Aac. Segurado et al., LABORATORY CHARACTERIZATION OF HUMAN T-CELL LYMPHOTROPIC VIRUS TYPE-1(HTLV-1) AND TYPE-2 (HTLV-2) INFECTIONS IN BLOOD-DONORS FROM SAO-PAULO, BRAZIL, The American journal of tropical medicine and hygiene, 57(2), 1997, pp. 142-148
Citations number
45
Categorie Soggetti
Public, Environmental & Occupation Heath","Tropical Medicine
Serologic screening for human T cell lymphotropic virus types 1/2 (HTL
V-1/2) infection in blood donors has been recently introduced in Brazi
l. Analysis of 351,639 blood donations in Sao Paulo from January 1992
to October 1993 identified 1,063 positive (0.30%) and 2,238 indetermin
ate (0.63%) samples based on serologic confirmation using a 21e Wester
n blot. A detailed analysis (serologic, molecular, and virologic), bas
ed on a laboratory diagnostic algorithm for characterization of HTLV-1
and HTLV-2 infections was undertaken in 50 seropositive or seroindete
rminate blood donors. Modified serologic assays (2.3 Western blot that
incorporate type-specific recombinant peptides) performed in 29 HTLV-
1/2 positive and 21 HTLV-1/2 indeterminate donors with the 21e Western
blot identified 25 as infected with HTLV-1, four with HTLV-2, five wi
th untypable HTLV-1/2, 15 as HTLV-1/2 indeterminate, and one as serone
gative. Polymerase chain reaction (PCR) analysis using DNA amplificati
on of proviral pol and tax sequences from peripheral blood mononuclear
cells confirmed HTLV-1 and HTLV-2 infections in all 2.3 Western blot
seropositive donors; of the five serologically untypable donors, three
were confirmed to be HTLV-1 positive, one HTLV-2 positive, and one ne
gative by PCR. All of the seroindeterminate donors were also negative
by PCR. Furthermore, HTLV-1 could be isolated in cocultures from 10 of
18 infected donors. Cell lines developed from two HTLV-l-infected don
ors were of T cell phenotype (CD2(+), CD3(+)), exhibiting surface mark
ers of activated CD4 cells (CD4(+) CD25(+) HLA-DR+). Thus, we provide
evidence for the high seroprevalence of HTLV infection in blood donor
population in Sao Paulo, Brazil compared with North American donors an
d propose a comprehensive serologic and genotypic diagnostic algorithm
for HTLV-infected donors that has strong implications for counseling
of these individuals.