Intrathecal injection of P/Q type voltage-gated calcium channel antibodies from paraneoplastic cerebellar degeneration cause ataxia in mice.

The role of antibodies against the P/Q type voltage-gated calcium channels (VGCC-ab) in the pathogenesis of paraneoplastic cerebellar degeneration (PCD) and lung cancer is unclear. We evaluated in mice the effect of intrathecal injection of IgG purified from serum of a patient with both PCD and Lambert-Eaton myasthenic syndrome (LEMS), and from another patient with isolated LEMS. Mice injected with PCD/LEMS IgG developed marked, reversible ataxia compared with those injected with LEMS or control IgG. These findings suggest that P/Q-type VGCC-ab may play a role in the pathogenesis of ataxia in patients with PCD and SCLC.