BACKGROUND:Differences in chest HRCT findings between myeloperoxidase (MPO)- antineutrophil cytoplasmic antibody (ANCA) and proteinase 3 (PR3)-ANCA in Japanese patients with ANCA-associated vasculitis (AAV) remain unclear. METHODS:We reviewed chest HRCT findings at diagnosis in 195 patients with AAV enrolled in the Remission Induction Therapy in Japanese Patients with ANCA-associated Vasculitis and Rapidly Progressive Glomerulonephritis (RemIT-JAV-RPGN) observational cohort study (2011-2013). Findings were classified by ANCA subtype and compared. RESULTS:Abnormal chest HRCT findings were observed in 172 of 195 patients. Main findings included ground-glass opacity (n = 92, 47%), reticulation (n = 79, 41%), traction bronchiectasis (n = 67, 34%), and honeycombing (n = 4 9, 25%). Honeycombing (n = 46, 29%) and reticulation (n = 70, 43%) predominated in patients with positive MPO-ANCA, whereas nodules (n = 4, 44%) and cavities (n = 3, 33%) were more frequent in those with positive PR3-ANCA. Interstitial pneumonia (IP) was diagnosed in 89 patients, with HRCT patterns of definite usual interstitial pneumonia (UIP) in 31 (35%), possible UIP in 22 (25%), and inconsistent with UIP in 36 (40%). IP was more frequent in patients with positive MPO-ANCA than in those with positive PR3-ANCA (47% vs 11%, respectively; p = 0.003). Definite UIP was more common in MPO-ANCA positivity than in other subtypes (41% vs 0%, respectively; p = 0.023). CONCLUSIONS:In Japanese patients with AAV, IP with a definite UIP pattern was more frequent in patients with MPO-ANCA positivity while nodules and cavities were more frequent in patients with positive PR3-ANCA.

Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is characterized by serum ANCA and systemic small-vessel vasculitis. Neutrophils are primed to express ANCA antigens on the plasma membrane. ANCA binding to the antigens can transduce signals into neutrophils, releasing reactive oxygen species (ROS) and contributing to AAV development. ANCA-mediated signals are transduced via two pathways: ANCA antigens crosslinked by ANCA, and Fcγ receptor (FcγR), to which the Fc portion of ANCA binds. This study aimed to demonstrate the association of ANCA-mediated neutrophil activation pathways with clinical manifestations of AAV, including renal dysfunction and kidney survival at 6 months after treatment. For this purpose, IgG was extracted from the serum of AAV patients before treatment (n = 112), and ROS production from neutrophils exposed to IgG and its suppression by FcγR inhibitors (FcX) were assessed. IgG exhibiting higher ROS production than control IgG was classified as ROS-inducing ANCA and the others as ROS-noninducing ANCA. The former was subclassified into antigen-driven ANCA and FcγR-driven ANCA according to whether the ROS production suppression rate by FcX was <50 % or ≧50 %, respectively. As a result, ANCA was classified into ROS-inducing antigen-driven ANCA (n = 74), ROS-inducing FcγR-driven ANCA (n = 22), and ROS-noninducing ANCA (n = 16). Serum levels of blood urea nitrogen and creatinine were significantly higher in patients with ROS-inducing FcγR-driven ANCA than in those with ROS-noninducing ANCA. Patients with ROS-inducing FcγR-driven ANCA had a significantly lower kidney survival rate 6 months after treatment than other patients. The collective findings suggest that ROS-inducing FcγR-driven ANCA may predict poor kidney prognosis in AAV.

