Clinical impact of subgrouping ANCA-associated vasculitis according to antibody specificity beyond the clinicopathological classification.

In ANCA-associated vasculitis (AAV), classifications have emerged to individualize homogeneous clinical and outcomes patterns, including the recently defined anti-MPO granulomatosis with polyangiitis (GPA) subgroup. This study aimed to retrospectively evaluate the impacts of re-classification based on clinicopathological criteria and/or ANCA specificity. A retrospective monocentric study conducted at Caen University Hospital led to the identification of PR3 or MPO-ANCA AAV patients from January 2000 or September 2011, respectively, to June 2016. Eosinophilic GPA patients were excluded. AAVs were thereby also classified either as GPA or microscopic polyangiitis (MPA) according to the European Medicines Agency vasculitis algorithm. A total of 150 AAV patients were included (94 GPA, 56 MPA; 87 anti-PR3 and 63 anti-MPO patients). GPA patients exhibited a worse relapse-free survival but a better renal survival (P < 0.001 and P = 0.021, respectively) than MPA patients. Overall, relapse-free and renal survival rates were similar between anti-PR3 and anti-MPO patients (P = 0.35, 0.17 and 0.15, respectively). Similarly, the prognosis was identical between anti-MPO MPA patients and anti-PR3 MPA patients (P = 0.33, 0.19 and 0.65, respectively), and between anti-MPO GPA patients and anti-PR3 GPA patients (P = 0.06, 0.99 and 0.64, respectively). Moreover, anti-PR3 GPA and anti-MPO GPA patients exhibited no differences in clinical manifestations or BVAS score. Clinicopathological classification appeared to be the strongest criterion for distinguishing among homogeneous prognoses of AAV. Individualizing the anti-MPO GPA subgroup does not appear to bring additional value to clinical practice, but multicentre studies are required to confirm this trend.

Deshayes S ，Martin Silva N ，Khoy K ，Yameogo S ，Mariotte D ，Lobbedez T ，Aouba A ... -  《-》

Clinical and prognostic features of Korean patients with MPO-ANCA, PR3-ANCA and ANCA-negative vasculitis.

Yoo J ，Kim HJ ，Ahn SS ，Jung SM ，Song JJ ，Park YB ，Lee SW ... -  《CLINICAL AND EXPERIMENTAL RHEUMATOLOGY》

Brief Report: Circulating Cytokine Profiles and Antineutrophil Cytoplasmic Antibody Specificity in Patients With Antineutrophil Cytoplasmic Antibody-Associated Vasculitis.

To evaluate circulating cytokine profiles in patients with antineutrophil cytoplasmic antibody-associated vasculitis (AAV), classified by antineutrophil cytoplasmic antibody (ANCA) specificity (proteinase 3 ANCA [PR3-ANCA] versus myeloperoxidase ANCA [MPO-ANCA]) or by clinical diagnosis (granulomatosis with polyangiitis [GPA] versus microscopic polyangiitis [MPA]). A panel of 29 cytokines was tested in 186 patients with active AAV at inclusion into the Rituximab in AAV trial. Cytokine concentrations were compared between groups within each classification system. Multivariable analyses adjusted for age, sex, and renal insufficiency were performed, with each biomarker as a dependent variable and ANCA specificity and clinical diagnosis as explanatory variables of interest. Levels of 9 circulating cytokines (interleukin-6 [IL-6], granulocyte-macrophage colony-stimulating factor [GM-CSF], IL-15, IL-18, CXCL8/IL-8, CCL-17/thymus and activation-regulated chemokine [TARC], IL-18 binding protein [IL-18 BP], soluble IL-2 receptor α [sIL-2Rα], and nerve growth factor β [NGFβ]) were significantly higher in PR3-AAV than MPO-AAV, 4 cytokines (sIL6R, soluble tumor necrosis factor receptor type II [sTNFRII], neutrophil gelatinase-associated lipocalin [NGAL], and soluble intercellular adhesion molecule 1 [sICAM-1]) were higher in MPO-AAV than in PR3-AAV, 6 cytokines (IL-6, GM-CSF, IL-15, IL-18, sIL-2Rα, and NGFβ) were higher in GPA than in MPA, and 3 cytokines (osteopontin, sTNFRII, and NGAL) were higher in MPA than in GPA (all P < 0.05). For nearly all cytokines, the difference between PR3-AAV and MPO-AAV was larger than that between GPA and MPA. The multivariate analysis showed that 8 cytokines (IL-15, IL-8, IL-18 BP, NGF-β, sICAM-1, TARC, osteopontin, and kidney injury molecule 1 (P < 0.05) distinguished patients with AAV better (lower P values and larger effect sizes) when grouped by ANCA specificity than by clinical diagnosis. Distinct cytokine profiles were identified for PR3-AAV versus MPO-AAV and for GPA versus MPA. Differences in these circulating immune mediators are more strongly associated with ANCA specificity than with clinical diagnosis, suggesting that heterogeneity in the AAV subtypes extends beyond clinical phenotypes.

