Patterns of HTLV-1 infection among family members of patients with adult T-cell leukemia/lymphoma and HTLV-1 associated myelopathy/tropical spastic paraparesis - abstract

ABSTRACT

Human T-cell lymphotropic virus type 1 (HTLV-1) is strongly associated with both ATL and HAM/TSP. Only a small proportion of HTLV-1 infected individuals develop either of these diseases with lifelong risk estimates between 1 percent and 5 percent. ATL is believed to be related to early childhood infection via mother to child and HAM/TSP is thought to result from sexually or parenterally acquired infection in adulthood. Through the evaluation of HTLV-1 seroprevalence among family members of ATL and HAM/TSP patients we provide data that early life exposure is important for later development of ATL. Cases of ATV and HAM/TSP and their first degree relatives were enrolled in the study at the UWI, Jamaica, HTLV-1 seroprevalence rates were compared. We enrolled 25 ATL and 31 HAM/TSP families. All cases were HTLV-1 positive. Females accounted for 56 percent of ATL cases and 80 percent of HAM/TSP cases with mean ages of 43 and 49 respectively. The seroprevalence of HTLV-1 among mothers of ATL patients was 100 percent compared to 27 percent among mothers of HAM/TSP patients (p=0.0003). Among fathers of ATL subjects the seroprevalence was 80 percent vs 0 percent for HAM/TSP (p=0.05). The seroprevalence among all family members was 49 percent for ATL and 20 percent for HAM/TSP (p=0.0003). In contrast spouses ofHAM/TSP cases had a 86 percent seroprevalence compared to 57 percent among spouses of ATL cases. ATL and HAM/TSP evolve from distinct pathogenic pathways supported by differences in epidemiologic association. This premise is strongly supported by our observation that family members of ATL patients, particularly mothers have a significantly higher prevalence of HTLV-1 infection (AU)