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Gerd R Burmester

Publications and source records attributed to Gerd R Burmester.

At least 19 recordsLinked to original sources

Initial clinical trial of epratuzumab (humanized anti-CD22 antibody) for immunotherapy of systemic lupus erythematosus.

B cells play an important role in the pathogenesis of systemic lupus erythematosus (SLE), so the safety and activity of anti-B cell immunotherapy with the humanized anti-CD22 antibody epratuzumab was evaluated in SLE patients. An open-label, single-center study of 14 patients with moderately active SLE (total British Isles Lupus Assessment Group (BILAG) score 6 to 12) was conducted. Patients received 360 mg/m2 epratuzumab intravenously every 2 weeks for 4 doses with analgesic/antihistamine premedication (but no steroids) prior to each dose. Evaluations at 6, 10, 18 and 32 weeks (6 months post-treatment) follow-up included safety, SLE activity (BILAG score), blood levels of epratuzumab, B and T cells, immunoglobulins, and human anti-epratuzumab antibody (HAHA) titers. Total BILAG scores decreased by > or = 50% in all 14 patients at some point during the study (including 77% with a > or = 50% decrease at 6 weeks), with 92% having decreases of various amounts continuing to at least 18 weeks (where 38% showed a >/= 50% decrease). Almost all patients (93%) experienced improvements in at least one BILAG B- or C-level disease activity at 6, 10 and 18 weeks. Additionally, 3 patients with multiple BILAG B involvement at baseline had completely resolved all B-level disease activities by 18 weeks. Epratuzumab was well tolerated, with a median infusion time of 32 minutes. Drug serum levels were measurable for at least 4 weeks post-treatment and detectable in most samples at 18 weeks. B cell levels decreased by an average of 35% at 18 weeks and remained depressed at 6 months post-treatment. Changes in routine safety laboratory tests were infrequent and without any consistent pattern, and there was no evidence of immunogenicity or significant changes in T cells, immunoglobulins, or autoantibody levels. In patients with mild to moderate active lupus, 360 mg/m2 epratuzumab was well tolerated, with evidence of clinical improvement after the first infusion and durable clinical benefit across most body systems. As such, multicenter controlled studies are being conducted in broader patient populations.

Adult↗

Immunopathologic role of B lymphocytes in rheumatoid arthritis: rationale of B cell-directed therapy.

Although the immunopathogenesis of rheumatoid arthritis (RA) remains unclear, recent advances have paved the way for new therapies, such as anti-cytokine and cell-directed therapies. Here, B cells have re-gained interest concerning the pathogenesis of a number of autoimmune diseases after observing that patients with RA and non-Hodgkin lymphoma, who received anti-CD20 therapy leading to B cell depletion, demonstrated remarkable improvements. The underlying modes of action appear to be related to B cell functions, such as deletion of memory B cells, interruption of immune activation, antigen-presentation and production of inflammatory cytokines. In many RA patients, synovial extrafollicular germinal centers develop, where B cells play an intimate role in local inflammation and the generation of memory B cells and plasma cells. These local processes lead to activation of the immune system and ultimately to joint destruction in RA. Recent data demonstrating the clinical value of B cell depletion in refractory RA patients substantiate the notion that B cells are important players in the pathogenesis of the disease. Future studies should clarify which functions are affected by B cell depletion, providing the promise of new avenues to patient-tailored therapies.

Animals↗

Detailed analysis of the variability of peptidylarginine deiminase type 4 in German patients with rheumatoid arthritis: a case-control study.

