@article{MorbachBeyersdorfKerkauetal.2021, author = {Morbach, Caroline and Beyersdorf, Niklas and Kerkau, Thomas and Ramos, Gustavo and Sahiti, Floran and Albert, Judith and Jahns, Roland and Ertl, Georg and Angermann, Christiane E. and Frantz, Stefan and Hofmann, Ulrich and St{\"o}rk, Stefan}, title = {Adaptive anti-myocardial immune response following hospitalization for acute heart failure}, series = {ESC Heart Failure}, volume = {8}, journal = {ESC Heart Failure}, number = {4}, doi = {10.1002/ehf2.13376}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-258907}, pages = {3348-3353}, year = {2021}, abstract = {Aims It has been hypothesized that cardiac decompensation accompanying acute heart failure (AHF) episodes generates a pro-inflammatory environment boosting an adaptive immune response against myocardial antigens, thus contributing to progression of heart failure (HF) and poor prognosis. We assessed the prevalence of anti-myocardial autoantibodies (AMyA) as biomarkers reflecting adaptive immune responses in patients admitted to the hospital for AHF, followed the change in AMyA titres for 6 months after discharge, and evaluated their prognostic utility. Methods and results AMyA were determined in n = 47 patients, median age 71 (quartiles 60; 80) years, 23 (49\%) female, and 24 (51\%) with HF with preserved ejection fraction, from blood collected at baseline (time point of hospitalization) and at 6 month follow-up (visit F6). Patients were followed for 18 months (visit F18). The prevalence of AMyA increased from baseline (n = 21, 45\%) to F6 (n = 36, 77\%; P < 0.001). At F6, the prevalence of AMyA was higher in patients with HF with preserved ejection fraction (n = 21, 88\%) compared with patients with reduced ejection fraction (n = 14, 61\%; P = 0.036). During the subsequent 12 months after F6, that is up to F18, patients with newly developed AMyA at F6 had a higher risk for the combined endpoint of death or rehospitalization for HF (hazard ratio 4.79, 95\% confidence interval 1.13-20.21; P = 0.033) compared with patients with persistent or without AMyA at F6. Conclusions Our results support the hypothesis that AHF may induce patterns of adaptive immune responses. More studies in larger populations and well-defined patient subgroups are needed to further clarify the role of the adaptive immune system in HF progression.}, language = {en} } @phdthesis{Hartmannsberger2021, author = {Hartmannsberger, Beate}, title = {The pathogenicity and origin of auto-antibodies in chronic inflammatory demyelinating polyradiculoneuropathy and the identification of cutaneous biomarkers in Charcot-Marie-Tooth 1A patients}, doi = {10.25972/OPUS-21145}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-211451}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2021}, abstract = {Peripheral neuropathies can severely affect patients. Causes for the disease are diverse but can be classified into two main groups, acquired and hereditary. Examples for these two types are chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and Charcot-Marie-Tooth disease type 1A (CMT1A). CIDP has an estimated prevalence of about 1-9:100 000. In this pathogenetically hetereo- geneous patient group about 5-10\% show auto-antibodies against the node of Ranvier and present with distinct symptoms. Treatment with rituximab - a monoclonal antibody that deletes CD20 + B cells - has been shown to be effective in a majority of auto-antibody as- sociated CIDP cases. This suggests that B cells and the produced auto-antibodies might be pathogenic. Previous studies delivered evidence that auto-antibodies alone can induce nerve damage. In this study, the aim was to investigate the pathomechanism of auto-antibodies in vivo and their exact origin: For the analysis of the pathogenicity of auto-antibodies, passive transfer experiments on Lewis rats were performed with whole IgG from a patient with anti-contactin-1 (CNTN1) IgG4 auto-antibodies. IgG was infused through an intrathe- cal catheter targeting the thoracic/lumbar region of the spine over a long-term, 3-week period. In a previous study of our group, the IgG from the same patient has been re- ported to have mild pathogenic effects when applied intraneurally into the sciatic nerve of Lewis rats. In this study however, binding of auto-antibodies to nerve roots could not be detected. Neither evaluation of electrophysiological properties after the injection period nor motor and sensory skills tested throughout the injection period showed differences when compared to animals infused