Eugen Feist

Disturbed Peripheral B Lymphocyte Homeostasis in Systemic Lupus Erythematosus

In patients with active systemic lupus erythematosus (SLE), a marked B lymphocytopenia was identified that affected CD19+/CD27− naive B cells more than CD19+/CD27+ memory B cells, leading to a relative predominance of CD27-expressing peripheral B cells. CD27high/CD38+/CD19dim/surface Iglow/CD20−/CD138+ plasma cells were found at high frequencies in active but not inactive SLE patients. Upon immunosuppressive therapy, CD27high plasma cells and naive CD27− B cells were markedly decreased in the peripheral blood. Mutational analysis of V gene rearrangements of individual B cells confirmed that CD27+ B cells coexpressing IgD were memory B cells preferentially using VH3 family members with multiple somatic mutations. CD27high plasma cells showed a similar degree of somatic hypermutation, but preferentially employed VH4 family members. These results indicate that there are profound abnormalities in the various B cell compartments in SLE that respond differently to immunosuppressive therapy.

Rheumatoid factor revisited.

Purpose of reviewInitial 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 findingsBy 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. SummaryIn 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.

Emerging cell and cytokine targets in rheumatoid arthritis

Despite major progress in the treatment of rheumatoid arthritis (RA), strong unmet medical need remains, as only a minor proportion of patients reach sustained clinical remission. New approaches are therefore necessary, and include manipulation of regulatory T cells, which might be able to restore the disturbed immune system and could even lead to a cure if this restored regulation were to prove sustainable. Logistical and conceptual problems, however, beset this attractive therapeutic approach, including difficulties with ex vivo expansion of cells, specificity of targeting and the optimal time point of administration. Therefore, alternative avenues are being investigated, such as targeting B-cell effector functions and newly identified proinflammatory cytokines. On the basis of success with B-cell depleting therapy using anti-CD20 agents, further treatment modalities are now exploring direct or indirect interference in B-cell-mediated immunity with the use of agents directed against other B-cell surface molecules. Novel approaches target intracellular B-cell signalling and regulatory B cells. New cytokine-directed therapies target important proinflammatory mediators such as GM-CSF, new members of the IL-1 family, IL-6 and its receptor, IL-17, IL-20, IL-21, IL-23 as well as synovium-specific targets. This article reviews these emerging cell and cytokine targets with special focus on biologic agents, some of which might reach the clinic soon whereas others will require considerable time in development. Nevertheless, these exciting new approaches will considerably enhance our repertoire in the battle against this potentially devastating disease.

Effectiveness and safety of the interleukin 6-receptor antagonist tocilizumab after 4 and 24 weeks in patients with active rheumatoid arthritis: the first phase IIIb real-life study (TAMARA)

Objectives To confirm the effectiveness and safety of the interleukin 6-receptor antagonist tocilizumab in patients with rheumatoid arthritis (RA) in a setting close to real-life medical care in Germany. Methods A multicentre open-label phase IIIb study was undertaken. Patients with active RA with a 28-joint Disease Activity Score (DAS28) >3.2 despite previous disease-modifying antirheumatic drugs (DMARDs) were treated with tocilizumab 8 mg/kg every 4 weeks. The primary end point was the proportion of patients achieving LDAS ≤3.2 at week 24; secondary end points included American College of Rheumatology (ACR), European League Against Rheumatism (EULAR) or Clinical Disease Activity Index (CDAI) responses and decrease in acute phase. Analyses in subgroups such as rheumatoid factor (RF)-positive versus RF-negative patients and patients with an inadequate response to treatment with DMARDs (DMARD-IR) versus those with an inadequate response to tumour necrosis factor (TNF) antagonists (TNF antagonist-IR) were performed. Safety was assessed by adverse event documentation. Results 286 patients were treated and 83.6% completed the study. 41.6% had previously been treated with TNF antagonists. 57% of the intention-to-treat patients achieved the primary end point of LDAS, 47.6% achieved DAS remission <2.6 and a EULAR ‘good response’ was achieved by 54.9%; ACR50/70 response rates at week 24 were 50.7% and 33.9%, respectively. The mean±SD decrease in CDAI from baseline to week 24 was 71±29%. C reactive protein levels normalised rapidly within 1 week. Major improvements in fatigue, pain and morning stiffness were observed in the first 4 weeks and further improved until week 24. DAS28, EULAR and ACR responses at week 24 did not differ between RF-positive and RF-negative patients. TNF antagonist-naive patients responded better than patients who had previously failed on TNF antagonists. The safety profile of tocilizumab was comparable to that previously observed in the phase III trial programme. Serious infections were observed in 3.1% of patients. Conclusions Tocilizumab is highly effective in a setting close to real-life medical care with a rapid and sustained improvement in signs and symptoms of RA. A manageable safety profile was seen over the 24-week study period.

