Central nervous system infections in the systemic vasculitides

Central nervous system infections are not uncommon in systemic vasculitides. Being vigilant of central nervous system infections as an alternative consideration, instead of systemic vasculitides per se, could prove to be lifesaving in certain circumstances.

Common pathogens, such as tuberculosis, Cryptococcus, and Listeria, still occur commonly as the major causes of central nervous system infection in systemic vasculitides. However, rare pathogens could be responsible among those immunocompromised hosts, and they should not be overlooked. The manifestation of central nervous system infection tends to be atypical among systemic vasculitides patients. History, physical, and cerebrospinal fluid analyses are still time-honored approaches to establishing the correct diagnosis. Newer techniques such as interferon-gamma release assay for tuberculosis, cerebrospinal fluid cytokine, or chemokine profiling need further validation and careful interpretation among such a special patient population. Immune disturbance, mainly due to immunosuppressive therapy, and polymorphism of the innate immune pathway (for example, Toll-like receptor) could be susceptibility factors for certain central nervous system infections. The biologic agents (for example, anti-tumor necrosis factor alpha, and B-cell depletion therapy) represent novel methods for treating systemic vasculitides, but they raise a critical issue owing to their increased likelihood for being associated with opportunistic infections.

Despite the recent progress in this special field, the mortality of central nervous system infection in systemic vasculitides is still high, and the prognostic factors are still largely undetermined.