Patients with antineutrophil cytoplasmic antibodies associated vasculitis in remission are hypercoagulable

Mechanisms and Screening for Atherosclerosis in Adults With Vasculitis

Vascular inflammation is a hallmark of both primary systemic vasculitis and atherosclerosis. As such, cardiovascular events are common in patients with vasculitis and likely due to both direct vascular inflammation and accelerated atherosclerosis. Direct cardiac involvement is possible in all vasculitides, though more commonly described in Takayasu arteritis, polyarteritis nodosa, and eosinophilic granulomatosis with polyangiitis. Accelerated atherosclerosis has been described in Takayasu arteritis and antineutrophil cytoplasmic antibody-associated vasculitis, though there remains a paucity of data in other forms of vasculitis. Multiple screening and management approaches for cardiovascular risk in people with vasculitis have been proposed, though evidence-based guidelines are lacking. In this review, we discuss the latest evidence in epidemiology, mechanisms, and screening for atherosclerosis in patients with primary systemic vasculitides.

Reproductive Health in Scleroderma, Vasculitis, and Sjögren Syndrome

ABSTRACT

Women with systemic chronic inflammatory disease, such as those with scleroderma, systemic vasculitis, and Sjögren syndrome, need preconception evaluation by a multidisciplinary team. Counseling and pregnancy management should be tailored to patients' needs, considering specific disease features, organ involvement, treatment options, and risk factors to minimize risks of maternal-fetal complications during pregnancy.Additionally, considerations regarding fertility, assisted reproductive techniques, and contraception also need to be addressed for these women.In this narrative review, we integrate the current published literature with our expert opinion to address the issues faced by patients with the aforementioned inflammatory conditions.

The intrinsic coagulation pathway plays a dominant role in driving hypercoagulability in ANCA-associated vasculitis

ABSTRACT

The risk of a venous thrombotic event (VTE) is increased in patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV); however, a detailed understanding of the underlying mechanisms of hypercoagulability is limited. We assessed prospectively different coagulation parameters in 71 patients with active AAV at baseline and after 6 months of follow-up. D-dimers and fibrinogen were increased in most patients at presentation and remained elevated in half of the patients. Particularly, thrombin-antithrombin (T:AT) complex and activated coagulation factors in complex with their natural inhibitors of the intrinsic coagulation pathway (ie, activated FXII:C1 esterase inhibitor [FXIIa:C1Inh], FXIa:AT, and FXIa:alpha1-antitrypsin [FXIa:α1AT]) were profoundly elevated in patients at baseline. Thrombin formation was dominantly correlated with coagulation factors of the intrinsic pathway (ie, FXIIa:AT, FXIa:AT, FXIa:α1AT, and FXIa:C1Inh) compared to the extrinsic pathway (ie, FVIIa:AT). Hypercoagulability correlated with higher disease activity, ANCA levels, C-reactive protein, serum creatinine, and proteinuria. VTEs were observed in 5 out of 71 (7%) patients within 1 month (interquartile range, 1-5) after inclusion. Baseline T:AT levels were significantly higher in patients with VTE than in those without VTE (P = .044), but other clinical or laboratory markers were comparable between both groups. Hypercoagulability is dominantly characterized by activation of the intrinsic coagulation pathway and elevated D-dimers in active AAV. The driving factors of hypercoagulability are yet to be studied but are most likely related to an interplay of increased disease activity, vascular inflammation, and endothelial damage. Future targets for intervention could include inhibitors of the intrinsic coagulation pathway and compounds specifically reducing the hyperinflammatory state.

Traditional and Disease-Specific Risk Factors for Cardiovascular Events in Antineutrophil Cytoplasmic Antibody-Associated Vasculitis: A Multinational Retrospective Study

OBJECTIVE

To investigate the occurrence of cardiovascular events (CVEs) in a large cohort of patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) across the European Union, China, Turkey, Russia, the United Kingdom, and the USA.

METHODS

Patients with a definite diagnosis of AAV who were followed for ≥ 3 months and had sufficient documentation were included. Data on myocardial infarction (MI) and stroke were collected retrospectively from tertiary vasculitis centers. Univariate and multivariate Cox regression models were used to estimate hazard ratios (HRs) and 95% CIs.

RESULTS

Over a median follow-up of 62.0 months (IQR 22.6-100.0), CVEs (mostly MIs) occurred in 245 (10.7%) of 2286 patients with AAV, with a higher frequency in China and the UK. On multivariate regression analysis, older age (55-64.9 yrs, HR 2.93, 95% CI 1.99-4.31), smoking (HR 1.98, 95% CI 1.48-2.64), Chinese origin (HR 4.24, 95% CI 3.07-5.85), and pulmonary (HR 1.50, 95% CI 1.09-2.06) and kidney (HR 3.02, 95% CI 2.08-4.37) involvement were independent variables associated with a higher occurrence of CVEs.

CONCLUSION

We showed that geographic region and both traditional and disease-specific (kidney involvement in particular) factors were independently associated with CVEs. Proper assessment and management of modifiable cardiovascular (CV) risk factors are essential for prevention of CV morbidity in patients with AAV.

Micro- and Macrovascular Effects of Inflammation in Peripheral Artery Disease-Pathophysiology and Translational Therapeutic Approaches

Inflammation has a critical role in the development and progression of atherosclerosis. On the molecular level, inflammatory pathways negatively impact endothelial barrier properties and thus, tissue homeostasis. Conformational changes and destruction of the glycocalyx further promote pro-inflammatory pathways also contributing to pro-coagulability and a prothrombotic state. In addition, changes in the extracellular matrix composition lead to (peri-)vascular remodelling and alterations of the vessel wall, e.g., aneurysm formation. Moreover, progressive fibrosis leads to reduced tissue perfusion due to loss of functional capillaries. The present review aims at discussing the molecular and clinical effects of inflammatory processes on the micro- and macrovasculature with a focus on peripheral artery disease.

[Diagnosis and therapy of granulomatosis with polyangiitis and microscopic polyangiitis-2023: consensus of the Austrian society of nephrology (ÖGN) and Austrian society of rheumatology (ÖGR)]

ANCA-associated vasculitides (AAV) are rare, complex systemic diseases that are often difficult to diagnose, because of unspecific clinical symptoms at presentation. However, the clinical course may be very dramatic and even life-threatening, necessitating prompt diagnosis and treatment.Therefore, it is important to increase disease awareness among physicians and support colleagues who are not confronted with these rare diseases on a regular basis. Here, the Austrian Society of Nephrology (ÖGN) and the Austrian Society of Rheumatology (ÖGR) provide a joint consensus on how to best diagnose and manage patients with granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA).

