J.W. Cohen Tervaert

Cardiovascular disease in autoimmune rheumatic diseases

Various autoimmune rheumatic diseases (ARDs), including rheumatoid arthritis, spondyloarthritis, vasculitis and systemic lupus erythematosus, are associated with premature atherosclerosis. However, premature atherosclerosis has not been uniformly observed in systemic sclerosis. Furthermore, although experimental models of atherosclerosis support the role of antiphospholipid antibodies in atherosclerosis, there is no clear evidence of premature atherosclerosis in antiphospholipid syndrome (APA). Ischemic events in APA are more likely to be caused by pro-thrombotic state than by enhanced atherosclerosis. Cardiovascular disease (CVD) in ARDs is caused by traditional and non-traditional risk factors. Besides other factors, inflammation and immunologic abnormalities, the quantity and quality of lipoproteins, hypertension, insulin resistance/hyperglycemia, obesity and underweight, presence of platelets bearing complement protein C4d, reduced number and function of endothelial progenitor cells, apoptosis of endothelial cells, epigenetic mechanisms, renal disease, periodontal disease, depression, hyperuricemia, hypothyroidism, sleep apnea and vitamin D deficiency may contribute to the premature CVD. Although most research has focused on systemic inflammation, vascular inflammation may play a crucial role in the premature CVD in ARDs. It may be involved in the development and destabilization of both atherosclerotic lesions and of aortic aneurysms (a known complication of ARDs). Inflammation in subintimal vascular and perivascular layers appears to frequently occur in CVD, with a higher frequency in ARD than in non-ARD patients. It is possible that this inflammation is caused by infections and/or autoimmunity, which might have consequences for treatment. Importantly, drugs targeting immunologic factors participating in the subintimal inflammation (e.g., T- and B-cells) might have a protective effect on CVD. Interestingly, vasa vasorum and cardiovascular adipose tissue may play an important role in atherogenesis. Inflammation and complement depositions in the vessel wall are likely to contribute to vascular stiffness. Based on biopsy findings, also inflammation in the myocardium and small vessels may contribute to premature CVD in ARDs (cardiac ischemia and heart failure). There is an enormous need for an improved CVD prevention in ARDs. Studies examining the effect of DMARDs/biologics on vascular inflammation and CV risk are warranted.

Immunologic, clinical, and radiologic status 14 months after cessation of natalizumab therapy

Objective: Natalizumab is a humanized recombinant monoclonal antibody against very late activation antigen-4 approved for the treatment of patients with multiple sclerosis (MS). A phase II study failed to demonstrate a difference between natalizumab treatment groups and the placebo group with regard to gadolinium enhancing lesions on MRI 3 months after discontinuation of therapy. The objective of this study was to assess clinical MS disease activity, surrogate disease markers on MRI, immunologic parameters in peripheral blood and CSF, as well as safety in patients with MS after discontinuation of natalizumab therapy. Methods: This study is a longitudinal and serial cross-sectional assessment, in which 23 patients who were treated with natalizumab in the context of two phase III clinical trials were originally enrolled. A subgroup of patients was followed over 14 months. The annual relapse rate, neurologic disease progression assessed by the Expanded Disability Status Scale, disease surrogate markers on MRI, cellular and humoral immune markers in peripheral blood and CSF, and adverse events of the drug were monitored. Results: With regard to clinical disease activity, neuroimaging, and immune responses, the majority of patients in our cohort were stable. Decreased lymphocyte cell numbers and altered cell ratios returned to normal 14 months after cessation of natalizumab. No infectious complications were observed. Conclusion: This is the first long-term follow-up of patients who discontinued natalizumab. We did not observe a clinical, radiographic, or immunologic rebound phenomenon after discontinuation of natalizumab therapy.

