Distinct transcriptomes and autocrine cytokines underpin maturation and survival of antibody-secreting cells in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by multiple autoantibody types, some of which are produced by long-lived plasma cells (LLPC). Active SLE generates increased circulating antibody-secreting cells (ASC). Here, we examine the phenotypic, molecular, structural, and functional features of ASC in SLE. Relative to post-vaccination ASC in healthy controls, circulating blood ASC from patients with active SLE are enriched with newly generated mature CD19-CD138+ ASC, similar to bone marrow LLPC. ASC from patients with SLE displayed morphological features of premature maturation and a transcriptome epigenetically initiated in SLE B cells. ASC from patients with SLE exhibited elevated protein levels of CXCR4, CXCR3 and CD138, along with molecular programs that promote survival. Furthermore, they demonstrate autocrine production of APRIL and IL-10, which contributed to their prolonged in vitro survival. Our work provides insight into the mechanisms of generation, expansion, maturation and survival of SLE ASC.

Obexelimab in Systemic Lupus Erythematosus With Exploration of Response Based on Gene Pathway Co-Expression Patterns: A Double-Blind, Randomized, Placebo-Controlled, Phase 2 Trial

OBJECTIVE

Obexelimab is an investigational, bifunctional, noncytolytic monoclonal antibody that binds CD19 and FcyRIIb to inhibit B cells, plasmablasts, and plasma cells. This trial evaluated the efficacy and safety of obexelimab in the treatment of patients with systemic lupus erythematosus (SLE).

METHODS

During screening, patients with active, non-organ-threatening SLE received corticosteroid injections to ameliorate symptoms while immunosuppressants were withdrawn (≤10 mg/day prednisone equivalent and ≤400 mg/day hydroxychloroquine allowed). Patients with improved disease activity were randomized 1:1 to obexelimab 5 mg/kg intravenously or placebo once every 2 weeks until week 32 or loss of improvement (LOI).

RESULTS

In this study, 104 patients were randomized. Analysis of the primary endpoint, proportion of patients reaching week 32 without LOI, used an efficacy-evaluable (EE) population defined as patients who completed the study or withdrew for flare or treatment-related toxicity. This endpoint did not reach statistical significance: 21 of 50 obexelimab-treated patients (42.0%) versus 12 of 42 patients (28.6%) treated with a placebo (P = 0.183). Time to LOI was increased in obexelimab-treated patients versus patients treated with a placebo in the EE (hazard ratio [HR] 0.53, P = 0.025) and intention-to-treat (HR 0.59, P = 0.062) populations. In obexelimab-treated patients, B cells decreased approximately 50%, and trough concentration and inclusion in baseline gene expression clusters with high B cell pathway modules were associated with increased time to LOI. Obexelimab was associated with infusion reactions but was generally safe and well-tolerated.

CONCLUSION

Although the primary endpoint was not reached, secondary analysis showed time to LOI was significantly increased in obexelimab-treated patients, and analysis of patient subsets defined by gene expression patterns at baseline suggests a responding subpopulation.

Efficacy and Safety of Inebilizumab in IgG4-Related Disease: Protocol for a Randomized Controlled Trial

INTRODUCTION

Immunoglobulin G4-related disease (IgG4-RD) is a debilitating multiorgan disease characterized by recurring flares leading to organ dysfunction, decreased quality of life, and mortality. Glucocorticoids, the standard of care for IgG4-RD, are associated with substantial treatment-related toxicity. Inebilizumab, an antibody directed against CD19, mediates the rapid and durable depletion of CD19+ B cells thought to be involved in IgG4-RD pathogenesis. We describe the first international, prospective, double-blind, placebo-controlled trial to evaluate the safety and efficacy of B-cell depletion for flare prevention in IgG4-RD (MITIGATE).

METHODS

The study was designed by an international panel of physicians with expertise in IgG4-RD. Critical trial design decisions included the selection of participants, definition of clinically meaningful primary and secondary endpoints, accommodation of standard of care, and development of flare diagnostic criteria. The study is approved for conduct in 22 countries.

PLANNED OUTCOMES

The primary efficacy endpoint is time from randomization to the occurrence of the first centrally adjudicated and investigator-treated disease flare during the 1-year randomized controlled period. A set of novel, organ-specific flare diagnostic criteria were developed specifically for this trial, incorporating symptoms and signs, laboratory findings, imaging study results, and pathology data. MITIGATE aims to accrue 39 flares for the primary endpoint, which provides sufficient power to detect a relative risk reduction of 65% in the inebilizumab group. It is anticipated that enrollment of 160 participants will achieve this goal. Additional endpoints include safety, annualized flare rate, flare-free complete remission, quality-of-life measures, and cumulative glucocorticoid use. MITIGATE represents the first randomized, double-blind, placebo-controlled trial of any treatment strategy conducted in IgG4-RD. Data from this study will provide insights into the natural history and pathophysiology of IgG4-RD and the efficacy and safety of B-cell depletion as a therapeutic avenue.

TRIAL REGISTRATION

NCT04540497.

Chronic inflammation, neutrophil activity, and autoreactivity splits long COVID

While immunologic correlates of COVID-19 have been widely reported, their associations with post-acute sequelae of COVID-19 (PASC) remain less clear. Due to the wide array of PASC presentations, understanding if specific disease features associate with discrete immune processes and therapeutic opportunities is important. Here we profile patients in the recovery phase of COVID-19 via proteomics screening and machine learning to find signatures of ongoing antiviral B cell development, immune-mediated fibrosis, and markers of cell death in PASC patients but not in controls with uncomplicated recovery. Plasma and immune cell profiling further allow the stratification of PASC into inflammatory and non-inflammatory types. Inflammatory PASC, identifiable through a refined set of 12 blood markers, displays evidence of ongoing neutrophil activity, B cell memory alterations, and building autoreactivity more than a year post COVID-19. Our work thus helps refine PASC categorization to aid in both therapeutic targeting and epidemiological investigation of PASC.

SLE Antibody-Secreting Cells Are Characterized by Enhanced Peripheral Maturation and Survival Programs

Systemic Lupus Erythematosus (SLE) is an autoimmune disease characterized by multiple autoantibodies, some of which are present in high titers in a sustained, B cell-independent fashion consistent with their generation from long-lived plasma cells (LLPC). Active SLE displays high numbers of circulating antibody-secreting cells (ASC). Understanding the mechanisms of generation and survival of SLE ASC would contribute important insight into disease pathogenesis and novel targeted therapies. We studied the properties of SLE ASC through a systematic analysis of their phenotypic, molecular, structural, and functional features. Our results indicate that in active SLE, relative to healthy post-immunization responses, blood ASC contain a much larger fraction of newly generated mature CD19- CD138+ ASC similar to bone marrow (BM) LLPC. SLE ASC were characterized by morphological and structural features of premature maturation. Additionally, SLE ASC express high levels of CXCR4 and CD138, and molecular programs consistent with increased longevity based on pro-survival and attenuated pro-apoptotic pathways. Notably, SLE ASC demonstrate autocrine production of APRIL and IL-10 and experience prolonged in vitro survival. Combined, our findings indicate that SLE ASC are endowed with enhanced peripheral maturation, survival and BM homing potential suggesting that these features likely underlie BM expansion of autoreactive PC.

