Uri Arad

Efficacy and safety of vaccination against pandemic 2009 influenza A (H1N1) virus among patients with rheumatic diseases.

To assess the efficacy and safety of vaccination against pandemic H1N1 virus in patients with rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), psoriatic arthritis (PsA), and ankylosing spondylitis (AS) compared with healthy controls.

Prevalence of TNF-α Blocker Immunogenicity in Psoriatic Arthritis

Objective. The longterm use of tumor necrosis factor (TNF)-α blockers is limited by the formation of neutralizing antibodies. To the best of our knowledge, immunogenicity in psoriatic arthritis (PsA) has not been investigated in depth. Our objective was to evaluate the prevalence and significance of TNF-α blocker immunogenicity in PsA. Methods. Consecutive patients with PsA treated with either infliximab (IFX), adalimumab (ADA), or etanercept (ETN) > 3 months participated in our cross-sectional study. Their demographic and clinical characteristics, skin and joint disease activity, and records of use of methotrexate (MTX) and other medications were collected. Drug levels (ELISA) and antidrug antibodies (ADAb; Bridging ELISA) were evaluated before the next injection or infusion. Results. A total of 93 patients with PsA were recruited (48 receiving ADA, 24 IFX, and 21 ETN), with a mean age of 53 years (range 21–83 yrs), composed of 53% women. One-fourth of the patients were concomitantly treated with MTX. Altogether, 77% of the patients demonstrated therapeutic drug levels. High levels of ADAb were found in 29% of patients taking ADA, 21% taking IFX, and 0% taking ETN. ADAb significantly correlated with lower drug levels, higher 28-joint Disease Activity Scores, and higher global assessments. MTX use correlated significantly with a lower prevalence of ADAb. Conclusion. Significant levels of ADAb were present in up to 29% of patients with PsA treated with ADA or IFX. ADAb clearly correlated with low therapeutic drug levels and higher disease activity variables. The use of MTX significantly decreased ADAb prevalence, and its use should be strongly considered in combination with TNF-α blocker antibodies in patients with PsA.

Independent Sets in Hypergraphs with Applications to Routing via Fixed Paths

The problem of finding a large independent set in a hyper-graph by an online algorithm is considered. We provide bounds for the best possible performance ratio of deterministic vs. randomized and non-preemptive vs. preemptive algorithms. Applying these results we prove bounds for the performance of online algorithms for routing problems via fixed paths over networks.

Longterm Efficacy of an Antipneumococcal Polysaccharide Vaccine among Patients with Autoimmune Inflammatory Rheumatic Diseases.

Objective. To estimate the longterm humoral response of an antipneumococcal polysaccharide vaccine (PPSV23) in patients with rheumatoid arthritis (RA), psoriatic arthritis (PsA), ankylosing spondylitis (AS), or inflammatory bowel disease (IBD)-associated spondyloarthropathy (SpA), and the effect of demographic and clinical factors and treatment on the longterm efficacy of the vaccine. Methods. A total of 145 consecutive patients treated with biologics [tumor necrosis factor-α (TNF-α) or interleukin 6 (IL-6) receptor inhibitors] or methotrexate (MTX) participated in this study. Fifteen were excluded because of absent information regarding their vaccination status (n = 9) or because of technical problems in obtaining their serum sample (n = 6). They were diagnosed with RA (n = 63, 48.5%), PsA (n = 29, 22.3%), AS (n = 28, 21.5%), or IBD-associated SpA (n = 3, 2.3%). Their mean age was 54.6 years, and 61.5% were women. Data were collected on the timing of vaccination, demographic and clinical characteristics, and treatment, and patients’ serum antipneumococcal antibody levels were tested. Results. Two-thirds of the patients (67.7%) had received PPSV23 45 months (mean) earlier. Treatment included TNF-α inhibitors (73.9%), IL-6 receptor inhibitors (13.1%), or MTX without a biological treatment (13%). The uptake of vaccination was significantly higher in the older population (> 65 yrs). Vaccinated patients had significantly higher antibody levels compared with vaccine-naive patients. The antibody levels had been preserved after 10 years. MTX use, but not biologics, was associated with significantly lower antibody levels. Conclusion. The longterm efficacy of the PPSV23 vaccination seems to be preserved among patients with RA, PsA, AS, and IBD-associated SpA for at least 10 years. Efficacy is slightly impaired by MTX, but it is not affected by biologics. These findings suggest that revaccination after 5 years might not be needed for all, and testing the antibody titers should be considered to identify those who may benefit from revaccination.

