http://repub.eur.nl/res/aut/2877/ List of Publications en http://repub.eur.nl/static-eur/img/logo.png http://repub.eur.nl http://repub.eur.nl/res/pub/21925/ 2010-12-01T00:00:00Z Objective: Paraneoplastic neurological syndromes associated with anti-Hu antibodies (Hu-PNS) are mediated by a T-cell immune response that is directed against the Hu antigens. In pregnancy, many Th1-mediated autoimmune diseases such as rheumatoid arthritis and multiple sclerosis regress. We hypothesised that this decreased disease activity during pregnancy may be related to high human chorionic gonadotropin (hCG) levels. Methods: 15 Hu-PNS patients were treated in a prospective, uncontrolled and unblinded trial with 10 000 IU daily of hCG administered by intramuscular injection during 12 weeks. Primary outcome measures were functional improvement defined as a decrease of one or more points on the modified Rankin Scale (mRS) or stabilisation in patients with mRS score ≤3 and improvement of neurological impairment assessed with the Edinburgh Functional Impairment Tests (EFIT). Secondary end points included the change in activities of daily living as evaluated using the Barthel Index. Results: Seven of 15 patients (47%) improved on the mRS or stabilised at mRS score ≤3. Four patients (27%) showed significant improvement of neurological impairment as indicated by an overall Edinburgh Functional Impairment Tests score of ≥1 point. Five patients improved on the Barthel Index (33%). Conclusion: Comparison with previous studies suggests that hCG may have immunomodulatory activity and may modify the course of Hu-PNS, although well-established confounding factors may have contributed in this uncontrolled trial. http://repub.eur.nl/res/pub/27732/ 2010-09-01T00:00:00Z Background: Hypothetically, T cells are involved in the pathogenesis of paraneoplastic neurological syndromes associated with Hu-antibodies (Hu-PNS). Objective: To identify genetic risk factors for Hu-PNS and investigate the role of T cells. Methods: HLA-A, B, DRB1 and DQB1 alleles were compared in 53 Hu-PNS patients with 24 small-cell lung-cancer (SCLC) patients and 2440 healthy controls (HC). Results: The frequency of both HLA-DQ2 and HLA-DR3 was significantly higher in Hu-PNS patients than in HC. Conclusions: This study indicates an association between Hu-PNS and presence of HLA-DQ2 and HLA-DR3, which supports a role for CD4+T cells in the pathogenesis of Hu-PNS. http://repub.eur.nl/res/pub/18108/ 2009-02-01T00:00:00Z http://repub.eur.nl/res/pub/14284/ 2008-11-01T00:00:00Z To detect HuD-specific T cells in patients with Hu-antibody associated paraneoplastic neurological syndromes (Hu-PNS), we used short-term stimulation assays with HuD protein spanning peptide pools (PSPP) with purities of at least 70% and found reproducible false-positive CD8+ T-cell responses in three of 127 individuals (two healthy controls and one Hu-PNS patient), which all shared HLA-A*2402 and HLA-B*1801. After testing the 15-mer peptides of the HuD antigen separately, we discovered that the same three 15-mers yielded the CD8+ T cell response in those three individuals. This highly unusual result could not be reproduced when using new batches of peptides with a higher level of purity (>82% and >95%). Therefore, we assumed this response was not directed against the HuD peptides and analyzed the HuD 15-mers by Fourier transform ion cyclotron resonance (FT-ICR) tandem mass spectrometry (MS/MS), which showed the presence of a cytomegalovirus (CMV)-encoded peptide (AIAEESDEEEAIVAY) as a contaminant. The three responding individuals all were CMV-seropositive and the contaminating peptide appeared to fit in the binding groove of HLAB* 18. Our data reveal that synthetic PSPP may contain immunogenic contaminations which may cause false positive results in T-cell stimulation assays. http://repub.eur.nl/res/pub/29282/ 2008-03-01T00:00:00Z In paraneoplastic neurological syndromes associated with Hu-antibodies (Hu-PNS) an important role for cellular immunity is hypothesized. We characterized the cerebrospinal fluid (CSF) pleocytosis in Hu-PNS patients by assessing the major lymphocyte subsets by flow cytometry. The B cell subset in the CSF of Hu-PNS patients showed a significant absolute (~ 20×) and relative (~ 3×) expansion, while the numbers of CD4+ T cells, CD8+ T cells and NK cells only showed an absolute expansion (~ 4-7×) compared to the controls. On the other hand, the NKT cell subset showed a significant relative reduction in CSF and in blood of Hu-PNS patients. The relative B cell expansion is consistent with the intrathecal synthesis of Hu-antibodies, while the increased number of T and NK cells supports an additional role for cellular immunity in the pathogenesis of Hu-PNS. In addition, the autoimmune hypothesis of Hu-PNS is supported by the