Poor immunogenicity upon SARS-CoV-2 mRNA vaccinations in autoimmune SLE patients is associated with pronounced EF-mediated responses and anti-BAFF/Belimumab treatment

Novel mRNA vaccines have resulted in a reduced number of SARS-CoV-2 infections and hospitalizations. Yet, there is a paucity of studies regarding their effectiveness on immunocompromised autoimmune subjects. In this study, we enrolled subjects naïve to SARS-CoV-2 infections from two cohorts of healthy donors (HD, n=56) and systemic lupus erythematosus (SLE, n=69). Serological assessments of their circulating antibodies revealed a significant reduction of potency and breadth of neutralization in the SLE group, only partially rescued by a 3rd booster dose. Immunological memory responses in the SLE cohort were characterized by a reduced magnitude of spike-reactive B and T cell responses that were strongly associated with poor seroconversion. Vaccinated SLE subjects were defined by a distinct expansion and persistence of a DN2 spike-reactive memory B cell pool and a contraction of spike-specific memory cTfh cells, contrasting with the sustained germinal center (GC)-driven activity mediated by mRNA vaccination in the healthy population. Among the SLE-associated factors that dampened the vaccine responses, treatment with the monoclonal antibody anti-BAFF/Belimumab (a lupus FDA-approved B cell targeting agent) profoundly affected the vaccine responsiveness by restricting the de novo B cell responses and promoting stronger extra-follicular (EF)-mediated responses that were associated with poor immunogenicity and impaired immunological memory. In summary, this study interrogates antigen-specific responses and characterized the immune cell landscape associated with mRNA vaccination in SLE. The identification of factors associated with reduced vaccine efficacy illustrates the impact of SLE B cell biology on mRNA vaccine responses and provides guidance for the management of boosters and recall vaccinations in SLE patients according to their disease endotype and modality of treatment.

Clinical Characteristics and Classification Criteria Performance in a Single-Center Cohort of 114 Patients With Immunoglobulin G4-Related Disease

INTRODUCTION/OBJECTIVES

Immunoglobulin G4-related disease (IgG4-RD) is a heterogeneous fibroinflammatory condition. The 2019 American College of Rheumatology (ACR)/European League Against Rheumatism (EULAR) Classification Criteria for IgG4-RD were published to provide unified classification criteria in clinical research. The purpose of this study was to characterize demographics, disease manifestations, and treatments of patients with IgG4-RD and assess performance of the Classification Criteria in a heterogeneous cohort with a large population of Black patients.

METHODS

This was a medical records review of all patients referred to a specialized IgG4-RD clinic. Demographics, serology, histopathology, disease manifestations, and treatment information were collected and analyzed. An ACR/EULAR Classification Criteria score for IgG4-RD was calculated to compare performance in definite diagnosis, probable diagnosis, and mimicker groups.

RESULTS

A total of 198 patients were evaluated. Eighty-five (43%) were mimickers. Of the remaining 114, 58 (51%) were classified as definite, and 56 (49%) as probable cases by treating clinicians. Pancreatitis was the most common presentation (37%) among 28 different organ manifestations of IgG4-RD. In patients with definite clinical diagnosis of IgG4-RD, 84% met the IgG4-RD Classification Criteria (i.e., score ≥20) with mean score of 29. Only 9% of the probable cases met this threshold with an average score of 8. None of the mimickers met the Classification Criteria.

CONCLUSIONS

This study highlights the broad spectrum of IgG4-RD and validates the use of the ACR/EULAR Classification Criteria for IgG4-RD, including a large proportion of Black patients. As shown in this study, IgG4-RD is a heterogeneous disease and continues to represent a diagnostic challenge to clinicians.

Performance of Modified ALMS and BLISS Criteria with Standard of Care Treatment in Two US Health Care Systems

OBJECTIVE

A retrospective cohort study was undertaken in a predominantly Black population undergoing standard treatment for lupus nephritis (LN) to estimate the incidence of, and risk factors for, complete response (CR) according to modified Aspreva Lupus Management Study (mALMS) and modified Belimumab International Study in Lupus Nephritis (mBLISS) criteria by 12 months.

METHODS

Patients with biopsy-proven LN class III or IV ± V, urine protein-to-creatinine ratio of ≥1gm/gm and estimated glomerular filtration rate of >50 ml/minute/1.73 m² at the time of the incident LN flare were included. The clinical, treatment, and laboratory factors associated with CR were identified using multivariable Cox regression.

RESULTS

Of 173 patients, 86.1% were women, 77.5% were Black, and over half (59.5%) had non-commercial insurance. By 12 months, 20.6% (95% confidence interval (95% CI) 14.6-28.6%) achieved mALMS CR and 33.7% (95% CI 26.4-42.4%) achieved mBLISS CR. Factors associated with mBLISS CR were commercial insurance (adjusted CR ratio = 3.5 [95% CI 1.9-6.7]; P < 0.001), albumin (adjusted CR ratio = 1.8 per 1 gm/dl increase in albumin; P = 0.02), and low C4 (adjusted CR ratio = 2.6; P = 0.03). Cumulative incidence of end-stage renal disease (ESRD) at 3 years was 23.1% (95% CI 15.7-31.3%) and 6.1% (95% CI 2.8-11.1%) for death. Patients with non-commercial insurance were more likely to develop ESRD, with cumulative incidence of 30.4% (95% CI 19.6-41.9%) compared to 12.7% (95% CI 5.0-24.2%) for patients with commercial insurance (P = 0.024).

CONCLUSION

In a primarily Black, uninsured LN population, despite achieving similar CR rates at 12 months, the incidence of ESRD and death exceeded those observed in controlled clinical trials with placebo arms.

Recurrent Pleural Effusions, Lymphedema, and Abnormal Nails in a 61 Year Old Man

A 61 year old man with history of hypertension, coronary artery disease (CAD) with prior stent placement, and chronic obstructive pulmonary disease (COPD) presented with a four month history of recurrent pleural effusions and progressive diffuse edema. Four months prior to hospital presentation, the patient began to notice new onset dyspnea on exertion, fatigue, and chest pain. Initial evaluation with troponin and EKG were negative. A chest x-ray (CXR) was done which revealed a moderate sized left pleural effusion. He did not have a history of pleural effusions or heart failure. Therefore, he underwent diagnostic thoracentesis and fluid studies were consistent with an exudative pleural effusion without malignant cells or microbial growth.

Outcomes of COVID-19 in a cohort of pediatric patients with rheumatic diseases

BACKGROUND

There are few reports of COVID-19 in pediatric patients with rheumatic diseases. This study describes the clinical presentation and outcomes of COVID-19 in this population.

METHODS

We analyzed a single-center case series of pediatric patients with rheumatic diseases and laboratory-confirmed COVID-19. Demographic, baseline and COVID-19 associated clinical features were compared between ambulatory and hospitalized patients using univariate analysis.

