HEPATITIS-G VIRUS-INFECTION IN HEMODIALYZED PATIENTS - EPIDEMIOLOGY AND CLINICAL RELEVANCE

Background. The prevalence, incidence, risk factors, and clinical impa ct of infection by the recently discovered hepatitis G virus (HGV) in haemodialysed (HD) patients, are poorly defined. Methods. All 119 HD p atients from two Belgian units selected for their different hepatitis C virus (HCV) prevalences (A: 19.2%, B: 3.4%) were tested for the pres ence of HGV-RNA, using the reverse transcriptase polymerase chain reac tion (RT-PCR) and primers from the 5'-NC and NS 5a genome regions. The results of anti-HCV antibodies and alanine aminotransferase levels (A LT) at the time of RT-PCR, number of transfusions from the onset of HD , and time on HD were retrieved from the medical charts. Forty patient s were retested by RT-PCR 3-64 months later. Results. HGV-RNA was dete cted with both sets of primers in 11/78 patients (14.1%) from centre A and 8/41 patients (19.5%) from centre B, for an average prevalence of 16%. One patient was indeterminate (positive with one set of primers) . The presence of HGV-RNA correlated neither with time on HD (P = 0.18 ), nor with the number of transfusions on HD (P = 0.14). It was associ ated with the presence of anti-HCV antibodies in centre A (P<0.01) but not B (P>0.5). Twenty-seven initially negative (-) patients (A: n = 1 8; B: n = 9)were retested: two became positive (+) both in the absence of transfusions for years, giving a yearly incidence of 1.7%. The 13 initially HGV-RNA (+) patients remained so over time (33 patient-years ). The presence of HGV-RNA alone does not increase significantly the A LT level, in contrast to the strong influence of HCV. Conclusion. The prevalence and yearly incidence of HGV infection are 16% and 1.7%, res pectively, in our HD patients. Neither the number of transfusions on H D nor the time on HD are significant risk factors. Although mixed HCV/ HGV infections indicate common risks, the prevalence of HCV in a parti cular setting does not predict prevalence of HGV. As new infections ar e detected in the absence of blood transfusions, HGV may be another ma rker of nosocomial viral transmission. Once acquired, the infection pe rsists for many years in HD patients.