Case Report: Contiguous presentation of anti-MDA5 juvenile dermatomyositis and anti-AQP4 neuromyelitis optica spectrum disorder in an adolescent patient.

Neuromyelitis optica spectrum disorder (NMOSD) is a rare inflammatory disorder of the central nervous system (CNS) that is known to be associated with other neurologic and organ-specific autoimmune conditions. There has been increasing recognition of the association between NMOSD and systemic autoimmune disease, most commonly systemic lupus erythematosus and Sjogren's syndrome. We report a case of an adolescent presenting with anti-melanoma differentiation-associated protein 5 juvenile dermatomyositis (anti-MDA5 JDM) and NMOSD, exhibiting clinical features of myelitis, polyarthritis, myositis, and skin involvement. Currently, only two other published cases have described NMOSD associated with anti-MDA5 dermatomyositis, both in adults. To the best of our knowledge, this is the first reported case in an adolescent patient.

Calcium Pyrophosphate Crystals in a Child With Wilson Disease: An Ominous Sign or Incidental Finding?

Calcium pyrophosphate dihydrate (CPPD) crystal deposition may cause acute arthritis (pseudogout), cartilage degeneration identified radiographically as chondrocalcinosis (CC), and other chronic degenerative joint changes in patients aged > 60 years. The few reported cases of CPPD disease in younger patients have been associated with underlying genetic or metabolic conditions.1,2.

Capturing critical data elements in Juvenile Idiopathic Arthritis: initiatives to improve data capture.

BACKGROUND: Documentation of critical data elements is a focus of the Pediatric Rheumatology Care and Outcomes Improvement Network to aid in clinical care and research for patients with juvenile idiopathic arthritis. We aimed to increase data capture for critical data elements and hypothesized that quality improvement methodology would improve data capture. We also hypothesized that data capture for all critical data elements would be lower for virtual visits compared to in-person visits. METHODS: All visits for patients with JIA between 9/14/2020 and 12/31/2021 at the University of Minnesota were included. We assessed completeness of critical data element capture. Sixteen interventions with providers were conducted, including email reminders, individual discussions, group meetings, and feedback reports. We used statistical process control charts to evaluate change over time. RESULTS: Baseline included 355 patient-visits: 221 (62%) in-person and 134 (38%) virtual with critical data elements entry ranging between 50 and 60%. Post-intervention included 1,596 patient-visits: 1,350 (85%) in-person and 246 (15%) virtual, with critical data elements entry reaching 91%. All providers improved data entry during this study. In-person visits had significantly higher data capture rates than virtual visits for all 4 critical data elements. CONCLUSION: We achieved our aim to increase critical data element documentation by focusing on provider buy-in, frequent reminders, and individualized feedback. We also found that collection of critical data elements occurred significantly less often with virtual visits than with in-person visits. Now that we improved capture of critical data elements, we can shift the focus to efforts aimed at improving outcomes for patients with juvenile arthritis.

Case Report: A Novel TNFAIP3 Mutation Causing Haploinsufficiency of A20 With a Lupus-Like Phenotype.

Genetic mutations that result in loss-of-function of the protein A20 result in an early-onset autoinflammatory disease-haploinsufficiency of A20 (HA20). The reported clinical presentations of HA20 include a Behcet's disease-like phenotype and a more lupus-like phenotype. We have identified a novel mutation in the gene encoding A20 in a pediatric patient with chronic lymphadenopathy, lupus-like symptoms, and progressive hypogammaglobulinemia. This case illustrates the wide range of clinical symptoms, including immunodeficiency, that can occur in patients with HA20.

Inhibition of mitochondrial oxidative metabolism attenuates EMCV replication and protects ß-cells from virally mediated lysis.

Viral infection is one environmental factor that may contribute to the initiation of pancreatic ß-cell destruction during the development of autoimmune diabetes. Picornaviruses, such as encephalomyocarditis virus (EMCV), induce a pro-inflammatory response in islets leading to local production of cytokines, such as IL-1, by resident islet leukocytes. Furthermore, IL-1 is known to stimulate ß-cell expression of iNOS and production of the free radical nitric oxide. The purpose of this study was to determine whether nitric oxide contributes to the ß-cell response to viral infection. We show that nitric oxide protects ß-cells against virally mediated lysis by limiting EMCV replication. This protection requires low micromolar, or iNOS-derived, levels of nitric oxide. At these concentrations nitric oxide inhibits the Krebs enzyme aconitase and complex IV of the electron transport chain. Like nitric oxide, pharmacological inhibition of mitochondrial oxidative metabolism attenuates EMCV-mediated ß-cell lysis by inhibiting viral replication. These findings provide novel evidence that cytokine signaling in ß-cells functions to limit viral replication and subsequent ß-cell lysis by attenuating mitochondrial oxidative metabolism in a nitric oxide-dependent manner.

The location of sensing determines the pancreatic ß-cell response to the viral mimetic dsRNA.

Viral infection is an environmental trigger that has been suggested to initiate pancreatic ß-cell damage, leading to the development of autoimmune diabetes. Viruses potently activate the immune system and can damage ß cells by either directly infecting them or stimulating the production of secondary effector molecules (such as proinflammatory cytokines) during bystander activation. However, how and where ß cells recognize viruses is unclear, and the antiviral responses that are initiated following virus recognition are incompletely understood. In this study, we show that the ß-cell response to dsRNA, a viral replication intermediate known to activate antiviral responses, is determined by the cellular location of sensing (intracellular versus extracellular) and differs from the cellular response to cytokine treatment. Using biochemical and immunological methods, we show that ß cells selectively respond to intracellular dsRNA by expressing type I interferons (IFNs) and inducing apoptosis, but that they do not respond to extracellular dsRNA. These responses differ from the activities of cytokines on ß cells, which are mediated by inducible nitric oxide synthase expression and ß-cell production of nitric oxide. These findings provide evidence that the antiviral activities of type I IFN production and apoptosis are elicited in ß cells via the recognition of intracellular viral replication intermediates and that ß cells lack the capacity to respond to extracellular viral intermediates known to activate innate immune responses.

