Seroindeterminate patterns and seroconversions to human T-lymphotropic virus type I positivity in blood donors from Martinique, French West Indies.
BACKGROUND
Screening for human T-lymphotropic virus type I (HTLV-I) antibodies in volunteer blood donors has been systematic in the French West Indies since 1989. Western blot-indeterminate results are commonly obtained. The significance of these indeterminate serologic patterns in HTLV-I-endemic areas is still unclear.


METHODS
During a 2-year period, 9759 blood donors were tested for HTLV-I antibodies. The epidemiologic features of HTLV-I-seropositive, -seroindeterminate, and -seronegative donors were compared. A lookback investigation was performed for the HTLV-I-seropositive donors, and the HTLV-I-seroindeterminate individuals were followed up.


RESULTS
Thirty-nine donors (0.4%) were HTLV-I seropositive and 49 (0.5%) were seroindeterminate. The age and sex ratio characteristics of the seroindeterminate donors are divergent from those of the HTLV-I-seropositive group and are more like those of the seronegative population. However, during the study period, three cases of seroconversion after an initial seroindeterminate profile were reported. Two cases were detected through follow-up of 38 HTLV-I-seroindeterminate donors over a mean of 8 months (2-24 months). The third seroconverter belonged to the HTLV-I-seropositive group and was identified through lookback investigation. This case is atypical, with p19 reactivity for several months before HTLV-I seropositivity.


CONCLUSIONS
These findings indicate that, although HTLV-I-seroindeterminate donors mainly are HTLV-I-noninfected, the rate of seroconversion in a repeat blood donor population from an endemic region must be taken into consideration. Moreover, the case of delayed seroconversion observed in this study suggests the difficulty of counseling seroindeterminate blood donors in endemic regions.
Césaire
R
R
Center for Blood Transfusion and the Neurology Service, University Hospital, Fort-de-France, Martinique. cesaire.raymond@wanadoo.fr
Bera
O
O
Maier
H
H
Lezin
A
A
Martial
J
J
Ouka
M
M
Kerob-Bauchet
B
B
Ould Amar
A K
AK
Vernant
J C
JC
D000328:Adult; D001782:Blood Donors; D015480:Deltaretrovirus Antibodies / Q000032:analysis*; D006800:Deltaretrovirus Infections / Q000175:diagnosis; D004812:Epidemiologic Methods; D005260:Female; D005500:Follow-Up Studies; D015368:Human T-lymphotropic virus 1 / Q000276:immunology*; D006801:Humans; D008297:Male; D008395:Martinique; D008875:Middle Aged; D012698:Serologic Tests; D013997:Time Factors
D015480:Deltaretrovirus Antibodies