ANNA‐3 anti‐neuronal nuclear antibody: Marker of lung cancer‐related autoimmunity

Abstract

Two anti-neuronal nuclear antibodies (ANNA-1 and ANNA-2) are markers of paraneoplastic neurological autoimmunity related to small-cell carcinoma. ANNA-2 is also related to breast carcinoma. Here we define a third IgG specificity (ANNA-3), identified in 11 patients (10 adults) by immunofluorescence screening of sera from approximately 68,000 patients with suspected paraneoplastic neurological syndromes. ANNA-3 binds prominently to nuclei of cerebellar Purkinje neurons, not to cytoplasm, granular neurons, or enteric neurons, but distinctively to renal glomerular podocytes. Western blots revealed an approximately 170 kDa antigen, in cerebellum and small-cell carcinoma. IgG eluted from this protein reproduced Purkinje and podocyte nuclear staining. ANNA-2 in 8 of 32 cases bound to podocyte nuclei but not to the 170 kDa protein. Healthy subjects and control neurological and cancer patients lack ANNA-3. Neurological accompaniments, subacute and usually multifocal, included sensory/sensorimotor neuropathies, cerebellar ataxia, myelopathy, brain stem and limbic encephalopathy. All of 9 adults followed had an intrathoracic neoplasm, seven biopsied within 7 months (five small-cell lung carcinomas and two adenocarcinomas, one lung, one esophagus) and two imaged, one early, the other 3 years later. Thus, immunohistochemical and Western blot criteria can now identify six IgG markers of neurological autoimmunity related to small-cell carcinoma, their frequency being ANNA-1 > collapsin response-mediator protein-5 > amphiphysin > Purkinje cell cytoplasmic antibody-2 = ANNA-2 = ANNA-3.

Amphiphysin autoimmunity: Paraneoplastic accompaniments

“…15,16 We defined amphiphysin-IgG by immunohistochemical characteristics (Fig 1), and always confirmed autoantibody specificities by Western blot analysis using antigenic proteins in an aqueous extract of adult rat cerebellum and also using recombinant proteins corresponding to human amphiphysin (residues 312-695) and CRMP-5 (full-length).…”

Purkinje Cell Cytoplasmic Autoantibody Type 1 Accompaniments

“…We used a previously described and clinically validated indirect immunofluorescence assay to detect PCA-1 IgG. 9 Neuropathologic data were obtained from 2 autopsied patients. The relationship between serum and CSF PCA-1 IgG titers in individuals for whom both serum and CSF samples were available was evaluated using the coefficient of determination (R 2 ), by use of JMP version 8.0 (SAS Institute Inc, Cary, North Carolina).…”

“…Neural-specific staining was ensured by the absorption of bovine liver powder in serum samples (3 times at 1:240 or greater dilution). 9 The patient's IgG binds to discrete cytoplasmic elements: A, Purkinje (P), molecular (M), and Golgi (G) neurons in the cerebellar cortex; B, cerebellar dentate neurons; C, the myenteric plexus and ganglionic neurons; D, hippocampal neurons; E, midbrain neurons; F, spinal cord neurons (SC), the nerve root (NR), and the dorsal root ganglion (DRG). Scale bars represent 40 µm (A-F).…”

Managing Paraneoplastic Neurological Disorders

“…Other antibodies associated with paraneoplastic encephalomyelitis include anti-CRMP5/CV2 [16], antiamphiphysin [34], and the less well-characterized ANNA-3 [35] and Purkinje cell antibody, PCA-2 [36].…”