B-cell depletion with rituximab combined with glucocorticoids is routine therapy for ANCA-associated vasculitis (AAV), yet 10–30% of patients fail to achieve remission and relapse is common, particularly after rituximab withdrawal. We conducted a double-blind trial in 35 patients with active proteinase-3 (PR3)-AAV, comparing belimumab-rituximab (BEL-RTX) with placebo-rituximab (PBO-RTX) over 52 weeks, followed by 52 weeks of observation after treatment withdrawal. ANCA negativity occurred in 29.4% BEL-RTX and 13.3% PBO-RTX patients, with a trend toward faster PR3-ANCA clearance with BEL-RTX (adjusted HR 4.70, 95% CI 0.65–33.76, p=0.12). In patients with high baseline ANCA levels, BEL-RTX produced greater PR3-ANCA suppression. Faster remission and delayed total and naive B-cell reconstitution occurred with BEL-RTX. Relapses occurred in 35% BEL-RTX versus 60% PBO-RTX. PR3-ANCA re-emerged in 80% after belimumab withdrawal. Overall, BEL-RTX may enhance disease control but does not provide durable immunological reset.

IgA vasculitis (IgAV) is an autoimmune disease that affects the small vessels of the skin, joints, gastrointestinal (GI) tract, and kidneys. In the long term, IgAV associated with nephritis (IgAV-N) can progress to kidney failure. Evidence-based clinical studies of IgAV-N are few, leading to huge variations in treatment approaches and suboptimal outcomes. The wealth of emerging efficacious treatments for IgA nephrology brings new opportunities to this disease. The aim of this report is to describe the proceedings of a multiprofessional collaborative workshop convened to identify the barriers to developing high quality evidence for patients with IgAV-N. A multiprofessional group consisting of 53 attendees from 13 countries met. The meeting was represented by a variety of professional backgrounds, including lay attendees, with different levels of expertise (32% professors and 19% midcareer doctors). Using predefined aims, key themes were extracted, and an action plan developed. Consensus was obtained that there is sufficient similarity between adults and children in terms of the organs involved, pathophysiology, histological features, and likely response to treatment. Important differences included the greater spontaneous improvement in children and worse kidney outcomes in some populations. It was agreed that patients at greatest risk of kidney failure should be the primary focus of initial clinical trials. Important considerations included the following: diagnostic classification for adult onset IgAV, observational data, evidence of scientific similarity to IgA nephropathy (IgAN), an age-inclusive approach to trial design, systemic disease secondary end points, and the inclusion of patient-reported outcomes. This manuscript communicates an expert-informed pathway to high-quality evidence for IgAV-N.

Abstract Background/Aims Granulomatosis with polyangiitis is a life-threatening systemic vasculitis, characterised by anti-neutrophil cytoplasmic autoantibodies (ANCA) against proteinase 3 (PR3), a protease expressed intracellularly and on the surface of neutrophils. Most cell surface PR3 is bound to the receptor CD177, however the molecular mechanism of the interactions is not well understood. Previous studies have suggested that the hydrophobic patch on PR3 is involved in binding with CD177. We aimed to solve the structure of the PR3-CD177 complex, and CD177 alone, and determine whether the PR3-CD177 binding site is an important epitope for PR3-ANCA binding. Methods X-ray crystallography was used to solve the structure of PR3-CD177 complex and of an unliganded CD177 construct containing all four LU domains. The study was possible using a site-directed mutagenesis screen to identify stable PR3 variants that are readily expressed and purified from HEK293 cultures. We employed a panel of eight PR3-ANCA positive GPA patient plasma samples to test ANCA binding to our recombinant PR3 variants using ELISAs. Results Crystal structures revealed that the binding interface between PR3 and CD177 is mainly hydrophobic and involves the first two LU domains of CD177. The structure of unliganded CD177 shows that it is composed of two subdomains, each containing two tightly packed LU domains, that are connected by a flexible linker. Our standardised PR3-ANCA ELISAs show that for most GPA plasma samples, there is reduced ANCA binding when a recombinant PR3 variant that has the CD177-binding site masked was used. Conclusion The previously identified hydrophobic patch of PR3 is significantly involved in the binding interface between PR3 and CD177, and this site is a major autoantibody epitope that is targeted in most GPA patients examined in this study. Disclosure E. Seiradake: None. S. Dubey: None. J. Joha: None. C. Zheng-Gerard: None. S. Draper: None. H. Lin: None. A. Salama: None. K. McHugh: None.