RESULTS

Fifty-five cases were identified: 45 (81.8%) in the ambulatory group and 10 (18.2%) hospitalized. African American race (OR 7.78; 95% CI [1.46-55.38]; p = 0.006) and cardiovascular disease (OR 19.40; 95% CI 2.45-254.14; p = 0.001) predominated in hospitalized patients. Active rheumatic disease (OR 11.83; 95% CI 1.43-558.37; p = 0.01), medium/high-dose corticosteroid use (OR 14.12; 95% CI [2.31-106.04]; p = 0.001), mycophenolate use (OR 8.84; 95% CI [1.64-63.88]; p = 0.004), rituximab use (OR 19.40; 95% CI [2.45-254.14]; p = 0.001) and severe immunosuppression (OR 34.80; 95% CI [3.94-1704.26]; p = < 0.001) were associated with increased odds of hospitalization. Fever (OR 7.78; 95% CI [1.46-55.38]; p = 0.006), dyspnea (OR 26.28; 95% CI [2.17-1459.25]; p = 0.003), chest pain (OR 13.20; 95% CI [1.53-175.79]; p = 0.007), and rash (OR 26.28; 95% CI [2.17-1459.25]; p = 0.003) were more commonly observed in hospitalized patients. Rheumatic disease flares were almost exclusive to hospitalized patients (OR 55.95; 95% CI [5.16-3023.74]; p < 0.001).. One patient did not survive.

CONCLUSIONS

Medium/high-dose corticosteroid, mycophenolate and rituximab use, and severe immunosuppression were risk factors for hospitalization. Fever, dyspnea, chest pain, and rash were high-risk symptoms for hospitalization. Rheumatic disease activity and flare could contribute to the need for hospitalization.

POS0173 METABOLOMIC PROFILING AND SYMPTOM BURDEN IN BLACK WOMEN WITH SYSTEMIC LUPUS ERYTHEMATOSUS

Background:

Black individuals with systemic lupus erythematosus (SLE), who are predominantly women, have disproportionately poorer health outcomes across the trajectory of their disease including increased mortality, higher symptom burden, and poor quality of life than non-Hispanic Whites. The heterogeneity of immunopathology and biochemical complexity of SLE create major knowledge gaps around the mechanisms of disease and differences in SLE symptom expression. Metabolomics may reveal biochemical dysregulation that underlies SLE symptoms and provide novel metabolic targets for precision symptom interventions.

Objectives:

We conducted untargeted metabolomic plasma profiling of Black females with SLE and Black female non-SLE controls to gain insight into metabolic disturbances associated with SLE.

Methods:

We analyzed blood specimens collected from 23 Black female patients with diagnosis of SLE during a routine outpatient rheumatology visit and from 21 Black female non-SLE controls whose data were collected as part of another study of obese caregivers. Data collection for both cases and controls was completed with harmonized protocols. Clinical data for cases were obtained via chart review and both cases and controls completed identical, reliable and valid measures of fatigue, depression, anxiety, and sleep disturbance. A commercial metabolomics analysis company within the US conducted untargeted metabolomics on the 44 plasma samples using ultrahigh performance liquid chromatography/tandem mass spectrometry along with metabolite identification and quantification to examine differences between SLE/non-SLE groups.

Results:

All SLE subjects met 2019 EULAR/ACR criteria (Aringer et al., 2019). SLE subjects were significantly (p < .05) younger (42.5 ± 12.2 vs. 63.2 ± 6.4), had a lower BMI (30.3 ± 9.4 vs. 34.9 ± 4.1), and greater co-morbidities (2.3 ± 1.3 vs. 1.1 ± 1.3) than non-SLE controls. SLE subjects reported higher symptoms than controls across all measures, but differences were not statistically significant. Metabolomics analysis revealed 290 biochemicals that were statistically significant (p ≤ .05) between SLE and non-SLE groups. Random Forest analysis had a predictive accuracy of 91% in differing between the two groups using out-of-bag sampling. Significant metabolic differences between groups were noted in biochemicals associated with glycolysis, the TCA cycle (see Table 1), fatty acid metabolism, branched chain amino acids, sterol levels, heme catabolism, and potential markers of renal impairment. Overall, the differences would suggest reduced energy production among SLE patients compared to controls.

Conclusion:

Black women with SLE had biochemical profiles consistent with reduced energy production which has implications for the high burden of fatigue and other symptoms in this population. Future work with larger sample sizes should involve integrating symptom and metabolomics data to identify potential biomarkers of symptom burden.

References:

Aringer, M., Costenbader, K., Daikh, D. et al. (2019). 2019 European League Against Rheumatism/American College of Rheumatology classification criteria for systemic lupus erythematosus. Ann Rheum Dis, 78,1151-1159.

Acknowledgements:

This work was supported by a research re-entry supplement to L. Kimble under the parent award 1P30NR018090-02S1 Center for the Study of Symptom Science, Metabolomics, and Multiple Chronic Conditions (Song, PI) funded by the National Institute of Nursing Research, National Institutes of Health, USA.

Disclosure of Interests:

Laura P. Kimble: None declared, Arezou Khosroshahi Consultant of: Have received honorarium for advisory board but has no relationship with this work., Grant/research support from: Have received a research grant from Pfizer; but has no relationship with this work., Ronald C. Eldridge: None declared, Glenna S. Brewster: None declared, Nicole S. Carlson: None declared, Elizabeth J. Corwin: None declared

Pregnancy in patients with systemic lupus erythematosus after cyclophosphamide therapy

Systemic lupus erythematosus (SLE) often affects females of reproductive age and Cyclophosphamide, an alkylating agent leading to premature ovarian insufficiency (POF) and labelled category D for pregnancy is used as induction therapy for severe manifestations of lupus. There have been multiple case series reflecting variable outcomes of pregnancies after cyclophosphamide use for cancers and autoimmune diseases. With increasing maternal age, we have an increasing population of lupus patients who may wish to conceive after having received cyclophosphamide therapy. The objective of our study was to improve our understanding of the impact of cyclophosphamide exposure on fertility and pregnancy outcomes in patients with SLE.We retrospectively reviewed the charts of all patients who had received intravenous cyclophosphamide at our academic institute in the time period from 2000-2018 and identified 440 patients which included 157 female patients of reproductive age. There were 37 documented pregnancies after the cyclophosphamide infusion, of which 23 patients had successful outcomes; 4 elective abortion and 10 miscarriages. There were 17 patients who developed POF, of which 7 also had end stage renal disease. The average cumulative dose of cyclophosphamide in the patients who had successful pregnancy was 4080.37 mg compared to 2806.25 mg in those who had a miscarriage (p 0.164) and 5526.47 mg in those who developed POF (p 0.046). Using multiple regressions to evaluate risk factors impacting pregnancy outcomes, when taken as a set, the predictors including race, serological profile, exposure to steroids and Mycophenolate mofetil, age at cyclophosphamide infusion, age at pregnancy, and cumulative cyclophosphamide dose accounted for 46.29% of the variance in outcome of pregnancy (p 0.23) and 39.58% of the variance in development of premature ovarian failure (p 0.008). We noted statistical significance in the impact of maternal age at time of pregnancy (p 0.04) and duration of time between the last infusions to subsequent pregnancy (p 0.02) to pregnancy outcome.Our findings suggest that a longer time interval between the last cyclophosphamide infusion and subsequent pregnancy was favorable for a successful outcome and higher cumulative cyclophosphamide dose is more likely to be associated with premature ovarian failure.

