Evidence-Based Guideline for the diagnosis and management of eosinophilic granulomatosis with polyangiitis.

Eosinophilic granulomatosis with polyangiitis (EGPA) is a rare anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis, characterized by asthma, eosinophilia and granulomatous or vasculitic involvement of several organs. The diagnosis and management of EGPA are often challenging and require an integrated, multidisciplinary approach. Current practice relies on recommendations and guidelines addressing the management of ANCA-associated vasculitis and not specifically developed for EGPA. Here, we present evidence-based, cross-discipline guidelines for the diagnosis and management of EGPA that reflect the substantial advances that have been made in the past few years in understanding the pathogenesis, clinical subphenotypes and differential diagnosis of the disease, as well as the availability of new treatment options. Developed by a panel of European experts on the basis of literature reviews and, where appropriate, expert opinion, the 16 statements and five overarching principles cover the diagnosis and staging, treatment, outcome and follow-up of EGPA. These recommendations are primarily intended to be used by healthcare professionals, pharmaceutical industries and drug regulatory authorities, to guide clinical practice and decision-making in EGPA. These guidelines are not intended to limit access to medications by healthcare agencies, nor to impose a fixed order on medication use.

Identification of Functional and Expression Polymorphisms Associated With Risk for Antineutrophil Cytoplasmic Autoantibody-Associated Vasculitis.

OBJECTIVE: To identify risk alleles relevant to the causal and biologic mechanisms of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). METHODS: A genome-wide association study and subsequent replication study were conducted in a total cohort of 1,986 cases of AAV (patients with granulomatosis with polyangiitis [Wegener's] [GPA] or microscopic polyangiitis [MPA]) and 4,723 healthy controls. Meta-analysis of these data sets and functional annotation of identified risk loci were performed, and candidate disease variants with unknown functional effects were investigated for their impact on gene expression and/or protein function. RESULTS: Among the genome-wide significant associations identified, the largest effect on risk of AAV came from the single-nucleotide polymorphism variants rs141530233 and rs1042169 at the HLA-DPB1 locus (odds ratio [OR] 2.99 and OR 2.82, respectively) which, together with a third variant, rs386699872, constitute a triallelic risk haplotype associated with reduced expression of the HLA-DPB1 gene and HLA-DP protein in B cells and monocytes and with increased frequency of complementary proteinase 3 (PR3)-reactive T cells relative to that in carriers of the protective haplotype. Significant associations were also observed at the SERPINA1 and PTPN22 loci, the peak signals arising from functionally relevant missense variants, and at PRTN3, in which the top-scoring variant correlated with increased PRTN3 expression in neutrophils. Effects of individual loci on AAV risk differed between patients with GPA and those with MPA or between patients with PR3-ANCAs and those with myeloperoxidase-ANCAs, but the collective population attributable fraction for these variants was substantive, at 77%. CONCLUSION: This study reveals the association of susceptibility to GPA and MPA with functional gene variants that explain much of the genetic etiology of AAV, could influence and possibly be predictors of the clinical presentation, and appear to alter immune cell proteins and responses likely to be key factors in the pathogenesis of AAV.

Do vaccinations affect the clinical course of systemic necrotising vasculitis? A prospective observational web-based study.

OBJECTIVES: To estimate the impact of vaccinations, infections and traumatic life events on the disease activity of a web-based cohort of systemic necrotising vasculitis (SNV) patients. METHODS: Adults diagnosed with SNV self-reported vaccinations, infectious episodes and traumatic life events every 3 months during follow-up on a secure dedicated website. Participants reported information on disease activity assessed with 3 scores: the French version of the Medical Outcome Study Short Form-36 (SF-36), the visual numerical scale for Patient Global Assessment (PGA) and the modified Disease Extent Index (mDEI). RESULTS: Between December 2005 and October 2008, 145 participants (mean ± SD age 53±13 years; 57% males) were included. Mean follow-up was 445±325 days. SNVs were distributed as follows: 46% granulomatosis with polyangiitis (Wegener's), 22% eosinophilic granulomatosis with polyangiitis (Churg-Strauss), 18% polyarteritis nodosa and 8% microscopic polyangiitis. During follow-up, 94 vaccinations, 57 acute infectious episodes and 274 traumatic life events were reported. In univariate and multivariate analyses, only traumatic life events were significantly associated with decreased SF-36 mental and physical component scores. No significant SF-36, PGA and mDEI scores variations were reported during the 3 months following acute infectious episode or vaccine administration. CONCLUSIONS: No significant clinical impact of vaccinations on SNV activity was found in this prospective observational study.