OBJECTIVE:Ear, nose, and throat (ENT) manifestations are common in antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). There is an unmet need for drugs to target these manifestations. Granuloma formation is characteristic of proteinase 3 (PR3)-AAV. In a zebrafish model, niclosamide inhibits PR3-induced granuloma formation. We hypothesized that intranasal niclosamide would reduce AAV-associated ENT symptoms. METHODS:PROTECT-V was a randomized, double-blind, placebo-controlled platform trial evaluating pre-exposure prophylaxis agents against COVID-19 infection. This subanalysis includes patients from a single center with AAV, enrolled into the intranasal niclosamide arm. Clinical data were retrospectively collected for nine months before, during, and nine months after treatment. Researchers were blinded to treatment allocation. RESULTS:Of 32 (14 niclosamide; 18 placebo) patients, 11 (34%) were female; the median age was 69 (interquartile range [IQR] 59-75) years. Median prior AAV disease duration was 5.4 (IQR 1.9-13.1) years; 19 (59%) had active disease in the year before treatment. Median treatment exposure was 200 (IQR 109-251) days. During treatment, ENT symptoms were identified in 1 of 14 (7%) of the niclosamide group compared with 7 of 18 (39%) of the placebo group (P = 0.04). No significant difference between groups was found in the nine months before or after treatment. Among PR3-ANCA-positive patients, 0 of 10 in the niclosamide group compared to 5 of 9 (56%) in the placebo group had ENT symptoms during treatment. CONCLUSION:These data are a signal of potential clinical effect on ENT manifestations in AAV. They support a role for the IL-6 and STAT3 pathway in AAV; intranasal niclosamide or other drug candidates in this pathway warrant further evaluation.

Introduction: Glucocorticoids (GCs) are pivotal in treating antineutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis (AAV); however, their use is associated with significant toxicities. Findings of recent trials support reduced GC dosing, demonstrating efficacy with fewer adverse events. Methods: This was a retrospective cohort study evaluating long-term outcomes of a rapid taper GC regimen in severe AAV. Fifty-eight patients treated with combination rituximab, low-dose i.v. cyclophosphamide, and a limited course of GC (total equivalent prednisolone: 1148 [887–1390] mg; median duration of GC: 14 [7–15] days) were followed-up with for a median of 41 (interquartile range: 27–48) months. Results: Median Birmingham Vasculitis Activity Score (BVAS), serum creatinine, estimated glomerular filtration rates (eGFR), and urinary protein-to-creatinine ratio (uPCR) at presentation were 14 (12–18), 176 (132–270) μmol/l, 29 (19–50) ml/min per 1.73 m2, and 152 (77–289) mg/mmol, respectively. At 3 months, 51 of 58 (88%) achieved remission without additional GC treatment, and this was sustained in 49 of 56 (88%) at 1 year, with improved kidney parameters (creatinine: 109 [83–162] μmol/l, eGFR: 54 [37–74]ml/min per 1.73 m2, uPCR: 35 [12–94] mg/mmol at 12 months). At 3 years, kidney and overall survival were 33 of 35 (94%) and 35 of 38 (93%), respectively; and 27 of 35 (77%) were in sustained remission without additional GC. Early improvements in disease activity and kidney function—and in long-term kidney and patient survival—were comparable with a previous cohort treated with an equivalent rituximab-cyclophosphamide regimen and a conventional GC taper, whereas adverse events (infection, new-onset diabetes) were less frequent. Conclusion: Ultrarapid GC withdrawal is safe and effective for many patients with AAV when used with combination induction regimens. This approach warrants confirmatory controlled studies and may have a place in the current management of patients at high risk of GC toxicities.

