P/Q- and N-type calcium-channel antibodies: Oncological, neurological, and serological accompaniments.

INTRODUCTION: Voltage-gated calcium-channel autoimmunity (VGCC-P/Q and VGCC-N types) occurs beyond Lambert-Eaton syndrome and lung cancer. METHODS: We reviewed records for 236 Mayo Clinic patients with VGCC antibodies found in evaluation for paraneoplastic neurological autoimmunity (generally without myasthenic syndromes). RESULTS: VGCC autoantibodies were detected in 3.4% of neurological patients, 1.7% of healthy controls, and 4% of neurologically asymptomatic lung cancer controls. Fifty neurological patients (21%) had ≥ 1 neoplasm, historically (46) or detected prospectively [small-cell lung carcinoma (2), breast adenocarcinoma (2), lymphoma (1), and suspected tonsillar carcinoma (1)]. Autoimmune neurological diagnosis frequencies (encephalopathy, ataxia, myelopathy, neuropathy, neuromuscular junction disorder, and myopathy) among patients with medium values (24%; 0.10-0.99 nmol/L) or low values (19%; 0.03-0.10 nmol/L) were fewer than among patients with antibody values exceeding 1.00 nmol/L (71%; P = 0.02 and 0.004, respectively). CONCLUSIONS: Among neuronal VGCC-autoantibody-seropositive patients, autoimmune neurological phenotypes and cancer types are diverse. Cautious interpretation of results (particularly medium and low values) is advised. Muscle Nerve, 2016 Muscle Nerve 54: 220-227, 2016.

Qualitative evidence of Ri specific IgG-synthesis in the cerebrospinal fluid from patients with paraneoplastic neurological syndromes.

The presence of Ri-specific oligoclonal IgG bands in the CSF was investigated in five patients with paraneoplastic anti-Ri associated neurological syndromes (PNS) and six controls. In 4/5 CSF samples reactivity of IgG bands with recombinant Ri antigen was found using isoelectrofocusing combined with affinity blotting; in one patient with absence of oligoclonal bands of total IgG in CSF Ri-specific oligoclonal bands were detected with the same sample, indicating a higher sensitivity of Ri-specific affinity blotting as compared to affinity blotting with anti-human IgG antibodies. Our results confirm previous studies demonstrating IgG synthesis against onconeuronal antigens by intrathecal B-cell clones in PNS and extend this observation to patients with anti-Ri syndrome. The pathogenic relevance of these antibodies, however, is further challenged by the finding that specific intrathecal IgG synthesis might not be a prerequisite of CNS involvement, because it was missed in one of our patients.

A case report of paraneoplastic neurological syndrome associated with occult breast cancer.

Paraneoplastic syndromes are the rarest neurological complications in patients with breast cancer. Here, we present a case of occult breast cancer presenting as paraneoplastic sensory neuropathy. A 47-year-old woman developed progressive upper and lower extremity weaknesses with paresthesia and gait ataxia. Multiple cerebrospinal fluid (CSF) analyses and magnetic resonance image (MRI) scans of her brain and spine offered no diagnosis. Although no paraneoplastic antibodies were found, paraneoplastic neurological syndrome was suspected after examination by the neurologist eliminated other possibilities. Her mammogram demonstrated pleomorphic calcifications. Although local and systemic therapies were given, no significant improvement in the neurologic condition was found.

Demonstration of anti-HuD specific oligoclonal bands in the cerebrospinal fluid from patients with paraneoplastic neurological syndromes. Qualitative evidence of anti-HuD specific IgG-synthesis in the central nervous system.

The presence of HuD-specific oligoclonal IgG bands in the CSF was investigated in five patients with paraneoplastic neurological syndromes. All patients revealed intrathecal synthesis of HuD specific antibodies in the CSF, as estimated from elevated antibody indices (>1.5) in an IgG-ELISA using recombinant HuD-protein as antigen. Isoelectrofocussing combined with affinity blotting showed reactivity of IgG bands with recombinant HuD antigen in all CSF samples. These data support the idea that HuD specific antibodies in the CSF are produced mainly by B-cell clones in the central nervous system. These findings support the hypothesis of autoimmunity in the pathogenesis of anti-Hu associated paraneoplastic neurological syndromes.