with control IgG. This suggests that in the chronic intrathecal protocol anti-CNTN1 auto-antibodies did not have a pathogenic effect. In peripheral blood, four B cell subsets capable to produce antibodies were previously described: memory B cells, plasmablasts (PBs), B1 cells and CD20 + CD38 hi cells. For the identification of the B cell subsets that produce auto-antibodies, purification and sort protocols as well as an enzyme-linked immuno spot (ELISpot) assay for IgG and IgM were established successfully. Since unstimulated B cell subsets produced very small amounts of IgG and IgM, peripheral blood mononuclear cells (PBMCs) were stimulated with IL-2 and R848 for 72 h prior to sorting. While the memory B cell frequency decreased after stimulation, the frequency of CD20 + CD38 hi cells increased and the overall number of antibody-secreting cells was increased. When stimulating patient PBMCs for 10 days though, detection of anti-neurofascin-155 (NF155) auto-antibodies in supernatants by enzyme-linked immunosorbent assay (ELISA) was possible in two out of three patient samples. Even though cell sorting was feasible after 10 days of stimulation, detection of auto-antibodies could not be accomplished using antigen-specific ELISpot. Although the implementation of the cell sorting and purification protocol was successful, further adjustments of the antigen-specific ELISpot need to be performed. However, we could show that after 10 days of stimulation auto-antibody detection is possible by ELISA which helps to pre-screen if patient PBMC contain auto-reactive B cells. CMT1A has an estimated prevalence of 1:5000 and is caused by a duplication of the peripheral myelin protein 22 kDa (PMP22) gene. Patients suffer from distal weakness and muscle wasting leading even to wheelchair-dependency in some cases. Although different treatment options for CMT1A have been tested in previous clinical trials, none of them have been successful. In this study, the aim was to identify objective and reproducible outcome measures that assess the actual nerve damage in a large cohort of CMT1A patients by analyzing a series of parameters. Glabrous skin samples were collected from 48 CMT1A, 7 CIDP and 16 small fiber neuropathy patients and 45 healthy controls. 40-µm cryosections from the lateral part of the index finger were double-labeled using immunoflu- orescence to investigate cutaneous innervation. The disease severity which was assessed using the Charcot-Marie-Tooth Neuropathy Score version 2 (CMTNSv2) and ranged between mild to severe (3-27) correlated with age in CMT1A patients. Furthermore, the intraepidermal nerve fiber density (IENFD) was reduced in CMT1A patients in comparison to controls and correlated negatively with the disease severity. In controls however, the IENFD correlated inversely with age. Meissner corpuscle density tended to be reduced and correlated inversely with age in CMT1A patients. This was not observed in healthy controls though. Compared to controls, Merkel cell density was also reduced in CMT1A, while the fraction of denervated Merkel cell was increased and correlated with age. Further differences were revealed concerning the node of Ranvier. Paranodes were shortened and the fraction of long nodes was decreased in CMT1A patients compared to controls. These data suggest that the IENFD, the Meissner corpuscle and Merkel cell densities are possible candidates for outcome measures as they are associated with disease severity or age of patients. However, a reliable statement about the suitability as a marker for disease progression can not be made in this study since only six CMT1A patients agreed to give a follow-up biopsy two years later.}, language = {en} } @article{DopplerSchusterAppeltshauseretal.2019, author = {Doppler, Kathrin and Schuster, Yasmin and Appeltshauser, Luise and Biko, Lydia and Villmann, Carmen and Weishaupt, Andreas and Werner, Christian and Sommer, Claudia}, title = {Anti-CNTN1 IgG3 induces acute conduction block and motor deficits in a passive transfer rat model}, series = {Journal of Neuroinflammation}, volume = {16}, journal = {Journal of Neuroinflammation}, number = {73}, doi = {10.1186/s12974-019-1462-z}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-200476}, year = {2019}, abstract = {Background: Autoantibodies against the paranodal protein contactin-1 have recently been described in patients with severe acute-onset autoimmune neuropathies and mainly belong to the IgG4 subclass that does not activate complement. IgG3 anti-contactin-1 autoantibodies are