Faculty Bibliography

BACKGROUNDUndifferentiated systemic autoinflammatory diseases (USAIDs) present diagnostic and therapeutic challenges. Chronic interferon (IFN) signaling and cytokine dysregulation may identify diseases with available targeted treatments.METHODSSixty-six consecutively referred USAID patients underwent underwent screening for the presence of an interferon signature using a standardized type-I IFN-response-gene score (IRG-S), cytokine profiling, and genetic evaluation by next-generation sequencing.RESULTSThirty-six USAID patients (55%) had elevated IRG-S. Neutrophilic panniculitis (40% vs. 0%), basal ganglia calcifications (46% vs. 0%), interstitial lung disease (47% vs. 5%), and myositis (60% vs. 10%) were more prevalent in patients with elevated IRG-S. Moderate IRG-S elevation and highly elevated serum IL-18 distinguished 8 patients with pulmonary alveolar proteinosis (PAP) and recurrent macrophage activation syndrome (MAS). Among patients with panniculitis and progressive cytopenias, 2 patients were compound heterozygous for potentially novel LRBA mutations, 4 patients harbored potentially novel splice variants in IKBKG (which encodes NF-κB essential modulator [NEMO]), and 6 patients had de novo frameshift mutations in SAMD9L. Of additional 12 patients with elevated IRG-S and CANDLE-, SAVI- or Aicardi-Goutières syndrome-like (AGS-like) phenotypes, 5 patients carried mutations in either SAMHD1, TREX1, PSMB8, or PSMG2. Two patients had anti-MDA5 autoantibody-positive juvenile dermatomyositis, and 7 could not be classified. Patients with LRBA, IKBKG, and SAMD9L mutations showed a pattern of IRG elevation that suggests prominent NF-κB activation different from the canonical interferonopathies CANDLE, SAVI, and AGS.CONCLUSIONSIn patients with elevated IRG-S, we identified characteristic clinical features and 3 additional autoinflammatory diseases: IL-18-mediated PAP and recurrent MAS (IL-18PAP-MAS), NEMO deleted exon 5-autoinflammatory syndrome (NEMO-NDAS), and SAMD9L-associated autoinflammatory disease (SAMD9L-SAAD). The IRG-S expands the diagnostic armamentarium in evaluating USAIDs and points to different pathways regulating IRG expression.TRIAL REGISTRATIONClinicalTrials.gov NCT02974595.FUNDINGThe Intramural Research Program of the NIH, NIAID, NIAMS, and the Clinical Center.

Systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA) are two common autoimmune rheumatic diseases that vary in severity, clinical presentation, and disease course between individuals. Molecular and genetic studies of both diseases have identified candidate genes and molecular pathways that are linked to various disease outcomes and treatment responses. Currently, patients can be grouped into molecular subsets in each disease, and these molecular categories should enable precision medicine approaches to be applied in rheumatic diseases. In this article, we will review key lessons learned about disease heterogeneity and molecular characterization in rheumatology, which we hope will lead to personalized therapeutic strategies.

