Carbonic anhydrase‐related protein <scp>VIII</scp> antibodies and paraneoplastic cerebellar degeneration

Abstract

Paraneoplastic cerebellar degeneration (PCD) is a common cause of subacute cerebellar ataxia caused by widespread loss of the Purkinje cells of the cerebellum. PCD diagnosis can be confirmed by detection of onconeural antibodies that may also indicate the underlying tumour type 1. Most onconeural antibodies associated with PCD recognize intracellular antigens in Purkinje cells 2. These antigens are supposed to induce, besides the antibody synthesis, an antigen‐specific cytotoxic T‐cell attack that probably is responsible of the Purkinje cell death and limited response to treatment 3, 4. The most common onconeural antibody in PCD is the Yo antibody that associates with breast and ovarian cancer 4. In a previous case report, we identified a new antibody, targeting the intracellular Purkinje cell protein carbonic anhydrase‐related protein VIII (CARP VIII), in a patient with PCD and melanoma 5. We provide further evidence for the association of CARP VIII antibodies with PCD by demonstrating a second patient with these antibodies, who had an ovarian adenocarcinoma and developed cerebellar ataxia.