Peptidylarginine deiminase type 4 (PADI4) genotypes were shown to influence susceptibility to rheumatoid arthritis (RA) in the Japanese population. Such an association could not previously be confirmed in different European populations. In the present study, we analysed exons 2-4 of PADI4 in 102 German RA patients and 102 healthy individuals to study the influence of PADI4 variability on RA susceptibility by means of haplotype-specific DNA sequencing. Analyses of the influence of PADI4 and HLA-DRB1 genotypes on disease activity and on levels of anti-cyclic citrullinated peptide antibodies were performed. Comparing the frequencies of PADI4 haplotype 4 (padi4_89*G, padi4_90*T, padi4_92*G, padi4_94*T, padi4_104*C, padi4_95*G, padi4_96*T) (patients, 14.7%; controls, 7.8%; odds ratio = 2.0, 95% confidence interval = 1.1-3.8) and carriers of this haplotype (patients, 27.5%; controls, 13.7%; odds ratio = 2.4, 95% confidence interval = 1.2-4.8), a significant positive association of PADI4 haplotype 4 with RA could be demonstrated. Other PADI4 haplotypes did not differ significantly between patients and controls. Regarding the individual PADI4 variants, padi4_89 (A-->G), padi4_90 (C-->T), and padi4_94 (C-->T) were significantly associated with RA (patients, 49.5%; controls, 38.7%; odds ratio = 1.6, 95% confidence interval = 1.1-2.3). Considering novel PADI4 variants located in or near to exons 2, 3, and 4, no quantitative or qualitative differences between RA patients (8.8%) and healthy controls (10.8%) could be demonstrated. While the PADI4 genotype did not influence disease activity and the anti-cyclic citrullinated peptide antibody level, the presence of the HLA-DRB1 shared epitope was significantly associated with higher anti-cyclic citrullinated peptide antibody levels (P = 0.033). The results of this small case-control study support the hypothesis that variability of the PADI4 gene may influence susceptibility to RA in the German population. Quantitative or qualitative differences in previously undefined PADI4 variants between patients and controls could not be demonstrated.

Adolescent↗

Anti-20S proteasome autoantibodies inhibit proteasome stimulation by proteasome activator PA28.

OBJECTIVE: The ubiquitin-proteasome system plays a central role in cellular homeostasis as well as in regulation of the inflammatory and stress responses. However, the occurrence of autoantibodies against 20S proteasome has, to date, been considered to be a non-specific epiphenomenon in patients with autoimmune disorders. This study was undertaken to analyze the properties of antiproteasome antibodies by investigating their influence on the proteolytic activity of the proteasome complex. METHODS: The 20S proteasome, with or without addition of the proteasome activator (PA28), was preincubated with affinity-purified human antiproteasome antibodies. Proteolytic activity was estimated using fluorogenic peptides as substrate. RESULTS: The baseline proteolytic properties of the 20S proteasome core complex were not influenced by the autoantibodies in vitro. In contrast, all human antiproteasome antibodies analyzed efficiently blocked the enhanced proteasomal substrate cleavage provided by PA28. A similar influence of proteasome activation was observed upon preincubation with affinity-purified sheep polyclonal or mouse monoclonal antiproteasome antibody, whereas human immunoglobulin controls exhibited no effect. CONCLUSION: Autoantibodies against 20S proteasomes are able to block proteasome activation by PA28, binding to their native antigen in vitro. Antibody targeting of the interaction between 20S proteasome and PA28 represents a novel mechanism of proteasome inhibition.

Antibody Specificity↗

Epratuzumab (humanised anti-CD22 antibody) in primary Sjögren's syndrome: an open-label phase I/II study.

This open-label, phase I/II study investigated the safety and efficacy of epratuzumab, a humanised anti-CD22 monoclonal antibody, in the treatment of patients with active primary Sjögren's syndrome (pSS). Sixteen Caucasian patients (14 females/2 males, 33-72 years) were to receive 4 infusions of 360 mg/m2 epratuzumab once every 2 weeks, with 6 months of follow-up. A composite endpoint involving the Schirmer-I test, unstimulated whole salivary flow, fatigue, erythrocyte sedimentation rate (ESR), and immunoglobulin G (IgG) was devised to provide a clinically meaningful assessment of response, defined as a > or = 20% improvement in at least two of the aforementioned parameters, with > or = 20% reduction in ESR and/or IgG considered as a single combined criterion. Fourteen patients received all infusions without significant reactions, 1 patient received 3, and another was discontinued due to a mild acute reaction after receiving a partial infusion. Three patients showed moderately elevated levels of Human anti-human (epratuzumab) antibody not associated with clinical manifestations. B-cell levels had mean reductions of 54% and 39% at 6 and 18 weeks, respectively, but T-cell levels, immunoglobulins, and routine safety laboratory tests did not change significantly. Fifty-three percent achieved a clinical response (at > or = 20% improvement level) at 6 weeks, with 53%, 47%, and 67% responding at 10, 18, and 32 weeks, respectively. Approximately 40%-50% responded at the > or = 30% level, while 10%-45% responded at the > or = 50% level for 10-32 weeks. Additionally, statistically significant improvements were observed in fatigue, and patient and physician global assessments. Further, we determined that pSS patients have a CD22 over-expression in their peripheral B cells, which was downregulated by epratuzumab for at least 12 weeks after the therapy. Thus, epratuzumab appears to be a promising therapy in active pSS, suggesting that further studies be conducted.

