Type I interferon blockade with anifrolumab in patients with systemic lupus erythematosus modulates key immunopathological pathways in a gene expression and proteomic analysis of two phase 3 trials.

INTRODUCTION: Anifrolumab is a type I interferon (IFN) receptor 1 (IFNAR1) blocking antibody approved for treating patients with systemic lupus erythematosus (SLE). Here, we investigated the immunomodulatory mechanisms of anifrolumab using longitudinal transcriptomic and proteomic analyses of the 52-week, randomised, phase 3 TULIP-1 and TULIP-2 trials. METHODS: Patients with moderate to severe SLE were enrolled in TULIP-1 and TULIP-2 and received intravenous anifrolumab or placebo alongside standard therapy. Whole-blood expression of 18 017 genes using genome-wide RNA sequencing (RNA-seq) (pooled TULIP; anifrolumab, n=244; placebo, n=258) and 184 plasma proteins using Olink and Simoa panels (TULIP-1; anifrolumab, n=124; placebo, n=132) were analysed. We compared treatment groups via gene set enrichment analysis using MetaBase pathway analysis, blood transcriptome modules, in silico deconvolution of RNA-seq and longitudinal linear mixed effect models for gene counts and protein levels. RESULTS: Compared with placebo, anifrolumab modulated >2000 genes by week 24, with overlapping results at week 52 and 41 proteins by week 52. IFNAR1 blockade with anifrolumab downregulated multiple type I and II IFN-induced gene modules/pathways and type III IFN-λ protein levels, and impacted apoptosis-associated and neutrophil extracellular trap-associated transcriptional pathways, innate cell activating chemokines and receptors, proinflammatory cytokines and B-cell activating cytokines. In silico deconvolution of RNA-seq data indicated an increase from baseline of mucosal-associated invariant and γδT cells and a decrease of monocytes following anifrolumab treatment. DISCUSSION: Type I IFN blockade with anifrolumab modulated multiple inflammatory pathways downstream of type I IFN signalling, including apoptotic, innate and adaptive mechanisms that play key roles in SLE immunopathogenesis.

Identification of connective tissue disease autoantibodies and a novel autoantibody anti-annexin A11 in patients with "idiopathic" interstitial lung disease.

BACKGROUND: Autoantibodies are a hallmark feature of Connective Tissue Diseases (CTD). Their presence in patients with idiopathic interstitial lung disease (ILD) may suggest covert CTD. We aimed to determine the prevalence of CTD autoantibodies in patients diagnosed with idiopathic ILD. METHODS: 499 patient sera were analysed: 251 idiopathic pulmonary fibrosis (IPF), 206 idiopathic non-specific interstitial pneumonia (iNSIP) and 42 cryptogenic organising pneumonia (COP). Autoantibody status was determined by immunoprecipitation. RESULTS: 2.4% of IPF sera had a CTD-autoantibody compared to 10.2% of iNSIP and 7.3% of COP. 45% of autoantibodies were anti-synthetases. A novel autoantibody targeting an unknown 56 kDa protein was found in seven IPF patients (2.8%) and two NSIP (1%) patients. This was characterised as anti-annexin A11. CONCLUSION: Specific guidance on autoantibody testing and interpretation in patients with ILD could improve diagnostic accuracy. Further work is required to determine the clinical significance of anti-annexin A11.

Differences in management approaches for lupus nephritis within the UK.

