Cytotoxic CD8+ T cells and CD138+ plasma cells prevail in cerebrospinal fluid in non-paraneoplastic cerebellar ataxia with contactin-associated protein-2 antibodies

Objective: the purpose of this paper is to report a patient with otherwise unexplained cerebellar ataxia with serum antibodies against contactin-associated protein-2 (caspr-2) and provide a detailed description of the composition of cellular infiltrates in the cerebrospinal fluid (csf) compared to the peripheral blood (pb). caspr-2 antibodies strongly labeling axons of cerebellar granule neurons have recently been identified in sera from nine patients with otherwise unexplained progressive cerebellar ataxia with mild to severe cerebellar atrophy.design: this is a report of a single case.methods: the study methods used were neurologic examination,magnetic resonance imaging,fluorodeoxyglucose positron emisson tomography,lumbar puncture and multicolor flow-cytometry.results: a 23-year-old caucasian male presented with a two-year history of a progressive cerebellar and brainstem syndrome. magnetic resonance imaging (mri) showed pronounced cerebellar atrophy,especially of the medial parts of the hemispheres and the vermis. cerebral fluorodeoxyglucose positron emission tomography (fdg-pet) showed pronounced hypometabolism of the whole cerebellum. caspr-2 antibodies were detected in the serum but not the csf,and none of the staging and laboratory assessments revealed other causes of progressive cerebellar degeneration. interestingly,flow-cytometry of the csf as compared to the pb showed increased fractions of cd138+ plasma cells as well as human leukocyte antigen (hla)-dr+ cd8+ t cells suggesting that both b cells and cd8+ t cells were preferentially recruited to and activated within the csf- (and putatively central nervous system (cns)-) compartment.conclusion: we confirm the association of caspr-2 serum antibodies with cerebellar ataxia and provide the first evidence for a combined humoral and cellular immune response in this novel antibody-associated inflammatory cns disease. © 2012 melzer et al.; licensee biomed central ltd.