Traditional and disease-related cardiovascular risk factors in ANCA-associated vasculitis: A prospective, two-centre cohort study

OBJECTIVES

ANCA-associated vasculitis (AAV) has been associated with increased risk of cardiovascular (CV) events. The aim was to assess traditional and disease-related CV risk determinants in a two-centre prospective cohort of AAV patients.

METHODS

Patients were recruited from centres in the Netherlands and Canada. A comprehensive CV risk assessment was performed at inclusion. Subjects were followed up yearly for 3-5 years until the first CV event, death or end of follow-up. Cox proportional hazards analyses were performed to relate baseline characteristics to the first CV event.

RESULTS

A total of 144 patients were included (mean age 62 years, female sex 44%, median Framingham risk score 14.3%). Insulin resistance was present in 73% of patients tested at inclusion, independent of concurrent prednisone therapy. After a median follow-up of 2.90 years, 16 patients (11%) experienced a CV event (14 non-fatal and 2 fatal). The incidence of CV events was 5.45 per 100 patient-years. Age, Framingham risk score, HbA1c level, Diabetes Mellitus (DM), and previous CV event were significantly associated with CV events. Other factors, such as sex, impaired renal function, dyslipidemia, hypertension, smoking history and microalbuminuria, or disease-specific variables, like ANCA serotype or disease activity, were not significantly related to CV events in univariable or age-adjusted cox regression analysis.

CONCLUSIONS

Determinants of an increased CV risk were identified. Disease-related factors and treatments can further modify individual risk factors, such as for steroids causing chronic insulin resistance and DM. Treatment of risk factors is essential to optimize long-term outcomes in AAV patients.

A comprehensive guide for managing the reproductive health of patients with vasculitis

Vasculitides and their therapies affect all areas of the reproductive life cycle. The ACR, EULAR and the Drugs and Lactation database offer guidance on the management of the reproductive health of patients with rheumatic diseases; however, these guidelines do not address patients with vasculitis specifically. This Review discusses the guidance from multiple expert panels and how these recommendations might apply to men and women with vasculitis, including the safety of contraception, use of assisted reproductive technology, preservation of fertility during cyclophosphamide therapy, disease management in pregnancy and the use of medications compatible with pregnancy and lactation. These discussions are augmented by the existing literature on vasculitis in pregnancy to enable physicians to provide comprehensive, precise and high quality care to patients with vasculitis. The contents of this Review, in conjunction with educational tools, serve to empower patients and physicians to participate in shared decision-making regarding pregnancy prevention, planning and management.

This Review discusses how best to manage the reproductive health of patients with vasculitis, including the safety of contraception, the use of assisted reproductive technology, preservation of fertility during therapy, disease management in pregnancy and the use of medications compatible with pregnancy and lactation.

Rheumatologists have the opportunity to initiate discussions with patients with vasculitis regarding family planning to make proactive decisions leading to improved pregnancy planning, management and outcomes.

Birth control options and infertility interventions for women with vasculitis depend on their risk of thrombosis, serological profile and comorbid conditions.

The majority of pregnancies in patients with vasculitis can be successful with the use of advanced family planning, medications compatible with pregnancy and lactation, and multidisciplinary collaboration among specialists.

Vasculitis exacerbations and pregnancy complications can present with similar and overlapping clinical manifestations.

Multiple expert panels provide guidelines and risk stratification regarding medication use in pregnancy and breastfeeding that can be applied to patients with vasculitis.

Cytomegalovirus infection is a risk factor for venous thromboembolism in ANCA-associated vasculitis

BACKGROUND

Venous thromboembolism (VTE) is a common complication in patients with anti-neutrophil cytoplasm antibody (ANCA)-associated vasculitides (AAV) and confers significant morbidity and mortality. Both acute and past cytomegalovirus (CMV) infection have been identified as risk factors for VTE in immunocompetent and immunosuppressed individuals. Here, we examine whether past exposure to CMV is a risk factor for VTE amongst patients with AAV.

METHODS

We retrospectively analysed outcomes of patients with a new diagnosis of AAV from a UK cohort. All confirmed cases of VTE where CMV IgG serology was available were recorded. Retrospective collection of the same data for patients at a North American centre was used as a validation cohort.

RESULTS

VTE was common with 12% of patients from the study cohort (total 259 patients) developing an event during the median follow-up period of 8.5 years of which 60% occurred within the first 12 months following diagnosis. Sixteen percent of CMV seropositive patients developed a VTE compared with 5% of patients who were seronegative (p = 0.007) and CMV seropositivity remained an independent predictor of VTE in multivariable analysis (HR 2.96 [1.094-8.011] p = 0.033). CMV seropositivity at diagnosis was confirmed as a significant risk factor for VTE in the American validation cohort (p = 0.032).

CONCLUSIONS

VTE is common in patients with AAV, especially within the first year of diagnosis. Past infection with CMV is an independent risk factor associated with VTE in AAV.

Increased risk of venous thromboembolism in patients with granulomatosis with polyangiitis: A population-based study

We assessed the risk and time trends of venous thromboembolism (VTE) including pulmonary embolism (PE) and deep venous thrombosis (DVT) in new granulomatosis with polyangiitis (GPA) cases compared to the general population. Using a population-level database from the entire province of British Columbia, Canada, we conducted a matched cohort study of all patients with incident GPA with up to ten age-, sex-, and entry time-matched individuals randomly selected from the general population. We compared incidence rates of VTE, PE, and DVT between the two groups, and calculated hazard ratios (HR), adjusting for relevant confounders. Among 549 individuals with incident GPA (57.6% female, mean age 55.4 years), the incidence rates for VTE, PE, and DVT were 7.22, 2.73, and 6.32 per 1,000 person-years, respectively; the corresponding rates were 1.36, 0.74, and 0.81 per 1,000 person-years among the 5,490 non-GPA individuals. Compared with the non-GPA cohort, the fully adjusted HRs among GPA patients were 2.90 (95% CI, 1.10-7.64), 4.70 (95% CI, 1.74-12.69), and 1.66 (95% CI, 0.52-5.27) for VTE, PE, and DVT, respectively. The risks of VTE, PE, and DVT were highest during the first year after GPA diagnosis with HR (95% CI) of 11.04 (1.37-88.72), 26.94 (4.56-159.24), and 2.68 (0.23-31.21), respectively. GPA patients are at significantly increased risk of PE, but not DVT. Monitoring for these complications is particularly warranted in this patient population, especially early after diagnosis.