Objectives: Outcomes of therapy for LN are often suboptimal. Guidelines offer varied options for treatment of LN and treatment strategies may differ between clinicians and regions. We aimed to assess variations in the usual practice of UK physicians who treat LN. Methods: We conducted an online survey of simulated LN cases for UK rheumatologists and nephrologists to identify treatment preferences for class IV and class V LN. Results: Of 77 respondents, 48 (62.3%) were rheumatologists and 29 (37.7%) were nephrologists. A total of 37 (48.0%) reported having a joint clinic between nephrologists and rheumatologists, 54 (70.0%) reported having a multidisciplinary team meeting for LN and 26 (33.7%) reported having a specialized lupus nurse. Of the respondents, 58 (75%) reported arranging a renal biopsy before starting the treatment. A total of 20 (69%) of the nephrologists, but only 13 (27%) rheumatologists, reported having a formal departmental protocol for treating patients with LN (P < 0.001). The first-choice treatment of class IV LN in pre-menopausal patients was MMF [41 (53.2%)], followed by CYC [15 (19.6%)], rituximab [RTX; 12 (12.5%)] or a combination of immunosuppressive drugs [9 (11.7%)] with differences between nephrologists' and rheumatologists' choices (P = 0.026). For class V LN, MMF was the preferred initial treatment, irrespective of whether proteinuria was in the nephrotic range or not. RTX was the preferred second-line therapy for non-responders. Conclusion: There was variation in the use of protocols, specialist clinic service provision, biopsies and primary and secondary treatment choices for LN reported by nephrologists and rheumatologists in the UK.

A path to Glucocorticoid Stewardship: a critical review of clinical recommendations for the treatment of systemic lupus erythematosus.

Glucocorticoids (GCs) have revolutionized the management of SLE, providing patients with rapid symptomatic relief and preventing flares when maintained at low dosages. However, there are increasing concerns over GC-associated adverse effects (AEs) and organ damage, which decrease patients' quality of life (QOL) and increase healthcare costs. This highlights the need to balance effective GC use and minimize toxicity in patients with SLE. Herein, we provide an overview of the theoretical considerations and clinical evidence, in addition to the variations and similarities across nine national and eight international recommendations regarding the use of GCs across SLE manifestations and how these compare with real-world usage. In line with this, we propose possible actions toward the goal of GC Stewardship to improve the QOL for patients with lupus while managing the disease burden.

Type 1 interferons: A target for immune-mediated inflammatory diseases (IMIDs).

The improved understanding of the molecular basis of innate immunity have led to the identification of type I interferons (IFNs), particularly IFN-α, as central mediators in the pathogenesis of several Immune-mediated inflammatory diseases (IMIDs) such as systemic lupus erythematosus (SLE), systemic sclerosis, inflammatory myositis and Sjögren's syndrome. Here, we review the main data regarding the opportunity to target type I IFNs for the treatment of IMIDs. Type I IFNs and their downstream pathways can be targeted pharmacologically in several manners. One approach is to use monoclonal antibodies against IFNs or the IFN-receptors (IFNARs, such as with anifrolumab). The downstream signaling pathways of type I IFNs also contain several targets of interest in IMIDs, such as JAK1 and Tyk2. Of these, anifrolumab is licensed and JAK1/Tyk2 inhibitors are in phase III trials in SLE. Targeting IFN-Is for the treatment of SLE is already a reality and in the near future may prove useful in other IMIDs. IFN assays will find a role in routine clinical practice for the care of IMIDs as further validation work is completed and a greater range of targeted therapies becomes available.

EULAR recommendations for the management of systemic lupus erythematosus: 2023 update.