Previously, we demonstrated in test and validation cohorts that type I IFN (T1IFN) activity can predict non-response to tumor necrosis factor inhibitors (TNFi) in rheumatoid arthritis (RA). In this study, we examine the biology of non-classical and classical monocytes from RA patients defined by their pre-biologic treatment T1IFN activity. We compared single cell gene expression in purified classical (CL, n = 342) and non-classical (NC, n = 359) monocytes. In our previous work, RA patients who had either high IFNβ/α activity (>1.3) or undetectable T1IFN were likely to have EULAR non-response to TNFi. In this study comparisons were made among patients grouped according to their pre-biologic treatment T1IFN activity as clinically relevant: "T1IFN undetectable (T1IFN ND) or IFNβ/α >1.3" (n = 9) and "T1IFN detectable but IFNβ/α ≤ 1.3" (n = 6). In addition, comparisons were made among patients grouped according to their T1IFN activity itself: "T1IFN ND," "T1IFN detected and IFNβ/α ≤ 1.3," and "IFNβ/α >1.3." Major differences in gene expression were apparent in principal component and unsupervised cluster analyses. CL monocytes from the T1IFN ND or IFNβ/α >1.3 group were unlikely to express JAK1 and IFI27 (p < 0.0001 and p 0.0005, respectively). In NC monocytes from the same group, expression of IFNAR1, IRF1, TNFA, TLR4 (p ≤ 0.0001 for each) and others was enriched. Interestingly, JAK1 expression was absent in CL and NC monocytes from nine patients. This pattern most strongly associated with the IFNβ/α>1.3 group. Differences in gene expression in monocytes among the groups suggest differential IFN pathway activation in RA patients who are either likely to respond or to have no response to TNFi. Additional transcripts enriched in NC cells of those in the T1IFN ND and IFNβ/α >1.3 groups included MYD88, CD86, IRF1, and IL8. This work could suggest key pathways active in biologically defined groups of patients, and potential therapeutic strategies for those patients unlikely to respond to TNFi.

Background/Purpose : T and B cells come together in ectopic lymphoid aggregates in myositis, suggesting that local T:B cell interactions could play a role in disease. T follicular helper cells are increased in circulation in patients with active myositis. We studied circulating Tfh cells from myositis patients using single-cell RNA-sequencing and examined the proximity of Tfh cells to B cells in patient biopsies. Methods : Tfh cells [CD3 + CXCR5 + PD-1 + CXCR3 neg and CD3 + CXCR5 + PD-1 + CXCR3 pos ] cells were sorted from peripheral blood and subsets were identified by chemokine markers to designate Tfh1 and Tfh2/17 cell subsets. RNA sequencing was performed on individual cells of (3 controls and 3 myositis patients) using Fluidigm C1 HT platform, and data were analyzed using a pseudo-temporal ordering using Monocle. Biopsies were stained using the OPAL standardized sequential immunofluorescence method for PD-1, CXCR5, CD19, and CD4 in human muscle, and machine learning was used to map proximity of B cells to all T-cells compared with Tfh cells. Results : We found various subsets within the Tfh pool, corresponding to Tfh1 and Tfh2/17 cells and some cells that looked to be transitioning between states. Tfh2/17 were enriched in myositis patients vs. controls. The Tfh2/17 cells demonstrated a type I interferon signature, while the Tfh1 cells had a type II interferon and proteasome signature. In tissue, we demonstrate Tfh cells in close proximity to B cells in lymphoid aggregates. Conclusion : Tfh cells are present in myositis biopsies juxtaposed to B cells, suggesting productive T:B interactions in the tissue. Tfh subsets in blood from patients demonstrate distinct pathological signatures when compared to controls

Objective/UNASSIGNED:Our aim was to identify cytokines and chemokines in patients with adult dermatomyositis (DM) and juvenile dermatomyositis (JDM) that predict changes in disease activity. Methods/UNASSIGNED:Multiplexed immunoassays (Meso Scale Discovery) enabled simultaneous measurement of interferon (IFN)-regulated chemokines and other pro- and anti-inflammatory cytokines specific to differentiation of specific T-cell and innate pathways. Cytokine scores were computed for IFNCK (IP-10, MCP-1), Th1 (IFNɣ, TNFα, and IL2), Th2 (IL4, IL10, IL12, and IL 13), Th17 (IL6, IL17, IL1β), macrophage (MIP-1α, MIP-1β, IL8), and regulatory (IL10, TNFα) factors. Spearman correlation and mixed models were used to examine whether cytokines at a previous visit predict change in disease activity at the next visit. Results/UNASSIGNED:< 0.001) disease activity scores. Preliminary results revealed significant correlations of previous IFNCK score and IL-6 with subsequent disease activity measures, but after adjustment for multiple visits per patient, these associations did not reach statistical significance. Conclusion/UNASSIGNED:There is a potential relationship between IFNCK and other cytokine scores seen in adult and juvenile DM with future disease states.