Identification of GP2, the major zymogen granule membrane glycoprotein, as the autoantigen of pancreatic antibodies in Crohn’s disease

Backround and aims: The aetiopathogenesis of Crohn’s disease, an inflammatory bowel disease (IBD), is not yet fully understood. Autoimmune mechanisms are thought to play a role in the development of Crohn’s disease, but the target antigens and the underlying pathways have not been sufficiently identified. Methods: Based on data from immunoblotting and matrix-assisted laser desorption ionisation time-of-flight (MALDI-TOF) mass spectrometry, the major antigenic target of pancreatic autoantibodies (PABs), which are specific for Crohn’s disease, was identified. Specificity of autoantibody reactivity was confirmed by enzyme-linked immunosorbent assay (ELISA) and indirect immunofluorescence (IIF) using purified rat and human recombinant GP2 synthesised in transiently transfected mammalian HEK 293 cells. Real-time polymerase chain reaction (rt-PCR) and IIF were used to detect mRNA and antigen localisation in human colon biopsies. Results: The major zymogen granule membrane glycoprotein 2 (GP2) was identified as the autoantigen of PABs in Crohn’s disease. PAB-positive sera from patients with Crohn’s disease (n = 42) displayed significantly higher IgG reactivity to rat GP2 in ELISA than either PAB-negative sera (n = 31), or sera from patients with ulcerative colitis (n = 49), or sera from blood donors (n = 69) (p<0.0001, respectively). Twenty-eight (66%) and 18 (43%) of 42 PAB-positive sera demonstrated IgG and IgA reactivity to human recombinant GP2 in IIF, respectively. Patients with PAB-negative Crohn’s disease (n = 31) were not reactive. GP2 mRNA transcription was significantly higher in colon biopsies from patients with Crohn’s disease (n = 4) compared to patients with ulcerative colitis (n = 4) (p = 0.0286). Immunochemical staining confirmed GP2 expression in human colon biopsies from patients with Crohn’s disease. Conclusion: Anti-GP2 autoantibodies constitute novel Crohn’s disease-specific markers, the quantification of which could significantly improve the serological diagnosis of IBD. The expression of GP2 in human enterocytes suggests an important role for anti-GP2 response in the pathogenesis of Crohn’s disease.

Automated evaluation of autoantibodies on human epithelial-2 cells as an approach to standardize cell-based immunofluorescence tests