OBJECTIVES: To update the EULAR recommendations for the management of systemic lupus erythematosus (SLE) based on emerging new evidence. METHODS: An international Task Force formed the questions for the systematic literature reviews (January 2018-December 2022), followed by formulation and finalisation of the statements after a series of meetings. A predefined voting process was applied to each overarching principle and recommendation. Levels of evidence and strengths of recommendation were assigned, and participants finally provided their level of agreement with each item. RESULTS: The Task Force agreed on 5 overarching principles and 13 recommendations, concerning the use of hydroxychloroquine (HCQ), glucocorticoids (GC), immunosuppressive drugs (ISDs) (including methotrexate, mycophenolate, azathioprine, cyclophosphamide (CYC)), calcineurin inhibitors (CNIs, cyclosporine, tacrolimus, voclosporin) and biologics (belimumab, anifrolumab, rituximab). Advice is also provided on treatment strategies and targets of therapy, assessment of response, combination and sequential therapies, and tapering of therapy. HCQ is recommended for all patients with lupus at a target dose 5 mg/kg real body weight/day, considering the individual's risk for flares and retinal toxicity. GC are used as 'bridging therapy' during periods of disease activity; for maintenance treatment, they should be minimised to equal or less than 5 mg/day (prednisone equivalent) and, when possible, withdrawn. Prompt initiation of ISDs (methotrexate, azathioprine, mycophenolate) and/or biological agents (anifrolumab, belimumab) should be considered to control the disease and facilitate GC tapering/discontinuation. CYC and rituximab should be considered in organ-threatening and refractory disease, respectively. For active lupus nephritis, GC, mycophenolate or low-dose intravenous CYC are recommended as anchor drugs, and add-on therapy with belimumab or CNIs (voclosporin or tacrolimus) should be considered. Updated specific recommendations are also provided for cutaneous, neuropsychiatric and haematological disease, SLE-associated antiphospholipid syndrome, kidney protection, as well as preventative measures for infections, osteoporosis, cardiovascular disease. CONCLUSION: The updated recommendations provide consensus guidance on the management of SLE, combining evidence and expert opinion.

Revision to the musculoskeletal domain of the BILAG-2004 index to incorporate ultrasound findings.

OBJECTIVES: To improve the definitions of inflammatory arthritis within the musculoskeletal (MSK) domain of the BILAG-2004 index by incorporating imaging findings and clinical features predictive of response to treatment. METHODS: The BILAG MSK Subcommittee proposed revisions to the BILAG-2004 index definitions of inflammatory arthritis, based on review of evidence in two recent studies. Data from these studies were pooled and analysed to determine the impact of the proposed changes on the severity grading of inflammatory arthritis. RESULTS: The revised definition for severe inflammatory arthritis includes definition of 'basic activities of daily living'. For moderate inflammatory arthritis, it now includes synovitis, defined by either observed joint swelling or MSK US evidence of inflammation in joints and surrounding structures. For mild inflammatory arthritis, the definition now includes reference to symmetrical distribution of affected joints and guidance on how US may help re-classify patients as moderate or no inflammatory arthritis. Data from two recent SLE trials were analysed (219 patients). A total of 119 (54.3%) were graded as having mild inflammatory arthritis (BILAG-2004 Grade C). Of these, 53 (44.5%) had evidence of joint inflammation (synovitis or tenosynovitis) on US. Applying the new definition increased the number of patients classified as moderate inflammatory arthritis from 72 (32.9%) to 125 (57.1%), while patients with normal US (n = 66/119) could be recategorized as BILAG-2004 Grade D (inactive disease). CONCLUSIONS: Proposed changes to the definitions of inflammatory arthritis in the BILAG-2004 index will result in more accurate classification of patients who are more or less likely to respond to treatment.

Management and treatment of children, young people and adults with systemic lupus erythematosus: British Society for Rheumatology guideline scope.

The objective of this guideline is to provide up-to-date, evidence-based recommendations for the management of SLE that builds upon the existing treatment guideline for adults living with SLE published in 2017. This will incorporate advances in the assessment, diagnosis, monitoring, non-pharmacological and pharmacological management of SLE. General approaches to management as well as organ-specific treatment, including lupus nephritis and cutaneous lupus, will be covered. This will be the first guideline in SLE using a whole life course approach from childhood through adolescence and adulthood. The guideline will be developed with people with SLE as an important target audience in addition to healthcare professionals. It will include guidance related to emerging approved therapies and account for National Institute for Health and Care Excellence Technology Appraisals, National Health Service England clinical commissioning policies and national guidance relevant to SLE. The guideline will be developed using the methods and rigorous processes outlined in 'Creating Clinical Guidelines: Our Protocol' by the British Society for Rheumatology.

What is the best instrument to measure disease activity in SLE? - SLE-DAS vs Easy BILAG.

