HTLV-I IN BURUNDI (EAST AFRICA) : LACK OF REACTIVITY TO THE HTLV-I IMMUNODOMINANT ENVELOPE EPITOPE

In this study conducted in Burundi sera from 485 hospitalized patients and 519 healthy subjects (total of 1004 sera) were analyzed for antibodies to human T-cell leukemia/lymphoma virus types I and II (HTLV-I/II) . Of this study group 494 were females and 510 were males. The mean age was 35.3 + or - 13.4 years. Sera were analyzed/screened for HTLV-I/II virus using enzyme-linked immunoassay (ELISA) techniques. Sera that tested positive for HTLV-I/II antibodies were further analyzed using the Western blot (WB) technique. ELISA screening yielded 19 (1.89%) positives from the 1004 sera tested. WB confirmed that 9 of those 19 were HTLV-I positive. This was shown in the WB when proteins p19 p24 gp46 and recombinant protein tgp21 strongly banded in the testing gel. These results indicate that the rate of HTLV infection is low in Burundi (1.34%) and that all seropositives were infected by the HTLV-I virus. This study also demonstrated that variation within the immunodominant epitopes of the structural proteins of HTLV produced an altered binding affinity of the monoclonal antibodies against the env protein. Amino acids may also differ in the Burundi specimens compared to others studied given the lack of MTA-1 reactivity.