Mother-to-child transmission of human T-cell-leukemia/lymphoma virus type I: implication of high antiviral antibody titer and high proviral load in carrier mothers.

In order to gain new insights into the risk factors influencing human-T-cell-leukemia/lymphoma-virus-type-I (HTLV-I) mother-to-child transmission, a retrospective study of HTLV-I infection among children born to HTLV-I-seropositive women was carried out in a highly HTLV-I-endemic population of African origin living in French Guyana. The study covered 81 HTLV-I-seropositive mothers and their 216 children aged between 18 months old and 12 years old. All plasma samples were tested for the presence of HTLV-I antibodies by ELISA, immunofluorescence assay and Western blot. HTLV-I provirus was detected, in the DNA extracted from peripheral-blood mononuclear cells, by polymerase chain reaction (PCR) using primers specific for 3 different HTLV-I genomic regions (LTR, gag and pX) and quantified by a competitive PCR assay. Out of the 216 children, 21 were found to be HTLV-I-seropositive, giving a crude HTLV-I transmission rate of 9.7%, while among the 180 breast-fed children 10.6% were HTLV-I-seropositive. Perfect concordance between serological and PCR results was observed, and none of the 195 HTLV-I-negative children was found HTLV-I-positive by PCR. In conditional (by family) logistic-regression models, HTLV-I seropositivity in children was associated with an elevated maternal anti-HTLV-I-antibody titer (OR 2.2, p = 0.0013), a high maternal HTLV-I proviral load (OR 2.6, p = 0.033) and child's gender, girls being more frequently HTLV-I-infected than boys: OR 3.6, p = 0.0077 in the model including maternal anti-HTLV-I-antibody titer and OR 4.1, p = 0.002 in the model including the maternal HTLV-I proviral load.

Risk factors for maternal HTLV-I infection in French Guiana: high HTLV-I prevalence in the Noir Marron population.

The aim of this study was to compare rates of human T-cell lymphotropic virus type I (HTLV-I) seroprevalence in pregnant women belonging to different ethnic groups in French Guiana and to determine the risk factors associated with HTLV-I seropositivity. All 1,873 deliveries between 1 July 1991 and 30 June 1993 in the only gynecologic and obstetric unit at Saint Laurent du Maroni were enrolled. Serologic status could be established for 1,727 women, with 75 (4.3%) being HTLV-I seropositive. The HTLV-I seroprevalence rate differed significantly between ethnic groups: 5.7% for Noir-Marron (70/1,302), 6.3% for Haitian (3/50), and 0% for Creole (126), Amerindians (166), and Hmong (64). In Noir-Marron pregnant women, HTLV-I seropositivity was associated with a maternal age of > 35 years [odds ratio (OR), 3.3; 95% confidence interval (CI), 1.4-7.6], prior miscarriage (OR, 1.7; CI, 1-2.8), prior cesarean section (OR, 2.1; CI, 1.1-4.0), a parity > 4 (OR, 4.0; CI, 1.8-8.8), a gravidity > 6 (OR, 4.2; CI, 2.0-7.2), and a negative Rhesus factor (OR, 2.2; CI, 1.1-4.5). Two separate stepwise logistic regressions were done because gravidity and parity were highly correlated. HTLV-I seropositivity remained associated with a gravidity > 6 (OR, 3.9; CI, 2.1-7.4) and a negative Rhesus factor (OR, 2.6; CI, 1.2-5.3) for the first model and with a parity > 4 (OR, 4.1; CI, 1.9-9.0) and a negative Rhesus factor (OR, 2.5; CI, 1.2-5.1) for the second model.(ABSTRACT TRUNCATED AT 250 WORDS)

Clustering and clinical diversity of adult T-cell leukemia/lymphoma associated with HTLV-I in a remote black population of French Guiana.

An epidemiological study was performed in French Guiana (population 115,000) to determine the prevalence and incidence of adult T-cell leukemia/lymphoma (ATL) associated with human T-cell leukemia/lymphoma virus type I (HTLV-I). From January 1990 to December 1993, all suspected cases of ATL were enrolled in this study, and their clinical, epidemiological and immunovirological features were analyzed. Out of the 19 suspected cases, 18 were considered as ATL associated with HTLV-I (8 acute forms, 8 lymphoma types and 2 smoldering cases). Before this study, only 2 ATL cases had been reported in French Guiana over a 10-year period. This demonstrates that the number of ATL cases is greatly under-estimated in most tropical HTLV-I endemic areas unless a specific disease search is performed. The mean age of the patients was 41 years. While HTLV-I antibodies were present in all cases, molecular studies demonstrated a clonal integration of HTLV-I in the tumoral cells in 7 cases out of the 9 tested. Fifteen patients died within a year of diagnosis. The crude incidence rate of ATL in French Guiana is around 3.5/100,000/year, a situation similar to that found in the Caribbean and in HTLV-I-endemic regions of Japan. However it reaches around 30/100,000/year (highest incidence ever described) in a small remote ethnic group of African origin (around 6200 inhabitants). Possible causes of ATL clustering in this ethnic group are presented.