Immune mechanisms in syphilis and its concurrence with human immunodeficiency virus infection

Abstract

The intensity and duration of cellular immune response determine differences in clinical manifestations of syphilis. Macrophages, CD4+ T lymphocytes, CD8+ T lymphocytes and natural killer (NK) cells all play important roles in cellular immunity in syphilis. Concurrent human immunodeficiency virus (HIV) infection increases the complexity of immune pathogenesis as well as variety in clinical manifestations of syphilis. In secondary syphilis concurrent with HIV infection, T helper type 1 (Th1) and Th17 cell-mediated immunity are enhanced, while changes in Th2 cell-mediated immunity remain unclear. The concurrence of syphilis and HIV infection may alter their immunologic mechanisms, clinical course and therapeutic outcomes. Thus, it is necessary for timely and effective treatment to screen for HIV infection in patients with syphilis and for syphilis in patients with HIV infection. Key words: Syphilis; HIV; Immunity; Treponema pallidum; Infection