The type I interferon pathway has been implicated in the pathogenesis of a number of rheumatic diseases, including systemic lupus erythematosus, Sjögren syndrome, myositis, systemic sclerosis, and rheumatoid arthritis. In normal immune responses, type I interferons have a critical role in the defence against viruses, yet in many rheumatic diseases, large subgroups of patients demonstrate persistent activation of the type I interferon pathway. Genetic variations in type I interferon-related genes are risk factors for some rheumatic diseases, and can explain some of the heterogeneity in type I interferon responses seen between patients within a given disease. Inappropriate activation of the immune response via Toll-like receptors and other nucleic acid sensors also contributes to the dysregulation of the type I interferon pathway in a number of rheumatic diseases. Theoretically, differences in type I interferon activity between patients might predict response to immune-based therapies, as has been demonstrated for rheumatoid arthritis. A number of type I interferon and type I interferon pathway blocking therapies are currently in clinical trials, the results of which are promising thus far. This Review provides an overview of the many ways in which the type I interferon system affects rheumatic diseases.

OBJECTIVE: We describe a 38-year-old woman presenting with a history of inflammatory arthritis, rash and daily fevers. She was noted to have chronic parvoviral infection with persistently detectable viral titers and a novel mutation in the ELANE gene. ELANE encodes neutrophil elastase, a neutrophil serine protease with important antimicrobial effects and is found as part of neutrophil extracellular trap (NET) complexes. Pathogenic ELANE mutations have been described in forms of hereditary neutropenia. However, our patient was never neutropenic. Because of the striking clinical scenario, we investigated this mutation functionally. METHODS: NET formation by neutrophils was assessed by scanning electron microscopy. Neutrophil activation and neutrophil elastase production were studied by flow cytometry and fluorescent substrate based functional assay, respectively. Multiplex assay was used to quantitate neutrophil inflammatory cytokine production. PYMOL software was used to generate three-dimensional models of mutant elastase. RESULTS: The patient's activated neutrophils demonstrated significantly decreased ability to form NETs by scanning electron microscopy, as well as quantitative defects in neutrophil activation and neutrophil elastase activity. The patient's neutrophils demonstrated altered levels of IL-12 and IL-8 - key cytokines for antiviral immunity and neutrophil chemotaxis. Three-dimensional mapping revealed that the mutation could alter protein folding and surface charge distribution, potentially perturbing protein trafficking. Thus, the mutation could impact neutrophil function by decreasing NETosis, and altering key antiviral activities of neutrophils. CONCLUSIONS: This is the first report of a human pathogenic ELANE mutation associated with a defect in NET-osis and a distinct syndrome of recurrent viral infection and chronic inflammation.

BACKGROUND:Discordance between patients with rheumatoid arthritis (RA) and their rheumatology health care providers is a common and important problem. The objective of this study was to perform a comprehensive clinical evaluation of patient-provider discordance in RA. METHODS:and rank sum tests. Multivariable logistic regression was used to develop a clinical model of discordance. RESULTS:Patient-provider discordance affected 114 (32.5%) of 350 consecutive patients. Of the total population, 103 patients (29.5%) rated disease activity higher than their providers (i.e., 'positive' discordance); only 11 (3.1%) rated disease activity lower than their providers and were excluded from further analysis. Positive discordance correlated with negative rheumatoid factor and anticyclic citrullinated peptide antibodies, lack of joint erosions, presence of comorbid fibromyalgia or depression, and use of opioids, antidepressants, or anxiolytics, or fibromyalgia medications. In the prospective study, the group with positive discordance was distinguished by higher pain intensity, neuropathic type pain, chronic widespread pain and associated polysymptomatic distress, and limited functional health status. Depression was found to be an important mediator of positive discordance in low disease activity whereas the widespread pain index was an important mediator of positive discordance in moderate-to-high disease activity states. Ultrasonography scores did not reveal significant differences in synovial inflammation between discordant and concordant groups. CONCLUSIONS:The findings provide a deeper understanding of patient-provider discordance than previously known. New insights from this study include the evidence that positive discordance is not associated with unrecognized joint inflammation by ultrasonography and that depression and fibromyalgia appear to play distinct roles in determining positive discordance. Further work is necessary to develop a comprehensive framework for patient-centered evaluation and management of RA and associated comorbidities in patients in the scenario of patient-provider discordance.