Adult↗

Heterozygous Arg753Gln polymorphism of human TLR-2 impairs immune activation by Borrelia burgdorferi and protects from late stage Lyme disease.

Lyme disease (LD) is caused by Borrelia burgdorferi and displays different stages, including localized, early disseminated, and persistent infection, all of which are associated with profound inflammatory reactions in the host. Induction of proinflammatory cytokines by B. burgdorferi is mainly mediated by outer surface proteins interacting with TLR-2/TLR-1 heterodimers. In this study, we show that TNF-alpha induction by Borrelia lysate was impaired in heterozygous TLR-2 knockout mice, while reactivity to lipoteichoic acid, another TLR-2 ligand signaling via TLR-2/TLR-6 heterodimers, was unaffected. Blood from individuals heterozygous for the TLR-2 polymorphism Arg753Gln was tested for cytokine release upon stimulation with Borrelia lysate, and induction of TNF-alpha and IFN-gamma was significantly lower as compared with individuals not exhibiting this variation. Overexpression of TLR-2 carrying the Arg753Gln polymorphism in HEK 293 cells led to a significantly stronger impairment of activation by TLR-2/TLR-1 ligands as compared with TLR-2/TLR-6 ligands. To study whether heterozygosity for the Arg753Gln variant of TLR-2 influenced susceptibility for LD, we analyzed 155 patients for this polymorphism. The Arg753Gln variant occurs at a significantly lower frequency in LD patients as compared with matched controls (5.8 vs 13.5%, odds ratio 0.393, 95% confidence interval 0.17-0.89, p = 0.033), with an even more pronounced difference when late stage disease was observed (2.3 vs 12.5%, odds ratio 0.163, 95% confidence interval 0.04-0.76, p = 0.018). These data suggest that Arg753Gln may protect from the development of late stage LD due to a reduced signaling via TLR-2/TLR-1.

Adult↗

A novel ultrasonographic synovitis scoring system suitable for analyzing finger joint inflammation in rheumatoid arthritis.

OBJECTIVE: To develop an ultrasonographic (US) synovitis scoring system suitable for evaluation of finger joint inflammation in patients with active rheumatoid arthritis (RA) and to compare semiquantitative US scoring with quantitative US measurements. METHODS: US was performed at the palmar and dorsal sides of the second through fifth metacarpophalangeal (MCP) and proximal interphalangeal (PIP) joints in 10 healthy subjects and in the clinically more affected hand in 46 RA patients. Ten patients additionally underwent magnetic resonance imaging (MRI). Synovitis was measured, standardized, and scored according to a semiquantitative method. The 2 methods (semiquantitative US scoring, quantitative US) were compared and statistical cutoffs were identified using receiver operating characteristic (ROC) curve analysis. MRI results were compared with semiquantitative US scoring and quantitative US results. The optimal US scoring method from 6 joint combinations was identified (ROC curve analysis). RESULTS: Synovitis was most frequently detected in the palmar proximal area (86% of affected joints). We found no significant differences between individual PIP joints or between individual MCP joints, indicating that all fingers within each of these joint groups should be treated equally for statistical calculations, although each joint group as a whole should be treated separately. The optimal cutoff point to distinguish between "health" and "pathology" was 0.6 mm both for MCP joints (sensitivity 94%, specificity 89%) and for PIP joints (sensitivity 90%, specificity 88%). There was no significant difference between semiquantitative US scores and quantitative US measurements. The best results for joint combinations were achieved using the "sum of 4 fingers" (second through fifth MCP and PIP joints) and "sum of 3 fingers" (second through fourth MCP and PIP joints) methods. Comparison of MRI results with semiquantitative US scores revealed high concordance. CONCLUSION: US evaluation of finger joint synovitis can be considerably simplified by focusing on the palmar side and by applying semiquantitative grading instead of quantitative measurements. For evaluation of treatment efficacy based on synovitis in RA patients, we recommend using the "sum of 3 fingers" method in longitudinal trials.

