C. Spirli

31 MONOCYTE/MACROPHAGE PERIBILIARY RECRUITMENT BY PKHD1-DEFECTIVE CHOLANGIOCYTES INDUCES EXPRESSION OF αvβ6 INTEGRIN ON BILIARY CYSTS VIA TGF-β1 AND TNF-α IN CONGENITAL HEPATIC FIBROSIS

implementation of the current HBV-DNA screening assay, as well as a look-back of blood recipients. Methods: Sequence analysis revealed identical HBV sequences in donor and recipient. Back-up samples testing negative by NAT minipool at previous donations were individually tested by more sensitive assays (Roche Individual NAT, and home-made real-time PCR of S region). When available, pre and post-transfusion samples of recipients were tested for HBV markers. Sequence analyses were conducted by ABIPrism 3100. Results: 28 back-up samples (1–3 per patient) from 13 OBI carriers (2 anti-HBc only, 2 anti-HBs only, 8 anti HBs/antiHBc, 1 without any marker) were available. Overall, 62% tested positive with at least one of the two assays. Of them, 42% were positive by Individual NAT, and 58% by home-made protocol. Six donors gave at least one unit to 4 recipients, for whom both preand post-transfusion samples were available. One recipient acquired infection, as indicated by seroconversion and ALT elevation, two had pre-existing immunity to HBV, and one remained seronegative. Conclusions: A substantial proportion of donations containing HBVDNA are not identified by current NAT minipool assays. These donations can cause acute infections in recipients. Current approaches are highly ineffective, and alternative strategies based on more sensitive protocols or anti-HBc testing should be developed.