R Charlewood1, P Flanagan. 1. New Zealand Blood Service, Auckland, New Zealand. richard.charlewood@nzblood.co.nz
Abstract
BACKGROUND: The low, fluctuating levels of DNA characteristic of occult hepatitis B infection make its detection by nucleic acid testing (NAT) a challenge. METHODS: Four year's routine use of the Ultrio and Ultrio Plus assays in blood donations in New Zealand was analysed. RESULTS: 0·09% of donations tested with Ultrio and Ultrio Plus assays showed reactivity in the multiplex assay, but non-reactivity in all three discriminatory assays and relevant mandatory serological assays (anti-HIV, anti-HCV, HBsAg). These donations were more likely to be anti-HBc reactive (Ultrio, 13%; Ultrio Plus, 57%; random donors, 6·8%). Thirty-four per cent of these anti-HBc-reactive donations were also reactive in either an alternate NAT assay or on repeat multiplex testing. Thirteen per cent of the donors of the discriminatory-negative, anti-HBc-reactive donations who had given other Ultrio- or Ultrio Plus-tested donations had at least one other multiplex reactive donation. CONCLUSION: These findings suggest that their HBV DNA levels are around the assay's limit of detection, that false reactivity cannot be presumed when a donor fails to discriminate and that caution should be applied when deciding whether to continue accepting donations from such donors.
BACKGROUND: The low, fluctuating levels of DNA characteristic of occult hepatitis B infection make its detection by nucleic acid testing (NAT) a challenge. METHODS: Four year's routine use of the Ultrio and Ultrio Plus assays in blood donations in New Zealand was analysed. RESULTS: 0·09% of donations tested with Ultrio and Ultrio Plus assays showed reactivity in the multiplex assay, but non-reactivity in all three discriminatory assays and relevant mandatory serological assays (anti-HIV, anti-HCV, HBsAg). These donations were more likely to be anti-HBc reactive (Ultrio, 13%; Ultrio Plus, 57%; random donors, 6·8%). Thirty-four per cent of these anti-HBc-reactive donations were also reactive in either an alternate NAT assay or on repeat multiplex testing. Thirteen per cent of the donors of the discriminatory-negative, anti-HBc-reactive donations who had given other Ultrio- or Ultrio Plus-tested donations had at least one other multiplex reactive donation. CONCLUSION: These findings suggest that their HBV DNA levels are around the assay's limit of detection, that false reactivity cannot be presumed when a donor fails to discriminate and that caution should be applied when deciding whether to continue accepting donations from such donors.
Authors: Claire E Styles; Anthea Cheng; Veronica C Hoad; Philip Kiely; Michael Watson; Clive R Seed Journal: Transfus Med Hemother Date: 2019-08-29 Impact factor: 3.747