Troublesome Diagnosis of HTLV-I Infection in Blood donors with indeterminate Western blot profiles in Cordoba, Argentina.

CAEIRO L; ESPINOSA P; GASTALDELLO R; MATURANO E; TREVIÑO E; DOMINGUEZ C; CUDOLÁ A; BEPRE H; GALLEGO S

Congreso; 10th International Conference on Human Retrovirology: HTLV and Related Viruses..; 2001

Concern about the presence of HTLV markers in blood donors populations from Cordoba (the main inland province of Argentina) have recently led several blood banks to include the screening of HTLV-I/II antibodies in blood donors. Since the screening of HTLV-I/II started, 4992 blood samples were studied. 36/4992 samples were reactive for HTLV-I/II antibodies by EIA (Vironostika HTLV-I/II, Organon Teknika) or PA (Particle agglutination assay, Serodia, Fujirebio Inc). All 36 reactive samples were assayed by Western blood (Bioblot HTLV, Biokit) to confirm the diagnosis: 2 were confirmed as positive for HTLV-I, 10 were negative, and 24 (66.70%) resulted indeterminate. Because of the high rate of indeterminate results found, all the reactive samples were also tested through an ?in house? indirect immunofluorescence assay (IFA). The 2 positive and 10 negative samples by Western blot, were also positive and negative by IFA: Meanwhile, all of the 24 Western blot indeterminate samples were negative by IFA. Because the significance of these indeterminate seroreactives is unclear, counselling of blood donors with such results can be difficult. Our results corroborates that IFA is a suitable alternative test for confirmatory diagnosis of HTLV infection among blood donors.