Systemic lupus erythematosus (SLE) is a heterogeneous condition making assessment of disease activity challenging. However, thorough assessment is essential to evaluate patients longitudinally, to guide therapeutic decisions, and for clinical trials. Currently, the most popular disease activity index in clinical practice and trials is SLEDAI-2K. Its main advantage is ease of use, but significant weaknesses of SLEDAI-2K are omission of several serious manifestations, inability to capture change within an organ system, and fixed severity weightings that are often inappropriate. Recently several groups have developing improved tools. We report here the debate held at CORA meeting on this issue. SLE-DAS includes 17 weighted clinical and laboratory parameters including continuous measures in 4 items with an online calculator. A higher sensitivity to change compared to SLEDAI-2K has been demonstrated in its validation studies. Easy BILAG is an improved format of the BILAG-2004 that retains its content but greatly simplified. Its scoring using a single-page form that incorporates concise definitions for key terms next to clinical items. Easy-BILAG demonstrates higher accuracy and less variability and increased and better user feedback compared to the standard BILAG-2004 format. Both the indices discussed at CORA showed an advantage in measuring disease activity compared to SLEDAI.

Musculoskeletal manifestations of systemic lupus erythematosus.

MSK is the most common and impactful symptom of lupus at a population level. It has a variety of different presentations, but joint swelling is often not present despite imaging-proven synovitis. Imaging with US and MRI has been shown to improve detection of inflammation and identify treatment-responsive patients. In contrast, the SLEDAI shows poor sensitivity, specificity, and responsiveness. While BILAG and SLE-DAS are superior, they are still less accurate than imaging. These issues may explain why the evidence for conventional and biologic therapies for MSK lupus is complex. In clinical practice, physicians must take care not to underestimate MSK inflammation and consider using imaging. Future research should investigate new therapeutic targets specifically for synovitis and more sensitive outcome measures and trials to evaluate them.

Deconvolution of whole blood transcriptomics identifies changes in immune cell composition in patients with systemic lupus erythematosus (SLE) treated with mycophenolate mofetil.

BACKGROUND: Systemic lupus erythematosus (SLE) is a clinically and biologically heterogeneous autoimmune disease. We explored whether the deconvolution of whole blood transcriptomic data could identify differences in predicted immune cell frequency between active SLE patients, and whether these differences are associated with clinical features and/or medication use. METHODS: Patients with active SLE (BILAG-2004 Index) enrolled in the BILAG-Biologics Registry (BILAG-BR), prior to change in therapy, were studied as part of the MASTERPLANS Stratified Medicine consortium. Whole blood RNA-sequencing (RNA-seq) was conducted at enrolment into the registry. Data were deconvoluted using CIBERSORTx. Predicted immune cell frequencies were compared between active and inactive disease in the nine BILAG-2004 domains and according to immunosuppressant use (current and past). RESULTS: Predicted cell frequency varied between 109 patients. Patients currently, or previously, exposed to mycophenolate mofetil (MMF) had fewer inactivated macrophages (0.435% vs 1.391%, p = 0.001), naïve CD4 T cells (0.961% vs 2.251%, p = 0.002), and regulatory T cells (1.858% vs 3.574%, p = 0.007), as well as a higher proportion of memory activated CD4 T cells (1.826% vs 1.113%, p = 0.015), compared to patients never exposed to MMF. These differences remained statistically significant after adjusting for age, gender, ethnicity, disease duration, renal disease, and corticosteroid use. There were 2607 differentially expressed genes (DEGs) in patients exposed to MMF with over-representation of pathways relating to eosinophil function and erythrocyte development and function. Within CD4 + T cells, there were fewer predicted DEGs related to MMF exposure. No significant differences were observed for the other conventional immunosuppressants nor between patients according disease activity in any of the nine organ domains. CONCLUSION: MMF has a significant and persisting effect on the whole blood transcriptomic signature in patients with SLE. This highlights the need to adequately adjust for background medication use in future studies using whole blood transcriptomics.

Rapid efficacy of anifrolumab across multiple subtypes of recalcitrant cutaneous lupus erythematosus parallels changes in discrete subsets of blood transcriptomic and cellular biomarkers.