Magnetic resonance imaging in diffuse idiopathic skeletal hyperostosis: similarities to axial spondyloarthritis

Diffuse idiopathic skeletal hyperostosis (DISH) is a non-inflammatory condition that involves calcification and ossification of the spinal ligaments and entheses. While, characteristic magnetic resonance imaging (MRI) lesions of the spine in patients with axial spondyloarthritis, another enthesitis-related disease, have been described and defined, there is a paucity of information regarding the MRI findings in DISH. The aim of this study was to describe the MRI findings of patients with DISH. We collected computed tomography studies with findings characteristic of DISH and that also had corresponding and concurrent MRI studies of the spine. For each patient, sagittal T1-weighted and STIR MRI sequences were evaluated for anterior/posterior vertebral corners of bone marrow edema (BME) and fat deposition. In total, we assessed 156 vertebral units in 10 patients that had both radiographic evidence of DISH and available MRI studies of the spine. Lesions consistent with BME corners were detected in five patients, and in three of them, three separate sites were involved, a finding that is suggestive of axial spondyloarthritis (SpA) according to the ASAS/OMERACT consensus statement. Fat deposition corners were detected in eight patients and in seven of them, several sites were involved. Spinal MRI lesions that are characteristic of axial SpA were commonly observed in a cohort of patients with DISH. This bears relevance to cases with diagnostic uncertainty and may imply overlapping pathogenetic mechanisms for new bone formation in both SpA and DISH. Further study is indicated to better characterize the similarities and differences between the MRI lesions of DISH and SpA.

Measurement of Cellular Immunity to Influenza Vaccination in Rheumatoid Arthritis; Comparison of Three Assays

Objective: Monitoring of immune responses is essential in the care of immunosuppressed individuals, including rheumatic patients. Evaluation of cellular immunity is essential for confirming virus-specific effector cell functions, but it is poorly standardized, and suffers from technical limitations and inaccurate results. There is, therefore, a need for reliable techniques for assessing cell-mediated immunity. In this study we compared the cell-mediated immunity response to influenza vaccine between a population of rheumatoid arthritis (RA) patients and healthy subjects by three methods. Methods: Trivalent influenza subunit vaccine was administered to 18 RA patients who were taking disease-modifying antirheumatic drugs and to 18 healthy controls. Peripheral blood mononuclear cells (PBMCs) and sera were obtained immediately before and ~28 days after vaccination. Cell-mediated immunity responses to vaccination were evaluated by (1) flow cytometric analysis of IL-2/IFN-γ production in activated CD4/CD8 T-cells, (2) enzyme-linked immunosorbent assay for the analysis of IFN-γ secretion, and (3) Granzyme B activity assay. Humoral response was evaluated by the hemagglutination inhibition assay. Results: Vaccination induced a significant increase in PBMC IFN-γ secretion and Granzyme B activity in the RA patients. Granzyme B activity also significantly increased in the controls, but there was no change in the levels of secreted IFN-γ. No group differences in the frequencies of IFN-γ/IL-2-producing activated CD4/CD8 T-cells were observed by flow cytometry. The geometric mean of hemagglutination inhibition antibody titers increased significantly for the H1N1/H3N2 influenza strains in both groups. Conclusions: Granzyme B activity assay was the only method to detect a significant cell-mediated immunity response in both groups while significant increase in IFN-γ secretion was demonstrated only in RA patients. Flow cytometric analysis failed to show IL-2 and IFN-γ production in both groups. Currently available methods for measuring cellular responsiveness to influenza vaccination are inconsistent and limited in their ability to reflect acquired cellular immunity.

Inhibition of nucleotide pyrophosphatase/phosphodiesterase 1: implications for developing a calcium pyrophosphate deposition disease modifying drug

