Walsh & Hoyt: Pathogenesis

The pathogenesis of CIDP remains unclear. Support for a cell-mediated component is based on the observation of a mononuclear cell infiltrate, both diffuse and perivascular, in spinal roots, spinal ganglia, and proximal nerve trunks of postmortem cases. The target for the infiltrate is not fully understood; however, the expression of endothelial leukocyte adhesion molecule (ELAM) was noted in the epineural vessels of five of 10 cases of CIDP evaluated with sural nerve biopsies. Transient expression of ELAMin response to cytokine stimulation has also been documented, suggesting that endothelial cells play a role in the extravasations of infiltrative cells in CIDP; however, the positive response of symptoms to plasma exchange suggests that there also may be a humoral component to the pathogenesis of the disease. IgG and IgM antibodies to the ganglioside GM1 have been found in the serum and CSF of a substantial percentage of patients. A similar finding in the sera of patients has also been found. Circulating TNF-alpha increases during the active phase in a subgroup of CIDP patients and may play a role in the demyelination and breakdown of the bloodnerve barrier.