BACKGROUND: Observations with rituximab suggest B-cell independent mechanisms of cutaneous lupus erythematosus (CLE) in systemic lupus erythematosus (SLE), especially discoid lupus erythematosus (DLE). Type-I interferon receptor blockade with anifrolumab shows efficacy in SLE, but efficacy for cutaneous disease of specific morphologies has not been studied. Interferon has pleotropic immune effects and it is unknown which of these are critical to therapeutic response. OBJECTIVES: We evaluated clinical efficacy and quality-of-life impact of type-I interferon-blockade in: (i) rituximab-refractory CLE; (ii) DLE and other morphologies and (iii) transcriptomic and flow cytometric biomarkers. METHODS: We conducted a prospective single-centre study of anifrolumab in refractory mucocutaneous SLE. CLE Disease Area and Severity Index (CLASI) activity score, health-related quality of life, 96-probe TaqMan® gene expression analysis capturing key SLE blood transcriptome signatures, and eight-colour flow cytometry were undertaken at baseline, 1, 3 and 6 months. RESULTS: Seven patients [DLE (n = 5), chilblain lupus erythematosus (n = 1), subacute CLE (n = 1)] were evaluated. The median number of prior therapies was six (range 3-15), including rituximab in six of seven patients. Median CLASI-A showed rapid and sustained improvement from 17 at baseline to 6 (P = 0.016) at 1 month and 0 (P < 0.001) by 3 months. The median percentage reduction in CLASI-A at 3 months was 60%. Significant improvements were observed in Dermatology Life Quality Index scores (P < 0.001), EuroQol 5D visual analogue scale (P = 0.002) and LupusQoL fatigue, image and planning domains (P ≤ 0.05). One patient discontinued treatment owing to severe herpes zoster. Clinical responses paralleled discrete suppression of interferon-stimulated genes (ISGs) from SLE blood transcriptome module M1.2 with more varied downregulation in other interferon modules. Myeloid and inflammation-annotated genes remained upregulated throughout treatment. Intermediate monocytes (CD14++CD16+) reduced to normal levels during therapy (P = 0.014), while other flow subsets showed no substantive changes. CONCLUSIONS: These data indicate rapid efficacy of anifrolumab in DLE and rituximab-resistant CLE. Response is associated with suppression of a subset of ISGs and decline in intermediate monocytes. Suppression of all ISGs or the wider SLE blood transcriptome is not required for response.

2022 EULAR points to consider for the measurement, reporting and application of IFN-I pathway activation assays in clinical research and practice.

BACKGROUND: Type I interferons (IFN-Is) play a role in a broad range of rheumatic and musculoskeletal diseases (RMDs), and compelling evidence suggests that their measurement could have clinical value, although testing has not progressed into clinical settings. OBJECTIVE: To develop evidence-based points to consider (PtC) for the measurement and reporting of IFN-I assays in clinical research and to determine their potential clinical utility. METHODS: EULAR standardised operating procedures were followed. A task force including rheumatologists, immunologists, translational scientists and a patient partner was formed. Two systematic reviews were conducted to address methodological and clinical questions. PtC were formulated based on the retrieved evidence and expert opinion. Level of evidence and agreement was determined. RESULTS: Two overarching principles and 11 PtC were defined. The first set (PtC 1-4) concerned terminology, assay characteristics and reporting practices to enable more consistent reporting and facilitate translation and collaborations. The second set (PtC 5-11) addressed clinical applications for diagnosis and outcome assessments, including disease activity, prognosis and prediction of treatment response. The mean level of agreement was generally high, mainly in the first PtC set and for clinical applications in systemic lupus erythematosus. Harmonisation of assay methodology and clinical validation were key points for the research agenda. CONCLUSIONS: IFN-I assays have a high potential for implementation in the clinical management of RMDs. Uptake of these PtC will facilitate the progress of IFN-I assays into clinical practice and may be also of interest beyond rheumatology.

Baricitinib for systemic lupus erythematosus: a double-blind, randomised, placebo-controlled, phase 3 trial (SLE-BRAVE-I).