A phase 1b study of nivolumab in patients with autoimmune disorders and advanced malignancies (AIM-NIVO)

TPS2676

Background: Nivolumab is an anti-PD1 monoclonal antibody approved for treatment of an increasing number of solid tumors and hematological malignancies. However, patients (pts) with history of autoimmune disorders are excluded from the majority of clinical trials testing immune-checkpoint inhibitors (ICI) such as anti-PD1/anti-PD-L1 antibodies. Consequently, the risks of flare ups, worsening of pre-existing autoimmune disorders or risk of de-novo immune related adverse events (irAEs) in pts with dysfunctional immune systems and tumor types who otherwise stand to benefit from ICI therapy are largely unknown, posing a challenge for oncologists. We are conducting a phase Ib study to test the hypothesis that nivolumab can be safely administered to pts with varying severity of Dermatomyositis, Systemic Sclerosis, Rheumatoid Arthritis, Systemic Lupus Erythematosus, Inflammatory Bowel Disease, Multiple Sclerosis and other autoimmune disorders (AIM-Nivo). Methods: AIM-Nivo is an open-label, multi-center ongoing phase Ib study with nivolumab 480mg IV every 28 days in pts with autoimmune diseases and advanced malignancies (NCT03816345). The study has autoimmune disease-specific cohorts overseen by a multidisciplinary group of experts. The primary objective is to assess the overall safety and toxicity profile of nivolumab in pts with autoimmune disorders and advanced malignancies. Secondary objectives are to evaluate the antitumor efficacy; the impact of nivolumab on the autoimmune disease severity indices; and to explore potential biomarkers of response, resistance, or toxicity for each of the autoimmune disease-specific cohorts. Key overall inclusion criteria include age ≥18 years, histologically confirmed advanced or metastatic malignancies in which ICI are approved or have shown clinical activity. Key overall exclusion criteria include prior therapy with anti-PD-1/PD-L1 antibodies. Specific eligibility criteria are defined for each disease-specific cohort. For each autoimmune disorder, severity level of the disease as defined by disease-specific severity indices will be assessed, and up to a total of 12 pts will be included in each disease cohort at each severity level (max 36 pts per cohort). Primary endpoints are dose-limiting toxicities, adverse events (AEs) and serious AEs. Continuous monitoring of toxicity will be conducted. Key secondary endpoints are best objective response per RECIST1.1; progression free and overall survival; and cohort specific tumor tissue, blood, and non-tumor tissue-based biomarkers. The AIM-Nivo trial opened in May 2019 and is enrolling pts through the National Cancer Institute Experimental Therapeutics Clinical Trials Network (ETCTN), Early Drug Development Opportunity Program (EDDOP), and Create Access to Targeted Cancer Therapy for Underserved Populations (CATCH-UP) sites. Clinical trial information: NCT03816345.

Clinical course and outcomes of COVID-19 in rheumatic disease patients: a case cohort study with a diverse population

Objective

To determine clinical course and outcomes in rheumatic disease patients with coronavirus disease 2019 (COVID-19) and compare results to uninfected patients.

Methods

We conducted a case cohort study of autoimmune disease patients with COVID-19 (confirmed by severe acute respiratory syndrome coronavirus 2 PCR) from February 1, 2020, to July 31, 2020, and compared them in a 1:3 ratio with uninfected patients who were matched based on race, age, sex, and comorbidity index. Patient demographics, clinical course, and outcomes were compared among these patient groups.

Results

A total of 70 rheumatic disease patients with COVID-19 (mean age, 56.6 years; 64% African American) were identified. The 34 (49%) patients who were hospitalized used oral glucocorticoids more frequently than those treated as outpatients (p < 0.01). All 10 patients using anti-TNFα medications were treated as outpatients (p < 0.01). Those hospitalized with COVID-19 more often required ICU admission (17 (50%) vs 27 (26%), p = 0.01) and intubation (10 (29%) vs 6 (6%), p < 0.01) than uninfected patients and had higher mortality rates (6 (18%) vs 3 (3%), p < 0.01). Of the six COVID-19 patients who died, only one was of African ancestry (p = 0.03).

Conclusion

Rheumatic disease patients infected with COVID-19 were more likely to require ICU admission, ventilation, and died more frequently versus uninfected patients with autoimmune disease. Patients on anti-TNFα medications were hospitalized less frequently, while those on chronic glucocorticoids were hospitalized more frequently. These findings have important implications for medication choice in rheumatic disease patients during the ongoing spread of COVID-19.

Key Points • We show that hospitalized rheumatic disease patients with COVID-19 have poorer outcomes including ICU admission, ventilation, and death compared to hospitalized rheumatic disease patients not infected with COVID-19. • This study adds further support regarding protective effects of anti-TNFα medications in COVID-19 disease course, with 0 of 10 of these patients required hospitalization.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10067-021-05578-x.

Abstract CT249: A phase 1b study of nivolumab in patients with autoimmune disorders and advanced malignancies (AIM-NIVO)

Background: Immune checkpoint inhibitors (ICI) such as anti-PD-1/PD-L1 antibodies have rapidly become a pivotal approach to cancer therapy. Nivolumab is an anti-PD1 antibody approved for treatment of melanoma, lung, renal cell, head and neck squamous, urothelial and increasing number of other solid and hematological malignancies. However, patients with history of autoimmune disorders are excluded from the majority of clinical trials testing ICI. Consequently, the risks of flare ups and worsening of pre-existing autoimmune disorders in patients with tumor types who otherwise stand to benefit from ICI therapy are largely unknown, posing a challenge for oncologists. We are conducting a phase Ib study to test the hypothesis that nivolumab can be safely administered to patients with varying severity of Dermatomyositis, Systemic Sclerosis, Rheumatoid Arthritis, Systemic Lupus Erythematosus, Inflammatory Bowel Disease, Multiple Sclerosis and others autoimmune disorders (AIM-Nivo). Methods: AIM-Nivo is an open-label, multi-center ongoing phase Ib study with nivolumab 480mg IV every 28 days in patients with autoimmune diseases and advanced or metastatic solid tumors. The study has autoimmune disease-specific cohorts overseen by a multidisciplinary group of experts. The primary objective is to assess the overall safety and toxicity profile of nivolumab in patients with autoimmune disorders and advanced or metastatic solid tumors. Secondary objectives are to evaluate the antitumor efficacy, the impact of nivolumab on the autoimmune disease severity indices, and to explore potential biomarkers of response, resistance or toxicity. Key overall inclusion criteria include age ≥18 years, histologically confirmed advanced or metastatic solid tumors in which ICI are approved or have shown clinical activity, Eastern Cooperative Oncology Group (ECOG) performance status 0-2. Key overall exclusion criteria include prior therapy with an anti-PD-1/PD-L1 antibodies. Specific eligibility criteria are defined for each disease-specific cohort. For each autoimmune disorder, severity level of the disease as defined by disease-specific severity indices will be assessed, and up to a total of 12 patients will be included in each disease cohort at each severity level. Primary endpoints are dose-limiting toxicities defined for each autoimmune disease-specific cohort, adverse events (AEs) and serious AEs. Continuous monitoring of toxicity will be conducted. Key secondary endpoints are best objective response, progression free and overall survival and cohort specific tumor tissue, blood and non-tumor tissue-based biomarkers. The AIM-Nivo trial opened in May 2019 and is currently enrolling patients in the participating sites through the National Cancer Institute Experimental Therapeutics Clinical Trials Network (ETCTN). Clinical trial information: NCT03816345.

Citation Format: Ecaterina E. Ileana Dumbrava, Maria Suarez-Almazor, Jeane Painter, Tanner M. Johanns, Michael L. Dougan, Laura Cappelli, Yinghong Wang, Clifton Bingham, Sarthak Gupta, Blake M. Warner, Osama Rahma, Jarushka Naidoo, Patrick A. Ott, David A. Hafler, Harriet Kluger, Arezou Khosroshahi, Rafeh Naqash, Lorinda Chung, Tamiko R. Katsumoto, Shivaani Kummar, Hussein Tawbi, Elad Sharon. A phase 1b study of nivolumab in patients with autoimmune disorders and advanced malignancies (AIM-NIVO) [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr CT249.

