Selective concentration of anti-Purkinje cell antibody in the CSF of two patients with paraneoplastic cerebellar degeneration.

An anti-Purkinje cell antibody (APCA) was found in serum and CSF of 2 patients with paraneoplastic cerebellar degeneration (PDC) and breast carcinoma. Integrity of the blood-brain barrier (BBB) was normal in one patient and slightly damaged in the other. In both patients CSF IgG index was normal, but CSF/serum APCA ratio and CSF IgG APCA index were elevated suggesting that a selective concentration of the APCA in CSF occurs in patients with PCD. This feature supports the hypothesis that APCA may play a role in the pathogenesis of PCD.