BackgroundRituximab is effective for induction and maintenance of remission in relapsing ANCA-associated vasculitis (AAV), but some patients do not achieve complete remission or experience relapse despite treatment. We aimed to describe the frequency, characteristics, and outcomes of patients with suboptimal response to rituximab within the RITAZAREM trial.MethodsPost hoc descriptive analysis, including patients with granulomatosis with polyangiitis (GPA) or microscopic polyangiitis (MPA) treated with rituximab for induction (N = 188) and those receiving rituximab maintenance (N = 85). Three scenarios of suboptimal response were examined: (i) failure to achieve protocol-defined remission at month 4 (n = 6); (ii) incomplete remission at month 4, defined as BVAS/WG = 1 (n = 10); and (iii) relapse during rituximab maintenance (n = 13). Data were summarized descriptively. Time to relapse from month 4 in patients with BVAS/WG = 1 versus BVAS/WG = 0 was explored using Kaplan–Meier analysis.ResultsSix of 188 patients (3%) did not achieve protocol-defined remission by month 4, 10 (5%) had residual low-grade disease activity (BVAS/WG = 1), and 13 of 85 patients (15%) receiving rituximab maintenance relapsed within 24 months during maintenance treatment. All patients with BVAS/WG = 1 at month 4 had a history of PR3-ANCA positivity and ear/nose/throat (ENT) baseline manifestations. Relapse occurred more frequently in this subgroup than in patients with BVAS/WG = 0, and time-to-relapse analysis showed shorter relapse-free survival, although interpretation is limited by the small sample size. Most first relapses were minor, and some patients subsequently experienced additional relapses, including major relapses.ConclusionIn this exploratory and hypothesis-generating analysis, a small subset of patients with relapsing AAV showed suboptimal outcomes with rituximab. Residual disease activity at month 4, particularly in patients with PR3-ANCA positivity and ENT involvement, may represent a clinical subgroup associated with an increased frequency of earlier relapse, although this observation requires confirmation.

OBJECTIVES:Eosinophilic granulomatosis with polyangiitis (EGPA) is classified as a subtype of anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). A recent genome-wide association study (GWAS) of EGPA in populations of European ancestry reported several susceptibility loci. In view of population differences in genetic factors of AAV, we made an attempt to examine the contribution of these loci to EGPA in a Japanese population. METHODS:The EGPA-associated variants in LPP, TSLP, IRF1/IL5, HLA, CDK6, 10p14 and 12q21 in European populations (EUR) were analysed in a total of 103 Japanese patients with EGPA, including 48 myeloperoxidase (MPO)-ANCA-positive and 45 ANCA-negative patients. Allele frequency data on approximately 60 000 Japanese individuals from the Japanese Multi Omics Reference Panel served as the controls. RESULTS:An increasing tendency in TSLP rs1837253 C allele was observed in total EGPA, MPO-ANCA-positive EGPA and ANCA-negative EGPA. In addition, association of HLA-DRB1*07:01 was observed in total EGPA and MPO-ANCA-positive EGPA. These findings supported the previous findings in the EUR. On the other hand, unlike in the EUR, association of DRB1*09:01 was observed in Japanese EGPA. With respect to amino acid residues in HLA-DRβ1, Val 78 encoded by DRB1*07:01 and *09:01 was associated with total EGPA and MPO-ANCA-positive EGPA with genome-wide significance (p<5.0E-08). Association with the other loci was not observed in Japanese EGPA. CONCLUSION:TSLP was suggested to be associated with EGPA both in the European and Japanese populations regardless of the ANCA status. In HLA-DRB1, both shared and population-specific susceptibility alleles were observed.

Background: This study aimed to clarify recent clinical features and treatment outcomes in Japanese patients with newly diagnosed Takayasu arteritis (TAK) during the first 2 years of treatment. Methods and Results: A nationwide multicenter retrospective cohort study for TAK was implemented to collect data between 2007 and 2014. The primary outcome of the study was clinical remission at Week 24. Of the 184 participants registered, 129 patients with newly diagnosed TAK were analyzed: 84% were female and the mean age at onset was 35 years. Clinical symptoms at diagnosis were mostly associated with large-vessel lesions. Frequent sites of vascular involvement included the carotid artery, subclavian artery, aortic arch, and descending aorta. The mean initial dose of prednisolone administered was 0.68 mg/kg/day, and 59% and 17% of patients received immunosuppressive drugs and biologics, respectively, by Week 104. Clinical remission at Week 24 and sustained clinical remission with daily prednisolone at <= 10mg at Week 52 were achieved in 107 (82.9%) and 51 (39.5%) patients, respectively. The presence of signs and symptoms linked to large-vessel lesions was associated with failure to achieve sustained clinical remission at Week 52. Conclusions: We elucidated the clinical characteristics, treatment outcomes, and factors associated with failure to achieve sustained clinical remission in patients with newly diagnosed TAK in Japan during the first 2 years of treatment.