A phase Ib study of nivolumab in patients with autoimmune disorders and advanced malignancies (AIM-NIVO)

TPS3158

Background: Immune checkpoint inhibitors (ICI) such as anti-PD-1/PD-L1 antibodies have become a pivotal approach to cancer therapy. Nivolumab is an anti-PD1 antibody approved for an increasing number of solid tumors and hematological malignancies. However, patients (pts) with history of autoimmune disorders are excluded from the majority of clinical trials testing ICI. Consequently, the risks of flares and worsening of pre-existing autoimmune disorders in pts with tumor types who otherwise stand to benefit from ICI therapy are largely unknown, posing a challenge for oncologists. We are conducting a phase Ib study to test the hypothesis that nivolumab can be safely administered to pts with varying severity of Dermatomyositis, Systemic Sclerosis, Rheumatoid Arthritis, Systemic Lupus Erythematosus, Inflammatory Bowel Disease, Multiple Sclerosis, Sjögren's Syndrome and Other Autoimmune Disorders (AIM-Nivo). Methods: AIM-Nivo is an open-label, multi-center ongoing phase Ib study with nivolumab 480mg IV every 28 days in pts with autoimmune diseases and advanced malignancies (NCT03816345). The study has autoimmune disease-specific cohorts overseen by a multidisciplinary group of experts. The primary objective is to assess the overall safety and toxicity profile of nivolumab in pts with autoimmune disorders and advanced malignancies. Secondary objectives are to evaluate the antitumor efficacy, the impact of nivolumab on the autoimmune disease severity indices, and to explore potential biomarkers of response, resistance or toxicity. Key overall inclusion criteria include age ≥18 years, histologically confirmed advanced malignancies in which ICI are approved or have shown clinical activity. Key overall exclusion criteria include prior therapy with anti-PD-1/PD-L1 antibodies. Specific eligibility criteria are defined for each disease-specific cohort. For each autoimmune disorder, severity level of the disease as defined by disease-specific severity indices will be assessed, and up to a total of 12 pts will be included in each disease cohort at each severity level. Primary endpoints are dose-limiting toxicities, adverse events (AEs) and serious AEs. Continuous monitoring of toxicity will be conducted. Key secondary endpoints are best objective response, progression free and overall survival and cohort specific tumor tissue, blood and non-tumor tissue-based biomarkers. The AIM-Nivo trial opened in May 2019 and is enrolling pts through the National Cancer Institute Experimental Therapeutics Clinical Trials Network (ETCTN). Clinical trial information: NCT03816345 .

The 2019 American College of Rheumatology/European League Against Rheumatism classification criteria for IgG4-related disease

IgG4-related disease (IgG4-RD) can cause fibroinflammatory lesions in nearly any organ. Correlation among clinical, serological, radiological and pathological data is required for diagnosis. This work was undertaken to develop and validate an international set of classification criteria for IgG4-RD. An international multispecialty group of 86 physicians was assembled by the American College of Rheumatology (ACR) and the European League Against Rheumatism (EULAR). Investigators used consensus exercises; existing literature; derivation and validation cohorts of 1879 subjects (1086 cases, 793 mimickers); and multicriterion decision analysis to identify, weight and test potential classification criteria. Two independent validation cohorts were included. A three-step classification process was developed. First, it must be demonstrated that a potential IgG4-RD case has involvement of at least one of 11 possible organs in a manner consistent with IgG4-RD. Second, exclusion criteria consisting of a total of 32 clinical, serological, radiological and pathological items must be applied; the presence of any of these criteria eliminates the patient from IgG4-RD classification. Third, eight weighted inclusion criteria domains, addressing clinical findings, serological results, radiological assessments and pathological interpretations, are applied. In the first validation cohort, a threshold of 20 points had a specificity of 99.2% (95% CI 97.2% to 99.8%) and a sensitivity of 85.5% (95% CI 81.9% to 88.5%). In the second, the specificity was 97.8% (95% CI 93.7% to 99.2%) and the sensitivity was 82.0% (95% CI 77.0% to 86.1%). The criteria were shown to have robust test characteristics over a wide range of thresholds. ACR/EULAR classification criteria for IgG4-RD have been developed and validated in a large cohort of patients. These criteria demonstrate excellent test performance and should contribute substantially to future clinical, epidemiological and basic science investigations.

Randomised prospective trial to assess the clinical utility of multianalyte assay panel with complement activation products for the diagnosis of SLE

Objective

We compared the physician-assessed diagnostic likelihood of SLE resulting from standard diagnosis laboratory testing (SDLT) to that resulting from multianalyte assay panel (MAP) with cell-bound complement activation products (MAP/CB-CAPs), which reports a two-tiered index test result having 80% sensitivity and 86% specificity for SLE.

Methods

Patients (n=145) with a history of positive antinuclear antibody status were evaluated clinically by rheumatologists and randomised to SDLT arm (tests ordered at the discretion of the rheumatologists) or to MAP/CB-CAPs testing arm. The primary endpoint was based on the change in the physician likelihood of SLE on a five-point Likert scale collected before and after testing. Changes in pharmacological treatment based on laboratory results were assessed in both arms. Statistical analysis consisted of Wilcoxon and Fisher’s exact tests.

Results

At enrolment, patients randomised to SDLT (n=73, age=48±2 years, 94% females) and MAP/CB-CAPs testing arms (n=72, 50±2 years, 93% females) presented with similar pretest likelihood of SLE (1.42±0.06 vs 1.46±0.06 points, respectively; p=0.68). Post-test likelihood of SLE resulting from randomisation in the MAP/CB-CAPs testing arm was significantly lower than that resulting from randomisation to SDLT arm on review of test results (−0.44±0.10 points vs −0.19±0.07 points) and at the 12-week follow-up visit (−0.61±0.10 points vs −0.31±0.10 points) (p<0.05). Among patients randomised to the MAP/CB-CAPs testing arm, two-tiered positive test results associated significantly with initiation of prednisone (p=0.034).

Conclusion

Our data suggest that MAP/CB-CAPs testing has clinical utility in facilitating SLE diagnosis and treatment decisions.

An International Multispecialty Validation Study of the IgG4-Related Disease Responder Index

OBJECTIVE

IgG4-related disease (IgG4-RD) can cause fibroinflammatory lesions in nearly any organ, leading to organ dysfunction and failure. The IgG4-RD Responder Index (RI) was developed to help investigators assess the efficacy of treatment in a structured manner. The aim of this study was to validate the RI in a multinational investigation.

METHODS

The RI guides investigators through assessments of disease activity and damage in 25 domains, incorporating higher weights for disease manifestations that require urgent treatment or that worsen despite treatment. After a training exercise, investigators reviewed 12 written IgG4-RD vignettes based on real patients. Investigators calculated both an RI score as well as a physician's global assessment (PhGA) score for each vignette. In a longitudinal assessment, 3 investigators used the RI in 15 patients with newly active disease who were followed up over serial visits after treatment. We assessed interrater and intrarater reliability, precision, validity, and responsiveness.