Glucocorticoids (GCs) are pivotal in treating antineutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis (AAV); however, their use is associated with significant toxicities. Findings of recent trials support reduced GC dosing, demonstrating efficacy with fewer adverse events. This was a retrospective cohort study evaluating long-term outcomes of a rapid taper GC regimen in severe AAV. Fifty-eight patients treated with combination rituximab, low-dose i.v. cyclophosphamide, and a limited course of GC (total equivalent prednisolone: 1148 [887-1390] mg; median duration of GC: 14 [7-15] days) were followed-up with for a median of 41 (interquartile range: 27-48) months. Median Birmingham Vasculitis Activity Score (BVAS), serum creatinine, estimated glomerular filtration rates (eGFR), and urinary protein-to-creatinine ratio (uPCR) at presentation were 14 (12-18), 176 (132-270) μmol/l, 29 (19-50) ml/min per 1.73 m2, and 152 (77-289) mg/mmol, respectively. At 3 months, 51 of 58 (88%) achieved remission without additional GC treatment, and this was sustained in 49 of 56 (88%) at 1 year, with improved kidney parameters (creatinine: 109 [83-162] μmol/l, eGFR: 54 [37-74]ml/min per 1.73 m2, uPCR: 35 [12-94] mg/mmol at 12 months). At 3 years, kidney and overall survival were 33 of 35 (94%) and 35 of 38 (93%), respectively; and 27 of 35 (77%) were in sustained remission without additional GC. Early improvements in disease activity and kidney function-and in long-term kidney and patient survival-were comparable with a previous cohort treated with an equivalent rituximab-cyclophosphamide regimen and a conventional GC taper, whereas adverse events (infection, new-onset diabetes) were less frequent. Ultrarapid GC withdrawal is safe and effective for many patients with AAV when used with combination induction regimens. This approach warrants confirmatory controlled studies and may have a place in the current management of patients at high risk of GC toxicities.

ANCA-associated vasculitis (AAV) is comprised of three specific conditions: granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA) and eosinophilic granulomatosis with polyangiitis (EGPA). Since the publication of the last British Society for Rheumatology (BSR) and British Health Professionals in Rheumatology (BHPR) guideline for the management of adults with AAV in 2014, a plethora of randomized controlled trials, additional research and recommendations have provided novel insights into how the management of AAV can be optimized, thus improving patient quality of life. The BSR AAV Working Group (WG) reviewed published guidelines, undertook a systematic literature review and utilized expertise from specialist vasculitis centres across the UK and patient representatives to formulate a list of 26 recommendations with corresponding strength of agreement (SOA) scores. Recommendations were updated from the published 2014 BSR and BHPR guideline. The 26 recommendations encompassed five key domains: 1. Treatment for GPA and MPA; 2. Management of subglottic stenosis and ear, nose and throat (ENT) manifestations of AAV; 3. Management and treatment for EGPA; 4. Service specifications; 5. Patient education and support. These recommendations provide an update on care delivery of AAV based on current evidence and specialist opinion. In addition, we have provided research and audit recommendations to support equitable access to care and improve health outcomes. The lay summary that accompanies this abstract can be found in Supplementary Data S1, available at Rheumatology online.

Background:Increasing numbers of older patients are undergoing kidney transplantation. While there is evidence for both sex- and age-related immunological variations increasing the risks of immunosuppression (IS), few centers enforce age- or sex-specific IS adjustments. Methods:We investigated outcomes of 148 kidney transplants performed in our center between April 2009 and March 2019 in recipients aged > 60 years and compared them to outcomes in 272 younger recipients (divided into age groups 18-34, 35-49, and 50-60 years), matched for degree of human leukocyte antigen (HLA) sensitization (calculated reaction frequency, cRF), number of donor-recipient HLA mismatches, and cytomegalovirus (CMV) serostatus, all treated with the same IS protocol. Outcomes were time to (i) first episode of biopsy-proven acute rejection (BPAR), (ii) first CMV viremia within the first 6 months, (iii) incidence of any new-onset malignancy, and (iv) development of donor-specific anti-HLA antibodies (DSAs). Results:Overall rates of BPAR were highest in the recipients under the age of 35, but with no evidence of a difference between older age groups. Conversely, the risk of CMV viremia and malignancy was significantly higher in older recipients; in the > 60-year-old group, CMV viremia HR: 2.66 (95% CI: 1.49-4.75), and malignancy HR: 7.3 (95% CI: 1.7-31.10) versus the youngest group with little evidence was confounded by comorbidity or donor factors on multivariate analysis. The risk of CMV infection was most marked in the oldest female group, while the risk of malignancy was greatest in older males. The development of DSA was equal across all age groups. Conclusion:Our data indicate that older recipient age is associated with increased risk of CMV viremia and malignancy after transplantation, suggesting an age-associated vulnerability to IS, with the risk occurring mostly in older women and older men, respectively. These data support the need to develop age- and sex-specific protocol adjustments.