Association of granulomatosis with polyangiitis (Wegener's) with HLA-DPB1*04 and SEMA6A gene variants: evidence from genome-wide analysis.

OBJECTIVE: To identify genetic determinants of granulomatosis with polyangiitis (Wegener's) (GPA). METHODS: We carried out a genome-wide association study (GWAS) of 492 GPA cases and 1,506 healthy controls (white subjects of European descent), followed by replication analysis of the most strongly associated signals in an independent cohort of 528 GPA cases and 1,228 controls. RESULTS: Genome-wide significant associations were identified in 32 single-nucleotide polymorphic (SNP) markers across the HLA region, the majority of which were located in the HLA-DPB1 and HLA-DPA1 genes encoding the class II major histocompatibility complex (MHC) DPß chain 1 and DPα chain 1 proteins, respectively. Peak association signals in these 2 genes, emanating from SNPs rs9277554 (for DPß chain 1) and rs9277341 (DPα chain 1) were strongly replicated in an independent cohort (in the combined analysis of the initial cohort and the replication cohort, P = 1.92 × 10(-50) and 2.18 × 10(-39) , respectively). Imputation of classic HLA alleles and conditional analyses revealed that the SNP association signal was fully accounted for by the classic HLA-DPB1*04 allele. An independent single SNP, rs26595, near SEMA6A (the gene for semaphorin 6A) on chromosome 5, was also associated with GPA, reaching genome-wide significance in a combined analysis of the GWAS and replication cohorts (P = 2.09 × 10(-8) ). CONCLUSION: We identified the SEMA6A and HLA-DP loci as significant contributors to risk for GPA, with the HLA-DPB1*04 allele almost completely accounting for the MHC association. These two associations confirm the critical role of immunogenetic factors in the development of GPA.

Meta-analysis of genetic polymorphisms in granulomatosis with polyangiitis (Wegener's) reveals shared susceptibility loci with rheumatoid arthritis.

OBJECTIVE: To examine the association of previously identified autoimmune disease susceptibility loci with granulomatosis with polyangiitis (Wegener's) (GPA), and to determine whether the genetic susceptibility profiles of other autoimmune diseases are associated with those of GPA. METHODS: Genetic data from 2 cohorts were meta-analyzed. Genotypes for 168 previously identified single-nucleotide polymorphisms (SNPs) associated with susceptibility to different autoimmune diseases were ascertained in a total of 880 patients with GPA and 1,969 control subjects of European descent. Single-marker associations were identified using additive logistic regression models. Associations of multiple SNPs with GPA were assessed using genetic risk scores based on susceptibility loci for Crohn's disease, type 1 diabetes, systemic lupus erythematosus, rheumatoid arthritis (RA), celiac disease, and ulcerative colitis. Adjustment for population substructure was performed in all analyses, using ancestry-informative markers and principal components analysis. RESULTS: Genetic polymorphisms in CTLA4 were significantly associated with GPA in the single-marker meta-analysis (odds ratio [OR] 0.79, 95% confidence interval [95% CI] 0.70-0.89, P = 9.8 × 10(-5) ). The genetic risk score for RA susceptibility markers was significantly associated with GPA (OR 1.05 per 1-unit increase in genetic risk score, 95% CI 1.02-1.08, P = 5.1 × 10(-5) ). CONCLUSION: RA and GPA may arise from a similar genetic predisposition. Aside from CTLA4, other loci previously found to be associated with common autoimmune diseases were not statistically significantly associated with GPA in this study.

IgA and IgG antineutrophil cytoplasmic antibody engagement of Fc receptor genetic variants influences granulomatosis with polyangiitis.

