Antigen-specific oligoclonal bands in cerebrospinal fluid and serum from patients with anti-amphiphysin- and anti-CV2/CRMP5 associated paraneoplastic neurological syndromes

Cerebrospinal fluid oligoclonal bands in Neuroborreliosis are specific for Borrelia burgdorferi

Background

Cerebrospinal fluid (CSF) oligoclonal bands (OCB) occur in chronic or post-acute phase of inflammatory diseases of the central nervous system.

Objective

To determine whether CSF OCB in patients with neuroborreliosis (NB) are specific for borrelia burgdorferi senso lato.

Methods

We performed isoelectric focusing followed by immunoblotting in CSF of 10 NB patients and 11 controls (7 patients with multiple sclerosis, 2 patients with neuromyelitis optica spectrum disease, 1 patient with dementia and 1 patient with monoclonal gammopathy). Immunoblotting was performed using an uncoated as well as a borrelia antigen pre-coated nitrocellulose membrane (NCM). OCB were counted by visual inspection and photometric analysis. OCB were compared between uncoated und pre-coated NCM both in the NB and control group. For validation purposes inter-assay precision was determined by calculating the coefficient of variation (CV)

Results

Borrelia-specific OCB were found in the CSF of 9 NB patients and in none of the control subjects resulting in a sensitivity of 90% and a specificity of 100%. Number of NB specific OCB were 11±7 bands by photometric analyses compared to 9±5 bands by visual inspection. Validation experiments revealed an inconsistent inter-assay precision between visual and photometric analyses (NB uncoated: visual 28% versus photometric 14%, control subject uncoated: visual 16% versus photometric 24%).

Conclusions

In CSF samples with positive OCB, Borrelia-specific bands were detected in almost all NB patients and in none of the control subjects. Inconsistent inter-assay precision may be explained by a poor comparability of visual and photometric approach.

Isoelectric Focusing in Agarose Gel for Detection of Oligoclonal Bands in Cerebrospinal and Other Biological Fluids

Isoelectric focusing (IEF) coupled with immunodetection (immunofixation or immunoblotting) has become the leading technique for the detection and study of oligoclonal bands (OCBs) in cerebrospinal fluid (CSF) and also is increasingly used in other body fluids such as the tear and serum. Limited commercial availability of precast agarose IEF gels for research and a need for customization prompted reporting a detailed general protocol for the preparation and casting of agarose IEF gel along with sample, control, and isoelectric point marker preparation and carrying out the focusing itself for CSF OCBs. However, the method is readily adaptable to the use of other body fluid specimens and, possibly, research specimens such as culture fluids as well.

Immunofixation Electrophoresis for Identification of Proteins and Specific Antibodies

Immunofixation electrophoresis (IFE) is a technique for the identification of proteins within complex mixtures after separation by either conventional zone electrophoresis or isoelectric focusing. Most commonly antigens (which are often immunoglobulins) are separated by electrophoresis followed by precipitation with specific antibodies in situ. However, immunoglobulins with specific reactivity can be also precipitated with the proper antigens after electrophoresis in reverse or reversed IFE. Because of its great versatility, potentially high sensitivity, ease to perform and customize, and relatively low cost with no requirement for expensive instrumentation, manual IFE remains a valuable tool for both clinical diagnostic testing and research. Any low-viscosity body fluid specimen or, possibly, culture fluid could be tested with IFE if proper antibodies (or antigens in reverse[d] IFE) are available. After pretreatment with chaotropic and/or reducing agents, even high-viscosity specimens might be amenable to testing with IFE.

Relation of intrathecal oligoclonal band production to inflammatory mediator and immunotherapy response in 208 children with OMS

In 208 children with opsoclonus-myoclonus syndrome (OMS), CSF IgG oligoclonal bands (OCB) and 22 immunomarkers in CSF and 21 in serum/blood were measured. In 36 untreated OMS, 58% were OCB(+), whereas 55% of treated OMS were OCB(-). OCB positivity or negativity did not alter concentrations or frequencies of immunomarkers. The phenotypes of OCB(+) and OCB(-) patients were not distinctive. CSF B cells were expanded in untreated OMS regardless of OCB positivity. These data reveal a much higher frequency of OCB positivity in untreated OMS than previously realized and a disconnect between intrathecal OCB and inflammatory mediator production.

'Medusa head ataxia': the expanding spectrum of Purkinje cell antibodies in autoimmune cerebellar ataxia. Part 3: Anti-Yo/CDR2, anti-Nb/AP3B2, PCA-2, anti-Tr/DNER, other antibodies, diagnostic pitfalls, summary and outlook