IntroductionAnalysis of autoantibodies (AAB) by indirect immunofluorescence (IIF) is a basic tool for the serological diagnosis of systemic rheumatic disorders. Automation of autoantibody IIF reading including pattern recognition may improve intra- and inter-laboratory variability and meet the demand for cost-effective assessment of large numbers of samples. Comparing automated and visual interpretation, the usefulness for routine laboratory diagnostics was investigated.MethodsAutoantibody detection by IIF on human epithelial-2 (HEp-2) cells was conducted in a total of 1222 consecutive sera of patients with suspected systemic rheumatic diseases from a university routine laboratory (n = 924) and a private referral laboratory (n = 298). IIF results from routine diagnostics were compared with a novel automated interpretation system.ResultsBoth diagnostic procedures showed a very good agreement in detecting AAB (kappa = 0.828) and differentiating respective immunofluorescence patterns. Only 98 (8.0%) of 1222 sera demonstrated discrepant results in the differentiation of positive from negative samples. The contingency coefficients of chi-square statistics were 0.646 for the university laboratory cohort with an agreement of 93.0% and 0.695 for the private laboratory cohort with an agreement of 90.6%, P < 0.0001, respectively. Comparing immunofluorescence patterns, 111 (15.3%) sera yielded differing results.ConclusionsAutomated assessment of AAB by IIF on HEp-2 cells using an automated interpretation system is a reliable and robust method for positive/negative differentiation. Employing novel mathematical algorithms, automated interpretation provides reproducible detection of specific immunofluorescence patterns on HEp-2 cells. Automated interpretation can reduce drawbacks of IIF for AAB detection in routine diagnostics providing more reliable data for clinicians.

Mavrilimumab, a human monoclonal antibody targeting GM-CSF receptor-α, in subjects with rheumatoid arthritis: a randomised, double-blind, placebo-controlled, phase I, first-in-human study

Objective To evaluate the safety, tolerability, pharmacokinetic and pharmacodynamic profiles of mavrilimumab, a human monoclonal antibody targeting the granulocyte-macrophage colony-stimulating factor receptor-α, in subjects with rheumatoid arthritis (RA). Methods A randomised, double-blind, placebo-controlled, dose-escalating phase I study in subjects with RA who received stable methotrexate treatment for ≥3 months before enrolment. Subjects received single intravenous escalating doses of mavrilimumab (0.01–10.0 mg/kg) or placebo. Results 32 subjects were enrolled in this study (1 unblinded subject at 0.01 mg/kg and another at 0.03 mg/kg were followed by five sequential double-blinded cohorts, n=6 each, treated with 0.1, 0.3, 1.0, 3.0 and 10.0 mg/kg, respectively). Adverse events were mild or moderate and were reported with similar frequency across all treatment cohorts. One subject (10.0 mg/kg) experienced moderate face and neck urticaria during infusion that resolved with symptomatic treatment. Systemic clearance of mavrilimumab approached that of endogenous IgG at doses >1.0 mg/kg; pharmacodynamic activity was confirmed in the 1.0 and 3.0 mg/kg cohorts by suppression of suppressor of cytokine signalling 3 mRNA transcripts. In exploratory analyses, reductions of acute phase reactants were observed in subjects with elevated C-reactive protein (>5 mg/l) and erythrocyte sedimentation rate (≥20.0 mm/h) at baseline. No significant change in Disease Activity Score 28-joint assessment (DAS28) was seen in any of the cohorts. In mavrilimumab-treated subjects (n=15) with baseline DAS28 >3.2, mean disease activity (DAS28) was significantly reduced at 4 weeks. Conclusion In this first-in-human study, mavrilimumab showed preliminary evidence of pharmacodynamic activity. Importantly, the safety and pharmacokinetic profiles of mavrilimumab support further clinical studies in RA. Trial registration number: NCT00771420.

Tenosynovitis of the flexor tendons of the hand detected by MRI: an early indicator of rheumatoid arthritis

OBJECTIVE To evaluate the potential of MRI of finger and wrist joints for diagnosing early RA. MRI was evaluated as a stand-alone tool and in combination with ACR criteria and serum markers such as RF. METHODS Ninety-nine patients (31 men, 68 women; median age 46 years) with unspecified arthritis or suspected RA and negative X-ray findings were included. MR images of the hand and wrist of these patients were retrospectively evaluated for the presence of synovitis, erosions and tenosynovitis. The clinical diagnosis (early RA or non-RA) was made by a rheumatologist after clinical follow-up for 6-41 months. Clinical and laboratory data were collected from all patients. RESULTS Fifty-eight patients had a clinical diagnosis of RA and 41 were diagnosed as non-RA. Step-wise logistic regression of all MR parameters evaluated identified tenosynovitis of the flexor tendons to be the most powerful predictor of early RA (sensitivity = 60%, specificity = 73%). Including ACR criteria in the analysis, positive serum RF and tenosynovitis were the strongest predictors of early RA (sensitivity = 83%, specificity = 63%). When serum anti-cyclic citrullinated peptides (CCP), ANA and CRP were included as additional parameters, anti-CCP and flexor tenosynovitis were the strongest predictors of early RA (sensitivity = 79%, specificity = 73%). CONCLUSIONS Flexor tenosynovitis diagnosed by MRI of the hand is a strong predictor of early RA. Combining flexor tenosynovitis on MRI with positive serum anti-CCP or positive RF is an even stronger predictor of early RA.