Recurrence rate of venous thromboembolic events in granulomatosis with polyangiitis

Objective

The incidence of first-time venous thromboembolic events (VTEs) is high in granulomatosis with polyangiitis (GPA). The incidence of recurrent VTEs is unknown. We aimed to describe the recurrence rate of second VTEs in patients with GPA.

Methods

Retrospective chart review was performed in patients with GPA and at least one VTE at a single centre from 2002 to 2016. Inclusion criteria were 1990 ACR criteria or 2012 Revised International Chapel Hill nomenclature for GPA, at least two follow-up visits, at least one VTE during the study period, and VTE occurrence after or within 3 months before GPA diagnosis. Second VTE event-free survival rates were estimated.

Results

Out of 147 patients initially screened for GPA and with at least one VTE, 84 met inclusion criteria. Median age at first VTE was 57 years. Incidence rate for second VTE was 8.4 events per 100 patient-years (95% CI: 5.7, 12.3). Eighty-three point three per cent of first VTEs and 57.7% of second VTEs occurred when disease was active (P < 0.001). Renal involvement and constitutional symptoms at the time of first VTE were associated with VTE recurrence.

Conclusion

GPA has a high rate of VTE recurrence compared with the reported data in the general population with unprovoked VTE. Our results suggest that VTE in GPA is a recurrent co-morbidity, not always during active vasculitis, and more so in those with renal involvement and constitutional symptoms at the time of first VTE.

Mechanisms of thrombosis in ANCA-associated vasculitis

Patients with anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) have a two- to threefold greater risk of developing venous as well as arterial thrombotic events. Although such thrombotic events are more commonly seen during phases of active AAV, they are also recognized to occur during AAV in remission. Endothelial injury is a key pathogenic event in AAV. Endothelial injury can be caused by neutrophil activation and release of thrombogenic tissue factor into the circulation. Neutrophil activation further results in the formation of neutrophil extracellular traps (NETs). NETs contribute to thrombosis by expressing tissue factor. NETs have also been detected in cutaneous thrombi from patients with AAV induced by hydralazine. Activated neutrophils in AAV patients release thrombogenic microparticles loaded with tissue factor which further enhances clotting of blood. Antiphospholipid antibodies (APLs) have been detected in up to a third of AAV and might also be induced by drugs such as cocaine adulterated with levamisole and propylthiouracil, which are known to trigger AAV. Such APLs further drive the thrombosis in AAV. Once thrombogenesis occurs, the homeostatic mechanisms resulting in clot dissolution are further impaired in AAV due to anti-plasminogen antibodies. The ongoing pandemic of coronavirus disease 2019 (COVID-19) is associated with endothelial injury and NETosis, mechanisms which are in common with AAV. Reports of new-onset AAV following COVID-19 have been described in the literature, and there could be shared mechanisms driving these processes that require further evaluation.

Thrombotic manifestations of VEXAS syndrome

VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) syndrome is a recently described autoinflammatory syndrome characterized by diffuse inflammatory manifestations, predisposition to hematological malignancy, and an association with a high rate of thrombosis. VEXAS is attributed to somatic mutations in the UBA1 gene in hematopoietic stem and progenitor cells with myeloid restriction in mature forms. The rate of thrombosis in VEXAS patients is approximately 40% in all reported cases to date. Venous thromboembolism predominates thrombotic events in VEXAS. These are classified as unprovoked in etiology, although systemic and vascular inflammation are implicated. Here, we review the clinical and laboratory characteristics in VEXAS that provide insight into the possible mechanisms leading to thrombosis. We present knowledge gaps in the mechanisms and management of VEXAS-associated thromboinflammation and propose areas for future investigation in the field.

Treatment-resistant venous thrombosis and pulmonary embolism in a patient with granulomatosis with polyangiitis: a case report

BACKGROUND

We herein present a case of venous thrombosis that developed more than 20 years after diagnosis of granulomatosis with polyangiitis (GPA), although many reports of GPA have described venous thrombosis within 1 year of diagnosis.

CASE PRESENTATION

A 73-year-old man with GPA was admitted for lower extremity swelling and diagnosed with venous thrombosis and pulmonary embolism. On the second day, catheter-based thrombolysis was unsuccessful, and inferior vena cava filter insertion and anticoagulation were performed. On the third day, respiratory disturbance and loss of consciousness appeared and progressed. The patient died on the fifth day. The autopsy revealed a large thrombus in the inferior vena cava filter, and death of progressive venous thrombosis was suspected.

CONCLUSIONS

We experienced a case of venous thrombosis that developed 20 years after diagnosis of GPA, although GPA is frequently associated with venous thrombosis immediately after diagnosis. The thrombosis progressed rapidly and was resistant to treatment.

Two Cases of Vasculitis with Renal Vein Thrombosis

We present a series of two cases of ANCA associated Vasculitis (AAV) presenting as Pulmonary Renal syndrome with associated renal vein thrombosis. Although there are enough evidences suggesting association of venous thrombosis with AAVs, the incidence of renal vein thrombosis is rare. Renal vein thrombosis should be ruled out in cases where there is delay in recovery of renal function in patients with AAV. Positive laboratory values for anti-Proteinase-3 (PR3) and anti-Myeloperoxidase (MPO) ANCA in the cases that presented as Rapidly Progressive Glomerulonephritis, helped in early initiation of treatment with complete recovery of Renal function.

[Thrombin generation assay in autoimmune disease]

Thrombin generation assay (TGA) is a useful tool to evaluate the initiation, propagation and inhibition of coagulation. TGA is a global test that is used to assess hemorrhagic risk in hemophilia patients, but it can also be used to study hypercoagulable states. The interest of TGA is to screen for cardiovascular risk, which is regularly associated with autoimmune disease (AID) such as antiphospholipid syndrome. Indeed, TGA has been used to evaluate hypercoagulability in patients with antiphospholipid syndrome treated with rivaroxaban versus warfarin. In other AIDs without thrombotic events, TGA measurement is elevated, mainly in rheumatoid arthritis (RA), systemic lupus erythematosus and Behçet's disease. These findings in RA are correlated with the inflammatory activity of the disease. In systemic lupus erythematosus and Behçet's disease, TGA appears to reflect disease activity. In conclusion, TGA remains relatively under used in the clinical evaluation of AID, but it could play a greater role in the evaluation of certain potentially thrombogenic treatments in AID. Finally, TGA helps measuring AID activity, due to the clearlink between coagulation and inflammation, despite some limitations of interpretation mainly due to a lack of standardization.

ANCA Status or Clinical Phenotype - What Counts More?

