Christiane Rasiah

Qualitative evidence of anti-Yo-specific intrathecal antibody synthesis in patients with paraneoplastic cerebellar degeneration

We investigated the presence of anti-Yo-specific oligoclonal antibody bands in cerebrospinal fluid (CSF) and serum samples of 9 patients with anti-Yo syndrome and 11 controls. Isoelectric focusing combined with affinity blotting, revealed anti-Yo-specific intrathecal antibody synthesis in all patients with anti-Yo syndrome: Four patients had positive anti-Yo-specific oligoclonal IgG bands in CSF which were not demonstrable in their sera; five CSF/serum pairs showed additional, more intensive, oligoclonal bands in CSF compared to the corresponding serum. Interestingly, four patients with absence of oligoclonal bands of total IgG in CSF revealed positive anti-Yo-specific oligoclonal bands in the same sample. This speaks for a higher sensitivity of detection of oligoclonal bands using an affinity blot loaded with Yo-specific antigen compared to an affinity blot coated with anti-human IgG used for the detection of oligoclonal bands of total IgG. In conclusion, the presence of anti-Yo-specific oligoclonal IgG bands in CSF which were absent, or less strong, in patients sera provides qualitative evidence of anti-Yo-specific IgG synthesis by intrathecal B-cell clones. These results could be of interest in detection of intrathecal-specific IgG synthesis in nervous system infectious diseases provided that the target antigen is known.

Specific antibody index in cerebrospinal fluid from patients with central and peripheral paraneoplastic neurological syndromes

We evaluated the concentration of antineuronal antibodies in paired cerebrospinal fluid (CSF) and serum samples from 19 patients with central and peripheral paraneoplastic neurological syndromes (PNS), using an enzyme linked immunosorbent assay (ELISA) employing recombinant antineuronal antigens (HuD, Yo, Ri, CV2/CRMP5, amphiphysin, PNMA2/Ma2). The specific antibody index (AI) [Qspec/QIgG] was calculated to estimate specific intrathecal antibody synthesis. An AI>1.3 was considered as evidence of intrathecal specific antibody synthesis. 14 (88%) of 16 patients with exclusive or predominant paraneoplastic involvement of the central nervous system (CNS) showed an AI>1.3, indicating a specific intrathecal antibody synthesis, while all three patients with isolated involvement of the peripheral nervous system showed an AI<0.8. All together, in 17 of 19 patients (89%) we found a significant association (p<0.05) between central or peripheral neurological manifestations on the one hand and presence or absence of specific intrathecal synthesis respectively on the other hand. These data support the hypothesis that autoimmunity is involved in the pathogenesis of PNS.

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.

SOX1 antibodies in sera from patients with paraneoplastic neurological syndromes.

Objectives –  SOX1 antibodies have been described in patients with Lambert–Eaton myasthenic syndrome (LEMS) in association with voltage‐gated calcium channel antibodies as serological markers of small cell lung cancer (SCLC). This study was aimed to screen for additional SOX1 autoimmunity in onconeural antibody‐positive sera from patients with paraneoplastic neurological syndromes (PNS) other than LEMS and to identify the clinical–immunological profile and associated tumours of patients with coexisting SOX1 antibodies. Methods– We retrospectively analysed sera from 55 patients with different PNS positive for well‐characterized antineuronal antibodies for the presence of SOX1 antibodies by recombinant ELISA and immunoblot. Results– Eight (14.5%) patients showed additional SOX1 antibodies in the ELISA and the recombinant immunoblot. Five patients had coexisting Hu antibodies, while the other three showed coexisting CV2/CRMP5, amphiphysin, and coexisting CV2/CRMP5 and Hu antibodies, respectively. PNS included (partially overlapping) subacute sensory neuropathy, subacute sensorimotor neuropathy, cerebellar degeneration, brainstem encephalitis, encephalomyelitis and limbic encephalitis. No tumour was detected in two patients, while the others had lung cancer (four SCLC and two non‐SCLC). One patient showed SOX1‐specific intrathecal antibody synthesis. Conclusions– We describe SOX1 reactivity for the first time overlapping with CV2/CRMP5 and amphiphysin antibodies. SOX1 reactivity is predominantly associated with Hu antibodies and SCLC, but can occur also in other types of lung cancer. Neurological manifestations present in patients with coexisting SOX1 antibodies and well‐characterized antineuronal antibodies do not differ from those previously described in patients positive for antineuronal antibodies but no SOX1‐specific anti‐glial antibodies.

Paraneoplastic antibody during follow-up of a patient with anti-Ri-associated paraneoplastic neurological syndrome.