relative NKT cell deficiency. http://repub.eur.nl/res/pub/36754/ 2007-12-01T00:00:00Z In paraneoplastic neurological syndromes (PNS) associated with small cell lung cancer (SCLC) and Hu antibodies, neuron-specific Hu antigens expressed by the tumour hypothetically trigger an immune response that cross-reacts with Hu antigens in the nervous system, resulting in tumour suppression and neuronal damage. To gain more insight into the hypothesized cell-mediated immune pathogenesis of these syndromes, we analysed the circulating lymphocyte subsets in untreated patients with SCLC, PNS and Hu antibodies (n = 18), SCLC without PNS (n = 19) and controls (n = 29) using flow cytometry. SCLC patients with PNS had a variety of imbalances within their circulating lymphocyte subsets as compared with SCLC patients without PNS and healthy controls: (i) a lymphopenia of the major subsets (i.e. B, CD4+and CD8+T lymphocytes); (ii) increased proportions of activated CD4+and CD8+T cells; (iii) reduced numbers of terminally differentiated effector CD8+T cells and cells with a cytotoxic T-cell phenotype (CD56+and CD57+). Although indirect, our data provide further support for the involvement of T cells in the pathogenesis of Hu antibody associated PNS. http://repub.eur.nl/res/pub/36067/ 2007-07-01T00:00:00Z Aim: In paraneoplastic neurological syndromes (PNS) associated with small cell lung cancer (SCLC) and Hu antibodies (Hu-PNS), Hu antigens expressed by the tumour hypothetically trigger an immune response that also reacts with Hu antigens in the nervous system, resulting in tumour suppression and neuronal damage. To gain more insight into the hypothesized CD8+T cell-mediated immune pathogenesis of these syndromes, we searched for circulating HuD-specific CD8+T cells in a large cohort of Hu-PNS patients and controls. Patients and methods: Blood was tested from 43 Hu-PNS patients, 31 Hu antibody negative SCLC patients without PNS and 54 healthy controls. Peripheral blood mononuclear cells (PBMC) were stimulated with HuD protein-spanning peptide pools (15-mers) and individual HuD-derived peptides (9-mers) and analysed by cytokine flow cytometry and interferon-γ ELISPOT-assays. Additionally, HuD-based Class I HLA multimers were used to visualize HuD-specific CD8+T cells. Results: No HuD-specific CD8+T cells could be detected in the blood of Hu-PNS patients or controls. Conclusions: Our results do not support a role for HuD-specific CD8+T cells in Hu-PNS. Further studies should focus on the detection of circulating HuD-specific CD4+T cells and examine the antigen specificity of T cells in affected tissues. http://repub.eur.nl/res/pub/10210/ 2007-06-13T00:00:00Z Paraneoplastic neurological syndromes (PNS) result from damage or dysfunction of the nervous system that is by definition not caused by tumor cell infiltration, infection, ischemia, metabolic and nutritional deficits, surgery or other forms of tumor treatment. Immunologic factors appear important in the pathogenesis of PNS because antineuronal antibodies against nervous system antigens have been defined for many of these disorders. The immunologic response is elicited by the ectopic expression of neuronal antigens by the tumor. Expression of these so-called ‘onconeural’ antigens is limited to the tumor and the nervous system. At the time of presentation of the neurological symptoms, most patients have not yet been diagnosed with cancer. Detection of paraneoplastic antibodies is extremely helpful in diagnosing an otherwise unexplained, and often rapidly progressive neurological syndrome as paraneoplastic. In addition, the paraneoplastic antibodies may also direct the search for an underlying neoplasm. The diagnosis and clinical management of PNS are reviewed in chapter 2. One of the most frequently involved solid tumors in PNS is small cell lung cancer (SCLC) and approximately 50% of patients with PNS and SCLC have high-titer Hu antibodies. This thesis focused on PNS that are associated with Hu-antibodies (Hu-PNS). http://repub.eur.nl/res/pub/36480/ 2007-04-04T00:00:00Z Protein-spanning peptide pools have proven valuable as a screening tool for detecting T-lymphocyte responses against a wide range of proteins. We have used this approach in our search for T cells reactive to the onconeural protein HuD. We found positive responses in only 3 of 127 individuals; however, these were highly unusual in that the same class I HLA alleles and peptides were involved. These T-cell responses were not confirmed when peptides re-synthesized by the same manufacturer with similar and with higher purity levels were used. Our observations indicated that these T-cell responses were not directed against the designed HuD peptides. Here, we report on (i) comparisons of the peptide batches analyzed by matrix-assisted laser desorption/ionization