Safety and efficacy of readministration of infliximab after longterm continuous therapy and withdrawal in patients with ankylosing spondylitis

OBJECTIVE: To analyze the safety and efficacy of the anti-tumor necrosis factor agent infliximab in patients with ankylosing spondylitis (AS) after discontinuation of longterm therapy over 1 year and readministration, using clinical and laboratory assessments including serum levels of antibodies to infliximab (ATI). METHODS: Altogether 42/43 patients with AS in a 3-year multicenter trial discontinued therapy after continuous treatment with infliximab (5 mg/kg/6 wks). Infliximab was only readministered in case of a clinical relapse [judged by Bath AS Disease Activity Index (BASDAI) and physician global assessment > 4]. ATI were measured at different timepoints. The primary outcome was safety, and efficacy outcomes were secondary. RESULTS: One patient dropped out after the eighth infusion after retreatment due to repeated local infections. ATI were detected in this patient only. No other relevant adverse events were observed. One patient remained in clinical remission without therapy for more than 1 year. The other 40 patients (97.6%) were reinfused because of clinical relapse. There was no correlation between ATI and clinical measures. BASDAI 50% responses were seen in 25 (63%) and partial remission in 12 (30%) patients. The mean (+/- SD) BASDAI score dropped from 6.0 +/- 1.4 at the time of relapse to 2.6 +/- 2.0, and the median C-reactive protein from 11.2 to 1.8 mg/l after 1 year (all p < 0.05). CONCLUSION: Readministration of infliximab after discontinuation of longterm treatment was generally safe and efficacious. Ongoing remission after discontinuation was rare. There was only one patient with relevant adverse events. ATI were detected only in this patient, but there was no correlation to clinical data. Formation of ATI seems to be rare after longterm infliximab therapy in AS.     

Krankheitsmodifizierende Effekte bei der rheumatoiden Arthritis durch Glukokortikoide

Drugs used for managing rheumatoid arthritis (RA) are designated disease-modifying antirheumatic drugs (DMARDs) if they reduce inflammation and pain, limit joint destruction, and improve long-term disease outcome. Glucocorticoids have long been known to have anti-inflammatory, immunosuppressive, and pain-reducing effects. Moreover, they have been shown in recent clinical trials, and also very recently in a systemic analysis of the results of these studies, to contribute to inhibition of the radiographic progression of RA. For these reasons, glucocorticoids can be considered DMARDs if they are used to treat patients suffering from early RA and, according to the current knowledge, are used in combination with other DMARDs.     

Glycan profiling of anti–citrullinated protein antibodies isolated from human serum and synovial fluid

Objective

Anti–citrullinated protein antibodies (ACPA) exhibit unique specificity for rheumatoid arthritis. However, it is incompletely understood whether and how ACPA contribute to disease pathogenesis. The Fc part of human IgG carries 2 N‐linked glycan moieties that are crucial for the structural stability of the antibody and that modulate both its binding affinity to Fcγ receptors and its ability to activate complement. We undertook this study to analyze Fc glycosylation of IgG1 ACPA in serum and synovial fluid (SF) in order to further characterize the immune response to citrullinated antigens.

Methods

ACPA were isolated by affinity purification using cyclic citrullinated peptides as antigen. IgG1 Fc glycosylation was analyzed by mass spectrometry. ACPA IgG1 glycan profiles were compared with glycan profiles of total serum IgG1 obtained from 85 well‐characterized patients. Glycan profiles of paired SF and serum samples were available from 11 additional patients.

Results

Compared with the pool of serum IgG1, ACPA IgG1 lacked terminal sialic acid residues. In SF, ACPA were highly agalactosylated and lacked sialic acid residues, a feature that was not detected for total SF IgG1. Moreover, differential ACPA glycan profiles were detected in rheumatoid factor (RF)–positive and RF‐negative patients.

Conclusion

ACPA IgG1 exhibit a specific Fc‐linked glycan profile that is distinct from that of total serum IgG1. Moreover, Fc glycosylation of ACPA differs markedly between SF and serum. Since Fc glycosylation directly affects the recruitment of Fc‐mediated effector mechanisms, these data could further our understanding of the contribution of ACPA to disease pathogenesis.

     

Mutation and citrullination modifies vimentin to a novel autoantigen for rheumatoid arthritis

OBJECTIVE: Modification of antigens represents a trigger for the generation of autoantibodies. In the pathogenesis of rheumatoid arthritis (RA), citrullination of proteins has been shown to be a critical process, and the determination of antibodies against citrullinated antigens has been a diagnostic milestone. We undertook this study to determine whether antibodies to mutated and citrullinated vimentin (MCV) could serve as a diagnostic and prognostic marker for RA. METHODS: We identified novel isoforms of human MCV in the synovial fluid of RA patients. The significance of these disease-related modifications was investigated by the analysis of autoantibody reactivities. In a group of 1,151 RA patients, the diagnostic significance and the prognostic value of an anti-MCV enzyme-linked immunosorbent assay (ELISA) were compared with that of an anti-cyclic citrullinated peptide (anti-CCP) ELISA. RESULTS: In RA, sensitivities of 82% and 72% were calculated for the anti-MCV and anti-CCP assays, respectively. The specificity of both assays was comparable (98% and 96%, respectively). In followup analyses of 16 RA patients with moderate disease activity (mean Disease Activity Score in 28 joints [DAS28] of 2.72) and 26 RA patients with active disease (mean DAS28 of 5.07), disease stratification of RA was possible using the anti-MCV assay (P = 0.0084). A significant correlation of anti-MCV antibodies with the DAS28 was documented (r = 0.5334, P = 0.0003), in 42 RA patients (n = 427 antibody determinations at different time points). CONCLUSION: Antigenic properties of vimentin were determined by mutation and citrullination. Anti-MCV antibodies are a novel diagnostic marker for RA. Furthermore, they may allow monitoring and-if confirmed in even larger series of patients-stratification of disease.     

