Table 1.
Overview of diagnostic tests for M. pneumoniae.
Figure 1.
Proposed schematic pathomechanisms in M. pneumoniae encephalitis.
(Left) Respiratory tract infection. M. pneumoniae resides mostly extracellularly on epithelial surfaces. Its close association allows the production of direct injury by a variety of local cytotoxic effects. Furthermore, it can induce inflammatory responses, elicited by both adhesion proteins and glycolipid epitopes that result in pneumonia. (Right) Encephalitis. Extrapulmonary disease of the CNS is characterized by systemic dissemination with resultant direct infection and local tissue injury (A) or immune-mediated injury (B,C). The latter may occur as a result of cross-reactive antibodies against myelin components, e.g., gangliosides and galactocerebroside C. These antibodies could theoretically have originated from intrathecal synthesis (B) or from outside the CNS (C). Figure adapted from [1]; see references in the text.
Figure 2.
Schematic structures responsible for molecular mimicry between M. pneumoniae and neuronal cells.
(Left) M. pneumoniae adhesion proteins and glycolipids. The immunogenic and major cytadherence proteins P1 and P30 are densely clustered at the tip structure. The P1 protein [31] and glycolipids, e.g., those forming a GalC-like structure [32], elicit cross-reactive antibodies induced by molecular mimicry. (Right) Host myelin glycolipids, to which antibodies were found in patients with M. pneumoniae encephalitis. Glycolipids are organized in specialized functional microdomains called “lipid rafts” and play a part in the maintenance of the cell membrane structure. Abbreviations: GalC, galactocerebroside C; GQ1b, ganglioside quadrosialo 1b; GM1, ganglioside monosialo 1 (the numbers stand for the order of migration on thin-layer chromatography, and the lower-case letters stand for variations within basic structures); HMW, high-molecular-weight. Structures of M. pneumoniae adhesion proteins and host glycolipids are adapted from [33] and [34], respectively.