PURPOSE OF REVIEW

There is ongoing debate concerning the classification of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis. That is, whether classification should be based on the serotype (proteinase 3 (PR3)- or myeloperoxidase (MPO)-ANCA) or on the clinical phenotype (granulomatosis with polyangiitis (GPA) or microscopic polyangiitis (MPA)). To add clarity, this review focused on integration of the most recent literature.

RECENT FINDINGS

Large clinical trials have provided evidence that a serology-based risk assessment for relapses is more predictive than distinction based on the phenotype. Research conducted in the past decade indicated that a serology-based approach more closely resembles the genetic associations, the clinical presentation (i.e., lung involvement), biomarker biology, treatment response, and is also predicting comorbidities (such as cardiovascular death). Our review highlights that a serology-based approach could replace a phenotype-based approach to classify ANCA-associated vasculitides. In future, clinical trials and observational studies will presumably focus on this distinction and, as such, translate into a "personalized medicine."

Cardiovascular events and the role of accelerated atherosclerosis in systemic vasculitis

The spectrum of inflammatory blood vessel diseases includes both atherosclerosis and the primary systemic vasculitides. Although the inciting triggers differ, significant overlap exists in the mechanisms that contribute to sustained inflammation and vascular damage in both entities. With improvement in therapeutics to control acute vasculitis leading to longer survival, cardiovascular morbidity and mortality has emerged as the leading cause of death for vasculitis patients. Cardiovascular events likely occur as a consequence of vasculitis, vascular damage from prior inflammation causing a sustained procoagulant state, and accelerated atherosclerosis. In this review, we discuss the latest evidence regarding risk of cardiovascular events in patients with major forms of primary systemic vasculitis, and review the mechanisms by which accelerated atherosclerosis may occur.

The risk factors for early mortality and end-stage renal disease in anti-neutrophil cytoplasmic antibody-associated glomerulonephritis: experiences from a single center

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a common disease with high mortality. Kidney involvement in AAV commonly performances as ANCA-associated glomerulonephritis (AAGN). We aimed to identify the risk factors for mortality and end-stage renal disease(ESRD) within 6 months since diagnosis in AAGN patients. A total of 350 AAGN patients were enrolled in our center between 2004 and 2017 retrospectively. We analyzed the demographic, clinical and follow-up data. Factors for mortality and ESRD were investigated with univariate and multivariate Cox regression models. The median follow-up time was 60.8 (IQR 31.2, 84.5) months and 40 (11.4%) patients died within the first 6 months. In the multivariate analysis, age ≥ 65 years (HR = 2.245, 95%CI 1.085-4.645, P = 0.029), high leukocyte counts (HR = 1.089, 95%CI 1.015-1.168, P = 0.018), high Birmingham Vasculitis Activity Score (BVAS) (HR = 1.089, 95%CI 1.017-1.165, P = 0.014), infection (HR = 2.023, 95%CI 1.013-4.042, P = 0.046) and low serum albumin (HR = 0.916, 95%CI 0.845-0.992, P = 0.030) were independent risk factors for all-cause mortality in the first 6 months. A total of 95 patients reached ESRD within the first 6 months. The renal survival rate was 72.9% at 6 months. Multivariate analysis showed that high BVAS (HR = 1.198, 95%CI 1.043-1.376, P = 0.011), high daily urine protein (HR = 1.316, 95%CI 1.046-1.656, P = 0.019) and low eGFR (HR = 0.877, 95%CI 0.804-0.957, P = 0.003) were independent risk factors for ESRD. The mortality and ESRD rates were high in the first 6 months for AAGN patients. High disease activity evaluated by BVAS impacted both on patients' survival and renal survival, while over 65 years of age and infection were risk factors for mortality.

Pulmonary embolism and diffuse alveolar bleeding: combination options and therapy features

The analysis of the mechanisms of the formation of a rare clinical combination of pulmonary embolism (PE) and diffuse alveolar hemorrhage (DAH), which are complications of systemic vasculitis associated with antibodies to the cytoplasm of neutrophils (primarily granulomatosis with polyangiitis), systemic lupus erythematosus and secondary antiphlogistic syndrome primary antiphospholipid syndrome and Goodpastures syndrome. Taking into account the chronological sequence of the occurrence of PE and DAH, 3 variants of the onset of these potentially fatal additions to the underlying disease were considered: the anticipatory DAH development of PE, delayed from DAH PE and joint (within 24 hours) formation of PE and DAH. A review of single descriptions of such a combination of complications of granulomatosis with polyangiitis is carried out, criteria are indicated, a working classification of severity is given and, taking this into account, a modern program of therapy for DAH as an independent event and in combination with PE.

Comorbidities in ANCA-associated vasculitis

The prognosis of patients with ANCA-associated vasculitis has improved over the past decades, but overall survival rates are still unsatisfactory. Recent research has focused on complications of immunosuppressive measures and comorbidities of ANCA-associated vasculitis. This review focuses on thromboembolic and cardiovascular events. A considerably increased risk of thromboembolic events has been reported, which is associated with active disease and impaired coagulation factors. There is mounting evidence that a hypercoagulable state is present even in patients in remission, and studies investigating the impact of tailored anticoagulation are needed to reduce the burden of thromboembolism. Cardiovascular mortality is one of the leading causes of death and accelerated atherosclerosis is frequently observed in patients with ANCA-associated vasculitis. A high frequency of patients develops hypertension, diabetes mellitus and hypercholesterolaemia, either as a consequence of immunosuppression or associated with the underlying disease. The current control of modifiable cardiovascular risk factors is insufficient and thorough reviews should be performed periodically. Treatment of these risk factors should be adopted according to current recommendations related to individual cardiovascular risk prediction.

Association of venous thromboembolic events with skin, pulmonary and kidney involvement in ANCA-associated vasculitis: a multinational study

OBJECTIVE

To investigate the occurrence of venous thromboembolic events (VTE) in a large cohort of patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) across the European Union, Turkey, Russia, UK, and North America.

