Absence of antiphospholipid/co-factor antibodies in Takayasu arteritis

The impact of antiphospholipid antibodies in Takayasu arteritis

BACKGROUND

The significance of antiphospholipid antibodies (aPL) is controversial in Takayasu arteritis (TA). This study was conducted to explore the frequency of aPL and their association with disease-related complications in TA.

METHODS

: This cross-sectional study was conducted to investigate the presence of anti-cardiolipin (aCL), anti-beta 2 glycoprotein- 1(aβ2G1) antibodies, and lupus anticoagulant (LA) in TA patients. TA patients admitted to the Department of Rheumatology of Hacettepe University Faculty of Medicine between December 2015 and September 2016 who fulfilled the American College of Rheumatology (ACR) classification criteria for TA were consecutively enrolled in the study. Patients were grouped according to aPL positivity and compared in terms of disease manifestations, type of vascular involvement at diagnosis, and vascular complications/interventions attributable to TA.

RESULTS

Fifty-three TA (49 female) patients were enrolled in the study. We detected 9 (16.9%) patients with IgM and/or IgG aβ2G1 and/or LA positivity. There were no patients with positive aCL. All aβ2G1 titers were low. There were no differences in terms of symptoms, signs, type of vascular involvement, the number of patients with disease-related complications or vascular interventions/surgery between aPL (+) and aPL(-) groups (p > 0.05 for all). The number of patients with thrombotic lesions was similar between the groups (p > 0.05). There were no patients with a history of venous thrombosis or on anticoagulant treatment in the aPL(+) group. Only 1 patient with IgM aβ2G1 (+) had a history of pregnancy loss.

DISCUSSION

Our results indicate that aPL positivity is not rare in TA. On the other hand, all aPL titers were low and no differences were found in the frequency of disease-related complications between aPL(+) and aPL(-) patient groups. Only TA patients with atypical manifestations with high suspicion of aPL-related complications should be considered to be investigated for aPL.

Microparticles from Endothelial Cells and Immune Cells in Patients with Takayasu Arteritis

AIM

This study was designed to analyze microparticles (MPs) from endothelial cells (EMPs) and immune cells from healthy individuals and paitents with Takayasu arteritis (TA), and any possible relationships between MPs and TA acitivity.

METHODS

MPs derived from the plasma of 51 subjects were analyzed, including 32 patients with TA and 19 healthy individuals. Flow cytometry was performed with Annexin (Anx)-V and antibodies against surface markers of endothelial cells (CD144), T cells (CD3), B cells (CD19), and monocytes (CD14).

RESULTS

The concentrations of total EMPs, AnxV＋ EMPs and AnxV- EMPs were significantly increased when comparing patients with TA and healthy controls (54×10³ vs. 32×10³ MPs /ml, P=0.0004; 22×10³ vs. 12×10³ MPs /ml, P=0.0006; and 31×10³ vs. 19×10³ MPs /ml, P=0.0005), and comparing active TA patients with remission ones (85×10³ vs. 45×10³ MPs /ml, P=0.016; 39×10³ vs. 14×10³ MPs /ml, P=0.0092; and 47×10³ vs.29×10³ MPs /ml, P=0.0371). In addition, the concentrations of total EMPs (odds ratio [OR]=1.024, 95% confidence interval [CI]: 1.001 to 1.048, P=0.037), AnxV＋(OR=1.089, 95%CI: 1.011 to 1.172, P=0.024), and AnxV- EMPs (OR=1.029, 95% CI: 1.002 to 1.056, P=0.034) were positively related to TA activity. With multiple linear regression analysis, platelet was associated with both total and AnxV- EMP concentrations independently, while erythrocyte sedimentation rate was independently correlated with AnxV＋EMPs.

CONCLUSION

Concentrations of endothelial microparticles are correlated with inflammation in Takayasu arteritis and may be useful markers to assess disease activity.

