Diagnostic follow-up of blood donors with indeterminate results to Western Blot for HIV infection in Palermo, Sicily

27,343 blood donors, were tested for HIV infection at the Poli- clinico of Palermo in the period 1999-2001 by using a com- mercial ELISA as screening test and a commercial Western Blot (WB) as confirmatory test. HIV infection was detected in two subjects, whereas five individuals reacted faintly at the screening and tested indeterminate at the confirmatory test showing the presence of only one band for gp41 (four cases) or p24 (one case). A one year follow-up was performed in these patients. All donors but one, spontaneously seroreverted during the follow-up; the only one who persisted as WB inde- terminate, tested also negative for HIV RNA by PCR assay at the end of follow-up. In conclusion, none of the subjects with an indeterminate WB developed an HIV infection. This result agree with the possible, future reintroduction of these donors in the donation pool, according to the more recent suggestions of the literature.