The relationship between atopy and neurological manifestations in HTLV-1 infection

INTRODUCTION: Human T-cell lymphotropic virus type 1 (HTLV-1)induces exaggerated Th1 responses, whereas atopy is associated with exacerbated Th2 responses. METHODS: Here, a cross-sectional study compared the prevalence of atopy in HTLV-1 carriers and HAM/TSP patients. It also compared the spontaneous cytokine production in HTLV-1-infected individuals. A retrospective cohort study evaluated the development of neurological manifestations in atopic and non-atopic carriers. RESULTS: Atopic HAM/TSP patients with high IFN-γ production exhibited higher IL-5 levels than non-atopic patients. Allergic rhinitis accelerated the development of Babinski signals and overactive bladders. CONCLUSIONS: Abnormal Th1 and Th2 responses coexist in HTLV-1-infected individuals and allergic diseases may worsen the clinical course of HTLV-1 infections.