CCR5 is a required signaling receptor for macrophage expression of inflammatory genes in response to viral double-stranded RNA.

Double-stranded (ds) RNA, both synthetic and produced during virus replication, rapidly stimulates MAPK and NF-κB signaling that results in expression of the inflammatory genes inducible nitric oxide synthase, cyclooxygenase 2, and IL-1ß by macrophages. Using biochemical and genetic approaches, we have identified the chemokine ligand-binding C-C chemokine receptor type 5 (CCR5) as a cell surface signaling receptor required for macrophage expression of inflammatory genes in response to dsRNA. Activation of macrophages by synthetic dsRNA does not require known dsRNA receptors, as poly(inosinic:cytidylic) acid [poly(I:C)] activates signaling pathways leading to expression of inflammatory genes to similar levels in wild-type and Toll-like receptor 3- or melanoma differentiation antigen 5-deficient macrophages. In contrast, macrophage activation in response to poly(I:C) is attenuated in macrophages isolated from mice lacking CCR5. These findings support a role for CCR5 as a cell surface signaling receptor that participates in activation of inflammatory genes in macrophages in response to the viral dsRNA mimetic poly(inosinic:cytidylic) acid by pathways that are distinct from classical dsRNA receptor-mediated responses.

Immune Checkpoint Inhibitor-Associated Type 1 Diabetes Mellitus: Case Series, Review of the Literature, and Optimal Management.

With the introduction of immune checkpoint inhibitors into clinical practice, various autoimmune toxicities have been described. Antibodies targeting the receptor:ligand pairing of programmed death receptor-1 (PD-1) and its cognate ligand programmed death-ligand 1 (PD-L1) in rare reports have been associated with autoimmune diabetes mellitus. We report 2 cases of rapid-onset, insulin-dependent, type 1 diabetes mellitus in the setting of administration of nivolumab, a fully human monoclonal antibody to PD-1, and atezolizumab, a humanized monoclonal antibody to PD-L1. This appears to be the first report of autoimmune diabetes mellitus associated with atezolizumab. In addition, we provide a brief review of similar cases reported in the literature and a discussion of potential mechanisms for this phenomenon and propose a diagnostic and treatment algorithm.

CCR5-Dependent Activation of mTORC1 Regulates Translation of Inducible NO Synthase and COX-2 during Encephalomyocarditis Virus Infection.

Encephalomyocarditis virus (EMCV) infection of macrophages results in the expression of a number of inflammatory and antiviral genes, including inducible NO synthase (iNOS) and cyclooxygenase (COX)-2. EMCV-induced macrophage activation has been shown to require the presence of CCR5 and the activation of PI3K-dependent signaling cascades. The purpose of this study was to determine the role of PI3K in regulating the macrophage responses to EMCV. We show that PI3K regulates EMCV-stimulated iNOS and COX-2 expression by two independent mechanisms. In response to EMCV infection, Akt is activated and regulates the translation of iNOS and COX-2 through the mammalian target of rapamycin complex (mTORC)1. The activation of mTORC1 during EMCV infection is CCR5-dependent and appears to function in a manner that promotes the translation of iNOS and COX-2. CCR5-dependent mTORC1 activation functions as an antiviral response, as mTORC1 inhibition increases the expression of EMCV polymerase. PI3K also regulates the transcriptional induction of iNOS and COX-2 in response to EMCV infection by a mechanism that is independent of Akt and mTORC1 regulation. These findings indicate that macrophage expression of the inflammatory genes iNOS and COX-2 occurs via PI3K- and Akt-dependent translational control of mTORC1 and PI3K-dependent, Akt-independent transcriptional control.

Macrophage Expression of Inflammatory Genes in Response to EMCV Infection.

The expression and production of type 1 interferon is the classic cellular response to virus infection. In addition to this antiviral response, virus infection also stimulates the production of proinflammatory mediators. In this review, the pathways controlling the induction of inflammatory genes and the roles that these inflammatory mediators contribute to host defense against viral pathogens will be discussed. Specific focus will be on the role of the chemokine receptor CCR5, as a signaling receptor controlling the activation of pathways leading to virus-induced inflammatory gene expression.

The autoimmunity-associated gene PTPN22 potentiates toll-like receptor-driven, type 1 interferon-dependent immunity.

Immune cells sense microbial products through Toll-like receptors (TLR), which trigger host defense responses including type 1 interferons (IFNs) secretion. A coding polymorphism in the protein tyrosine phosphatase nonreceptor type 22 (PTPN22) gene is a susceptibility allele for human autoimmune and infectious disease. We report that Ptpn22 selectively regulated type 1 IFN production after TLR engagement in myeloid cells. Ptpn22 promoted host antiviral responses and was critical for TLR agonist-induced, type 1 IFN-dependent suppression of inflammation in colitis and arthritis. PTPN22 directly associated with TNF receptor-associated factor 3 (TRAF3) and promotes TRAF3 lysine 63-linked ubiquitination. The disease-associated PTPN22W variant failed to promote TRAF3 ubiquitination, type 1 IFN upregulation, and type 1 IFN-dependent suppression of arthritis. The findings establish a candidate innate immune mechanism of action for a human autoimmunity "risk" gene in the regulation of host defense and inflammation.