SEROLOGICAL EVIDENCE FOR REACTIVATION OF EBV INFECTION DUE TO UREMIC IMMUNODEFICIENCY

Background. Reactivation of EBV infection is a common finding in immun ocompromised individuals. The influence of 'uraemic immunodeficiency' on EBV infection is so far not well defined. Methods. We determined sp ecific antibodies to EBV nuclear antigens (EBNA) 1 and 2 in sera of 28 6 patients with immunodeficiency due to progressive chronic renal fail ure and of 51 healthy controls. We used the baculovirus vector express ion system for recombinant production of EBNA1 and EBNA2. Results. Ser ological evidence of reactivated or chronic persistent EBV infection, i.e. an anti-EBNA1/antiEBNA2 ratio (E1/E2)<1, was found in 18% of pati ents with chronic renal failure not yet receiving renal replacement th erapy (CRF), 11% of peritoneal dialysis patients (CAPD), 25% of haemod ialysis patients (HD), 24% of renal transplant recipients (TX), and in 6% of healthy controls. Rate of EBV reactivation was significantly in creased in HD (P = 0.004) and TX (P = 0.006) patients compared to heal thy controls. Moreover, the difference between HD and CAPD patients wa s statistically significant (P < 0.05). This finding may reflect addit ional effects modulating the function of the immunosystem, probably th rough activation of immunologically competent cells by contact with th e artificial surfaces of dialysis membranes. Although the rate of EBV reactivations is expected to increase further under conditions of ther apeutic immunosuppression, our serological approach did not detect an additional effect of immunosuppressive therapy following renal transpl antation. However, this finding may reflect an impaired endogenous syn thesis of antibodies caused by immunosuppressive agents. Conclusions. We conclude that determination of E1/E2 is useful for assessment of EB V infection in patients with chronic renal failure and 'uraemic immuno deficiency'. In patients with immunosuppressive therapy following rena l transplantation additional testing, including direct estimation of v iral load, is necessary to correctly assess the state of EBV infection .