Antiendothelial cell antibodies in vasculitis and connective tissue disease

Antiendothelial cell antibodies (AECA) are a heterogeneous family of antibodies reacting with endothelial cell antigens. These antibodies are found in various diseases and recognise several antigen determinants. Different pathophysiological effects have been observed in in vitro experiments, which include direct or indirect cytotoxicity and endothelial cell apoptosis. Furthermore, some AECA activate endothelial cells, resulting in increased leucocyte adhesiveness, activation of coagulation and vascular thrombosis. In animal models, it has been shown that AECA could promote vascular damage. Neither the endothelial cell antigens nor their precise role in the pathogenecity of different diseases in which AECA are found is well characterised. Nowadays, it is not known whether AECA are an epiphenomenon accompanying vascular injury or whether they are pathogenic. It is controversial whether fluctuations in AECA titres are associated with disease activity during follow-up studies. This review summarises the present knowledge about AECA, AECA antigens and their potential role in the pathogenecity of vasculitis and connective tissue diseases.

Translational Mini‐Review Series on Immunology of Vascular Disease: Accelerated atherosclerosis in vasculitis

Premature atherosclerosis has been observed during the course of different systemic inflammatory diseases such as rheumatoid arthritis and sytemic lupus erythematosus. Remarkably, relatively few studies have been published on the occurrence of accelerated atherosclerosis in patients with vasculitis. In giant cell arteritis (GCA), mortality because of ischaemic heart disease is not increased. In addition, intima media thickness (IMT) is lower in patients with GCA than in age-matched controls. In contrast, IMT is increased significantly in Takayasu arteritis, another form of large vessel vasculitis occurring in younger patients. In Takayasu arteritis and in Kawasaki disease, a form of medium-sized vessel vasculitis, accelerated atherosclerosis has been well documented. In small vessel vasculitis because of anti-neutrophil cytoplasmic autoantibodies-associated vasculitis, cardiovascular diseases are a major cause of mortality. IMT measurements reveal conflicting results. During active disease these patients experience acceleration of the atherosclerotic process. However, when inflammation is controlled, these patients have atherosclerotic development as in healthy subjects. Several risk factors, such as diabetes and hypertension, are present more often in patients with vasculitis compared with healthy controls. In addition, steroids may be pro-atherogenic. Most importantly, many patients have impaired renal function, persistent proteinuria and increased levels of C-reactive protein, well-known risk factors for acceleration of atherosclerosis. Enhanced oxidation processes, persistently activated T cells and reduced numbers of regulatory T cells are among the many pathophysiological factors that play a role during acceleration of atherogenesis. Finally, autoantibodies that may be relevant for acceleration of atherosclerosis are found frequently in elevated titres in patients with vasculitis. Because patients have an increased risk for cardiovascular events, vasculitis should be treated with as much care as possible. In addition, treatment should be considered with angiotensin-converting-enzyme inhibitors and/or angiotensin receptor-1 blockers, statins and acetylsalicyl acid. Finally, classical risk factors for cardiovascular disease should be monitored and treated as much as possible.

A novel enzyme-linked immunosorbent assay using a mixture of human native and recombinant proteinase-3 significantly improves the diagnostic potential for antineutrophil cytoplasmic antibody-associated vasculitis

BACKGROUND Antineutrophil cytoplasmic antibodies (ANCA) with a C-ANCA or P-ANCA pattern are detected in ANCA-associated vasculitis (AAV). While in most patients with AAV a C-ANCA pattern is due to reactivity with proteinase-3 (PR3)-ANCA, some C-ANCA-positive sera do not react with PR3. OBJECTIVE The development and evaluation of a direct enzyme-linked immunosorbent assay (ELISA) for PR3-ANCA with increased sensitivity. METHODS A mixture of human native (hn) and human recombinant (hr) PR3 was used as antigen coating. The resulting ELISA (anti-PR3-hn-hr) was compared with ELISAs using directly coated hn-PR3 or hr-PR3, as well as with a hn-PR3 capture ELISA. Assay characteristics were determined in patients with AAV (n = 248), with special attention for those patients with C-ANCA (n = 132), as well as disease controls (n = 585) and healthy controls (n = 429). Additionally, for prediction of relapses serial samples of 46 patients with PR3-AAV were analysed. RESULTS At a predefined specificity of 99% both ELISAs containing hr-PR3 revealed a substantial increase in sensitivity. For the prediction of relapses by rises in PR3-ANCA titres the capture ELISA was most optimal (odds ratio 12.5). With an odds ratio of 8.9 the novel anti-PR3-hn-hr ELISA was second best. CONCLUSIONS Owing to the very high sensitivity of the novel anti-PR3-hn-hr ELISA for the detection of PR3-ANCA in C-ANCA-positive samples of patients with AAV this assay has an excellent diagnostic performance. This feature is combined with a good predictability of clinical relapses in patients with PR3-AAV. These characteristics challenge the dogma that, for detection of PR3-ANCA, capture ELISAs are superior for diagnosis and follow-up.

