Cytokines Involved in CNS Manifestations Caused by Mycoplasma pneumoniae

Mycoplasma pneumoniae sometimes causes central nervous system manifestations, which may involve the host immune response, as the organism does not directly damage neural cells, or release toxins. Therefore we measured the levels of interleukin-6, interleukin-8, interleukin-18, interferon-γ, tumor necrosis factor-α, and transforming growth factor-β1 in serum and cerebrospinal fluid samples from patients who manifested central nervous system manifestations during acute M. pneumoniae infection. The subjects were nine patients with early-onset encephalitis (central nervous system disease onset within 7 days from the onset of fever), four with late-onset encephalitis (onset at 8 days or later), three with encephalitis but without fever, and three with aseptic meningitis. Intrathecal elevations of interleukin-6 and interleukin-8 in all four types of central nervous system manifestations, and of interleukin-18 in late-onset encephalitis were observed. None of the cerebrospinal fluid samples contained detectable levels of interferon-γ, tumor necrosis factor-α, or transforming growth factor-β1. In conclusion, interleukin-6, interleukin-8, and interleukin-18 might be involved in the inflammatory process leading to the central nervous system manifestations caused by M. pneumoniae.