RESULTS

The 26 physician investigators included representatives from 6 specialties and 9 countries. The interrater and intrarater reliability of the RI was strong (0.89 and 0.69, respectively). Correlations (construct validity) between the RI and PhGA were high (Spearman's r = 0.9, P < 0.0001). The RI was sensitive to change (discriminant validity). Following treatment, there was significant improvement in the RI score (mean change 10.5 [95% confidence interval (95% CI) 5.4-12], P < 0.001), which correlated with the change in the PhGA. Urgent disease and damage were captured effectively.

DISCUSSION

In this international, multispecialty study, we observed that the RI is a valid and reliable disease activity assessment tool that can be used to measure response to therapy.

IgG4-Related Disease with Emphasis on Its Gastrointestinal Manifestation

IgG4-related disease is an immune-mediated fibroinflammatory condition with a diverse spectrum of organ involvement, commonly in the pancreas and bile ducts among other organs such as salivary and lacrimal glands. Classic histopathologic findings are the gold standard for confirmation of diagnosis, although diagnosis remains challenging, as biomarkers to date are neither sufficient nor necessary. Glucocorticoids are the most effective initial treatment, generally having a dramatic response, although limited clinical evidence exists regarding effective maintenance therapy. This review summarizes key GI manifestations of this condition for the practicing gastroenterologist and addresses the pathology, disease mechanism, and current therapeutic recommendations.

Diagnostic and treatment workup for IgG4-related disease

INTRODUCTION

IgG4-Related Disease is a newly recognized condition which is increasingly diagnosed by practitioners due to improvement in clinical awareness. Men and women have been found to be affected by this disease in various organs, more commonly with involvement of the salivary and lacrimal glands as well as pancreas and liver. Areas covered: The diagnosis and management of this condition remain challenging as biomarkers and therapies are being investigated. Hallmark features on histology are still the gold standard for confirmation of diagnosis, whereas serum IgG4 level has been shown to be neither necessary nor sufficient for the diagnosis. Glucocorticoids remain the most effective initial management for this condition while there are limited clinical trials on the effectiveness of maintenance therapy. Expert commentary: This review serves as an update on approaches for diagnosis and management of IgG4-RD. Most of the known data in this field comes from retrospective cohort studies and expert consensus guidelines but new ongoing prospective studies, clinical trials and better understanding of the pathogenesis of this condition are promising.

Rituximab for IgG4-related disease: a prospective, open-label trial

OBJECTIVES

To evaluate the efficacy of rituximab (RTX) in IgG4-related disease (IgG4-RD) in an open-label pilot trial.

METHODS

We treated 30 IgG4-RD patients with two doses of RTX (1000 mg each). The participants were either treated with RTX alone (n = 26; 87%) or required to discontinue baseline glucocorticoids (GC) within 2 months (n = 4; 13%). Disease activity was measured by the IgG4-RD Responder Index (IgG4-RD RI) and physician's global assessment (PGA). Disease response was defined as the improvement of the IgG4-RD RI by two points. The primary outcome, measured at 6 months, was defined as: (1) decline of the IgG4-RD RI ≥2 points compared with baseline; (2) no disease flares before month 6; and (3) no GC use between months 2 and 6. Complete remission was defined as an IgG4-RD RI score of 0 with no GC use.

RESULTS

Disease responses occurred in 97% of participants. The baseline IgG4-RD RI and PGA values, 11±7 and 63±22 mm, respectively, declined to 1±2 and 11±16 mm at 6 months (both p<0.00001). The primary outcome was achieved by 23 participants (77%). Fourteen (47%) were in complete remission at 6 months, and 12 (40%) remained in complete remission at 12  months. Among the 19 with elevated baseline serum IgG4, IgG4 concentrations declined from a mean of 911 mg/dL (range 138-4780 mg/dL) to 422 mg/dL (range 56-2410 mg/dL) at month 6 (p<0.05). However, only 8 (42%) of the 19 achieved normal values.

CONCLUSIONS

RTX appears to be an effective treatment for IgG4-RD, even without concomitant GC therapy.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov identifier: NCT01584388.

The diagnostic utility of serum IgG4 concentrations in IgG4-related disease

OBJECTIVES

We evaluated the sensitivity, specificity and positive and negative predictive values of elevated serum IgG4 concentrations for the diagnosis of IgG4-RD.

METHODS

Between 2001 and 2011, 190 unique patients had elevated serum IgG4 measurements. We reviewed electronic medical records to determine the indication for IgG4 measurement and underlying clinical diagnosis. Additionally, we reviewed the records of 190 other randomly selected patients from a pool of 3360 with normal results, to evaluate test characteristics of the IgG4 measurement.

RESULTS

Among 380 patients analysed, 72 had either probable or definite IgG4-RD. Sixty-five of the 72 IgG4-RD patients had elevated serum IgG4 concentrations (mean: 405 mg/dL; range 140-2000 mg/dL), for a sensitivity of 90%. Among the 308 subjects without IgG4-RD, 125 had elevated IgG4 (mean: 234 mg/dL; range 135-1180 mg/dL) and 183 had normal IgG4 concentrations, for a specificity of 60%. The negative predictive value of a serum IgG4 assay was 96%, but the positive predictive value only 34%. Analysis of the serum IgG4/total IgG ratio did not improve these test characteristics. Doubling the cutoff for IgG4 improved specificity (91%) but decreased sensitivity to 35%.

DISCUSSION

Multiple non-IgG4-RD conditions are associated with elevated serum IgG4, leading to poor specificity and low positive predictive value for this test. A substantial subset of patients with biopsy-proven IgG4-RD do not have elevated serum IgG4. Neither doubling the cutoff for serum IgG4 nor examining the serum IgG4/IgG ratio improves the overall test characteristics for the diagnosis of IgG4-RD.

IgG4-related disease and hypertrophic pachymeningitis

Hypertrophic pachymeningitis (HP) is an inflammatory condition in which the dura mater of the cranium or spine becomes thickened, leading to symptoms that result from mass effect, nerve compression, or vascular compromise. The differential diagnosis of HP includes immune-mediated conditions such as rheumatoid arthritis and vasculitis, malignancies, and infections. Many times, no diagnosis is reached; in such cases, the disease has been described as idiopathic HP. IgG4-related disease (IgG4-RD) is a recently described inflammatory condition known to cause tumefactive lesions at myriad anatomical locations. Both IgG4-RD and idiopathic HP share similar demographics, histopathology, and natural history. We hypothesized that IgG4-RD is a common cause of idiopathic HP.To investigate this hypothesis, we identified all pathology specimens diagnosed as noninfectious HP during 25 years at our institution. Fourteen cases had stained slides and paraffin blocks to permit review of the original hematoxylin and eosin stained slides as well as immunostaining of cell blocks. Recently published consensus guidelines describing characteristic histopathology and the necessary quantity of IgG4+ plasma cell infiltrate were used to diagnose IgG4-RD.Four cases (66.6%) that had been regarded previously as representing idiopathic HP were diagnosed as IgG4-RD; of all the reviewed cases, IgG4-RD represented 29% of cases. Of the remaining cases, 3 cases were associated with granulomatosis with polyangiitis (GPA), 2 with lymphoma, and 1 each with rheumatoid arthritis, giant cell arteritis, and sarcoidosis. Two of the cases could not be diagnosed more precisely and were classified as undifferentiated HP. Clinical history, serologic tests, cerebrospinal fluid studies, and radiology alone could not identify the cause of HP. Rather, biopsy with histopathology and immunostaining was necessary to reach an accurate diagnosis. Significant IgG4+ plasma cell infiltrates were observed in rheumatoid arthritis, granulomatosis with polyangiitis, and lymphoma, underscoring the importance of histopathology in making the diagnosis of IgG4-RD.This case series demonstrates that IgG4-RD may be the most common etiology of noninfectious HP and highlights the necessity of biopsy for accurate diagnosis.