Background:Posttransplant immunosuppression in kidney transplant recipients is associated with an increased risk of developing cutaneous squamous cell carcinoma (CSCC), contributing to significant morbidity and mortality. Various dermatological and immunosuppression modulation strategies have been identified that may reduce the risk of CSCC, both in primary and secondary prevention settings. Recent recommendations have provided consensus regarding dermatological approaches to prevent CSCC. Comparable transplant nephrology recommendations to guide immunosuppression modulation for CSCC prevention are currently lacking, leading to marked variation in practice. Methods:To address this knowledge gap, 46 international transplant nephrology experts participated in a 3-round Delphi survey to develop consensus recommendations for CSCC secondary prevention based on the actinic damage and skin cancer index stages of CSCC. Results:The panel of experts reached consensus to consider a change in immunosuppression after multiple low-risk invasive CSCC (stage 5a, 1/y >3 y) and encouraged collaboration with dermatology to optimize dermatologic preventative care after the first CSCC. There was also consensus to prioritize azathioprine modification where this is present in an immunosuppressive regimen. Conclusions:This study provides the first international consensus recommendations for management of immunosuppression in kidney transplant recipients at discrete stages of CSCC. Additional prospective studies are necessary to determine the optimal management of immunosuppression in this patient population. These recommendations have been endorsed by the Board of the American Society of Transplantation.

INTRODUCTION:Alpha-1 antitrypsin deficiency (AATD) is a genetic disorder characterised by low circulating levels of alpha-1 antitrypsin (AAT) protein, a key inhibitor of neutrophil elastase and proteinase 3 (PR3) which is also the main autoantigen in granulomatosis with polyangiitis (GPA). This systematic review examines the association between AATD and GPA. METHODS:A systematic search of PubMed, Embase, Cochrane, EBSCO Medline and Scopus (December 2024) identified studies on AATD and GPA. Data extraction and quality assessment followed PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. A random-effects meta-analysis was conducted to calculate pooled odds ratios and assess heterogeneity. RESULTS:23 studies (9634 individuals) met inclusion criteria. The Z-allele prevalence was 11.65% in GPA compared to 3.29% in controls and the S-allele prevalence was 10.8% in GPA compared to 5.26% in controls. Among 1755 individuals with GPA across 10 studies that provided specific genotype data, 22 (1.25%) were homozygous for the Z-allele. Meta-analysis showed that Z-allele carriers had 3.11 times higher odds of developing GPA (eight studies; 95% CI 2.43-3.9; I2: 0%). CONCLUSION:This meta-analysis reinforces the link between AATD and GPA, particularly in carriers of the Z-allele, supporting the role of PR3 dysregulation in GPA pathogenesis.

Lymphocyte depleting induction is recommended for kidney transplant recipients (KTRs) at high immunological risk, which traditionally includes those with detectable anti-human leucocyte antigen antibodies. Data to support this approach in the modern era of histocompatibility testing are limited. We investigated outcomes in KTRs who underwent Basiliximab induction between 2012–2023 in the UK. We stratified outcomes by levels of sensitisation and T cell epitope mismatch (PIRCHE-II) scores. 1348 KTRs were included; 859 (63.7%) were unsensitised, 351 (26.0%) sensitised (calculated reaction frequency [cRF] 1%–84%), and 138 (10.3%) highly sensitised (cRF 85%–100%). Patient survival, allograft survival, and death-censored graft survival (DCGS) were 97%, 94%, and 97% at 1 year, and 88%, 78%, and 84% at 5 years respectively. There were no differences in outcomes between unsensitised and sensitised recipients; graft survival was lower in highly sensitised patients. T cell epitope mismatch scores were higher in those with rejection at 1 year (ln[PIRCHE+1] 3.94 ± 1.01 no rejection vs. 4.25 ± 0.58 rejection, p = 0.02) and epitope mismatch was associated with early rejection in multivariable analyses (Odds Ratio 1.58, 95% CI 1.01–2.62). Hence, non-depleting induction provides good outcomes in unsensitised and sensitised KTRs. T cell epitope mismatches inform rejection risk in the first post-transplant year.

