Value of anti-HBc screening of blood donors for prevention of HBV infection: results of a 3-year prospective study in Northwestern Greece
BACKGROUND: The risk of infection with transfusion-transmitted viruses has been reduced remarkably. However, a zero-risk blood supply remains a popular goal. Some authorities have introduced the screening for antibody to HBc (anti-HBc) as a surrogate test for the presence of several infectious agents. A 3-year prospective study was conducted in the Epirus region of Greece to determine the prevalence of several blood-borne viruses. One component of the study was the prevalence of HBV infection markers and the potential value of anti-HBc testing of donors in this area. STUDY DESIGN AND METHODS: Between January 1, 1995, and December 31, 1997, some 6696 donors were investigated for the presence of HBV infection markers by standard EIAs. Every sample that tested HBsAg-negative but anti-HBc-reactive alone or in combination with either or both antibodies to HBV e antigen (anti-HBe) and low-titered antibodies to HBsAg (anti-HBs < 20 mIU/mL) was further investigated for the presence of HBV DNA by a combination of PGR and DNA EIA. RESULTS: Of these 6696 donors, 15.8 percent tested positive for at least one serologic marker of HBV infection (HBsAg prevalence, 0.85%). Anti-HBc reactivity alone or in combination with either or both anti-HBe and low-titered anti-HBs was found in 282 donors (4.2%). None tested HBV-DNA positive. No transfusion-associated HBV infections were recorded in the recipients of the above 282 blood units. CONCLUSION: A moderate prevalence of HBV infection markers was found, However, taking into account previous studies from this region, it appears that the HBsAg prevalence has declined. in addition, the present study cannot recommend the introduction of anti-HBe screening as a surrogate marker of occult HBV infection. The adoption of this exclusion criterion in this region would result in unacceptably high rejection rates among otherwise healthy donors. The absence of any case of transfusion-associated HBV infection after the transfusion of ail HBsAg-negative, anti-HBc-positive units appears to provide further support for the negative HBV DNA results. Before a consideration of screening donors, efforts must be focused on reducing the number of false-positive anti-HBe results.