Adolescent↗

Sustained benefits of infliximab therapy for dermatologic and articular manifestations of psoriatic arthritis: results from the infliximab multinational psoriatic arthritis controlled trial (IMPACT).

OBJECTIVE: To investigate the efficacy and tolerability of infliximab therapy for the articular and dermatologic manifestations of active psoriatic arthritis (PsA). METHODS: One hundred four patients with PsA in whom prior therapy with at least 1 disease-modifying antirheumatic drug (DMARD) had failed were recruited into this investigator-initiated, multicenter, randomized, double-blind, placebo-controlled clinical trial. During the initial blinded portion of the study, patients received infusions of infliximab (5 mg/kg) or placebo at weeks 0, 2, 6, and 14. After week 16, patients initially assigned to receive placebo crossed over to receive infliximab 5 mg/kg every 8 weeks through week 50, while patients initially randomized to infliximab continued to receive active treatment at the same dose through week 50. The primary efficacy outcome was achievement of the American College of Rheumatology 20% criteria for improvement in rheumatoid arthritis (ACR20) at week 16. Additional predefined clinical efficacy assessments included the Psoriasis Area and Severity Index (PASI) score, the ACR50 and ACR70 criteria, the Disease Activity Score in 28 joints, the Health Assessment Questionnaire, ratings of enthesitis and dactylitis, and the Psoriatic Arthritis Response Criteria score. RESULTS: The proportion of infliximab-treated patients who achieved an ACR20 response at week 16 (65%) was significantly higher than the proportion of placebo-treated patients who achieved this response (10%). In addition, 46% of infliximab-treated patients achieved an ACR50 response, and 29% achieved an ACR70 response; no placebo-treated patient achieved these end points. Among patients who had PASI scores of >/=2.5 at baseline, 68% of infliximab-treated patients achieved improvement of >/=75% in the PASI score at week 16 compared with none of the placebo-treated patients. Continued therapy with infliximab resulted in sustained improvement in articular and dermatologic manifestations of PsA through week 50. The incidence of adverse events was similar between the treatment groups. CONCLUSION: Therapy with infliximab at a dose of 5 mg/kg significantly improved the signs and symptoms of arthritis, psoriasis, dactylitis, and enthesitis in patients with active PsA that had been resistant to DMARD therapy. With continued infliximab treatment, benefits were sustained through 50 weeks. The benefit-to-risk ratio appeared favorable in this study population.

Adult↗

Perspectives and limitations of gene expression profiling in rheumatology: new molecular strategies.

The deciphering of the sequence of the human genome has raised the expectation of unravelling the specific role of each gene in physiology and pathology. High-throughput technologies for gene expression profiling provide the first practical basis for applying this information. In rheumatology, with its many diseases of unknown pathogenesis and puzzling inflammatory aspects, these advances appear to promise a significant advance towards the identification of leading mechanisms of pathology. Expression patterns reflect the complexity of the molecular processes and are expected to provide the molecular basis for specific diagnosis, therapeutic stratification, long-term monitoring and prognostic evaluation. Identification of the molecular networks will help in the discovery of appropriate drug targets, and permit focusing on the most effective and least toxic compounds. Current limitations in screening technologies, experimental strategies and bioinformatic interpretation will shortly be overcome by the rapid development in this field. However, gene expression profiling, by its nature, will not provide biochemical information on functional activities of proteins and might only in part reflect underlying genetic dysfunction. Genomic and proteomic technologies will therefore be complementary in their scientific and clinical application.

Animals↗

Strategies using functional genomics in rheumatic diseases.

For functional genomics of inflammatory disorders and infection, rheumatic diseases offer unique features to analyse the transition from infection to chronic inflammation, autoimmunity and immunopathology, both systemic and tissue specific. The diseases are frequent and of considerable socio-economic impact. Well-defined cohorts of patients are available. The tissues and cells involved are readily accessible for molecular analysis. Both genetic predisposition and infection are involved in the aetiopathogenesis of rheumatic diseases. The number of susceptibility and severity genes has been estimated to be at least 30, but only few of them have been identified so far. There is an urgent need for developing new therapies adapted to genetic risk and based on a functional genetic and molecular understanding of chronic inflammation. It is evident that gene analysis in inflammatory rheumatic diseases will not only be beneficial for the large number of patients involved, but will also lead to a better understanding of other inflammatory disorders, thereby possibly leading to novel diagnostic and therapeutic strategies in this important group of disorders.