BACKGROUND: Baricitinib is an oral selective inhibitor of Janus kinase 1 and 2 approved for the treatment of rheumatoid arthritis, atopic dermatitis, and alopecia areata. In a 24-week phase 2 study in patients with systemic lupus erythematosus (SLE), baricitinib 4 mg significantly improved SLE disease activity compared with placebo. The objective of this trial was to evaluate the efficacy and safety of baricitinib in patients with active SLE in a 52-week phase 3 study. METHODS: In a multicentre, double-blind, randomised, placebo-controlled, parallel-group, phase 3 study, SLE-BRAVE-I, patients (aged ≥18 years) with active SLE receiving stable background therapy were randomly assigned 1:1:1 to baricitinib 4 mg, 2 mg, or placebo once daily for 52 weeks with standard of care. Glucocorticoid tapering was encouraged but not required per protocol. The primary endpoint was the proportion of patients reaching an SLE Responder Index (SRI)-4 response at week 52 in the baricitinib 4 mg treatment group compared with placebo. The primary endpoint was assessed by logistic regression analysis with baseline disease activity, baseline corticosteroid dose, region, and treatment group in the model. Efficacy analyses were done on a modified intention-to-treat population, comprising all participants who were randomly assigned and received at least one dose of investigational product. Safety analyses were done on all randomly assigned participants who received at least one dose of investigational product and who did not discontinue from the study for the reason of lost to follow-up at the first post-baseline visit. This study is registered with ClinicalTrials.gov, NCT03616912. FINDINGS: 760 participants were randomly assigned and received at least one dose of baricitinib 4 mg (n=252), baricitinib 2 mg (n=255), or placebo (n=253). A significantly greater proportion of participants who received baricitinib 4 mg (142 [57%]; odds ratio 1·57 [95% CI 1·09 to 2·27]; difference with placebo 10·8 [2·0 to 19·6]; p=0·016), but not baricitinib 2 mg (126 [50%]; 1·14 [0·79 to 1·65]; 3·9 [-4·9 to 12·6]; p=0·47), reached SRI-4 response compared with placebo (116 [46%]). There were no significant differences between the proportions of participants in either baricitinib group reaching any of the major secondary endpoints compared with placebo, including glucocorticoid tapering and time to first severe flare. 26 (10%) participants receiving baricitinib 4 mg had serious adverse events, 24 (9%) participants receiving baricitinib 2 mg, and 18 (7%) participants receiving placebo. The safety profile of baricitinib in participants with SLE was consistent with the known baricitinib safety profile. INTERPRETATION: The primary endpoint in this study was met for the 4 mg baricitinib group. However, key secondary endpoints were not. No new safety signals were observed. FUNDING: Eli Lilly and Company.

Breakthrough SARS-CoV-2 infections and prediction of moderate-to-severe outcomes during rituximab therapy in patients with rheumatic and musculoskeletal diseases in the UK: a single-centre cohort study.