Significance Statement Early identification of patients at risk of renal flares in ANCA vasculitis is crucial. However, current clinical parameters have limitations in predicting renal relapse accurately. This study investigated the use of urinary CD4 + T lymphocytes as a predictive biomarker for renal flares in ANCA vasculitis. This study, including urine samples from 102 patients, found that the presence of urinary CD4 + T cells was a robust predictor of renal relapse within a 6-month time frame, with a sensitivity of 60% and a specificity of 97.8%. The diagnostic accuracy of urinary CD4 + T cells exceeded that of ANCA titers, proteinuria, and hematuria. Monitoring urinary CD4 + T lymphocytes could help assess the risk of future renal relapse, enabling early preventive measures and tailored treatment strategies. Background In ANCA-associated vasculitis, there is a lack of biomarkers for predicting renal relapse. Urinary T cells have been shown to differentiate active GN from remission in ANCA-associated vasculitis, but their predictive value for renal flares remains unknown. Methods The PRE-FLARED study was a prospective multicenter biomarker study including 102 individuals with ANCA-associated vasculitis in remission aimed to predict renal relapse by quantifying urinary CD4 + T-cell subsets using flow cytometry at baseline and monitoring clinical outcomes over a 6-month follow-up. Results Among the participants, ten experienced renal relapses, two had non–renal flares, and 90 remained in stable remission. The median baseline urinary CD4 + T-cell count was significantly higher in patients who relapsed compared with those in remission. Receiver operating characteristic curve analysis of urinary CD4 + T-cell counts showed an area under the curve value of 0.88 for predicting renal flares, outperforming ANCA titers, hematuria, and proteinuria. Using a cutoff of 490 CD4 + T cells per 100 ml urine, the sensitivity and specificity in identifying patients with future renal flares were 60% and 97.8%, respectively. In a post hoc analysis, combining urinary CD4 + T-cell counts with proteinase-3 ANCA levels suggested improved predictive performance in the PR3 + subgroup. In addition, the number of urinary CD4 + T cells showed a limited correlation with a decline in GFR and an increase in proteinuria over the follow-up period. Conclusions This study concluded that urinary CD4 + T-cell counts could identify patients with ANCA-associated vasculitis at a substantial risk of renal relapse within 6 months. Combining these counts with ANCA levels further improved the prediction of relapse. Clinical Trial registry name and registration number: Urinary T Lymphocytes Predict Renal Flares in Patients With Inactive ANCA-associated Glomerulonephritis (PRE-FLARED), NCT04428398.

Introduction Myocardial ischaemia-reperfusion injury (IRI) is a major cause of morbidity and mortality in patients with chronic kidney disease (CKD). The dietary adenine model of CKD is one of the most representative models of human CKD. However, most studies administer adenine throughout the entire study, which risks potential direct cardiotoxic effects of adenine. Therefore, we aimed to modify this model to address if the CKD-associated cardiovascular dysfunction persists following the withdrawal of adenine. Methods Male Wistar rats, aged 8–9 weeks, received 0.3% adenine diet for 10 weeks and normal chow for additional 8 weeks. Urine and blood samples were collected to evaluate the induction of CKD. Heart function was assessed by echocardiography. The sensitivity to myocardial IRI was assessed ex vivo. Inflammation profile of rats with CKD was assessed via RNA sequencing, ELISA and tissue histology. Results Induction of CKD was confirmed by a significant increase in serum creatine and urinary albumin to creatine ratio. Histology revealed extensive glomerular and tubular damage. Diastolic dysfunction, measured by the reduction of E/A ratio, was apparent in rats with CKD from 16 weeks. Hearts from rats with CKD had significantly larger infarcts compared to control hearts, indicating impaired resistance to IRI. The CKD rats also had higher levels of inflammatory cytokines including MPO, IL-6 and IL-33; and RNA sequencing revealed increase in inflammatory signalling pathways. Conclusion We have established a modified model of adenine-induced CKD model, which leads to cardiovascular dysfunction that is maintained up to two months following return to normal diet. Conflict of Interest None

