The introduction of Laboratory testing for anti-HBcore in blood donors

Introduction. The introduction of screening testing for antibodies to the hepatitis B virus nuclear antigen (anti-HBcore) is designed to prevent the procurement of donated blood from individuals with the latent (occult) form of viral hepatitis B, in which surface HBsAg is not identified.Aim – to evaluate the frequency of anti-HBcore markers’ occurrence in donors under the current regulatory and legal framework.Materials and methods. This retrospective observational study was conducted with a follow-up period of one year among blood donors of the Blood Center (BC) of the Federal Medical-Biological Agency. The screening study for anti-HBcore in blood donors and its components was selective in accordance with the requirements of Appendix № 4 of Order № 1166n of October 28, 2020 of the Ministry of Health of Russia.Results. During the study period, the BC was visited by 17,180 donors who donated blood and its components 35,840 times. There were 181 anti-HBcore tests (0.5 % of all blood samples) in 178 unique donors of blood and blood components (1.03 % of all donors). There were 14 positive, 2 questionable and 166 negative results on anti-HBcore tests. The probability of finding a positive result depending on the conditions was 9 % (7.3–14.7 %). There were no statistically significant differences in the detection of anti-HBcore in primary versus regular donors (OR = 2.539; 95% CI: 0.7321–8; p = 0.13), as well as for male donors compared with female donors (OR = 2.448; 95% CI: 0.7141–11.11; p = 0.17). 86.7 % of donors with a positive test for anti-HBcore previously had no signs of viral hepatitis B disease, the presence of questionable HBsAg was not detected, i. e. these cases may be associated with an occult form. Donors who did not previously have questionable results for various bloodborne infections during their donor career had a slightly higher probability of detecting a positive anti-HBcore test compared to donors who previously had these questionable results (OR = 1.24; 95% CI”: 0.42–3.69; p = 0.69). During the period of the donor career, 233 donations of blood and its components were made by donors with a positive result for anti-HBcore, 468 units of donor components were received, of which 365 units were given to medical institutions.Conclusion. The probability of obtaining a positive test for anti-HBcore in the current regulatory environment is random and does not depend on the results of other infectious markers testing. It is recommended to perform anti-HBcore testing with each donation of blood and blood components.