Background: Concerns have been raised regarding the reduced immunogenicity of vaccines against COVID-19 in patients with autoimmune diseases treated with rituximab. However, the incidence and severity of breakthrough infections in unbiased samples of patients with specific rheumatic and musculoskeletal diseases are largely unknown. We aimed to assess the incidence of breakthrough SARS-CoV-2 infection, compare rates of moderate-to-severe COVID-19 with any severe infection event, and evaluate predictors of moderate-to-severe COVID-19 outcomes in patients treated with rituximab. Methods: We did a retrospective cohort study in all rituximab-treated patients with rheumatic and musculoskeletal diseases in a single centre in Leeds, UK between March 1, 2020 (the index date), and April 1, 2022. Adults aged 18 years and older, who fulfilled classification criteria for established rheumatic and musculoskeletal diseases, and received therapy with at least one rituximab infusion between Sept 1, 2019 (6 months before the pandemic in the UK), and April 1, 2022, were eligible for inclusion in the study. SARS-CoV-2 infection was defined by antigen test or PCR. COVID-19 outcomes were categorised as mild (from ambulatory to hospitalised but not requiring oxygen support) or moderate-to-severe (hospitalised and requiring oxygen support or death). The primary outcome was breakthrough COVID-19 infection, which was defined as an infection occurring 14 days or more after the second vaccine dose. Predictors of moderate-to-severe COVID-19 outcomes were analysed using Cox regression proportional hazards. Findings: Of the 1280 patients who were treated with at least one cycle of rituximab since Jan 1, 2002, 485 (38%) remained on rituximab therapy on April 1, 2022. Of these patients, 400 fulfilled all inclusion criteria and were included in our final analysis. The mean age at the index date was 58·9 years (SD 14·6), 288 (72%) of 400 patients were female and 112 (28%) were male, 333 (83%) were White, and 110 (28%) had two or more comorbidities. 272 (68%) of 400 patients had rheumatoid arthritis, 48 (12%) had systemic lupus erythematosus, 48 (12%) had anti-neutrophil cytoplasmic antibody-associated vasculitis, and 46 (12%) had other rheumatic and musculoskeletal diseases. During the study, 798 rituximab cycles were administered. Of the 398 (>99%) of 400 patients with vaccine data, 372 (93%) were fully vaccinated. Over the 774·6 patient-years of follow-up, there was an incremental increase in all SARS-CoV-2 severity types over the three pandemic phases (wild-type or alpha, delta, and omicron), but most infections were mild. The rates of moderate-to-severe COVID-19 were broadly similar across these three variant phases. Of 370 patients who were fully vaccinated and with complete data, 110 (30%) had all severity type breakthrough COVID-19, 16 (4%) had moderate-to-severe breakthrough COVID-19, and one (<1%) died. In the post-vaccination phase (after Dec 18, 2020), the incidence rates of all severity type and moderate-to-severe COVID-19 were substantially lower in those who were fully vaccinated compared with unvaccinated or partially vaccinated individuals (22·83 per 100 person-years [95% CI 18·94-27·52] in those who were fully vaccinated vs 89·46 per 100 person-years [52·98-151·05] in those who were partially vaccinated or unvaccinated for infections of all severities, and 3·32 per 100 person-years [2·03-5·42] in those who were fully vaccinated vs 25·56 per 100 person-years [9·59-68·10] in those who were partially vaccinated or unvaccinated for moderate-to-severe infections). The rate of moderate-to-severe COVID-19 was broadly similar to other severe infection events in this cohort (5·68 per 100 person-years [95% CI 4·22-7·63]). In multivariable Cox regression analysis, factors associated with an increased risk of moderate-to-severe COVID-19 were the number of comorbidities (hazard ratio 1·46 [95% CI 1·13-1·89]; p=0·0037) and hypogammaglobulinaemia (defined by a pre-rituximab IgG concentration of <6 g/L; 3·22 [1·27-8·19]; p=0·014). This risk was reduced with each vaccine dose received (0·49 [0·37-0·65]; p<0·0001). Other factors, including concomitant prednisolone use, rituximab-associated factors (eg, rituximab dose and time to vaccination since last rituximab dose), and vaccine-associated factors (eg, vaccine type and peripheral B-cell depletion) were not predictive of moderate-to-severe COVID-19 outcomes. Interpretation: This study presented detailed analyses of rituximab-treated patients during various phases of the COVID-19 pandemic. In later stages of the pandemic, the SARS-CoV-2 breakthrough infection rate was high but severe COVID-19 rates were similar to any severe infection event rate in patients who were vaccinated. The risk-benefit ratio might still favour rituximab in vaccinated patients with severe rheumatic and musculoskeletal diseases who have few other treatment options. Increased vigilance is needed in the presence of comorbidities and hypogammaglobulinaemia for all infection types. Funding: Wellcome Trust and Eli Lilly.

Gene Expression and Autoantibody Analysis Revealing Distinct Ancestry-Specific Profiles Associated With Response to Rituximab in Refractory Systemic Lupus Erythematosus.