rare, but have been detected during the acute onset of disease in some cases. There is evidence that anti-contactin-1 prevents adhesive interaction, and chronic exposure to anti-contactin-1 IgG4 leads to structural changes at the nodes accompanied by neuropathic symptoms. However, the pathomechanism of acute onset of disease and the pathogenic role of IgG3 anti-contactin-1 is largely unknown. Methods: In the present study, we aimed to model acute autoantibody exposure by intraneural injection of IgG of patients with anti-contacin-1 autoantibodies to Lewis rats. Patient IgG obtained during acute onset of disease (IgG3 predominant) and IgG from the chronic phase of disease (IgG4 predominant) were studied in comparison. Results: Conduction blocks were measured in rats injected with the "acute" IgG more often than after injection of "chronic" IgG (83.3\% versus 35\%) and proved to be reversible within a week after injection. Impaired nerve conduction was accompanied by motor deficits in rats after injection of the "acute" IgG but only minor structural changes of the nodes. Paranodal complement deposition was detected after injection of the "acute IgG". We did not detect any inflammatory infiltrates, arguing against an inflammatory cascade as cause of damage to the nerve. We also did not observe dispersion of paranodal proteins or sodium channels to the juxtaparanodes as seen in patients after chronic exposure to anti-contactin-1. Conclusions: Our data suggest that anti-contactin-1 IgG3 induces an acute conduction block that is most probably mediated by autoantibody binding and subsequent complement deposition and may account for acute onset of disease in these patients. This supports the notion of anti-contactin-1-associated neuropathy as a paranodopathy with the nodes of Ranvier as the site of pathogenesis.}, language = {en} } @article{GruenewaldBennettToykaetal.2016, author = {Gr{\"u}newald, Benedikt and Bennett, Jeffrey L. and Toyka, Klaus V. and Sommer, Claudia and Geis, Christian}, title = {Efficacy of Polyvalent Human Immunoglobulins in an Animal Model of Neuromyelitis Optica Evoked by Intrathecal Anti-Aquaporin 4 Antibodies}, series = {International Journal of Molecular Sciences}, volume = {17}, journal = {International Journal of Molecular Sciences}, number = {9}, doi = {10.3390/ijms17091407}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-166000}, pages = {1407}, year = {2016}, abstract = {Neuromyelitis Optica Spectrum Disorders (NMOSD) are associated with autoantibodies (ABs) targeting the astrocytic aquaporin-4 water channels (AQP4-ABs). These ABs have a direct pathogenic role by initiating a variety of immunological and inflammatory processes in the course of disease. In a recently-established animal model, chronic intrathecal passive-transfer of immunoglobulin G from NMOSD patients (NMO-IgG), or of recombinant human AQP4-ABs (rAB-AQP4), provided evidence for complementary and immune-cell independent effects of AQP4-ABs. Utilizing this animal model, we here tested the effects of systemically and intrathecally applied pooled human immunoglobulins (IVIg) using a preventive and a therapeutic paradigm. In NMO-IgG animals, prophylactic application of systemic IVIg led to a reduced median disease score of 2.4 on a 0-10 scale, in comparison to 4.1 with sham treatment. Therapeutic IVIg, applied systemically after the 10th intrathecal NMO-IgG injection, significantly reduced the disease score by 0.8. Intrathecal IVIg application induced a beneficial effect in animals with NMO-IgG (median score IVIg 1.6 vs. sham 3.7) or with rAB-AQP4 (median score IVIg 2.0 vs. sham 3.7). We here provide evidence that treatment with IVIg ameliorates disease symptoms in this passive-transfer model, in analogy to former studies investigating passive-transfer animal models of other antibody-mediated disorders.}, language = {en} } @phdthesis{SoutoCarneiro2000, author = {Souto-Carneiro, Maria Margarida}, title = {Molecular and functional analyses of human synovial B-lymphocytes in rheumatoid arthritis}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-2308}, school = {Universit{\"a}t W{\"u}rzburg}, year = {2000}, abstract = {B-cells of the rheumatoid synovial tissue are a constant part of and, in some histopathological subtypes, the dominant population of the inflammatory infiltrate, located in the region of tissue destruction. The pattern of B-cell distribution and the relationship to the corresponding antigen-presenting cells (follicular dendritic reticulum cells: FDCs) show a great variety. B-cells may