and third months) were collected from transplant recipients; in pediatric oncology patients blood samples were collected four times, once before immunosuppressive treatment and three times thereafter (at first, third and sixth months), while the control group had a single blood sample collected. Serological profiles for EBV were searched by Paul-Bunnel and immunoblotting tests; VCA IgG avidity by ELISA and viral load by Rt-PCR. EBV-DNA was found positive in 3 (4.8%) of the renal transplant patients. While in these patients the CD4/CD8 ratio was significantly lowered in the first week and third month posttransplant, no PTLD or organ rejection developed. EBV-DNA was positive in 3 (8.1%) of the pediatric oncology patients. This positivity was attributed to Hodgkin's disease in two of these cases and to reactivation in the third case. EBV-DNA positivity was present in 10 (20%) of the control subjects. In the adult controls whose immunoblot results were compatible with the serologic pattern of an acute infection, the correlation among positive EBV-DNA, positive Paul-Bunnel and low IgG avidity results was statistically significant. As for children in the control group, this serologic profile was significantly correlated with low IgG avidity only. The data obtained from this study indicated that no risk of EBV-related PTLD or acute rejection was found in the first three months in the adult renal transplant patients. In children with EBV-related malignancy the search for EBV-DNA by RtPCR before therapy may be useful in the diagnosis, follow-up and prognostic evaluation. Serologic results should be supported by IgG avidity and PCR in order to ascertain the presence of EBV reactivation in immunosuppressive patients.