OBJECTIVE:This study aimed to evaluate the Ministry of Health, Labour and Welfare (MHLW) diagnostic criteria for antineutrophil cytoplasmic antibody-associated vasculitis compared to the new American College of Rheumatology/European Alliance of Associations for Rheumatology 2022 criteria.METHODS:Two nationwide cohort studies were used, and participants were categorised as having eosinophilic granulomatosis with polyangiitis, granulomatosis with polyangiitis (GPA), or microscopic polyangiitis (MPA) according to the American College of Rheumatology/European Alliance of Associations for Rheumatology 2022 and MHLW criteria.RESULTS:Of the entire patient population, only 10 (2.1%) were unclassifiable according to the MHLW probable criteria, while a significant number of patients (71.3%) met at least two criteria. The MHLW probable criteria for MPA had some challenges in differentiating between MPA and eosinophilic granulomatosis with polyangiitis, and the same was true for MHLW probable criteria for GPA in differentiating MPA from GPA. Nevertheless, improved classification results were obtained when the MHLW probable criteria were applied in the order of eosinophilic granulomatosis with polyangiitis, MPA, and GPA.CONCLUSIONS:The application of MHLW criteria could categorise a substantial number of patients with antineutrophil cytoplasmic antibody-associated vasculitis into one of the three antineutrophil cytoplasmic antibody-associated vasculitis diseases. The classification was in accordance with the American College of Rheumatology/European Alliance of Associations for Rheumatology 2022 criteria when considering the order of application.

OBJECTIVES:This study elucidated the prognosis and risk factors associated with damage accrual during long-term remission maintenance therapy for patients with antineutrophil cytoplasmic antibody-associated vasculitis (AAV).METHODS:We obtained data from 120 patients registered in a nationwide prospective cohort study on remission induction therapy in Japanese patients with AAV and rapidly progressive glomerulonephritis (RemIT-JAV-RPGN), who achieved remission at 24 months after treatment initiation and were followed up for additional 24 months. The primary outcome was the vasculitis damage index (VDI) score at Month 48, and the secondary outcome included risk factors associated with increased total VDI at Month 48.RESULTS:The understudied patients comprised 52 men and 68 women aged 68 ± 13 years. Between Months 25 and 48, the patients' survival rate was 95% (114/120). End-stage renal disease developed in seven patients by Month 48, and 64 cases had increased VDI. The multivariable analysis results revealed that oral prednisolone (PSL) doses at Month 24 were associated with damage accrual between Months 24 and 48.CONCLUSIONS:VDI accrual was observed in more than half of patients with AAV during maintenance therapy, and increased VDI scores were associated with oral PSL doses 24 months after initiating remission induction therapy in Japan.

OBJECTIVES This study investigated the current practice of prophylactic treatment against PCP (Pneumocystis jirovecii) and its effectiveness in patients with anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV). METHODS This study included 319 patients registered from 53 institutions in Japan and newly diagnosed with AAV. During the 2-year observation period, we examined the frequency of usage, effectiveness and safety of prophylactic drugs against PCP. RESULTS Most patients received prophylactic drugs against PCP with the initiation of immunosuppressive agents, and >50% of these remained on chemoprophylaxis against PCP at 2 years after. The initial daily dose of oral prednisolone and proportion of cyclophosphamide administration were higher in patients who received chemoprophylaxis against PCP than in those who did not. PCP occurred in nine patients (3%) and resulted in the death of four. The incidence rate of PCP in patients who received chemoprophylaxis was 1.13/100 patient-years (95% confidence interval, 0.38-2.68) and that in those who did not was 2.74 (1.04-6.02). The incidence rate ratio was 0.41 (0.11-1.53). CONCLUSION The markedly low incidence of PCP may be attributed to the continuous chemoprophylaxis against PCP received by >50% of Japanese patients with AAV, though the effectiveness of chemoprophylaxis against PCP was not statistically confirmed.

Objective The objective of this study was to compare the American College of Rheumatology/European Alliance of Associations for Rheumatology 2022 criteria with the previous classification algorithm for anti-neutrophil cytoplasmic antibody-associated vasculitis. Methods We used data from two nationwide, prospective, inception cohort studies. The enrolled patients were classified as having eosinophilic granulomatosis with polyangiitis (EGPA), granulomatosis with polyangiitis (GPA), or microscopic polyangiitis (MPA) according to the new criteria; these criteria were compared with Watts' algorithm. Results Among 477 patients, 10.7%, 9.9%, and 75.6% were classified as having EGPA, GPA, and MPA, respectively; 6.1% were unclassifiable. Three patients met both the EGPA and MPA criteria, and eight patients met both the GPA and MPA criteria. Of 78 patients with GPA classified using Watts' algorithm, 27 (34.6%) patients were reclassified as having MPA. Ear, nose, and throat involvement was significantly less frequent in patients reclassified as having MPA than in those reclassified as having GPA. Of 73 patients unclassifiable using Watts' algorithm, 62 were reclassified as having MPA. All patients reclassified as having MPA were myeloperoxidase-anti-neutrophil cytoplasmic antibody positive, and 46 had interstitial lung disease. Conclusion Although the American College of Rheumatology/European Alliance of Associations for Rheumatology 2022 criteria cause overlapping multiple criteria fulfilments in some patients, those items contribute to classifying unclassifiable patients using Watts' algorithm into MPA.