METHODS

Patients with a definite diagnosis of AAV who were followed for at least 3 months and had sufficient documentation were included. Data on VTE, including either deep vein thrombosis or pulmonary embolism, were collected retrospectively from tertiary vasculitis centers. Univariate and multivariate regression models were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

Over a median follow up of 63 (29; 101) months, VTE occurred in 278 (9.7%) of 2869 AAV patients with a similar frequency across different countries (from 6.3% to 13.7%), and AAV subtype (granulomatosis with polyangiitis: 9.8%; 95% CI 8.3-11.6, microscopic polyangiitis: 9.6%; 95% CI 7.9-11.4, and eosinophilic granulomatosis with polyangiitis: 9.8%; 95% CI 7.0-13.3). Most VTE (65.6%) were reported in the first-year post diagnosis. Multiple factor logistic regression analysis adjusted for sex and age showed that skin (OR 1.71, 95% CI 1.01-2.92), pulmonary (OR 1.78, 95% CI 1.04-3.14) and kidney involvement (eGFR 15-60 mL/min/1.73 m2, OR 2.86, 95% CI 1.27-6.47; eGFR < 15 mL/min/1.73 m2, OR 6.71, 95% CI 2.94-15.33) were independent variables associated with a higher occurrence of VTE.

CONCLUSION

Two thirds of VTE occurred during the initial phase of active disease. We confirmed previous findings from smaller studies that a decrease in kidney function, skin involvement and pulmonary disease are independently associated with VTE.

Deep vein thrombosis: An unusual way of revealing microscopic polyangiitis. Deep vein thrombosis in microscopic polyangiitis

Unexplained deep vein thrombosis may justify screening for antineutrophil cytoplasmic antibody-associated vasculitis as it can be an unusual presentation of this disease.

COVID-19, rheumatic diseases and immune dysregulation-a perspective

The COVID-19 pandemic has resulted in widespread hospitalisations and deaths around the world. As patients with rheumatic diseases generally have increased risk of infections and complications, understandably, there is significant concern of the impact of SARS-CoV-2 on these patients. However, there is a paucity of data in rheumatic patients. We review mechanisms through which SARS-CoV-2 results in infection, including ACE2 receptor, and complications (including immune dysregulation, thrombosis and complement activation). We assess these pathways in patients with rheumatic disease and those on immune modulating therapy. Although data thus far does not appear to show worse outcomes in rheumatic patients as a whole, given alterations in the underlying immune pathways in certain diseases (such as systemic lupus erythematosus), we posit that the risk is not equal in all rheumatic patients. We also discuss the benefit of underlying disease control with respect to COVID-19 risk reduction and potential increased risk of disease flares following viral infection from an immune standpoint.

Venous thromboembolism in anti-neutrophil cytoplasmic antibody-associated vasculitis: an underlying prothrombotic condition?

Objectives

We investigated the incidence and potential underlying risk factors of venous thromboembolism (VTE) in patients with AAV. We assessed haemostatic disturbances and factors that might contribute to the risk of development of VTE.

Methods

ANCA-positive AAV patients (n = 187) were included. Previously identified risk factors for VTE and current medication were retrieved from the medical records. We assessed haemostasis using different methods [endogenous thrombin potential (ETP), overall haemostatic potential (OHP), overall coagulation potential (OCP) and overall fibrinolysis potential (OFP)] in patients with active AAV (n = 19), inactive AAV (n = 15) and healthy controls (n = 15).

Results

Twenty-eight VTEs occurred in 24 patients over a total follow-up time of 1020 person-years. A majority of VTEs occurred within the first year after diagnosis. Old age (P < 0.01), ongoing prednisolone treatment and recent rituximab administration were more common in the VTE group (P < 0.05 for all). ETP and OHP were significantly increased and OFP significantly decreased in plasma from active compared with inactive AAV patients (P < 0.05, P < 0.01 and P < 0.05, respectively) and healthy controls (P < 0.001). We could not confirm previously reported risk factors for VTE development.

Conclusion

A high prevalence of VTE in AAV patients was seen within the first year after diagnosis, suggesting that disease activity contributes to development of VTE. Old age and concurrent treatment should also be taken into account when estimating VTE risk. The results also indicate disturbances in the haemostatic balance towards pro-thrombotic conditions in AAV patients, where ETP and OHP might be useful markers for identifying patients at high risk.

Comorbidities and health-related quality of life in Patients with Antineutrophil Cytoplasmic Antibody (ANCA) - associated vasculitis

BACKGROUND AND OBJECTIVES

The optimization of immunosuppressive therapies has led to a marked improvement in the survival of ANCA-associated vasculitides (AAV). The main issue now appears to be the management of comorbidities and the improvement of quality of life. The objective of this review was to investigate the incidence and the impact of AAV-associated comorbidities, as well as the determinants of health-related quality of life (HRQoL).

METHODS

We performed a systematic literature review of articles published in Medline from 2001 to 04/28/2020. We selected relevant articles about AAV-associated comorbidities as well as HRQoL and fatigue. For each selected article, data on the incidence of comorbidity were extracted, and factors associated with the Mental component score (MCS) and the Physical component score (PCS) were identified.

RESULTS

Among the 10,993 references identified, 103 were retained for the final analysis. A significant increase in cardiovascular risk was evidenced, particularly for coronary artery disease and thromboembolic events, especially during the active phase of the disease. AAV was also associated with bronchiectasis, thyroid diseases and osteoporosis. A marked decrease in HRQoL and an increase in fatigue and anxiety were reported. Decrease in PCS and MCS was associated with fatigue, mood disorders, sleep disturbance, and/or unemployment.

CONCLUSION

The excess mortality of AAV is still a concern, partly in connection with cardiovascular and thromboembolic comorbidities. AAV patients also experiment a reduction in their HRQoL that requires integrated management. Patients with AAV need comorbidity management strategies to improve their quality of life and outcomes.

Trends in the Inpatient Burden of Coronary Artery Disease in Granulomatosis With Polyangiitis: A Study of a Large National Dataset

OBJECTIVE

Cardiovascular (CV) diseases are serious comorbidities in patients with granulomatosis with polyangiitis (GPA). In a sample of patients hospitalized for GPA, we sought to examine trends in the burden of coronary artery disease (CAD) and its 2 serious manifestations, acute myocardial infarction (AMI) and heart failure (HF).

METHODS

We used the National Inpatient Sample to conduct a retrospective cross-sectional analysis. Our sample consisted of hospitalizations for GPA between 2005 and 2014. We examined trends in the proportion of CAD, AMI, and HF in all hospitalizations with GPA compared to those without GPA. We used logistic regression adjusted for potential confounders and included interaction terms.

RESULTS

Among a total of 103,453 GPA hospitalizations, 20,351 (19.7%) hospitalizations had a concurrent diagnosis of CAD. GPA with CAD was associated with overall lower burden of traditional CV risk factors compared to non-GPA with CAD, with the exception of chronic kidney disease (57% vs 21%). Over the 10-year study period, there were rising trends in the inpatient burden of CAD (16.6% in 2005 to 22.7% in 2014) and CAD with HF (4.3% in 2005 to 9.9% in 2014), but not AMI (1.2% in 2005 to 1.1% in 2014), in GPA hospitalizations compared to non-GPA controls.