Updates in Pathophysiology, Diagnosis and Management of Takayasu Arteritis

BACKGROUND

Takayasu arteritis (TA) is a rare, systemic, inflammatory vasculitis of granulomatous nature, and still of unknown etiology. It mainly involves the aorta and its major branches and is more commonly seen in women of childbearing age and Asians. TA leads to stenosis, occlusion, or aneurysmal degeneration of large arteries, and its pathogenesis seems to be mainly due to an abnormal cell-mediated immunity, although other molecular and genetic abnormalities may contribute. The diagnosis and treatments lie on clinical and arteriographic findings. Because of its fluctuating course, both clinical scores and biomarkers are currently evaluated. The aim of this review is to report a comprehensive and methodologically robust state of the art about Takayasu arteritis, including the latest data and evidences in the definition, epidemiology, pathogenesis and etiology, clinical manifestations and classification, diagnosis, assessment of disease activity and progression, biomarkers, and treatment.

METHODS

We searched all publications addressing definition, epidemiology, pathogenesis, etiology, classification, diagnosis, biomarkers, and treatment of TA. Randomized trials, cohort studies, and reviews were contemplated to give a breadth of clinical data. PubMed and Scopus were searched from August 2010 to November 2015.

RESULTS

Of the 3,056 records found, 267 matched our inclusion criteria. After reading the full-text articles, we decided to exclude 169 articles because of the following reasons: (1) no innovative or important content; (2) no multivariable analysis; (3) insufficient data; (4) no clear potential biases or strategies to solve them; (5) no clear end-points; and (6) inconsistent or arbitrary conclusions. The final set included 98 articles.

CONCLUSIONS

This review presents the last updates in all fields of Takayasu arteritis. Still today, large areas of TA pathogenesis and disease-activity assessment need to be further investigated to better treat patients with TA.

Pathogenesis of Takayasu's arteritis: a 2011 update

While our knowledge of the pathogenesis of Takayasu's arteritis (TA) has considerably improved during the last decade, the exact pathogenic sequence remains to be elucidated. It is now hypothesised that an unknown stimulus triggers the expression of the 65kDa Heat-shock protein in the aortic tissue which, in turn, induces the Major Histocompatibility Class I Chain-Related A (MICA) on vascular cells. The γδ T cells and NK cells expressing NKG2D receptors recognize MICA on vascular smooth muscle cells and release perforin, resulting in acute vascular inflammation. Pro-inflammatory cytokines are released and increase the recruitment of mononuclear cells within the vascular wall. T cells infiltrate and recognize one or a few antigens presented by a shared epitope, which is associated with specific major Histocompatibility Complex alleles on the dendritic cells, these latter being activated through Toll-like receptors. Th1 lymphocytes drive the formation of giant cells through the production of interferon-γ, and activate macrophages with release of VEGF resulting in increased neovascularisation and PDGF, resulting in smooth muscle migration and intimal proliferation. Th17 cells induced by the IL-23 microenvironnement also contribute to vascular lesions through activation of infiltrating neutrophils. Although still controversial, dendritic cells may cooperate with B lymphocytes and trigger the production of anti-endothelial cell auto-antibodies resulting in complement-dependent cytotoxicity against endothelial cells. In a near future, novel drugs specifically designed to target some of the pathogenic mechanisms described above could be expanding the physician's therapeutic arsenal in Takayasu's arteritis.

Coronary involvement in Takayasu's arteritis

Coronary involvement may appear in up to a third of patients with Takayasu's arteritis. This affliction may have a dominant impact on the clinical manifestations of the patient. Occlusion of the ostia of the left main coronary artery and of proximal segments of the coronary arteries is the most frequent finding of the coronary vasculature in patients with Takayasu's arteritis. Beyond the vasculitic process enhanced atherosclerosis has a significant and detrimental impact on the disease development. Revascularizations are often unsuccessful particularly when the inflammatory disease is not under satisfactory control. New techniques have been developed in order to use vessels that have not been damaged by the disease as grafts.