BACKGROUND: Deficiency of IL-1 receptor antagonist (DIRA) is a rare autoinflammatory disease that presents with life-threatening systemic inflammation, aseptic multifocal osteomyelitis, and pustulosis responsive to IL-1-blocking treatment. This study was performed (a) to investigate rilonacept, a long-acting IL-1 inhibitor, in maintaining anakinra-induced inflammatory remission in DIRA patients, (b) to determine doses needed to maintain remission, and (c) to evaluate the safety and pharmacokinetics of rilonacept in young children (<12 years). METHODS: Six mutation-positive DIRA patients (children, ages 3-6 years), treated with daily anakinra, were enrolled into an open-label pilot study of subcutaneous rilonacept for 24 months. Clinical symptoms and inflammatory blood parameters were measured at all visits. A loading dose (4.4 mg/kg) was administered, followed by once weekly injections (2.2 mg/kg) for 12 months. Dose escalation (4.4 mg/kg) was allowed if inflammatory remission was not maintained. Subjects in remission at 12 months continued rilonacept for an additional 12 months. RESULTS: Five of six patients required dose escalation for findings of micropustules. Following dose escalation, all patients were in remission on weekly rilonacept administration, with stable laboratory parameters for the entire study period of 24 months. All children are growing at normal rates and have normal heights and weights. Quality of life improved while on rilonacept. No serious adverse events were reported. CONCLUSION: Rilonacept was found to maintain inflammatory remission in DIRA patients. The once weekly injection was well tolerated and correlated with increased quality of life, most likely related to the lack of daily injections. TRIAL REGISTRATION: ClinicalTrials.gov NCT01801449. FUNDING: NIH, NIAMS, and NIAID.

OBJECTIVE: Evaluate healthcare utilization and occurrence of comorbidities in a population-based cohort of patients of juvenile idiopathic arthritis (JIA) with an age- and sex-matched comparator group. METHODS: Prevalent cases of JIA in 1994-2013 were identified in Olmsted County, Minnesota, along with age- and sex-matched non-JIA comparators. Surgeries, hospitalizations, pregnancies, and comorbidities were identified by medical record review. Poisson methods were used to generate rate ratios (RR) with 95% confidence intervals (CI) to compare outcomes between JIA and non-JIA cohorts separately during childhood (age < 18 years) and adulthood (age >/= 18 years). RESULTS: A total of 89 JIA and 89 non-JIA comparators were identified [64% female; mean (SD) age 8.6 (5.1) years at JIA incidence/index date and mean follow-up in childhood 6.3 (4.4) years for JIA; similar for comparators]. Among them, 38 pairs had follow-up into adulthood with mean follow-up of 8.0 (5.5) years for JIA. Children with JIA were more likely to have joint surgery (RR = 3.93, 95% CI: 1.18-24.94), non-joint surgery (RR = 1.90, 95% CI: 1.05-3.67), and hospitalizations (RR = 2.25, 95% CI: 1.04-5.53) than non-JIA comparators. As adults only joint surgeries remained significantly different (RR = 8.5, 95% CI: 2.27-120.1). Depression during childhood was more common in JIA (RR = 2.49, 95% CI: 1.01-6.13). There were no differences in educational achievement, employment status, or pregnancy outcomes between the 2 groups. CONCLUSIONS: In a population-based cohort, inpatient healthcare utilization is higher for patients with JIA including surgery and hospitalization during childhood but not extending into adulthood. Understanding long-term comorbidities and healthcare needs for patients with JIA is necessary to provide comprehensive care.