Background –  The role of classical antineuronal antibody determinations to confirm the paraneoplastic aetiology of a neurological syndrome is well established. However, the value of antineuronal antibody estimation during follow‐up of paraneoplastic neurological syndromes (PNS) is not known.

Screening for Well-Characterized Paraneoplastic Antineuronal Antibodies in Multiple Sclerosis

ABSTRACT Some epidemiological surveys have shown an increased incidence of malignancies in patients with multiple Sclerosis (MS). Furthermore, in rare cases central demyelinating disorders like optic neuritis, encephalomyelitis, and myelitis could be of paraneoplastic origin. Antineuronal antibodies are frequently associated with paraneoplastic neurological syndromes (PNS) but are also described in cancer patients without neurological symptoms. In this study, we retrospectively analyzed sera from 247 patients with MS and clinically isolated syndrome (CIS) for the presence of anti-HuD, Yo, Ri, CV2/CRMP5, Ma2, and amphiphysin antibodies using ELISA employing recombinant onconeural antigens. None of the sera revealed high titers of antineuronal antibodies and only two sera from MS patients show weak reactivity, representing in all probability background activity. Furthermore, cancer incidence in our study is low (0.8%). Our analysis does not support an association between MS and well-characterized paraneoplastic antineuronal antibodies, suggestive of a secondary humoral autoimmune response, underlying latent malignancy, or paraneoplastic origin in our cohort. In reverse, negative screening results in samples of MS patients confirm the high specificity of these antibodies for PNS.

Prevalence of anti-SOX1 reactivity in various neurological disorders☆

OBJECTIVES Anti-SOX1 antibodies are associated with small cell lung cancer (SCLC) and predict a paraneoplastic etiology in Lambert-Eaton myasthenic syndrome (LEMS). In 2010, a study described these antibodies in a small cohort of putative non-paraneoplastic, immune-mediated neuropathies. In this respect, we investigated the seroprevalence and specificity of anti-SOX1 antibodies in a large cohort of neurological disorders. METHODS Overall, serum samples of 1493 consecutive patients were screened for anti-SOX1 reactivity by an ELISA: 471 with well-defined neurological disorders (multiple sclerosis, motor neuron disease, Guillain-Barré syndrome, and chronic inflammatory demyelinating polyneuropathy), 185 with polyneuropathy (PNP) of unknown origin, and 837 with neurological syndromes of suspicious paraneoplastic etiology. These were compared to eight positive controls with definite paraneoplastic neurological syndromes (PNS) and 92 healthy individuals. We also collected demographic and clinical data, including well-characterized onconeural antibodies in anti-SOX1-positive patients. RESULTS Fifteen patients (1.0%) showed anti-SOX1 reactivity: two with multiple sclerosis, two with PNP of unknown origin, and 11 suspicious PNS cases. Remarkably, 9/15 anti-SOX1-positive patients had a PNP. However, antibody concentrations were significantly lower compared to positive controls, and none additionally harbored well-characterized onconeural antibodies. During a follow-up of at least four years, only five patients had cancer: one thyroid, one Hodgkin lymphoma, two breast, and one patient had multiple malignancies - prostate, penis, cecum, liver, and non-small cell lung cancer. However, none had SCLC, typically associated with SOX1 antibodies. CONCLUSIONS The seroprevalence of anti-SOX1 antibodies in patients with various neurological disorders is low. These patients predominantly have PNPs, which might represent a group of immune-mediated diseases.

Recombinant immunoblot for assessment of intrathecally synthesised paraneoplastic antineuronal antibodies in cerebrospinal fluid from patients with paraneoplastic neurological syndromes.

Paraneoplastic neurological syndromes (PNS) are rare disorders associated with malignancy, but they cannot be ascribed directly to the tumour itself, metastases or its treatment (1). Detection of well-characterised paraneoplastic antineuronal antibodies (ANAbs) in serum or cerebrospinal fluid (CSF) essentially contribute to the hypothesis that PNS are caused by autoimmune cross-reactions between antigens both expressed by the tumour and nervous system (2). PNS can affect the central nervous system (CNS) and also the peripheral nervous system, or both. There is evidence of a clinical-immunologic correlation between CNS involvement in patients with PNS and presence of intrathecal synthesis (IS) of ANAbs (3, 4). This study evaluates the suitability of an immunoblot employing recombinant antigens for estimation of intrathecal ANAbs synthesis. For that purpose, serum and CSF samples, positive for ANAbs of various specificities (Table 1), from 19 patients with previously diagnosed definite PNS according to established criteria (1) were simultaneously investigated. Preliminary detection of ANAbs was carried out by immunohistochemistry and confirmed by immunoblot with crude cerebellar extract and/or recombinant antigens. CSF and serum pairs from sev-