Purkinje Cell Cytoplasmic Autoantibody Type 1 (PCA-1)

Purkinje cell cytoplasmic autoantibody type 1 has been recognized for 25 years as a biomarker of an immune response to ovarian or breast carcinoma in women presenting with cerebellar ataxia of subacute onset and rapid progression.1,2 Molecular and immunological studies of specimens obtained from patients seropositive for PCA-1 IgG have been instructive in conveying an understanding of the pathophysiology of inflammatory paraneoplastic neurological disorders mediated by CD8+ cytotoxic T lymphocytes.3- 5 The 52-kDa antigen identified by Western blotting of central nervous system tissue and cancer tissue, and encoded by a clone isolated from a cerebellar complementary DNA library, was identified as cdr23. Early clues that the spectrum of neurological disorders associated with PCA-1 IgG may be broader than cerebellar degeneration included the detection of cdr2 in noncerebellar tissue from the central nervous system and also from the peripheral and autonomic nervous systems.6- 8