CONCLUSION

In this national sample of GPA hospitalizations, we found that the burden of CAD and CAD with HF was on the rise over the 10-year period compared to non-GPA; however, it was not the case for AMI.

High incidence of venous thromboembolism but not of coronary artery disease in granulomatosis with polyangiitis in first years after diagnosis

Objectives

Granulomatosis with polyangiitis (GPA), previously known as Wegener's granulomatosis, is one of antineutrophil cytoplasmic autoantibody (ANCA) - associated vasculitis. In patients with GPA an increased incidence of venous thromboembolism (VTE), mainly during active disease, has been described. The aim of the present study was to assess the incidence of VTE and its relation with classic risk factors for atherosclerosis, presence of coronary artery disease (CAD), echocardiographic parameters and laboratory findings in GPA patients.

Methods

The group of consecutive patients with GPA were followed in the study. In all patients echocardiography and laboratory tests were performed.

Results

Ninety six patients with GPA were followed for mean 3 years. In 16 patients (16.6%) VTEs occurred in association with GPA, of which 56% occurred 6 months before or one year after diagnosis of GPA. Classic risk factors for atherosclerosis were present in 77 patients (80.2%) at some moment during follow-up. In patients with VTE there were larger right ventricle diameter (p=0.041) and higher right ventricle systolic pressure (p=0.022) observed. VTEs occurred significantly less frequently in patients treated with cyclophosphamide (p=0.049). In this study group VTE occurred more frequently than CAD: 16 (16.7%) vs. 4 (4.2%); p=0,0049. Patients with VTE were younger than those with CAD (p=0.053) and had higher levels of ANCA-PR 3 (p=0.016).

Conclusions

Patients with granulomatosis with polyangiitis in first years after diagnosis have higher risk of venous thromboembolism than coronary artery disease. This finding is probably related to hypercoagulability induced by the disease and its therapy.

Narrative Review of Hypercoagulability in Small-Vessel Vasculitis

Pauci-immune necrotizing and crescentic glomerulonephritis (GN) is the most common etiology of rapidly progressive GN. Clinical presentation in those afflicted is usually related to rapid loss of kidney function. We report the case of a 70-year-old woman who came to medical attention for signs and symptoms related to lower-extremity deep vein thrombosis (DVT). At presentation, the patient had biochemical abnormalities consistent with active GN, which quickly progressed to rapid loss in kidney function requiring renal replacement therapy. Kidney biopsy revealed small-vessel vasculitis with glomerular crescents. Serologic studies were negative for antineutrophil cytoplasmic antibody antibodies and other causes of acute GN. Plasmapheresis, immunosuppressive, and anticoagulant therapies were prescribed. Absence of other apparent end-organ involvement with vasculitis pointed toward renal-limited small-vessel vasculitis, yet presence of unprovoked DVT argues for systemic vascular inflammation. This case illustrates that venous thrombosis can be the presenting manifestation in patients with vasculitis and silent, severe end-organ involvement. The epidemiology and pathophysiology of venous thromboembolism in small-vessel vasculitis are discussed in this report.

An unusual neurological manifestation of granulomatosis with polyangiitis: A case report and literature review

Ischemic stroke is an incredibly rare manifestation of granulomatosis with polyangiitis. It is important for the clinician to be aware of this unusual complication so that efforts can be made to reduce the risk of this event.

Venous Thrombotic Events in ANCA-Associated Vasculitis: Incidence and Risk Factors

Background

The incidence of venous thromboembolism (VTE) is increased in ANCA-associated vasculitis (AAV). We assessed the frequency of VTE observed among patients with AAV evaluated at our center and identified risk factors.

Methods

Patients from the Johns Hopkins Vasculitis Center cohort who were evaluated between 1998 and 2018 and had a diagnosis of granulomatosis with polyangiitis (GPA) or microscopic polyangiitis (MPA) were eligible for analysis. Baseline demographics and clinical and serologic data were extracted. Univariate and multivariate analyses were performed to identify factors associated with VTE in AAV.

Results

A total of 162 patients with AAV were identified, 105 (65%) with GPA; 22 (14%) of these patients had a recorded VTE with a median time to VTE of 1 month. The mean (SD) age in the VTE versus non-VTE groups was 54±20 versus 55±17 years (P=0.99), 64% versus 60% female (P=0.93), 82% versus 49% PR3-ANCA positive (P=0.01), with a total mean BMI of 33.3±5.7 versus 28.3±6.1 kg/m2, (P<0.001) respectively. The median Birmingham Vasculitis Activity Score (BVAS version 3) was 19 versus 14 (P=0.02). Univariate analyses identified PR3-ANCA, rapidly progressive GN (RPGN), and hypoalbuminemia. In multivariate analysis, the significant associations with VTE included PR3-ANCA (OR, 4.77; P=0.02), hypoalbuminemia (OR, 4.84; P=0.004), and BMI (OR, 1.18; P<0.001).

Conclusions

VTE is a surprisingly common complication of AAV. PR3-ANCA and hypoalbuminemia are risk factors for developing VTEs. Further studies are needed to confirm these findings.

Podcast

This article contains a podcast at https://www.asn-online.org/media/podcast/K360/2020_04_30_KID0000572019.mp3.

Elevated levels of d-dimer are associated with inflammation and disease activity rather than risk of venous thromboembolism in patients with granulomatosis with polyangiitis in long term observation

PURPOSE

Granulomatosis with polyangiitis (GPA) is one of antineutrophil cytoplasmic autoantibody (ANCA) - associated vasculitis. The disease is characterized by necrotizing inflammation of small vessels causing tissue ischemia in a variety of organs. The aim of the present study was an evaluation of inflammation, coagulation and fibrinolysis biomarkers, and their possible associations with various clinical and laboratory parameters in GPA patients.

METHODS

A group of 100 consecutive patients with GPA were prospectively followed in the study. In all patients, echocardiography and laboratory tests were performed.

RESULTS

The patients were followed-up for a median of 4.0 ± 1.9 years. Circulating d-dimer concentrations were elevated in a majority (56%) of GPA patients, and were significantly higher in GPA patients in the active stage compared to those in remission (median 652 vs. 405 ng/ml, p = 0.0002). In 23 patients (23%) venous thromboembolism (VTE) was diagnosed during observation. However, there were no differences in d-dimer concentrations between patients with and without VTE either in active stage or in remission. Correlation analysis showed that the levels of d-dimer correlated with hs-CRP (r = 0.42, p < 0.0001) and creatinine concentrations (r = 0.58; p < 0.0001), but not with ANCA levels.