Takayasu's arteritis: An update on physiopathology

Takayasu's arteritis (TA) is a chronic large vessel vasculitis. The physiopathology of TA has not been completely elucidated, but it appears to be multifactorial and to mainly involve cellular immunity. The pathologic sequence could implicate stimulation from an antigen that triggers heat shock protein (HSP)-65 expression in aortic tissue which, in turn, induces MHC class I-related chain A (MICA). T-cells and natural killer (NK) cells expressing NKG2D receptors could recognize MICA, resulting in acute inflammation. Pro-inflammatory cytokines released from these infiltrating cells induce matrix metalloproteinases and amplify the inflammatory response, inducing more MHC antigen and costimulatory molecule expression on vascular cells and, thus, recruiting more mononuclear cells. Alpha-beta T-cells then infiltrate and specifically recognize one or a few autoantigens presented by a shared epitope associated with specific MHC on the dendritic cells (DC). These DC simultaneously cooperate to some extent with B-cells and determine a humoral immunity mainly constituted by anti-endothelial cell autoantibodies that could trigger complement-dependent cytotoxicity against endothelial cells. The use of corticosteroids and of other immunosuppressive agents can bring TA into remission in most patients. A better understanding of the immunological mechanisms responsible for the vascular injury has led to trials of anti-TNF-alpha agents with encouraging results. In the near future, new drugs specifically designed to target some of the mechanisms described above may be able to expand the physician's therapeutic arsenal in TA.

Rare association of antiphospholipid syndrome and Takayasu arteritis

The antiphospholipid syndrome (APS) is characterized by obstetric and thrombotic complications in the presence of antiphospholipid antibodies. It can happen in an isolated way or in association with diffuse connective tissue diseases, mainly systemic lupus erythematosus. The association of APS with Takayasu arteritis (TA) is rarely described in the literature. We described a case of primary APS in a female patient who developed obstruction in large-size arteries, in spite of the use of oral anticoagulant, and increase of erythrocyte sedimentation rate, suggesting TA. The favorable response to prednisone treatment and later to infliximab reinforced the diagnosis of TA. The present report illustrates the existence of APS associated to TA, whose recognition is very important once the therapeutic strategy is radically different.

Takayasu Arteritis with High Titre of Antiphospholipid Antibodies and MTHFR Polymorphism

The association of antiphospholipid antibodies and Takayasu arteritis is very rare and few cases have been reported in the past. Though Takayasu arteritis patients were treated in the past with stenting, there have been no reports of patients with this association being treated with carotid stenting. We present here a young Bahraini female with Takayasu arteritis, primary antiphospholipid antibody syndrome and methylene tetrahydrofolate reductase C 677 T and A 1298 C polymorphism, who was treated with carotid stenting and anticoagulants.

Takayasu's disease

Takayasu's arteritis (TA) is a chronic inflammatory disease of unknown etiology that can produce stenosis, occlusion, or aneurysmal degeneration of large arteries. TA occurs worldwide but disproportionately affects young females of Asian descent. A variable acute phase of largely constitutional symptoms is followed by a chronic phase in which symptoms related to arterial compromise predominate. Diagnosis is made using a combination of clinical and angiographic criteria. Initial therapy involves the use of corticosteroids to induce remission of acute phase activity, with the addition of cytotoxic medications for nonresponders. Angioplasty and stenting can be used in the treatment of shorter stenoses such as those encountered in the renal arteries. Surgical bypass is the preferred treatment of longer segment stenoses and occlusions. Bypass grafts should originate from unaffected arteries to ensure durable inflow. Endovascular therapy is effective initially but long-term durability data are lacking.

Takayasu's arteritis

The frequency of Takayasu's arteritis (TA) has been estimated to be 2.9 cases per 1 million people, with a female preponderance, although female-to-male ratio varies from different geographic areas. A high frequency of haplotype A24-B52-DR2 has been found in Japanese patients, without this association in other populations. TA has a striking predilection for the aortic arch and its branches. Evidence favors an autoimmune pathogenesis. Segmental inflammation (active and inactive lesions) may coexist. Due to its enhanced resolution, magnetic resonance imaging and magnetic resonance angiography eventually will replace catheterization angiography. Mortality reduction with glucocorticoid treatment has not been firmly established.