OBJECTIVE: Gene expression profiles are associated with the clinical heterogeneity of systemic lupus erythematosus (SLE) but are not well studied as biomarkers for therapy. We studied gene expression and response to rituximab in a multiethnic UK cohort who were refractory to standard therapy. METHODS: We evaluated baseline expression levels of transcripts known to associate with clinical features of SLE using a 96-probe TaqMan array and whole blood samples from 213 patients with active SLE who had been prospectively enrolled in the British Isles Lupus Assessment Group (BILAG) Biologics Register. We measured autoantibodies using immunoprecipitation and enzyme-linked immunosorbent assays. We determined responses to first-cycle rituximab at 6 months from treatment start in 110 SLE patients by assessing BILAG 2004 disease activity. RESULTS: Interferon gene expression scores were lower in patients of European ancestry than in all other ancestry groups. The relationship between blood interferon gene expression scores and scores annotated to plasmablasts, neutrophils, myeloid lineage, inflammation, and erythropoiesis differed between patients of European and non-European ancestries. Hierarchical clustering revealed 3 distinct non-European ancestry patient subsets with stratified responses to rituximab that were not explained by sociodemographic and clinical variables, with responses lowest in an interferon-low, neutrophil-high cluster and highest in a cluster with high expression levels across all signatures (P < 0.001). Clusters in European ancestry patients did not predict response to rituximab but segregated patients by global disease activity and renal involvement. In both ancestral groups, interferon-high clusters were associated with U1 RNP/Sm antibodies. CONCLUSION: Ancestry appears central to the immunologic and clinical heterogeneity in SLE. These results suggest that ancestry, disease activity, and transcriptional signatures could each assist in predicting the effectiveness of B cell depletion therapies.

Comprehensive genetic and functional analyses of Fc gamma receptors influence on response to rituximab therapy for autoimmunity.

BACKGROUND: Rituximab is widely used to treat autoimmunity but clinical response varies. Efficacy is determined by the efficiency of B-cell depletion, which may depend on various Fc gamma receptor (FcγR)-dependent mechanisms. Study of FcγR is challenging due to the complexity of the FCGR genetic locus. We sought to assess the effect of FCGR variants on clinical response, B-cell depletion and NK-cell-mediated killing in rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). METHODS: A longitudinal cohort study was conducted in 835 patients [RA = 573; SLE = 262]. Clinical outcome measures were two-component disease activity score in 28-joints (2C-DAS28CRP) for RA and British Isles Lupus Assessment Group (BILAG)-2004 major clinical response (MCR) for SLE at 6 months. B-cells were evaluated by highly-sensitive flow cytometry. Single nucleotide polymorphism and copy number variation for genes encoding five FcγRs were measured using multiplex ligation-dependent probe amplification. Ex vivo studies assessed NK-cell antibody-dependent cellular cytotoxicity (ADCC) and FcγR expression. FINDINGS: In RA, carriage of FCGR3A-158V and increased FCGR3A-158V copies were associated with greater 2C-DAS28CRP response (adjusted for baseline 2C-DAS28CRP). In SLE, MCR was associated with increased FCGR3A-158V, OR 1.64 (95% CI 1.12-2.41) and FCGR2C-ORF OR 1.93 (95% CI 1.09-3.40) copies. 236/413 (57%) patients with B-cell data achieved complete depletion. Homozygosity for FCGR3A-158V and increased FCGR3A-158V copies were associated with complete depletion in combined analyses. FCGR3A genotype was associated with rituximab-induced ADCC, and increased NK-cell FcγRIIIa expression was associated with improved clinical response and depletion in vivo. Furthermore, disease status and concomitant therapies impacted both NK-cell FcγRIIIa expression and ADCC. INTERPRETATION: FcγRIIIa is the major low affinity FcγR associated with rituximab response. Increased copies of the FCGR3A-158V allele (higher affinity for IgG1), influences clinical and biological responses to rituximab in autoimmunity. Enhancing FcγR-effector functions could improve the next generation of CD20-depleting therapies and genotyping may stratify patients for optimal treatment protocols. FUNDING: Medical Research Council, National Institute for Health and Care Research, Versus Arthritis.