Objectives We conducted a Phase 3, multicentre, randomised, double-blind, placebo-controlled, parallel-group trial to evaluate the efficacy and safety of intravenous immunoglobulin (IVIg) in patients with glucocorticoid-refractory neuropathy associated with microscopic polyangiitis. Methods Patients received immunoglobulin or placebo intravenously for 5 consecutive days at baseline and after 4 weeks. The IVIg and placebo groups received IVIg and placebo, respectively, after 8 weeks. The primary and major secondary end-points were the least squares mean of the change in the manual muscle test (MMT) sum score after 8 and 4 weeks, respectively. Results A total of 37 patients were randomised into two groups (IVIg [19] and placebo [18]). The least squares mean for the change in the MMT sum score was 9.02 for IVIg and 6.71 for placebo (difference 2.32, 95% confidence interval -2.60 to 7.23, p = .345) after 8 weeks and 6.81 and 2.83 (difference 3.99, 95% confidence interval -1.22 to 9.19, p = .129), respectively, after 4 weeks. There were no new safety concerns for IVIg. Conclusions MMT sum scores improved with IVIg compared with placebo after 8 weeks of dosing and two courses of treatment, but the differences were not statistically significant, and the results showed no clear efficacy of IVIg in this patient population. No new safety concerns were raised.

Background Disease relapse remains a major problem in the management of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). In European populations, HLA-DPB1*04:01 is associated with both susceptibility and relapse risk in proteinase 3-ANCA positive AAV. In a Japanese population, we previously reported an association between HLA-DRB1*09:01 and DQB1*03:03 with susceptibility to, and DRB1*13:02 with protection from, myeloperoxidase-ANCA positive AAV (MPO-AAV). Subsequently, the association of DQA1*03:02 , which is in strong linkage disequilibrium with DRB1*09:01 and DQB1*03:03 , with MPO-AAV susceptibility was reported in a Chinese population. However, an association between these alleles and risk of relapse has not yet been reported. Here, we examined whether HLA-class II is associated with the risk of relapse in MPO-AAV. Methods First, the association of HLA-DQA1*03:02 with susceptibility to MPO-AAV and microscopic polyangiitis (MPA) and its relationship with previously reported DRB1*09:01 and DQB1*03:03 were examined in 440 Japanese patients and 779 healthy controls. Next, the association with risk of relapse was analyzed in 199 MPO-ANCA positive, PR3-ANCA negative patients enrolled in previously reported cohort studies on remission induction therapy. Uncorrected P values (P uncorr ) were corrected for multiple comparisons in each analysis using the false discovery rate method. Results The association of DQA1*03:02 with susceptibility to MPO-AAV and MPA was confirmed in a Japanese population (MPO-AAV: P uncorr =5.8x10 -7 , odds ratio [OR] 1.74, 95% confidence interval [CI] 1.40–2.16, MPA: P uncorr =1.1x10 -5 , OR 1.71, 95%CI 1.34–2.17). DQA1*03:02 was in strong linkage disequilibrium with DRB1*09:01 and DQB1*03:03 , and the causal allele could not be determined using conditional logistic regression analysis. Relapse-free survival was shorter with nominal significance in carriers of DRB1*09:01 (P uncorr =0.049, Q=0.42, hazard ratio [HR]:1.87), DQA1*03:02 (P uncorr =0.020, Q=0.22, HR:2.11) and DQB1*03:03 (P uncorr =0.043, Q=0.48, HR:1.91) than in non-carriers in the log-rank test. Conversely, serine carriers at position 13 of HLA-DRβ1 (HLA-DRβ1_13S), including DRB1*13:02 carriers, showed longer relapse-free survival with nominal significance (P uncorr =0.010, Q=0.42, HR:0.31). By combining DQA1*03:02 and HLA-DRβ1_13S, a significant difference was detected between groups with the highest and lowest risk for relapse (P uncorr =0.0055, Q=0.033, HR:4.02). Conclusion HLA-class II is associated not only with susceptibility to MPO-AAV but also with risk of relapse in the Japanese population.