Animals↗

Rheumatoid factor revisited.

PURPOSE OF REVIEW: Initial studies of the pathogenesis of rheumatoid arthritis focused on the role of rheumatoid factor and immune complex-associated vasculitis and synovitis. Subsequent work has delineated T cell responses, the role of cytokines, chemokines, and the aggressive nature of rheumatoid synovitis. Recent findings underscore the importance of humoral immunity in this entity and are the subject of this review. RECENT FINDINGS: By the discovery of anti-cyclic citrullinated peptide, anti-RA33, and anti-GPI antibodies in the human and mouse systems, respectively, the impact of humoral autoimmunity in rheumatoid arthritis regained remarkable interest. This review summarizes recent insights into humoral autoimmunity in rheumatoid arthritis in the context of the generation of rheumatoid factors, including B cell activation via toll-like receptors and genetic predispositions that can trigger the induction of rheumatoid arthritis. The generation of rheumatoid factors that can also be found during host defense against infectious agents and under pathologic conditions, such as rheumatoid arthritis, Sjögren syndrome, and hepatitis C-associated mixed cryoglobulinemia after hepatitis C infection is likely the result of genetic predispositions and the intensity of the (primary) immune reaction. Models of the role of rheumatoid factors in health and disease, including related lymphomagenesis, will be discussed. SUMMARY: In patients with rheumatoid arthritis, the induction of rheumatoid factors can be taken as an indicator of severe disease with a striking involvement of B cell activation. Very recent clinical trials using B cell depletion support the concept that humoral immunity, as evidenced by the production of rheumatoid factors, plays a significant role in the course of the disease.

Animals↗

Correlation between circulating CD27high plasma cells and disease activity in patients with systemic lupus erythematosus.

OBJECTIVE: Disease activity in systemic lupus erythematosus (SLE) is usually assessed with complex disease activity scores comprising a variety of different parameters. In order to determine whether SLE disease activity correlates with abnormal B lymphocyte activity, B cell subsets were analyzed, and their relationship to clinical and humoral measures of disease activity was assessed. METHODS: The distribution of B cell subsets was determined by fluorescence-activated cell sorting analysis and assessed in relation to the autoantibody profile, disease activity measured by the SLE Disease Activity Index (SLEDAI) and the European Consensus Lupus Activity Measure scores, disease duration, and therapy. RESULTS: The number and frequency of CD27(high) plasma cells were significantly correlated with the SLE disease activity indices and with the titer of anti-double-stranded DNA (anti-dsDNA) autoantibodies. Circulating B cell subsets were not influenced by age or sex, but appeared to relate to the duration of disease and the therapeutic regimen, with the number and frequency of CD27(high) plasma cells increasing and those of CD27- naive B cells decreasing over time. Patients were divided into those with a SLEDAI score of 0-8 (low disease activity) and those with SLEDAI score >8 (high disease activity). Patients with high disease activity had an increased frequency of both CD19+ B cells and CD27(high) plasma cells. By using a nonparametric data sieving algorithm, we observed that these B cell abnormalities provided predictive values for nonactive and active disease of 78.0% and 78.9%, respectively. The predictive value of the B cell abnormalities (78.9%) was greater than that of the humoral/clinical data pattern (71.4%), including anti-dsDNA antibody levels, circulating immune complexes, increased erythrocyte sedimentation rate, mucocutaneous involvement, and acute renal involvement. CONCLUSION: Flow cytometric monitoring of B cell subsets in the peripheral blood provides new insights into abnormalities of B cell function in SLE and may also be a diagnostically valuable option for monitoring the activity of this autoimmune disease.

Adult↗

Detection of oncofetal h19 RNA in rheumatoid arthritis synovial tissue.