CONCLUSIONS

In patients with GPA elevated levels of d-dimer are associated with disease activity and inflammation rather than with the risk of venous thromboembolism. The value of d-dimer as a biomarker of venous thromboembolism episodes in patients with small vessel vasculitis is low.

Role of direct oral anticoagulants in patients with kidney disease

The anticoagulation field is experiencing a renaissance that began with regulatory approval of the direct thrombin inhibitor dabigatran, a direct oral anticoagulant (DOAC), in 2010. The DOAC medication class has rapidly evolved to include the additional approval of 4 direct factor Xa inhibitors. Commensurately, DOAC use has increased and collectively account for the majority of new anticoagulant prescriptions. Despite exclusion of patients with moderate-to-severe kidney disease from most pivotal DOAC trials, DOACs are increasingly used in this setting. An advantage of DOACs is similar or improved antithrombotic efficacy with less bleeding risk when compared with traditional agents. Several post hoc analyses, retrospective studies, claims data studies, and meta-analyses suggest that these benefits extend to patients with kidney disease. However, the lack of randomized controlled trial data in specific kidney disease settings, with their unique pathophysiology, should be a call to action for the kidney community to systematically study these agents, especially because early data suggest that DOACs may pose less risk of anticoagulant-related nephropathy than do vitamin K antagonists. Most DOACs are renally cleared and are significantly protein bound in circulation; thus, the pharmacokinetics of these drugs are influenced by reduced renal function and proteinuria. DOACs are susceptible to altered metabolism by P-glycoprotein inhibitors and inducers, including drugs commonly used for the management of kidney disease comorbidities. We summarize the currently available literature on DOAC use in kidney disease and illustrate knowledge gaps that represent important opportunities for prospective investigation.

Elevated Microparticle Tissue Factor Activity Differentiates Patients With Venous Thromboembolism in Anti-neutrophil Cytoplasmic Autoantibody Vasculitis

Introduction

Venous thromboembolism (VTE) is a life-threatening complication of anti-neutrophil cytoplasmic autoantibody (ANCA) vasculitis whose mechanism remains incompletely elucidated. We tested the hypothesis that elevated microparticle tissue factor activity (MPTFa) or anti-plasminogen antibodies (anti-Plg) may identify patients at risk for VTE.

Methods

In this prospective study, patients were enrolled during active disease and followed longitudinally. Twelve patients who experienced a VTE (VTE^pos) were compared with patients without VTE (VTE^neg, n = 29) and healthy controls (HC, n = 70). MPTFa, anti-Plg, interleukin-6, high-sensitivity C-reactive protein (hs-CRP), D-dimer, serum creatinine, and serum albumin were assessed. Fisher’s exact tests and Wilcoxon tests compared categorical and continuous variables, respectively. Cox regression for time to VTE or last follow-up was performed.

Results

VTE^pos patients had higher MPTFa (peak median = 14.0, interquartile range = 4.3–36.6) than HC (0, 0–3.5) and VTE^neg patients (0, 0–1.4). In time-to-event analysis, MPTFa was associated with VTE when measured during both active disease (hazard ratio [HR]; 95% confidence interval [CI]: 1.04; 1.01–1.08) and remission (1.4; 1.11–1.77). Anti-Plg during remission was also associated with VTE (1.17; 1.03–1.33). Each g/dl decrease of serum albumin was associated with a 4-fold increase in VTE risk (4.4; 1.5–12.9). Adjusting for estimated glomerular filtration rate (eGFR), anti-Plg during remission remained significantly associated with VTE.

Conclusion

Elevated MPTFa and increased anti-Plg in remission are strong indicators of VTE independent of renal function. Association of anti-Plg during remission with VTE implies hypercoagulability even during disease quiescence. Hypoalbuminemia strongly portends VTE risk, which is a novel finding in ANCA vasculitis. A thrombotic signature would allow improved management of patients to minimize VTE risk and complications of anticoagulation.

Platelets release proinflammatory microparticles in anti-neutrophil cytoplasmic antibody-associated vasculitis

OBJECTIVES

The biological functions of the platelets contributing to ANCA-associated vasculitis (AAV) are largely unclear. The current study aimed to investigate the potential role of platelet-derived microparticles (PMPs) in AAV.

METHODS

In the current study, microparticles in AAV patients were analysed by flow cytometry, and PMPs were probed for relative levels of 640 bioactive proteins secreted from patients' platelets using antibody microarrays. These data were then correlated with clinical and pathological parameters.

RESULTS

PMPs were significantly increased in 69 AAV patients, predominantly MPO-ANCA positive patients in active stage compared with in remission [4406.8/μl (2135.4, 5485.0) vs 549.7/μl (350, 708.5), P < 0.0001], and 43% of microparticles in active AAV were PMPs. Compared with 15 patients in remission, highly expressed proinflammatory molecules in the microparticles from platelets in 15 AAV patients in active stage revealed that potential functions of PMPs were promotion of the effect of chemotaxis, adhesion, growth and apoptosis (all the patients for array analysis were MPO-ANCA positive). The level of PMPs had a significant association with disease activity, inflammation, and renal damage.

CONCLUSION

PMPs may serve as inflammatory propagators through their wide production of proinflammatory cytokines in AAV, potentially providing a novel therapeutic target.

Risk of Cardiovascular Disease and Venous Thromboembolism Among Patients With Incident ANCA-Associated Vasculitis: A 20-Year Population-Based Cohort Study

OBJECTIVE

To assess the cardiovascular disease (CVD) and venous thromboembolism (VTE) risks among patients with newly diagnosed antineutrophil cytoplasmic antibodies (ANCA)-associated vasculitis (AAV).

PATIENTS AND METHODS

A population-based incident AAV cohort of 58 patients diagnosed between 1996 and 2015 in Olmsted County, MN, was identified by medical record review. For each patient, 3 age- and sex-matched non-AAV comparators were randomly selected from the same population and assigned an index date corresponding to the AAV incidence date. Medical records of cases and comparators were reviewed for CVD events, which included cardiac events (coronary artery disease, heart failure, and atrial fibrillation), cerebrovascular accidents (CVA), peripheral vascular disease (PVD), and VTE, which included deep vein thrombosis (DVT) and pulmonary embolism (PE).