Abstract Background and Aims Protein tyrosine kinases (PTKs) are enzymes responsible for the phosphorylation of tyrosine residues in lymphocytes. In 2017, Mkaddem et al. suggested that unique PTK signatures in peripheral leukocytes (PBMC) are associated with lupus nephritis (LN) activity [1]. Lymphocytes express two important PTKs, Lyn and Fyn, that modulate inhibitory or activatory signals depending on ligand avidity or phosphorylation status. SHP-1 tyrosine 536 phosphorylation (pSHP1-Y536) by Lyn activates inhibitory signaling and Fyn-dependent phosphorylation of SHP-1 serine 591 (pSHP1-S591) inactivates the phosphatase, enabling activatory immunoreceptor signaling. We hypothesized that active and refractory patients with proliferative LN have a different PTK profile in PBMC, with lower expression of pSHP1-Y536 and greater expression of pSHP1-S591, in comparison with those who have responded to treatment. Method In a cohort from the Royal Free Hospital, UCL (London, UK) we performed western blotting of PBMC lysates for SHP1-phospho-S591 and-Y536 from healthy individuals (HC; n = 19), LN patients in remission (n = 11) and with ongoing disease activity (n = 4). Densitometry of bands was carried out and a ratio of S591:Y536 expression was calculated (both normalized to actin). For the flow cytometry analysis, we followed up a Brazilian cohort of LN (n = 24) from Hospital das Clinicas, UFPE (Recife, Brazil). All patients had ongoing active LN with initial renal biopsy (class III, IV or/and V). PBMC samples were collected at 0, 3, 6, 9, 12, 18, and 24 months after biopsy. Isolated PBMC samples were stored at −80°C. PBMC samples were stained with antibodies against pSHP1 S591 and p-SHP1 Y536 and cell viability was checked using zombie red dye. Samples were acquired on the Accuri C6 cytometer (BD) and analyzed using the FLOJO software (BD). Results The western blotting relative expression of pSHP-1 S591:Y536 in PBMC was not significantly different when we compared HC with active LN (p = 0.098) and active with remission LN (p = 0.10), Fig. 1. The results obtained by flow cytometry expression ratio of pSHP1-S591:Y536 did not show a significant correlation with the median of proteinuria (Fig. 2), C3, C4, or SLEDAI from time of active kidney biopsy during LN flare throughout induction treatment. Conclusion There was no expression pattern of pSHP-1 Y536 and S591 in PBMC of LN patients, regardless of their renal activity or inflammatory status. Therefore, we cannot state those markers as a potential “liquid biopsy” for LN.

ABSTRACTBackgroundKidney disease is fairly unique due to the lack of symptoms associated with disease activity, and it is therefore dependent on biological monitoring. Dried biofluids, particularly dried capillary blood spots, are an accessible, easy‐to‐use technology that have seen increased utility in basic science research over the past decade. However, their use is yet to reach the kidney patient population clinically or in large‐scale discovery science initiatives. The aim of this study was to systematically evaluate the existing literature surrounding the use of dried biofluids in kidney research.MethodsA systematic literature review was conducted using three search engines and a predefined search term strategy. Results were summarised according to the collection method, type of biofluid, application to kidney disease, cost, sample stability and patient acceptability.ResultsIn total, 404 studies were identified and 67 were eligible. In total, 34,739 patients were recruited to these studies with a skew towards male participants (> 73%). The majority of samples were blood, which was used either for monitoring anti‐rejection immunosuppressive drug concentrations or for kidney function. Dried biofluids offered significant cost savings to the patient and healthcare service. The majority of patients preferred home microsampling when compared to conventional monitoring.ConclusionThere is an unmet need in bringing dried microsampling technology to advance kidney disease despite its advantages. This technology provides an opportunity to upscale patient recruitment and longitudinal sampling, enhance vein preservation and overcome participation bias in research.

We have brought together opinion leaders to provide up to date reviews on common autoimmune rheumatic diseases with clinically relevant diagnostic and management strategies, as well as insightful updates on pathogenesis, classification and outcomes.