exhibit (i) a follicular organization forming secondary follicles; (ii) follicle-like patterns with irregularly formed FDC networks, and (iii) a diffuse pattern of isolated FDCs. Molecular analysis of immunoglobulin VH and VL genes from human synovial B-cell hybridomas and synovial tissue demonstrates somatic mutations due to antigen activation. The FDC formations in the synovial tissue may therefore serve as an environment for B-cell maturation, which is involved in the generation of autoantibodies. An autoantibody is defined as "pathogenic" if it fulfills the Witebsky-Rose-Koch criteria for classical autoimmune diseases: definition of the autoantibody; induction of the disease by transfer of the autoantibody; and isolation of the autoantibody from the disease-specific lesion. B-cells from rheumatoid synovial tissue show specificity for FcIgG, type II collagen, COMP, sDNA, tetanus toxoid, mitochondrial antigens (M2), filaggrin and bacterial HSPs. The contributions of these antigens to the pathogenesis of RA are still hypothetical. A possible contribution could derive from crossreactivity and epitope mimicry: due to crossreaction, an antibody directed originally against a foreign infectious agent could react with epitopes from articular tissues, perpetuating the local inflammatory process. The characteristic distribution pattern, the localisation within the area of tissue destruction, the hypermutated IgVH and IgVL genes, and their exclusive function to recognize conformation-dependent antigens suggest a central role for B-cells in the inflammatory process of rheumatoid arthritis. Therefore, the analysis of synovial B-cell hybridomas and experimental expression of synovial IgVH and IgVL genes will help to characterise the antigens responsible for the pathogenesis of rheumatoid arthritis. In the present study 55 IgVH genes amplified from 3 different anatomical regions of a RA patient were analysed adding further information on synovial B-cell maturation and recirculation in RA. This analysis demonstrated somatically mutated IgVh genes in all different regions with amino acid deletions and mixed IgVh molecules, suggesting the existence of a novel pathway to generate (auto)antibody specificities. The comparison of amino acid sequences of amplified genes belonging to the VH1 family (with predominantly the same germline counterpart) exhibited a strong homology, indicating an apparently conserved mutational pattern. This suggests that the number of antigens activating B-cells in the different locations is restricted. The most striking result was the finding of clonally related sequences in different anatomical regions indicating a recirculation of activated B-cells between the different affected joints. Also in the present study a synovial B-cell hybridoma was analyzed for its specific recognition of cartilage antigens. A heptameric peptide of cartilage oligomeric protein (COMP) could be defined as the target structure. The IgVH-gene (IgHV4-59*01) of the IgG2l hybridoma has somatically mutated genes with high R/S values in the CDR regions (9:2). Thus, indicating that this hybridoma originates from a synovial B-cell which has been antigen activated/selected for its affinity. To analyse the presence of the clonotypic IgHV4-59*01 sequences in other cases of RA and osteoarthritis (OA) synovitis, primers specific for the CDR3 rearrangement of this hybridoma were used. The clonotypic and clone related sequences (98 per cent ± 1 per cent homology) could only be detected in synovitis of RA cases but not in OA cases indicating that this B-cell is specific to RA synovitis. The identified heptameric peptide of COMP was used in a peptide ELISA to analyse whether there is a specific binding in RA serum samples. Serum samples (IgG) from RA patients (n=22) showed a significant higher efficiency to the COMP heptamer than the OA sera (n=24) and the age matched healthy controls (n=20) (for both p<1x10-4, Students t-test). The specificity of this B-cell hybridoma may therefore be defined as RA specific. Since COMP is restricted to cartilage and tendons which are organs specifically affected in RA this COMP specific autoantibody represents the first organ specific autoantibody in RA. The IgG2 COMP specific autoantibody with somatically mutated IgVH genes is different from germline encoded, antigen clearing IgM autoantibodies and may therefore be directly involved as an "arthritogenic autoantibody" in cartilage and tendons destruction by complement activation.}, subject = {Rheumatoide Arthritis}, language = {en} }