RESULTS

Baseline total cholesterol, high-density lipoprotein, and current smoking rate were lower in AAV than in comparators (P=.03, P=.01, and P=.04, respectively), whereas other CVD risk factors and Framingham risk score were not significantly different between the 2 groups. The CVD events developed in 13 patients and 17 comparators, corresponding to a more than 3-fold increased risk (hazard ratio [HR], 3.15; 95% CI, 1.51-6.57). By subtypes, risks were increased for cardiac events (HR, 2.96; 95% CI, 1.42-6.15) and CVA (HR, 8.16; 95% CI, 2.45-27.15), but not for PVD. The HR for VTE was 3.26 (95% CI, 0.84-12.60), significantly increased for DVT (HR, 6.25; 95% CI, 1.16-33.60), but not for PE (HR, 1.33; 95% CI, 0.23-7.54).

CONCLUSION

Despite a similar prevalence of CVD risk factors at baseline, the risk of CVD is more than 3-fold higher and for CVA 8-fold higher in patients with incident AAV than in matched comparator subjects.

Clinical associations with venous thromboembolism in anti-neutrophil cytoplasm antibody-associated vasculitides

Objective

To assess potential associations for the development of venous thromboembolic events in patients with ANCA-associated vasculitides (AAV).

Methods

Four hundred and seventeen patients enrolled to participate in randomized controlled trials conducted by the European Vasculitis Society were identified. Univariate and multivariate analyses were performed to validate previously proposed and identify novel risks associated with venous thromboembolism (VTE) in AAV.

Results

VTE occurred in 41 of 417 (9.8%) patients. Uncorrected univariate analysis identified BVAS (odds ratio, OR = 1.05, 95% CI: 1.01, 1.10; P = 0.013), subsequent development of malignancy (OR = 2.6, 95% CI: 1.19, 5.71; P = 0.017), mucous membrane or eye involvement (OR = 2.13, 95% CI: 1.10, 4.11; P = 0.024) and baseline creatinine (OR = 1.08, 95% CI: 0.99, 1.18; P = 0.037) as being associated with the development of VTE. Multivariate analysis highlighted CRP (per 10 mg/l increase, OR = 1.05, 95% CI: 1.01, 1.09; P = 0.025), cutaneous involvement (OR = 4.83, 95% CI: 1.63, 14.38; P = 0.005) and gastrointestinal involvement (OR = 6.27, 95% CI: 1.34, 29.37; P = 0.02) among the BVAS items as well as baseline creatinine (per 100 µmol/l increase, OR = 1.17, 95% CI: 1.02, 1.35; P = 0.029) as being associated with VTEs.

Conclusion

Our results highlight a role of CRP, baseline creatinine, and cutaneous and gastrointestinal involvement in the risk stratification as being associated with thromboembolic events. Moreover, there might be an association between VTEs and subsequent development of malignancy and disease activity in general.

Endothelial progenitor cells are differentially impaired in ANCA-associated vasculitis compared to healthy controls

Background

Endothelial progenitor cells (EPC) are of major importance in vascular repair under healthy circumstances. Vascular injury in need of repair occurs frequently in ANCA-associated vasculitis (AAV). A specialized T cell subset enhancing EPC function and differentiation has recently been described. These angiogenic T cells (T_ang) may have an important impact on the vascular repair process. Therefore, the aim of our study was to investigate EPC and T_ang in AAV.

Methods

Fifty-three patients suffering from AAV and 29 healthy controls (HC) were enrolled in our study. Forty-four patients were in remission, nine patients were in active state of disease. Patients were either untreated or were under monotherapy with low-dose steroids (max. 5 mg/day) at the time of sampling. Circulating EPC and T_ang were determined by flow cytometry (FACS). The functional capacity of EPC was assessed by established cell culture methods.

Results

Circulating EPC were significantly decreased in AAV as compared to HC. The capacity of EPC to differentiate and proliferate was differentially impaired in patients as compared to HC. The outgrowth of endothelial colony-forming cells (ECFC) was severely decreased in patients whereas colony-forming units-endothelial cell (CFU-EC) outgrowth was unaffected. ECFC and CFU-EC differentiation was strictly T cell-dependent. Patients with a relapsing disease course had an impaired ECFC outgrowth and expansion of T_ang as compared to patients with a stable, nonrelapsing disease.

Conclusions

The differentiation process of EPC is impaired in AAV. This may favor insufficient vascular repair promoting a relapsing disease course. Finally, these factors may explain a higher cardiovascular morbidity as has been previously documented in AAV.

Proteinase 3-ANCA Vasculitis versus Myeloperoxidase-ANCA Vasculitis

In patients with GN or vasculitis, ANCAs are directed against proteinase 3 (PR3) or myeloperoxidase (MPO). The differences between PR3-ANCA-associated vasculitis (AAV) and MPO-AAV described in the past have been supplemented during the last decade. In this review, we discuss the differences between these two small-vessel vasculitides, focusing especially on possible etiologic and pathophysiologic differences. PR3-AAV is more common in northern parts of the world, whereas MPO-AAV is more common in southern regions of Europe, Asia, and the Pacific, with the exception of New Zealand and Australia. A genetic contribution has been extensively studied, and there is a high prevalence of the HLA-DPB1*04:01 allele in patients with PR3-AAV as opposed to patients with MPO-AAV and/or healthy controls. Histologically, MPO-AAV and PR3-AAV are similar but show qualitative differences when analyzed carefully. Clinically, both serotypes are difficult to distinguish, but quantitative differences are present. More organs are affected in PR3-AAV, whereas renal limited vasculitis occurs more often in patients with MPO-AAV. For future clinical trials, we advocate classifying patients by ANCA serotype as opposed to the traditional disease type classification.

Thrombosis in vasculitis: from pathogenesis to treatment

In recent years, the relationship between inflammation and thrombosis has been deeply investigated and it is now clear that immune and coagulation systems are functionally interconnected.

Inflammation-induced thrombosis is by now considered a feature not only of autoimmune rheumatic diseases, but also of systemic vasculitides such as Behçet’s syndrome, ANCA-associated vasculitis or giant cells arteritis, especially during active disease.

These findings have important consequences in terms of management and treatment. Indeed, Behçet’syndrome requires immunosuppressive agents for vascular involvement rather than anticoagulation or antiplatelet therapy, and it is conceivable that also in ANCA-associated vasculitis or large vessel-vasculitis an aggressive anti-inflammatory treatment during active disease could reduce the risk of thrombotic events in early stages.

In this review we discuss thrombosis in vasculitides, especially in Behçet’s syndrome, ANCA-associated vasculitis and large-vessel vasculitis, and provide pathogenetic and clinical clues for the different specialists involved in the care of these patients.