Serological testing for anti-neural autoantibodies is important in patients presenting with idiopathic cerebellar ataxia, since these autoantibodies may indicate cancer, determine treatment and predict prognosis. While some of them target nuclear antigens present in all or most CNS neurons (e.g. anti-Hu, anti-Ri), others more specifically target antigens present in the cytoplasm or plasma membrane of Purkinje cells (PC). In this series of articles, we provide a detailed review of the clinical and paraclinical features, oncological, therapeutic and prognostic implications, pathogenetic relevance, and differential laboratory diagnosis of the 12 most common PC autoantibodies (often referred to as 'Medusa head antibodies' due to their characteristic somatodendritic binding pattern when tested by immunohistochemistry). To assist immunologists and neurologists in diagnosing these disorders, typical high-resolution immunohistochemical images of all 12 reactivities are presented, diagnostic pitfalls discussed and all currently available assays reviewed. Of note, most of these antibodies target antigens involved in the mGluR1/calcium pathway essential for PC function and survival. Many of the antigens also play a role in spinocerebellar ataxia. Part 1 focuses on anti-metabotropic glutamate receptor 1-, anti-Homer protein homolog 3-, anti-Sj/inositol 1,4,5-trisphosphate receptor- and anti-carbonic anhydrase-related protein VIII-associated autoimmune cerebellar ataxia (ACA); part 2 covers anti-protein kinase C gamma-, anti-glutamate receptor delta-2-, anti-Ca/RhoGTPase-activating protein 26- and anti-voltage-gated calcium channel-associated ACA; and part 3 reviews the current knowledge on anti-Tr/delta notch-like epidermal growth factor-related receptor-, anti-Nb/AP3B2-, anti-Yo/cerebellar degeneration-related protein 2- and Purkinje cell antibody 2-associated ACA, discusses differential diagnostic aspects and provides a summary and outlook.

Brain-reactive antibodies and disease

Autoimmune diseases currently affect 5-7% of the world's population; in most diseases there are circulating autoantibodies. Brain-reactive antibodies are present in approximately 2-3% of the general population but do not usually contribute to brain pathology. These antibodies penetrate brain tissue only early in development or under pathologic conditions. This restriction on their pathogenicity and the lack of correlation between serum titers and brain pathology have, no doubt, contributed to a delayed appreciation of the contribution of autoantibodies in diseases of the central nervous system. Nonetheless, it is increasingly clear that antibodies can cause damage in the brain and likely initiate or aggravate multiple neurologic conditions; brain-reactive antibodies contribute to symptomatology in autoimmune disease, infectious disease, and malignancy.

Usefulness of antibody index assessment in cerebrospinal fluid from patients negative for total-IgG oligoclonal bands

Background

Testing for cerebrospinal fluid (CSF)-restricted oligoclonal bands (OCB) by isoelectric focusing is used to detect intrathecally produced total IgG. By contrast, antibody indices (AI) are assessed to test for intrathecally produced antigen-specific IgG. A number of previous cases reports have suggested that AI testing might be more sensitive than OCB testing in detecting intrathecal IgG synthesis.

Findings

Here we report on 21 patients with positive AI for either herpes simplex virus, varicella zoster virus, cytomegalovirus, measles virus, rubella virus, or Borrelia burgdorferi in the absence of total-IgG OCB and, accordingly, in the presence of a normal total-IgG CSF/serum ratio.

Conclusion

Our findings indicate that AI testing should not generally be omitted in OCB-negative patients and provide a rationale for systematic and prospective studies on the comparative sensitivity and specificity of AI and total-IgG OCB testing in infectious and other diseases of the CNS.

Immunofixation electrophoresis for identification of proteins and specific antibodies

Immunofixation electrophoresis (IFE) is a technique for the identification of proteins within complex mixtures after separation by either conventional zone electrophoresis or isoelectric focusing. Most commonly antigens (which are often immunoglobulins) are separated by electrophoresis followed by precipitation with specific antibodies in situ. However, immunoglobulins with specific reactivity can be also precipitated with the proper antigens after electrophoresis in reverse or reversed IFE. Because of its great versatility, potentially high sensitivity, ease to perform and customize, and relatively low cost with no requirement for expensive instrumentation, manual IFE remains a valuable tool for both clinical diagnostic testing and research. Any low-viscosity body fluid specimen or, possibly, culture fluid could be tested with IFE if proper antibodies (or antigens in reverse[d] IFE) are available. After pretreatment with chaotropic and/or reducing agents, even high-viscosity specimens might be amenable to testing with IFE.

Isoelectric focusing in agarose gel for detection of oligoclonal bands in cerebrospinal and other biological fluids

Isoelectric focusing (IEF) coupled with immunodetection (immunofixation or immunoblotting) has become the leading technique for the detection and study of oligoclonal bands (OCBs) in cerebrospinal fluid (CSF) and also is increasingly used in other body fluids such as the tear and serum. Limited commercial availability of precast agarose IEF gels for research and a need for customization prompted reporting a detailed general protocol for the preparation and casting of agarose IEF gel along with sample, control, and isoelectric point marker preparation and carrying out the focusing itself for CSF OCBs. However, the method is readily adaptable to the use of other body fluid specimens and, possibly, research specimens such as culture fluids as well.

Anti-CV2 associated cerebellar degeneration after complete response to chemoradiation of head and neck carcinoma

Paraneoplastic cerebellar degeneration is a rare neurological disorder that frequently precedes the detection of malignancy. Here, we report the case of a 60 year-old woman with locally advanced squamous cell carcinoma of the tongue who developed a subacute cerebellar syndrome associated with the presence of anti-CV2/CRMP5 antibodies in the cerebrospinal fluid, after achieving complete remission of the primary tumor and the involved cervical lymph nodes by chemoradiation. The patient's symptoms on presentation were dizziness and gait unsteadiness. On examination she showed dysarthria, nystagmus and limb and gait ataxia. The diagnosis of paraneoplastic cerebellar syndrome was made on the basis of the clinical findings and immunological testing that revealed the presence of anti-CV2/CRMP5 antibodies in the patient's cerebrospinal fluid. This syndrome, which is very rare in association with head and neck cancer, commonly precedes the detection of malignancy by a year or more and has been documented in only a few cases after completion of anticancer treatment.