Fourier transform mass spectrometry (MALDI-FTMS) that did -and did not - elicit T-cell responses and (ii) a detailed analysis of the various by-products of peptides, irrespective of T-cell assay outcome. We found numerous differences between the peptide batches, such as omissions of amino acids in the primary structure of the peptides. Furthermore, some batches revealed strong interactions with calcium ions or contained sulfated peptides. Our data reveal that different batches from the same peptide may contain artefacts that influence the outcome of HLA-restricted T-cell response assays. Copyright http://repub.eur.nl/res/pub/21738/ 2006-03-01T00:00:00Z Abstract Paraneoplastic neurological syndromes (PNS) are remote effects of cancer that are not caused by invasion of the tumor or its metastases. Immunologic factors appear important in the pathogenesis of PNS because antineuronal autoantibodies and T-cell responses against nervous system antigens have been defined for many of these disorders. The immunologic response is elicited by the ectopic expression of neuronal antigens by the tumor. Expression of these so-called "onconeural" antigens is limited to the tumor and the nervous system and sometimes also the testis. At the time of presentation of the neurological symptoms, most patients have not yet been diagnosed with cancer. Detection of paraneoplastic antibodies is extremely helpful in diagnosing an otherwise unexplained and often rapidly progressive neurological syndrome as paraneoplastic. In addition, the paraneoplastic antibodies may also direct the search for an underlying neoplasm. On the other hand, in patients known to have cancer, the presentation of a PNS may herald recurrence of the tumor or a second tumor. The number of paraneoplastic antibodies is still growing, and at least seven of these can now be considered well characterized. Based on the clinical syndrome, the type of antibody, and the presence or absence of cancer, patients are classified as having a "definite" or "possible" PNS. Despite the presumed autoimmune etiology of PNS, the results of various forms of immunotherapy have been disappointing, with some exceptions. Rapid detection and immediate treatment of the underlying tumor appears to offer the best chance of stabilizing the patient and preventing further neurological deterioration. http://repub.eur.nl/res/pub/13989/ 2006-01-01T00:00:00Z Paraneoplastic neurological syndromes (PNS) are remote effects of cancer that are not caused by invasion of the tumor or its metastases. Immunologic factors appear important in the pathogenesis of PNS because antineuronal autoantibodies and T-cell responses against nervous system antigens have been defined for many of these disorders. The immunologic response is elicited by the ectopic expression of neuronal antigens by the tumor. Expression of these so-called "onconeural" antigens is limited to the tumor and the nervous system and sometimes also the testis. At the time of presentation of the neurological symptoms, most patients have not yet been diagnosed with cancer. Detection of paraneoplastic antibodies is extremely helpful in diagnosing an otherwise unexplained and often rapidly progressive neurological syndrome as paraneoplastic. In addition, the paraneoplastic antibodies may also direct the search for an underlying neoplasm. On the other hand, in patients known to have cancer, the presentation of a PNS may herald recurrence of the tumor or a second tumor. The number of paraneoplastic antibodies is still growing, and at least seven of these can now be considered well characterized. Based on the clinical syndrome, the type of antibody, and the presence or absence of cancer, patients are classified as having a "definite" or "possible" PNS. Despite the presumed autoimmune etiology of PNS, the results of various forms of immunotherapy have been disappointing, with some exceptions. Rapid detection and immediate treatment of the underlying tumor appears to offer the best chance of stabilizing the patient and preventing further neurological deterioration. http://repub.eur.nl/res/pub/21818/ 2006-01-01T00:00:00Z Abstract Anti-CD20 monoclonal antibody (rituximab) is effectively used in the treatment of B-cell lymphomas. Recent reports in the literature suggest that antibody associated autoimmune disorders may respond to rituximab. We therefore treated nine patients with anti-Hu or anti-Yo associated paraneoplastic neurological syndromes (PNS) with a maximum of four monthly IV infusions of rituximab (375mg/m(2)). In this uncontrolled, unblinded trial of rituximab, three patients improved > or =1 point on the Rankin Scale (RS). One patient with limbic encephalitis improved dramatically (RS from 5 to 1). Further studies of rituximab in autoantibody associated PNS are warranted.