Rethinking Ormond's disease: "idiopathic" retroperitoneal fibrosis in the era of IgG4-related disease

Idiopathic retroperitoneal fibrosis (RPF) is a periaortic sclerotic disease that encases adjacent retroperitoneal structures, particularly the ureters. A subset of idiopathic RPF cases can be associated with IgG4-related disease, but the frequency of this association is not clear. We selected 23 cases of idiopathic RPF and identified IgG4-related RPF cases based on the presence of IgG4+ plasma cells in the tissue, using an IgG4/IgG ratio cutoff of >40%. We then compared the IgG4-related RPF patients and the non-IgG4-related RPF patients in terms of both the presence of histopathologic features typical of IgG4-related disease and the simultaneous occurrence (or history) of other organ manifestations typical of IgG4-related disease. The IgG4-related RPF and non-IgG4-related RPF groups were also analyzed in terms of clinical, laboratory, and radiologic features and treatment review. We identified 13 cases of IgG4-related RPF (57% of the total cohort). The distinguishing features of IgG4-related RPF were histopathologic and extra-organ manifestations of IgG4-related disease. The IgG4-related RPF patients were statistically more likely than non-IgG4-related RPF patients to have retroperitoneal biopsies showing lymphoplasmacytic infiltrate (p = 0.006), storiform fibrosis (p = 0.006), or tissue eosinophilia (p = 0.0002). Demographics of the 2 groups, including a middle-aged, male predominance (mean age, 58 yr; 73% male), were similar. IgG4-related disease accounts for a substantial percentage of patients with "idiopathic" RPF. Histopathologic features such as storiform fibrosis, obliterative phlebitis, and tissue eosinophilia are critical to identifying this disease association. Extraretroperitoneal manifestations of IgG4-related disease are also often present among patients with IgG4-related RPF. Elevated IgG4/total IgG ratios in tissue biopsies are more useful than the number of IgG4+ plasma cells per high-power field in cases of RPF that are highly fibrotic.

Tocilizumab for the treatment of large-vessel vasculitis (giant cell arteritis, Takayasu arteritis) and polymyalgia rheumatica

OBJECTIVE

The interleukin-6 pathway is up-regulated in giant cell arteritis (GCA), Takayasu arteritis (TA), and polymyalgia rheumatica (PMR). We retrospectively assessed the outcomes of 10 patients with relapsing/refractory GCA, TA, or PMR treated with tocilizumab (TCZ).

METHODS

Patients with GCA (n = 7), TA (n = 2), and PMR (n = 1) received TCZ. Seven subjects had failed at least 1 second-line agent. The outcomes evaluated were symptoms of disease activity, inflammatory markers, ability to taper glucocorticoids, and cross-sectional imaging when indicated clinically.

RESULTS

The mean followup time of this cohort since diagnosis was 27 months (range 16-60 months). The patients were treated with TCZ for a mean period of 7.8 months (range 4-12 months). Before TCZ therapy, the patients experienced an average of 2.4 flares/year. All patients entered and maintained clinical remission during TCZ therapy. The mean daily prednisone dosages before and after TCZ initiation were 20.8 mg/day (range 7-34.3 mg/day) and 4.1 mg/day (range 0-10.7 mg/day), respectively (P = 0.0001). The mean erythrocyte sedimentation rate declined from 41.5 mm/hour (range 11-68 mm/hour) to 7 mm/hour (range 2.2-11.3 mm/hour; P = 0.0001). The adverse effects of TCZ included mild neutropenia (n = 4) and transaminitis (n = 4). One patient flared 2 months after TCZ discontinuation. An autopsy on 1 patient who died from a postoperative myocardial infarction following elective surgery revealed persistent vasculitis of large and medium-sized arteries.

CONCLUSION

TCZ therapy led to clinical and serologic improvement in patients with refractory/relapsing GCA, TA, or PMR. The demonstration of persistent large-vessel vasculitis at autopsy of 1 patient who had shown a substantial response requires close scrutiny in larger studies.

Consensus statement on the pathology of IgG4-related disease

IgG4-related disease is a newly recognized fibro-inflammatory condition characterized by several features: a tendency to form tumefactive lesions in multiple sites; a characteristic histopathological appearance; and-often but not always-elevated serum IgG4 concentrations. An international symposium on IgG4-related disease was held in Boston, MA, on 4-7 October 2011. The organizing committee comprising 35 IgG4-related disease experts from Japan, Korea, Hong Kong, the United Kingdom, Germany, Italy, Holland, Canada, and the United States, including the clinicians, pathologists, radiologists, and basic scientists. This group represents broad subspecialty expertise in pathology, rheumatology, gastroenterology, allergy, immunology, nephrology, pulmonary medicine, oncology, ophthalmology, and surgery. The histopathology of IgG4-related disease was a specific focus of the international symposium. The primary purpose of this statement is to provide practicing pathologists with a set of guidelines for the diagnosis of IgG4-related disease. The diagnosis of IgG4-related disease rests on the combined presence of the characteristic histopathological appearance and increased numbers of IgG4⁺ plasma cells. The critical histopathological features are a dense lymphoplasmacytic infiltrate, a storiform pattern of fibrosis, and obliterative phlebitis. We propose a terminology scheme for the diagnosis of IgG4-related disease that is based primarily on the morphological appearance on biopsy. Tissue IgG4 counts and IgG4:IgG ratios are secondary in importance. The guidelines proposed in this statement do not supplant careful clinicopathological correlation and sound clinical judgment. As the spectrum of this disease continues to expand, we advocate the use of strict criteria for accepting newly proposed entities or sites as components of the IgG4-related disease spectrum.

Rituximab for the treatment of IgG4-related disease: lessons from 10 consecutive patients

Patients with IgG4-related disease (IgG4-RD) typically have elevated serum concentrations of IgG4 and share histopathologic features that are similar across affected organ(s). IgG4-RD patients frequently require prolonged treatment with glucocorticoids and are often unable to taper these medications. Traditional disease-modifying antirheumatic drugs (DMARDs) are generally ineffective. We assessed the clinical and serologic responses to B lymphocyte depletion therapy in 10 consecutive patients with steroid- and DMARD-refractory IgG4-RD.Ten patients with IgG4-RD were treated with rituximab (RTX) (2 infusions of 1000 mg, 15 days apart). Clinical improvement was assessed by monitoring the patient's ability to taper prednisone to discontinuation and to stop DMARDs; by serial measurements of total IgG and IgG subclasses; and by follow-up radiologic assessments guided by the patient's particular pattern of organ involvement. We also developed and retrospectively applied the IgG4-RD Disease Activity Index and Flare Tool.Organ involvement included the pancreas, biliary tree, aorta, salivary glands (submandibular and parotid), lacrimal glands, lymph nodes, thyroid gland, and retroperitoneum. Nine of 10 patients demonstrated striking clinical improvement within 1 month of starting RTX. One patient with advanced thyroid fibrosis associated with Riedel thyroiditis and a history of disease in multiple other organ systems did not have improvement in the thyroid gland, but the disease did not progress to involve new organs. All 10 patients were able to discontinue prednisone and DMARDs following RTX therapy. Significant decreases in IgG concentrations were observed for the IgG4 subclass only. Four patients were re-treated with RTX after 6 months because of either symptom recurrence and increasing IgG4 concentration at the time of peripheral B cell reconstitution (n = 2) or because of physician discretion (n = 2). Repeated courses of RTX maintained their effectiveness and resulted in further decreases in IgG4 concentrations. In patients who had an increased IgG4 concentration at the time of presentation, the level of serum IgG4 appeared to be a reliable measure of disease activity.IgG4-RD is an idiopathic, multiorgan inflammatory disease in which diverse organ manifestations are linked by characteristic histopathologic and immunohistochemical features. Treatment with RTX led to prompt clinical and serologic improvement in refractory IgG4-RD in all patients with active inflammation. Serial treatments with RTX may lead to progressive declines in serum IgG4 concentrations and better disease control. Serum IgG4 concentrations may remain low, and clinical disease activity may remain quiescent even after B cell reconstitution in a significant proportion of patients.