The therapeutic potential of targeting B cells and anti-oxLDL antibodies in atherosclerosis.

While the involvement of T cells in atherosclerosis is nowadays well accepted, little is known about the role of B cells. Obviously, B cells as the source of antibodies, in particular antibodies to oxLDL, have gained a lot of attention in atherosclerosis. In addition, B cells do harbour other functions in adaptive immunity. In this review, we provide an overview of the current knowledge on both the role of B cells and antibodies, i.e., anti-oxLDL antibodies, in atherosclerosis. It appears that B cells and also anti-oxLDL antibodies may comprise pro- and anti-atherogenic effects. Therefore, the establishment of effective therapy, targeting B cells or anti-oxLDL antibodies, warrants further research to unravel these opposite effects.

Evaluation of a Novel Line-Blot Immunoassay for the Detection of Antibodies to Extractable Nuclear Antigens

Abstract: We have evaluated the performance of a novel line‐blot immunoassay (LIA; Mikrogen) and compared results with those obtained by CIE (in‐house), ELISA (Pharmacia Diagnostics), and FEIA (Pharmacia Diagnostics). Sera from systemic lupus erythematosus (SLE) patients (n= 123), systemic sclerosis patients (n= 25), and healthy controls (n= 40) were analyzed for the presence of antibodies to RNP, Sm, SSA, SSB, CENP‐B, Scl‐70, and Jo‐1. Reading of LIA results, as compared with a cutoff control, was performed by automatic analysis of the test strips. Because LIA enables recognition of separate subunits of RNP (68, A, and C), Sm (B and D), and SSA (52 and 60), at least two of the RNP antigens and either one of the Sm or SSA antigens should be detected for considering the test RNP, Sm, or SSA‐positive, respectively. LIA had the highest sensitivity in patients with autoimmune connective tissue diseases: 131 specificities (not PO, PCNA, or histones), as compared with ELISA (121), FEIA (119), and CIE (80). However, LIA revealed three positive reactions in healthy controls; other assays were completely negative. LIA is better than CIE, but similar to ELISA and FEIA, in terms of detecting systemic sclerosis‐associated antibodies (CENP‐B and Scl‐70). Furthermore, LIA had the highest sensitivity (17.9%) for the SLE‐specific anti‐Sm antibodies, as compared with ELISA (11.4%), CIE (8.1%), and FEIA (5.7%). Finally, anti‐SSA antibodies were far more prevalent by LIA in the systemic sclerosis samples because of anti‐SSA52 reactivity. The clinical relevance of the latter finding remains to be determined. In conclusion, LIA is suitable for routine evaluation of autoantibodies to extractable nuclear antigens.

Silicone implant incompatibility syndrome (SIIS): a frequent cause of ASIA (Shoenfeld's syndrome).