Berti A ，Warner R ，Johnson K ，Cornec D ，Schroeder D ，Kabat B ，Langford CA ，Hoffman GS ，Fervenza FC ，Kallenberg CGM ，Seo P ，Spiera R ，St Clair EW ，Brunetta P ，Stone JH ，Merkel PA ，Specks U ，Monach PA ，RAVE-ITN Research Group ... -  《-》

Myeloperoxidase-ANCA-positive granulomatosis with polyangiitis is a distinct subset of ANCA-associated vasculitis: A retrospective analysis of 455 patients from a single center in China.

Antineutrophil cytoplasmic antibody (ANCA) directed to proteinase 3 (PR3) used to be considered the serologic marker for granulomatosis with polyangiitis (GPA). However, patients with myeloperoxidase (MPO)-ANCA positive GPA have been increasingly reported. The aim of this study was to analyze the clinical and pathological characteristics and outcome of Chinese patients with MPO-ANCA positive GPA. The clinical and renal histology data, renal outcomes, response to treatment, relapse and mortality were compared between patients with MPO-ANCA positive GPA and MPO-ANCA positive microscopic polyangiitis (MPA) as well as proteinase 3 (PR3)-ANCA positive GPA. 455 patients with ANCA-associated vasculitis (AAV) were recruited in this study. 276/455 patients were classified as MPO-ANCA positive MPA, 4/455 patients were classified as PR3-ANCA positive MPA, 124/455 were MPO-ANCA positive GPA and 51/455 were PR3-ANCA positive GPA. Compared with MPO-ANCA positive MPA patients, MPO-ANCA positive GPA patients had significantly higher level of BVAS and milder renal lesion at diagnosis. The probability of developing ESRD was significantly higher in patients with MPO-ANCA positive MPA than MPO-ANCA positive GPA. MPO-ANCA positive GPA patients were likely to have relapse than MPO-ANCA positive MPA patients. Compared with PR3-ANCA positive GPA patients, MPO-ANCA positive GPA patients had significantly higher proportion of female, less constitutional symptoms and milder renal lesion at diagnosis. Patients with MPO-ANCA positive GPA should be regarded as a unique subset of AAV. This subset of AAV patients had relatively milder renal injury. Although ANCA specificities play an important role in differentiating AAV, taking the disease type together to classify AAV may be more rational.

Chang DY ，Li ZY ，Chen M ，Zhao MH ... -  《-》

Myeloperoxidase-Antineutrophil Cytoplasmic Antibody (ANCA)-Positive Granulomatosis With Polyangiitis (Wegener's) Is a Clinically Distinct Subset of ANCA-Associated Vasculitis: A Retrospective Analysis of 315 Patients From a German Vasculitis Referral Cent

To compare the phenotype, clinical course, and outcome of myeloperoxidase (MPO)-antineutrophil cytoplasmic antibody (ANCA)-positive granulomatosis with polyangiitis (Wegener's) (GPA) to proteinase 3 (PR3)-ANCA-positive GPA and to MPO-ANCA-positive microscopic polyangiitis (MPA). We characterized all MPO-ANCA-positive patients classified as having GPA by the European Medicines Agency algorithm who attended our center, in a retrospective chart review. A second cohort of patients with PR3-ANCA-positive GPA matched for age and sex was characterized. Patients with MPO-ANCA-positive MPA from a recently published cohort were also included in the analysis. All patients were diagnosed and treated according to a standardized interdisciplinary approach at a vasculitis referral center. Comprehensive data were available for 59 patients with MPO-ANCA-positive GPA, and they were compared to 118 patients with PR3-ANCA-positive GPA and 138 patients with MPO-ANCA-positive MPA. We observed a distinct phenotype in MPO-ANCA-positive GPA as compared to the other 2 cohorts. Patients with MPO-ANCA-positive GPA frequently had limited disease without severe organ involvement, had a high prevalence of subglottic stenosis, and had less need for aggressive immunosuppressive therapy (cyclophosphamide/rituximab). The patients with MPO-ANCA-positive GPA were also younger than the MPA patients and were predominantly female (significantly different than the MPA cohort). While GPA patients had higher survival rates compared to MPA patients (due to a high prevalence of pulmonary fibrosis in MPA), patients with MPO-ANCA had significantly lower relapse rates than those with PR3-ANCA. Patients with MPO-ANCA-positive GPA show significantly different clinical courses compared to those with PR3-ANCA-positive GPA or MPO-ANCA-positive MPA, which should be considered in their clinical management. Classification according to ANCA specificity may improve the evaluation of relapse risk.

Schirmer JH ，Wright MN ，Herrmann K ，Laudien M ，Nölle B ，Reinhold-Keller E ，Bremer JP ，Moosig F ，Holle JU ... -  《-》