Granulomatosis with polyangiitis (Wegener's) is a rare autoimmune neutrophil-mediated vasculitis that can cause renal disease and mucosal manifestations. Antineutrophil cytoplasmic antibodies (ANCA) are present in many patients, vary in level over time, and induce neutrophil activation through engagement with Fc receptors (FcRs). Given roles for FcRs in ANCA-mediated neutrophil activation and IgA antibodies in mucosal immunity, we hypothesized that FcR genetics and previously unappreciated IgA ANCA affect clinical presentation. We assembled a total of 673 patients and 413 controls from two multicenter cohorts, performed ELISA and immunofluorescence assays to determine IgA and IgG ANCA positivity, and used Illumina, TaqMan, or Pyrosequencing to genotype eight haplotype-tagging SNPs in the IgA FcR (FCAR) and to determine NA1/NA2 genotype of FCGR3B, the most prevalent neutrophil IgG FcR. We evaluated neutrophil activation by measuring degranulation marker CD11b with flow cytometry or neutrophil extracellcular trap formation with confocal microscopy. Functional polymorphisms in FCGR3B and FCAR differed between patient groups stratified by renal involvement. IgA ANCA were found in ∼30% of patients and were less common in patients with severe renal disease. Neutrophil stimulation by IgA or IgG ANCA led to degranulation and neutrophil extracellcular trap formation in a FcR allele-specific manner (IgA:FCAR P = 0.008; IgG:FCGR3B P = 0.003). When stimulated with IgA and IgG ANCA together, IgG ANCA induced neutrophil activation was reduced (P = 0.0001). FcR genotypes, IgA ANCA, and IgG ANCA are potential prognostic and therapeutic targets for understanding the pathogenesis and presentation of granulomatosis with polyangiitis (Wegener's).

Alpha1-antitrypsin deficiency-related alleles Z and S and the risk of Wegener's granulomatosis.

OBJECTIVE: Deficiency of α(1) -antitrypsin (α(1) AT) may be a determinant of susceptibility to Wegener's granulomatosis (WG). Several previous, mainly small, case-control studies have shown that 5-27% of patients with WG carried the α(1) AT deficiency Z allele. It is not clear whether the S allele, the other major α(1) AT deficiency variant, is associated with WG. This study investigated the relationship of the α(1) AT deficiency Z and S alleles with the risk of developing WG in a large cohort. METHODS: We studied the distribution of the α(1) AT deficiency alleles Z and S in 433 unrelated Caucasian patients with WG and 421 ethnically matched controls. Genotyping was performed using an allele discrimination assay. Results were compared between cases and controls using exact statistical methods. RESULTS: Among the patients with WG, the allele carriage frequencies of Z and S were 7.4% and 11.5%, respectively. The frequencies of the 6 possible genotypes differed in a statistically significant manner between cases and controls (P = 0.01). The general genetic 2-parameter codominant model provided the best fit to the data. Compared with the normal MM genotype, the odds ratio (OR) for MZ or MS genotypes was 1.47 (95% confidence interval [95% CI] 0.98-2.22), and the OR for ZZ, SS, or SZ genotypes was 14.58 (95% CI 2.33-∞). ORs of similar direction and magnitude were observed within the restricted cohorts that excluded cases and controls carrying ≥1 Z or ≥1 S allele. CONCLUSION: Both Z and S alleles display associations with risk of WG in a codominant genetic pattern. These findings strengthen the evidence of a causal link between α(1) AT deficiency and susceptibility to WG.

Epidemiological features of Wegener's granulomatosis and microscopic polyangiitis: two diseases or one 'anti-neutrophil cytoplasm antibodies-associated vasculitis' entity?

Because of their multiple overlapping clinical characteristics, Wegener's granulomatosis (WG) and microscopic polyangiitis (MPA) have increasingly been conceptualized as different expressions of a unique anti-neutrophil cytoplasm antibodies (ANCA)-associated vasculitis (AAV) disease spectrum. However, this continuum theory remains hindered by uncertainty surrounding a potentially common etiology. This review sheds light on our current understanding of the epidemiology of WG and MPA with the aim of weighing the evidence supporting whether or not these two vasculitis forms are distinct diseases. At present, some epidemiological evidence exists that WG and MPA might correspond to mere variants of a single AAV entity.