Silicon has a molecular mass of 28 daltons. In nature, silicon is found as silicon dioxide (silica) or in a variety of silicates (e.g., in talc or asbestos). Furthermore, silicon is present in silicones, polymerized siloxanes, which are often used as medical silicones in breast implants. Silicon exposure is associated with different systemic autoimmune diseases such as systemic lupus erythematosus, rheumatoid arthritis, progressive systemic sclerosis, and vasculitis. Remarkably, silicon in silicone-filled breast implants is considered to be safe, not increasing the risk of developing autoimmune diseases. We analyzed the impact of silicone-filled breast implants on the immune system in 32 consecutive patients attending a specialized autoimmunity clinic. All 32 patients had silicone implant incompatibility syndrome and complaints fulfilling the diagnostic criteria of ASIA (autoimmune/inflammatory syndrome induced by adjuvants). Furthermore, in 17 of the 32 patients, a systemic autoimmune disease was diagnosed, and 15 of the 32 patients had an impaired humoral immune system. Patients developed symptoms and signs after long-term follow-up, suggesting that these symptoms and signs started after implant aging and/or rupture. We postulate that silicon in silicone-filled breast implants may increase the risk of developing (auto) immune diseases and immune deficiencies.

Evaluation of the FIDIS vasculitis multiplex immunoassay for diagnosis and follow-up of ANCA-associated vasculitis and Goodpasture's disease

Abstract:  We have evaluated a new‐multiplex immunoassay (FIDIS Vasculitis) for simultaneous detection and quantification of anti‐MPO, ‐PR3, and ‐glomerular basement membrane (GBM) antibodies in diagnosis and follow‐up of ANCA‐associated vasculitides (AAV) and Goodpastures disease. ANCA were determined in sera of (a) 87 consecutive patients with biopsy‐proven pauci‐immune NCGN and 72 controls; (b) 9 patients with Goodpastures disease; and (c) 60 WG patients and 60 controls, previously used in a multicenter comparison of direct and capture ELISA for PR3‐ANCA. Finally, for prediction of relapses, PR3‐ANCA was measured in samples preceding relapse in 23 PR3‐AAV patients and in 23 matched PR3‐AAV patients without relapse. The relative sensitivity of the FIDIS Vasculitis assay was 97.4% for MPO‐ANCA and 92.3% for PR3‐ANCA; specificity was 100% and 97.2%, respectively. Evaluation of the anti‐GBM antibody detection revealed a sensitivity of 100% and a specificity of 99.6%. The sensitivity for WG of the PR3‐ANCA detection (71.6%) approached the performance of capture ELISA (74%), although at the cost of specificity (96.7% versus 100%). For prediction of relapses a rise of 50% in ANCA level by FIDIS Vasculitis appeared optimal (ROC curve) for prediction of relapses. However, as compared to capture ELISA, both positive (63% versus 76%) and negative (68% versus 72%) predictive values were reduced. In conclusion, simultaneous detection of anti‐MPO, ‐PR3, and ‐GBM antibodies in the multiplex FIDIS Vasculitis assay has excellent performance in terms of diagnosis of patients with AAV or Goodpastures disease. However, detection of rises in PR3‐ANCA for prediction of relapses gives less optimal results when compared to capture ELISA.

Use of statins is associated with an increased risk of rheumatoid arthritis

Objectives Statins offer significant cardiovascular benefits. Their use, however, influences immune regulation, which may potentially facilitate autoimmunity, eventually resulting in autoimmune diseases such as rheumatoid arthritis (RA).The authors studied whether statin use was associated with an increased risk of developing RA by conducting a case–control study using the Netherlands Information Network of General Practice database. Methods The authors identified 508 patients aged 40 years or older with a first-time diagnosis of RA in the period 2001–2006. Each RA case was matched to five controls for age, sex and index date, which was selected 1 year before the first diagnosis of RA. Odds ratios for the first-time diagnosis of RA were verified by a referral to a rheumatologist and/or at least one prescription of disease-modifying anti-rheumatic drugs and/or two prescriptions of corticosteroids after the date of first diagnosis. Results Cases were more often users of statins (15.9%) compared to controls (8.6%). After adjustment for cardiovascular risk factors and use of comedication, statin use was associated with an increased risk of incident RA (adjusted OR, 1.71 (95% CI 1.16 to 2.53); p=0.007). A consistent trend of increasing risk with increased cumulative duration, cumulative defined daily doses and number of prescriptions was not observed. However, a small trend between the potency of statin treatment and the risk of RA was found. Conclusions Statin use seems to be associated with an increased risk of developing RA. Our findings should be replicated by additional studies.