Magnetic resonance imaging of active sacroiliitis: Do we really need gadolinium?

INTRODUCTION Magnetic resonance imaging (MRI) of active inflammatory changes of the sacroiliac joint (SIJ) in spondyloarthritis (SpA) is performed with short tau inversion recovery (STIR) sequences and fat-saturated T1-weighted fast spin-echo (FSE) sequences after administration of gadolinium-based contrast medium (T1/Gd). The aim of the present study was to compare these two pulse sequences in terms of diagnosis, diagnostic confidence, and quantification of inflammatory changes. MATERIALS AND METHODS The study included 105 patients with suspected SpA; 72 patients developed clinical SpA over time. All patients were examined with STIR and T1/Gd and each of the two sequences was analyzed separately in conjunction with unenhanced T1 FSE images. For quantitative estimation of inflammatory changes, each sacroiliac joint (SIJ) was divided into 4 quadrants (and severity per quadrant was assigned a score of 0-4, resulting in a maximum sum score of 16 per SIJ). Diagnostic confidence was assessed on a visual analogue scale ranging from 0 to 10. RESULTS Active sacroiliitis was diagnosed in 46 patients and ruled out in 34 using STIR, whereas findings were inconclusive in 25 patients. The corresponding numbers for T1/Gd were 47, 44, and 14. Diagnostic confidence was significantly lower for STIR (7.3+/-2.6) compared with T1/Gd (8.7+/-1.9) (p<0.001). The sum scores were 2.5 (+/-3.3) for STIR and 2.2 (+/-3.2) for T1/Gd for the right SIJ and 2.2 (+/-2.9) (STIR) and 1.9 (+/-3.1) (T1/Gd) for the left SIJ. Agreement was high with intraclass correlation coefficient (ICC) values of 0.86 for the right SIJ and 0.90 for the left SIJ and positive correlation (r=0.62 right, 0.60 left). SUMMARY STIR sequences alone are sufficient for establishing a reliable diagnosis and quantify the amount of inflammation in active sacroiliitis. A contrast-enhanced study is dispensable in patients with established disease or in the setting of clinical follow-up studies. However, a contrast-enhanced MR sequence is beneficial to ensure maximum diagnostic confidence when patients with early sacroiliitis are examined.

IL1-receptor antagonist anakinra provides long-lasting efficacy in the treatment of refractory adult-onset Still’s disease

New therapeutic strategies are required in the management of adult-onset Still’s disease (AOSD) refractory to glucocorticoids, disease-modifying antirheumatic drugs (DMARDs) or anti-tumour necrosis factor α antagonists (anti-TNFs). It has been suggested that interleukin 1 (IL1) plays a key role in the maintenance of the chronic inflammatory diseases, providing a rationale for an IL1-blocking therapy.1 2 Anakinra, an IL1 receptor antagonist (IL1-RA) approved for the treatment of rheumatoid arthritis,3 has shown promising results in small cohorts of patients with AOSD.4 5 6 7 8 However, it is unclear whether these effects can be sustained over a long treatment period. We report rapid and long-lasting responses to anakinra in eight patients with AOSD refractory to glucocorticoids, DMARDs and/or anti-TNFs. From December 2004, eight consecutive patients with refractory adult-onset …