OBJECTIVES AND METHODS:Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is an autoimmune disorder that causes vasculitis in small blood vessels throughout the body. Low-density granulocytes (LDGs) in autoimmune diseases, such as SLE and AAV, might play a critical role in the pathogenesis of these diseases. Here, we aimed to determine the characteristics of LDGs in patients with AAV. We assessed the number of whole white blood cells, neutrophil extracellular traps (NETs) productivity, proportion of cell surface markers (e.g. CD10), responses to immunosuppressants, and proteomics of LDGs in patients with AAV.RESULTS:We found more LDGs in peripheral blood mononuclear cells (PBMCs) of patients with AAV than PBMCs of healthy controls (HCs) and confirmed that these LDGs in AAV produced more NETs than normal density granulocytes (NDGs) in HCs. We identified CD10-positive LDGs with mature neutrophil features and CD10-negative LDGs with immature granulocyte properties; the proportion of the two LDG types decreased and increased, respectively, in the patients during treatment. Proteomic analysis revealed that the two LDG groups shared protein expression that differed from those of NDGs.CONCLUSION:We identified distinct CD10-positive and CD10-negative LDGs in patients with AAV. The roles of these LDGs in AAV pathology will require further investigation.

Background Neutrophil extracellular traps (NETs) are critically involved in microscopic polyangiitis (MPA) pathogenesis, and some patients with MPA possess anti-NET antibody (ANETA). Anti-myosin light chain 6 (MYL6) antibody is an ANETA that affects NETs. This study aimed to determine the significance of anti-MYL6 antibody in MPA. Methods The influence of anti-MYL6 antibody on NET formation and actin rearrangement necessary for NET formation was assessed by fluorescent staining. An enzyme-linked immunosorbent assay was established to detect serum anti-MYL6 antibody, and the prevalence of this antibody in MPA was determined. Furthermore, the disease activity and response to remission-induction therapy of MPA were compared between anti-MYL6 antibody-positive and anti-MYL6 antibody-negative MPA patients. Results Anti-MYL6 antibody disrupted G-actin polymerization into F-actin, suppressing phorbol 12-myristate 13-acetate-induced NET formation. Serum anti-MYL6 antibody was detected in 7 of 59 patients with MPA. The Birmingham vasculitis activity score (BVAS) of anti-MYL6 antibody-positive MPA patients was significantly lower than anti-MYL6 antibody-negative MPA patients. Among the nine BVAS evaluation items, the cutaneous, cardiovascular, and nervous system scores of anti-MYL6 antibody-positive MPA patients were significantly lower than anti-MYL6 antibody-negative MPA patients, although other items, including the renal and chest scores, were equivalent between the two groups. The proportion of patients with remission 6 months after initiation of remission-induction therapy in anti-MYL6 antibody-positive MPA patients was significantly higher than in anti-MYL6 antibody-negative MPA patients. Conclusions Collective findings suggested that anti-MYL6 antibody disrupted actin rearrangement necessary for NET formation and could reduce the disease activity of MPA.

The life prognosis of elderly patients with myeloperoxidase–anti-neutrophil cytoplasmic antibodies-associated vasculitis (MPO-AAV) has been improved by reducing the corticosteroid or cyclophosphamide dose to avoid opportunistic infection. However, many elderly MPO-AAV patients experience recurrence and renal death. An effective and safer maintenance treatment method is necessary to improve the renal prognosis of MPO-AAV. Patients with MPO-AAV who reached complete or incomplete remission after induction therapy were prospectively and randomly divided into mizoribine (MZR; n = 25) and control (n = 28) groups. The primary endpoint was relapse of MPO-AAV. The patients’ serum MZR concentration was measured before (C0) and 3 h after taking the MZR. The maximum drug concentration (Cmax) and the serum MZR concentration curves were determined using population pharmacokinetics parameters. We also assessed the relationship between the MZR concentrations and adverse events. The observation period was 12 months. Fifty-eight MPO-AAV patients from 16 hospitals in Japan were enrolled. Ten patients relapsed (MZR group, n = 6; control group, n = 4; a nonsignificant between-group difference). Changes in the serum MZR concentration could be estimated for 22 of the 25 MZR-treated patients: 2 of the 11 patients who reached a Cmax of 3 μg/mL relapsed, whereas 4 of the 11 patients who did not reach this Cmax relapsed. The treatment of one patient with C0 > 1 μg/mL was discontinued due to adverse events. No serious adverse events occurred. There was no significant difference in the recurrence rate of MPO-AAV between treatment with versus without MZR.