Objectives Calcium pyrophosphate deposition (CPPD) is associated with osteoarthritis and is the cause of a common inflammatory articular disease. Ecto-nucleotide pyrophosphatase/phosphodiesterase 1 (eNPP1) is the major ecto-pyrophosphatase in chondrocytes and cartilage-derived matrix vesicles (MVs). Thus, eNPP1 is a principle contributor to extracellular pyrophosphate levels and a potential target for interventions aimed at preventing CPPD. Recently, we synthesized and described a novel eNPP1-specific inhibitor, SK4A, and we set out to evaluate whether this inhibitor attenuates nucleotide pyrophosphatase activity in human OA cartilage. Methods Cartilage tissue, chondrocytes and cartilage-derived MVs were obtained from donors with OA undergoing arthroplasty. The effect of SK4A on cell viability was assayed by the XTT method. eNPP1 expression was evaluated by western blot. Nucleotide pyrophosphatase activity was measured by a colorimetric assay and by HPLC analysis of adenosine triphosphate (ATP) levels. ATP-induced calcium deposition in cultured chondrocytes was visualized and quantified with Alizarin red S staining. Results OA chondrocytes expressed eNPP1 in early passages, but this expression was subsequently lost upon further passaging. Similarly, significant nucleotide pyrophosphatase activity was only detected in early-passage chondrocytes. The eNPP1 inhibitor, SK4A, was not toxic to chondrocytes and stable in culture medium and human plasma. SK4A effectively inhibited nucleotide pyrophosphatase activity in whole cartilage tissue, in chondrocytes and in cartilage-derived MVs and reduced ATP-induced CPPD. Conclusion Nucleotide analogues such as SK4A may be developed as potent and specific inhibitors of eNPP1 for the purpose of lowering extracellular pyrophosphate levels in human cartilage with the aim of preventing and treating CPPD disease.

Expression levels of selected genes can predict individual rheumatoid arthritis patient response to tumor necrosis factor alpha blocker treatment

Abstract Objectives: Rheumatoid arthritis (RA) patients have many therapeutic options; however, tools to predict individual patient response are limited. The Genefron personal diagnostic kit, developed by analyzing large datasets, utilizes selected interferon stimulated gene expressions to predict treatment response. This study evaluates the kit’s prediction accuracy of individual RA patients’ response to tumor necrosis alpha (TNFα) blockers. Methods: A retrospective analysis was performed on RA patients reported in published datasets. A prospective analysis assessed RA patients, before and 3 months after starting a TNFα blocker. Clinical response was evaluated according to EULAR response criteria. Blood samples were obtained before starting treatment and were analyzed utilizing the kit which measures expression levels of selected genes by quantitative real time polymerase chain reaction (PCR). ROC analysis was applied to the published datasets and the prospective data. Results: The Genefron kit analysis of retrospective data predicted the response to a TNFα blocker in 53 of 61 RA patients (86.8% accuracy). In the prospective analysis, the kit predicted the response in 16 of 18 patients (89% accuracy) achieving a EULAR moderate response, and in 15 of 18 patients achieving a EULAR good response (83.3% accuracy). ROC analysis applied to the two published datasets yielded an AUC of 0.89. ROC analysis applied to the prospective data yielded an AUC of 0.83 (sensitivity – 100%, specificity – 75%) The statistical power obtained in the prospective study was .9. Conclusion: The diagnostic kit predicted the response to TNFα blockers in a high percentage of patients assessed retrospectively or prospectively. This personal kit may guide selection of a suitable biological drug for the individual RA patient.

AB0138 Interferon-gamma challenge of PBMC from patients with lupus nephritis in remission decreases suppressor of cytokine signaling 1 (SOCS1) and regulatory t cells (TREGS) and promotes immune activation

