Tómasson, Gunnar

Abstract Objectives To systematically review the psychometric properties of outcome measurement instruments used in ANCA-associated vasculitis (AAV). Methods Medline, EMBASE, Cochrane, Scopus and Web of Science were searched from inception to 14 July 2020 for validation studies of instruments used in AAV. Following the COnsensus-based Standards for the selection of health status Measurement INstruments (COSMIN) and OMERACT frameworks, different psychometric properties (validity, reliability, responsiveness and feasibility) were summarized. Risk of bias was assessed according to the COSMIN checklist. Results From 2505 articles identified, 32 met the predefined selection criteria, providing information on 22 instruments assessing disease activity (n = 7), damage (n = 2), activity and damage (n = 1), health-related quality of life (HRQoL; n = 9) and function (n = 3). Most of the instruments were tested in AAV as a group or in granulomatosis with polyangiitis only. The BVAS, any version, the Vasculitis Damage Index (VDI) and the AAV-Patient-Reported Outcome (AAV-PRO) have been more extensively validated than the other instruments. BVAS for Wegener Granulomatosis (BVAS/WG) has been shown to be valid for measuring disease activity [correlation with Physician global assessment (r = 0.90)], reliability (inter-observer intraclass correlation coefficient = 0.97), responsiveness and feasibility. For damage, VDI was shown to be moderately valid (correlations with BVAS version 3 at 6 months r = 0.14, BVAS/WG at 1 year r = 0.40 and 5 years r = 0.20), and feasible. For HRQoL, AAV-PRO demonstrated validity (correlations of the six AAV-PRO domains with EQ-5D-5L: −0.78 to −0.55; discrimination between active disease and remission, P < 0.0001 for all comparisons). The overall performance of instruments assessing function was low-to-moderate. Conclusion Among the 22 outcome measurement instruments used for AAV, BVAS (any version), VDI and AAV-PRO had the strongest psychometric properties.

ObjectiveImproved biomarkers of current disease activity and prediction of relapse are needed in antineutrophil cytoplasmic antibody–associated vasculitis (AAV). For clinical relevance, biomarkers must perform well longitudinally in patients on treatment and in patients with nonsevere flares.MethodsTwenty‐two proteins were measured in 347 serum samples from 74 patients with AAV enrolled in a clinical trial. Samples were collected at Month 6 after remission induction, then every 3 months until Month 18, or at the time of flare. Associations of protein concentrations with concurrent disease activity and with future flare were analyzed using mixed‐effects models, Cox proportional hazards models, and conditional logistic regression.ResultsForty‐two patients had flares during the 12‐month follow‐up period, and 32 remained in remission. Twenty‐two patients had severe flares. Six experimental markers (CXCL13, IL‐6, IL‐8, IL‐15, IL‐18BP, and matrix metalloproteinase‐3 [MMP‐3]) and ESR were associated with disease activity using all three methods (P < 0.05, with P < 0.01 in at least one method). A rise in IL‐8, IL‐15, or IL‐18BP was associated temporally with flare. Combining C‐reactive protein (CRP), IL‐18BP, neutrophil gelatinase‐associated lipocalin (NGAL), and sIL‐2Rα improved association with active AAV. CXCL13 and MMP‐3 were increased during treatment with prednisone, independent of disease activity. Marker concentrations during remission were not predictive of future flare.ConclusionSerum biomarkers of inflammation and tissue damage and repair have been previously shown to be strongly associated with severe active AAV were less strongly associated with active AAV in a longitudinal study that included mild flares and varying treatment. Markers rising contemporaneously with flare or with an improved association in combination merit further study.

ObjectiveTo 1) describe the distribution of patient global assessment (PtGA) scores of disease activity in patients with granulomatosis with polyangiitis (GPA; Wegener's), 2) explore the discordance between PtGA scores and physician global assessment (PhGA) scores of disease activity, and 3) explore whether PtGA scores during disease remission are associated with future disease relapse.MethodsData from the Wegener's Granulomatosis Etanercept Trial (WGET) were used. PtGA and PhGA scores were assessed on 100‐mm visual analog scales (VAS). Presence of active disease was determined using the Birmingham Vasculitis Activity Score for WG (BVAS/WG), and remission was defined as a BVAS/WG score of 0. Disease relapse was defined as a BVAS/WG score of >0 after remission had been achieved. Discordance between PtGA and PhGA scores was defined as a difference of ≥20 points between the two measures. Mixed linear models were used in longitudinal analysis of PtGA scores.ResultsData were obtained from 180 patients in the WGET cohort, seen at a total of 1,719 study visits. The mean ± SD PtGA and PhGA disease activity scores (on 100‐mm VAS) at baseline were 64.2 ± 27.4 and 55.5 ± 23.4, respectively. PtGA–PhGA discordance occurred in 53% of patients at baseline, and this was inversely associated with newly diagnosed disease (as opposed to relapsing disease) at baseline (odds ratio 0.37, 95% confidence interval [95% CI] 0.20–0.68) but not with age, sex, or presence of renal or pulmonary disease. Patients were in disease remission during 62% of the study visits. The mean PtGA score during visits immediately prior to relapse was 4.52 points higher (95% CI 0.66–8.4) than that at other remission visits (P = 0.03).ConclusionPtGA–PhGA discordance is common in GPA. A rise in the PtGA disease activity score during times defined by physicians as periods of remission is associated with subsequent occurrence of disease relapse. These findings support the addition of PtGA as an outcome measure for GPA.