A novel patient cluster in antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) may be identified in Japan. We performed multiple correspondence and cluster analysis regarding 427 clinically diagnosed AAV patients excluding eosinophilic granulomatosis with polyangiitis. Model 1 included the ANCA phenotype, items of the Birmingham Vasculitis Activity Score, and interstitial lung disease; model 2 included serum creatinine (s-Cr) and C-reactive protein (CRP) levels with model 1 components. In seven clusters determined in model 1, the ANCA-negative (n = 8) and proteinase 3-ANCA-positive (n = 41) groups emerged as two distinct clusters. The other five myeloperoxidase-ANCA-positive clusters were characterized by ear, nose, and throat (ENT) (n = 47); cutaneous (n = 36); renal (n = 256), non-renal (n = 33); and both ENT and cutaneous symptoms (n = 6). Four clusters in model 2 were characterized by myeloperoxidase-ANCA negativity (n = 42), without s-Cr elevation (< 1.3 mg/dL) (n = 157), s-Cr elevation (≥ 1.3 mg/dL) with high CRP (> 10 mg/dL) (n = 71), or s-Cr elevation (≥ 1.3 mg/dL) without high CRP (≤ 10 mg/dL) (n = 157). Overall, renal, and relapse-free survival rates were significantly different across the four clusters in model 2. ENT, cutaneous, and renal symptoms may be useful in characterization of Japanese AAV patients with myeloperoxidase-ANCA. The combination of s-Cr and CRP levels may be predictive of prognosis.

BACKGROUND:The detection of leukocyte-derived CD11b (α subunit of integrin Mac-1) and CD163 (scavenger receptor) in urine may reflect renal inflammation in antineutrophil cytoplasmic antibody-associated glomerulonephritis (ANCA-GN). The objective of this study was to evaluate the clinical significance of urinary CD11b (U-CD11b) and CD163 (U-CD163) in ANCA-GN. METHODS:U-CD11b and U-CD163 were examined using enzyme-linked immunosorbent assay in ANCA-GN urine samples from our institutional cohort (n = 88) and a nationwide cohort (n = 138), and their association with renal histology was subsequently analyzed. Logistic regression analyses were performed on a nationwide ANCA cohort to determine the associations of the two urinary molecules with renal remission failure at 6 months or with yearly estimated glomerular filtration rate (eGFR) slope over a 24-month observation period. RESULTS:U-CD11b and U-CD163 were significantly associated with cellular crescent formation and leukocyte accumulation in glomerular crescents. With regard to interstitial inflammation, both levels of U-CD11b and U-CD163 at diagnosis remarkably increased in ANCA-GN compared with the levels observed in nonglomerular kidney disorders including nephrosclerosis, immunoglobulin G4-related disease and tubulointerstitial nephritis; however, the presence of U-CD11b alone was significantly correlated with tubulointerstitial leukocyte infiltrates. Although neither U-CD11b nor U-CD163 at diagnosis was associated with remission failure at 6 months, multivariate analysis demonstrated that the baseline U-CD11b levels were significantly associated with the increase in eGFR following immunosuppressive therapy. CONCLUSIONS:Although both U-CD11b and U-CD163 reflect renal leukocyte accumulation, U-CD11b at diagnosis provides additional clinical value by predicting the recovery rate after the treatment of ANCA-GN.

An international consensus on antineutrophil cytoplasm antibodies (ANCA) testing in eosinophilic granulomatosis with polyangiitis (EGPA) is presented. ANCA, specific for myeloperoxidase (MPO), can be detected in 30-35% of patients with EGPA. MPO-ANCA should be tested with antigen-specific immunoassays in any patient with eosinophilic asthma and clinical features suggesting EGPA, including constitutional symptoms; purpura; polyneuropathy; unexplained heart, gastrointestinal, or kidney disease; and/or pulmonary infiltrates or hemorrhage. A positive MPO-ANCA result contributes to the diagnostic workup for EGPA. Patients with MPO-ANCA-associated EGPA have vasculitis features, such as glomerulonephritis, neuropathy, and skin manifestations, more frequently than patients with ANCA-negative EGPA. However, the presence of MPO-ANCA is neither sensitive nor specific enough to identify whether a patient should be subclassified as having "vasculitic" or eosinophilic" EGPA. At present, ANCA status cannot guide treatment decisions, that is, whether cyclophosphamide, rituximab, or mepolizumab should be added to conventional glucocorticoid treatment. In EGPA, monitoring of ANCA is only useful when MPO-ANCA was tested positive at disease onset.