The expression of oncofetal H19 RNA and its localization/cellular source was analyzed in synovial tissue (ST) and isolated synovial macrophages (Mphi) or synovial fibroblasts (SFBs) by reverse transcriptase-polymerase chain reaction (RT-PCR), in situ hybridization, and immunohistochemistry. RT-PCR showed significantly higher H19 expression in ST from patients with rheumatoid arthritis (RA) (P = 0.000) and osteoarthritis (OA) (P = 0.009) than in normal/joint trauma controls (N/JT), but comparable levels in reactive arthritis. In situ hybridization demonstrated strong signals in all RA-ST samples (n = 8), with > or =85% positive cells in the lining layer, diffuse infiltrates, and stroma regions. In lymphoid aggregates and endothelial cells only 20% were positive. RA-ST contained a significantly higher percentage of strongly positive lining cells than OA-ST and N/JT-ST. H19 RNA was expressed in both Mphi and SFBs, as confirmed by RT-PCR in isolated RA Mphi and SFBs (n = 3). In RA-SFBs, low constitutive H19 RNA expression in culture (10% fetal calf serum) was strongly increased on starvation (3.5-fold, 1% fetal calf serum), with or without the addition of interleukin-1beta (10 to 100 U/ml), tumor necrosis factor-alpha (1 to 25 ng/ml), or platelet-derived growth factor-BB (2.5 to 10 U/ml). In OA-SFBs, this starvation-induced increase was lower (twofold), reaching significant differences compared with RA-SFBs after stimulation with interleukin-1beta and platelet-derived growth factor-BB. In both RA- and OA-SFBs, the MAP-kinase ERK-1/2 pathway and the phosphatidylinositol-3 kinase pathway influenced H19 RNA expression, as shown by inhibitor studies. Significant overexpression of H19 RNA and its increased sensitivity to starvation/cytokine regulation in RA suggests a pathogenetic role of this oncofetal gene, possibly reflecting embryonal dedifferentiation of the adult ST and/or ongoing inflammatory/oxidative stress.

Adult↗

The role of B cells in rheumatoid arthritis: mechanisms and therapeutic targets.

Our understanding of the role of B cells as part of the immune system has been remarkably expanded in the past few years. Autoimmunity, the production of autoantibodies or the activation and expansion of autoimmune T cells, is relatively common, whereas the development of autoimmune diseases with destruction of tissue is much less frequent. In rheumatoid arthritis, the autoantigen(s) involved in tissue damage and their role in disease have not been fully elucidated. Recent data suggest that the impact of B cells in rheumatoid arthritis may be of significance; therefore, a depleting anti-B cell therapy appears to be another therapeutic strategy. This review will focus on recent findings of the role of B cells in rheumatoid arthritis and the implications to target B cells in this disease.

Antirheumatic Agents↗

Analysis of immunoglobulin light chain rearrangements in the salivary gland and blood of a patient with Sjögren's syndrome.

Patients with Sjögren's syndrome (SS) have characteristic lymphocytic infiltrates of the salivary glands. To determine whether the B cells accumulating in the salivary glands of SS patients represent a distinct population and to delineate their potential immunopathologic impact, individual B cells obtained from the parotid gland and from the peripheral blood were analyzed for immunoglobulin light chain gene rearrangements by PCR amplification of genomic DNA. The productive immunoglobulin light chain repertoire in the parotid gland of the SS patient was found to be restricted, showing a preferential usage of particular variable lambda chain genes (V lambda 2E) and variable kappa chain genes (V kappa A27). Moreover, clonally related V(L) chain rearrangements were identified; namely, V kappa A27-J kappa 5 and V kappa A19-J kappa 2 in the parotid gland, and V lambda 1C-J lambda 3 in the parotid gland and the peripheral blood. V kappa and V lambda rearrangements from the parotid gland exhibited a significantly elevated mutational frequency compared with those from the peripheral blood (P < 0.001). Mutational analysis revealed a pattern of somatic hypermutation similar to that found in normal donors, and a comparable impact of selection of mutated rearrangements in both the peripheral blood and the parotid gland. These data indicate that there is biased usage of V(L) chain genes caused by selection and clonal expansion of B cells expressing particular V(L) genes. In addition, the data document an accumulation of B cells bearing mutated V(L) gene rearrangements within the parotid gland of the SS patient. These results suggest a role of antigen-activated and selected B cells in the local autoimmune process in SS.

Aged↗