Adalimumab alone and in combination with disease-modifying antirheumatic drugs for the treatment of rheumatoid arthritis in clinical practice: the Research in Active Rheumatoid Arthritis (ReAct) trial

OBJECTIVE: To evaluate the safety and effectiveness of adalimumab alone or in combination with standard disease-modifying antirheumatic drugs (DMARDs) for the treatment of rheumatoid arthritis (RA). METHODS: Patients with active RA despite treatment with DMARDs or prior treatment with a tumour necrosis factor antagonist participated in a multicentre, open-label clinical study of adalimumab 40 mg every other week for 12 weeks with an optional extension phase. Patients were allowed to continue with pre-existing traditional DMARDs. Long-term safety results are reported for all patients (4210 patient-years (PYs) of adalimumab exposure). The observed effectiveness results at week 12 are reported using American College of Rheumatology (ACR) and European League Against Rheumatism (EULAR) response criteria. RESULTS: Among the 6610 treated patients, adalimumab was generally well tolerated. Serious infections occurred in 3.1% of patients (5.5/100 PYs, including active tuberculosis, 0.5/100 PYs). Demyelinating disease (0.06%) and systemic lupus erythematosus (0.03%) were rare serious adverse events. The standardised incidence ratio of malignancy was 0.71 (95% CI 0.49 to 1.01). The standardised mortality ratio was 1.07 (95% CI 0.75 to 1.49). At week 12, 69% of patients achieved an ACR20 response, 83% a moderate, and 33% a good EULAR response. Adalimumab was effective in combination with a variety of DMARDs. The addition of adalimumab to antimalarials was comparably effective to the combination of adalimumab and methotrexate. CONCLUSIONS: Considering the limitations of an open-label study, adalimumab alone or in combination with standard DMARDs appeared to be well tolerated and effective in 6610 difficult-to-treat patients with active RA treated in clinical practice.     

Neue Aspekte der molekularbiologischen Diagnostik Array-Technologie und Expressionsprofile für die Charakterisierung rheumatischer Erkrankungen Array-Technologie und Expressionsprofile für die Charakterisierung rheumatischer Erkrankungen

Die zunehmende Verfügbarkeit der Hochdurchsatz-Technologien, die exponentiell anwachsenden Informationen zum humanen Genom und der Genexpression, sowie die globale Vernetzung von Datenbanken mit strukturierten biomedizinischen Informationen wird die Betrachtungsweise entzündlich-rheumatischer Krankheitsbilder grundlegend ver?ndern. Es stehen bereits heute in mehreren Forschungslaboren erste Datens?tze zu umfangreichen Expressionsanalysen zur Verfügung. Der Umgang mit diesen Techniken lehrt, dass neben einer gewissenhaften Auswertung, Prüfung und Validierung der Ergebnisse auch auf Zellpopulationsebene eine anspruchsvolle Charakterisierung der Patienten nach besten konventionellen klinischen, labordiagnostischen, bildgebenden und insbesondere auch histologischen Methoden unabdingbar ist. Zur funktionellen Beurteilung werden invitro-Testsysteme, Tiermodelle und Medikamentenwirkungsstudien weiteren Aufschluss geben. Entwicklungsbedarf hat auch die bioinformatische Aufarbeitung der sich entwickelnden immensen Datenmengen. Das gesteckte Ziel ist, nach initialer genomweiter Betrachtung diejenigen Gene zu identifizieren, die zur Charakterisierung der Erkrankung, zur Einteilung nach molekular pathophysiologischen Gesichtspunkten, zur Beurteilung der Prognose und zur Entscheidungsfindung für das richtige therapeutische Vorgehen beitragen. Aus dem verbesserten Verst?ndnis über die molekularen Abl?ufe werden sich weitere und – so die Erwartung – entscheidende Ans?tze für eine effektive Therapie der chronischen Entzündung, Organ-Destruktion und pathologischen Immunantwort rheumatischer Erkrankungen ableiten lassen.     

Medical applications of transforming growth factor-beta

Transforming growth factor-beta (TGF-beta) proteins and their antagonists have entered clinical trials. These multi-functional regulators of cell growth and differentiation induce extracellular matrix proteins and suppress the immune system making TGF-betas useful in treatment of wounds with impaired healing, mucositis, fractures, ischemia-reperfusion injuries, and autoimmune disease. In diseases such as keloids, glomerulonephritis and pulmonary fibrosis, excessive expression of TGF-beta has been implicated as being responsible for accumulation of detrimental scar tissue. In these conditions, agents that block TGF-beta have prevented or reversed disease. Similarly, in carcinogenesis, blocking TGF-beta activity may be valuable in stimulating an immune response towards metastasis. As these blocking agents receive approval, we will likely have new therapies for previously recalcitrant diseases.