Assessment of the item selection and weighting in the Birmingham vasculitis activity score for Wegener's granulomatosis.

OBJECTIVE: To assess the Birmingham Vasculitis Activity Score for Wegener's Granulomatosis (BVAS/WG) with respect to its selection and weighting of items. METHODS: This study used the BVAS/WG data from the Wegener's Granulomatosis Etanercept Trial. The scoring frequencies of the 34 predefined items and any "other" items added by clinicians were calculated. Using linear regression with generalized estimating equations in which the physician global assessment (PGA) of disease activity was the dependent variable, we computed weights for all predefined items. We also created variables for clinical manifestations frequently added as other items, and computed weights for these as well. We searched for the model that included the items and their generated weights yielding an activity score with the highest R(2) to predict the PGA. RESULTS: We analyzed 2,044 BVAS/WG assessments from 180 patients; 734 assessments were scored during active disease. The highest R(2) with the PGA was obtained by scoring WG activity based on the following items: the 25 predefined items rated on >or=5 visits, the 2 newly created fatigue and weight loss variables, the remaining minor other and major other items, and a variable that signified whether new or worse items were present at a specific visit. The weights assigned to the items ranged from 1 to 21. Compared with the original BVAS/WG, this modified score correlated significantly more strongly with the PGA. CONCLUSION: This study suggests possibilities to enhance the item selection and weighting of the BVAS/WG. These changes may increase this instrument's ability to capture the continuum of disease activity in WG.

Hypotheses on the etiology of antineutrophil cytoplasmic autoantibody associated vasculitis: the cause is hidden, but the result is known.

The first description of what is now known as antineutrophil cytoplasmic autoantibody-associated necrotizing vasculitis appeared more than 140 yr ago. Since then, many aspects of the pathogenic pathway have been elucidated, indicating the involvement of antineutrophil cytoplasmic autoantibodies, but why antineutrophil cytoplasmic autoantibodies are produced in the first place remains unknown. Over the years, many hypotheses have emerged addressing the etiology of antineutrophil cytoplasmic antibody production, but no exclusive factor or set of factors can so far be held responsible. Herein is reviewed the most influential hypotheses regarding the causes of antineutrophil cytoplasmic antibody-associated vasculitis with the aim of placing in an epidemiologic background the different hypotheses that are centered on environmental and genetic influences.

Antiendothelial cell antibodies in patients with Wegener's granulomatosis: prevalence and correlation with disease activity and manifestations.

OBJECTIVE: Previous studies in small cohorts of patients with Wegener's granulomatosis (WG) or antineutrophil cytoplasmic antibody (ANCA) associated vasculitis have yielded conflicting data regarding the prevalence of antiendothelial cell antibodies (AECA), ranging from 8% to 100%, and the use of AECA as a measure of disease activity. We examined a large, well-characterized cohort of patients with WG and active disease for the presence of AECA. METHODS: Serum from subjects with WG who participated in a clinical therapeutic trial was collected at baseline, when all subjects had active disease. Clinical manifestations and disease activity were documented using the Birmingham Vasculitis Activity Score for WG (BVAS/WG). Serum AECA (IgG) was measured by cyto-ELISA using unfixed human umbilical vein endothelial cells (HUVEC). The AECA positivity cutoff was determined using 71 healthy control samples. Statistical analyses utilized Student's t test, chi-square and Fisher's exact tests, and linear regression. RESULTS: AECA were detected in 34 of 173 (20%) evaluated serum samples. Mean BVAS/WG did not differ between patients with (7.3 +/- 3.2) or without AECA (7.0 +/- 3.3) (p = 0.58). Among the 34 patients positive for AECA, the antibody titer did not correlate with disease activity (BVAS/WG; r = 0.09, p = 0.60). There were no statistically significant differences in the frequency of major clinical manifestations between patients with or without AECA. CONCLUSION: AECA, as measured using HUVEC, are not highly prevalent among patients with active WG, are not associated with specific clinical manifestations, and do not correlate with level of disease activity.