THROMBOSPONDIN-1 EXPRESSION IN HUMAN T-LYMPHOTROPIC VIRUS 1 ASYMPTOMATIC CARRIERS AND PATIENTS WITH HTLV-ASSOCIATED MYELOPATHY/TROPICAL SPASTIC PARAPARESIS

Human T-lymphotropic Virus type 1 (HTLV-1) is associated with a myelopathy (namedHTLV-associated myelopathy/Tropical Spastic Paraparesis–HAM/TSP). Thrombospondin-1 (TSP-1) is a matrix protein which interferes with cell adhesion, motility, and proliferation. The expression levels of the mRNA for this protein were evaluated in HTLV-1 infected individuals: 11 asymptomatic, 18 with myelopathy or oligosymptomatic, and 13 non-infected participants. RNA from peripheral blood mononuclear cells was submitted to TSP-1 RT-PCR analysis. The number of individuals expressing thrombospondin-1 was more frequent in the symptomatic group (14/18, p=0.007). In general, a tendency to higher values of the protein´s mRNA was observed in the HTLV-1-infected group (p=0.062). The highest mRNA TSP-1 expression levels were detected at the beginning of the clinical symptoms of myelopathy. Additional studies with larger sample sizes are deemed to further elucidate the role of this matrix protein in the inflammatory network related to the HTLV-associated myelopathy/Tropical Spastic Paraparesis.