IgG4-related systemic disease as a cause of "idiopathic" orbital inflammation, including orbital myositis, and trigeminal nerve involvement

IgG4-related systemic disease (IgG4-RD) is an inflammatory condition of unknown etiology that has been identified as the cause of tumefactive lesions in a number of tissues and organs. The role of the IgG4 remains to be clarified fully, but the histopathologic diagnosis hinges upon the finding of IgG4-bearing plasma cells in addition to characteristic morphologic features, with or without elevated seum IgG4. We present a 56-year-old man with orbital pseudotumor in whom, after 30 years of intractable disease, biopsy showed IgG4-RD involving the lacrimal gland, extraocular muscles, intraconal fat, and trigeminal nerve. Six months after initiating treatment with rituximab, his disease remained dormant, with improvement in his proptosis and normalization of serum IgG4 levels. We review the differential of idiopathic orbital inflammatory disease, including IgG4-RD, and emphasize the need for biopsy for accurate diagnosis and to guide appropriate treatment.

Treatment approaches to IgG4-related systemic disease

PURPOSE OF REVIEW

IgG4-related systemic disease (IgG4-RSD) is a systemic fibroinflammatory condition that can affect any organ system. Prompt recognition and management of this disease process are necessary to prevent sclerosis and permanent organ damage. Here, we review the advances in treatment approaches to IgG4-RSD.

RECENT FINDINGS

Most information regarding treatment is derived from retrospective case series of patients with autoimmune pancreatitis (AIP), and follow-up periods have generally been short. A variety of IgG4-RSD presentations respond rapidly to glucocorticoid treatment. Glucocorticoids have become a standard therapy for AIP, but the indications requiring treatment as well as the appropriate starting dose and duration of therapy remain controversial. The importance of maintenance of glucocorticoids following remission induction is debatable. As our knowledge grows regarding other organ manifestations of IgG4-RSD with longer follow-ups, the necessity of steroid-sparing agents to manage frequent relapses becomes clear.

SUMMARY

The natural history and long-term prognosis of IgG4-RSD are not well understood. Large prospective studies and randomized controlled trials of patients with wide spectrum manifestations of IgG4-RSD are required to support better approaches to treatment.

Riedel's thyroiditis and multifocal fibrosclerosis are part of the IgG4-related systemic disease spectrum

OBJECTIVE

Riedel's thyroiditis is a chronic fibrosing disorder of unknown etiology often associated with "multifocal fibrosclerosis." IgG4-related systemic disease is characterized by IgG4+ plasma cell infiltration and fibrosis throughout many organs. We hypothesized that Riedel's thyroiditis is part of the IgG4-related systemic disease spectrum.

METHODS

We searched our institution's pathology database using the terms "Riedel's," "struma," "thyroid," and "fibrosis," and identified 3 cases of Riedel's thyroiditis. Riedel's thyroiditis was diagnosed if there was a fibroinflammatory process involving all or a portion of the thyroid gland, with evidence of extension of the process into surrounding tissues. Immunohistochemical stains for IgG4 and IgG were performed. The histopathologic and immunohistochemical features of each involved organ were evaluated. The clinical features of one patient with multiple organ system disease were described.

RESULTS

All 3 thyroidectomy samples stained positively for IgG4-bearing plasma cells. One patient had extensive extrathyroidal involvement diagnostic of IgG4-related systemic disease, including cholangitis, pseudotumors of both the lung and lacrimal gland, and a lymph node contiguous to the thyroid that stained intensely for IgG4+ plasma cells. The histologic features of all organs involved were consistent with IgG4-related systemic disease. Patient 3 had 10 IgG4+ plasma cells per high-power field initially, but rebiopsy 2 years later demonstrated no IgG4+ plasma cells. That patient's second biopsy, characterized by fibrosis and minimal residual inflammation, further solidifies the link between IgG4-bearing plasma cells in tissue and the histologic evolution to Riedel's thyroiditis.

CONCLUSION

Riedel's thyroiditis is part of the IgG4-related systemic disease spectrum. In many cases, multifocal fibrosclerosis and IgG4-related systemic disease are probably the same entity.

Rituximab therapy leads to rapid decline of serum IgG4 levels and prompt clinical improvement in IgG4-related systemic disease

OBJECTIVE

Patients with IgG4-related systemic disease (IgG4-RSD) frequently show an incomplete response to treatment with glucocorticoids and traditional disease-modifying antirheumatic drugs (DMARDs). B lymphocyte depletion is a therapeutic strategy known to be effective for pemphigus vulgaris, an autoimmune condition mediated by IgG4 autoantibodies. This study was performed to assess the clinical and serologic responses to B lymphocyte depletion therapy with rituximab in patients with IgG4-RSD.

METHODS

Four patients with IgG4-RSD were treated with 2 intravenous doses (1 gram each) of rituximab. Clinical improvement was assessed by monitoring the tapering/discontinuation of prednisone and DMARDs, and by measuring the serum concentrations of B lymphocytes, immunoglobulins, and IgG subclasses before and after therapy.

RESULTS

Clinical features of IgG4-RSD in these 4 patients included autoimmune pancreatitis, sclerosing cholangitis, lymphoplasmacytic aortitis, salivary gland involvement, orbital pseudotumor, and lacrimal gland enlargement. The 3 patients with elevated serum IgG and IgG4 levels at baseline had a mean IgG concentration of 2,003 mg/dl (normal range 600-1,500 mg/dl) and a mean IgG4 concentration of 2,160 mg/dl (normal range 8-140 mg/dl). Among these patients, the serum IgG4 concentrations declined by a mean of 65% within 2 months of rituximab administration. All 4 patients demonstrated striking clinical improvement within 1 month of the initiation of rituximab therapy, and tapering or discontinuation of their treatment with prednisone and DMARDs was achieved in all 4 patients. A decrease in IgG concentration was observed for the IgG4 subclass only.

CONCLUSION

Treatment with rituximab led to prompt clinical and serologic improvement in these patients with refractory IgG4-RSD, and is a viable treatment option for this condition. The decline in serum IgG4 concentrations was substantially steeper than that of the autoantibody concentrations in immune-mediated conditions in which rituximab is effective, such as in rheumatoid arthritis. In addition, the reduction in IgG-subclass levels appeared to be specific for IgG4. The swift improvement of IgG4-RSD suggests that rituximab achieves its effects in IgG4-RSD by depleting the pool of B lymphocytes that replenish short-lived IgG4-secreting plasma cells.