Background Interferon-gamma (IFN-γ) plays an important role in the development of lupus nephritis (LN). Regulation of IFN-γ signaling that occurs in disease remission and in active LN is herein addressed. Objectives To study the impact of IFN-γ on PBMC obtained from patients with LN in remission as compared to active LN. Methods Sixteen patients fulfilling the ACR classification criteria for systemic lupus erythematosus were recruited. All patients had a history of LN of whom 10 were in remission (as defined by EULAR criteria) and 6 had active LN (as defined by SLEDAI-2K or BILAG). Healthy subjects (n=10) were included as a control group. Sera and PBMC were obtained from each individual. Flow cytometry, western blots and real time RT-PCR were used in processing and detection of cell subtypes, protein and mRNA levels. Recombinant human IFN-γ (rhIFN-γ) and anti-IFN-γ neutralizing antibody were used in vitro. Mann-Whitney and student t-tests were used for statistical analysis. Results In active LN there was a significant 2-fold increase in CD4+CD69+ activated T cells as compared to healthy subjects and patients in remission. Reactivity to interferon-gamma receptor was determined by the phosphorylation of its predominant transcription factor, signal transducer and activator of transcription 1 (STAT1) in the cells that were incubated with rhIFN-γ or with media alone. In active LN, 3- and 6-fold increase in pSTAT1 occurred with rhIFN-γ incubation during 24h and 48h, respectively, and healthy subjects responded likewise. In patients in remission, pSTAT1 increase was even higher (by 8- and 10-fold at 24h and 48h, respectively). After 24h incubation with rhIFN-g all groups had elevated (mRNA) expression of SOCS1, but at 48h, it significantly decreased in healthy subjects and in patients in remission by 34% and 50%, respectively. Further, at 24h the frequency of CD4+CD127lowFoxP3+ regulatory T cells (e.g. Tregs) increased by 27–30% in active LN and in healthy subjects, and in remission it was minimally changed. At 48h, the frequency of Tregs significantly decreased in healthy subjects (to baseline levels before rhIFN-γ challenge) and in patients in remission (by 24%, p=0.003). A challenge of PBMC from LN patients in remission with sera (at 1% concentration) derived from patients with active LN resulted in 7.5-fold increase in pSTAT1 expression and 20–30% decrease in Tregs, however, combination of sera and anti-IFN-g neutralizing antibody resulted in 5-fold decrease in pSTAT1 expression and significantly diminished the decrease in Tregs. Conclusions In LN in remission a challenge with IFN-γ could lead to immune activation and a risk of flare-up, as it results in a decrease in both SOCS1 and Tregs and a robust STAT1 phosphorylation. In active LN, STAT1 phosphorylation is less diminishing, as both SOCS1 and Tregs are saturated, which could affect their suppressive effectiveness. Disclosure of Interest None declared

AB0440 The fine line between takayasu and giant cell arteritis: a retrospective study

Background Takayasu arteritis (TAK) and Giant cell arteritis (GCA) are classified as two different vasculitides.[1] The differentiation is based on age at onset (under 40y for TAK, above 50y for GCA) and vascular distribution (aorta and its primary branches for TAK and mainly extracranial arteries for GCA). However, both diseases involve large vessels and share histopathology findings. Objectives Our goal is to describe a series of patients above the age of 50y with large vessel arteritis and vascular involvement typical of TAK. Methods Eighteen Patients (median age 64y, 16 females) were selected from 3 centers in Israel. A retrospective review of the cases was preformed with special emphasis on clinical characteristics (including clinical course and outcome), laboratory values and vascular involvement. Vascular imaging by CT angiography, MRI angiography or planar angiography was done in all cases. Results Five patients fulfilled the ACR criteria for GCA, 5 the ACR criteria for TAK, 3 both GCA and TAK criteria, while 5 patients had clear involvement of large vessels without fulfilling the criteria for either disease. The dominant presenting symptoms were constitutional, while only a few patients had cranial or peripheral symptoms. On physical examination, 61% had signs of vascular compromise including: blood pressure arm differences, non palpable limb pulses or vascular bruits. All patients had elevated acute phase reactants, 78% had anemia. Temporal artery biopsy showed giant cell arteritis in 6 out of 9 biopsies. The majority (78%) showed either involvement of the ascending aorta, the aortic arch, descending aorta or a combination of these. The distribution of vessel involvement was as following: carotid arteries in 9 patients, subclavian arteries in 12, axillary arteries in 5, abdominal aorta in 9, mesenteric or celiac trunk in 7, renal arteries in 3, iliac arteries in 7 and femoral arteries in 2. All the patients were treated with prednisone and 50% with steroid sparing drug. Nine out of 15 patients (60%) that have completed at least 1 year of follow-up achieved remission. Three additional patients had a partial remission. Three patients of the remission group relapsed. A comparison between the patients who fulfilled the ACR criteria for GCA and those who fulfilled for TAK showed that the first group was slightly older (70y vs. 64y) and had more constitutional symptoms while the second group had more peripheral symptoms and more vascular involvement signs in physical examination. The acute phase reactants were slightly higher in the GCA group. However, no substantial differences in the distribution of vascular involvement, type of treatment or outcome measures were observed. Conclusions Vascular involvement typical of TAK in patients above the age of 50y with large vessel arteritis seems to be more frequent than previously assumed. The differences between those who fulfill the criteria for each disease are minor. Our findings support the assumption that TAK and GCA represent a spectrum of the same disease. References Fries JF, Hunder GG, Bloch DA, et al. The ACR 1990 criteria for the classification of vasculitis. Arthritis Rheum. 1990;33:1135-6. Disclosure of Interest None Declared