The interferon-rich skin environment regulates Langerhans cell ADAM17 to promote photosensitivity in lupus.

The autoimmune disease lupus erythematosus (lupus) is characterized by photosensitivity, where even ambient ultraviolet radiation (UVR) exposure can lead to development of inflammatory skin lesions. We have previously shown that Langerhans cells (LCs) limit keratinocyte apoptosis and photosensitivity via a disintegrin and metalloprotease 17 (ADAM17)-mediated release of epidermal growth factor receptor (EGFR) ligands and that LC ADAM17 sheddase activity is reduced in lupus. Here, we sought to understand how the lupus skin environment contributes to LC ADAM17 dysfunction and, in the process, differentiate between effects on LC ADAM17 sheddase function, LC ADAM17 expression, and LC numbers. We show through transcriptomic analysis a shared IFN-rich environment in non-lesional skin across human lupus and three murine models: MRL/lpr, B6.Sle1yaa, and imiquimod (IMQ) mice. IFN-I inhibits LC ADAM17 sheddase activity in murine and human LCs, and IFNAR blockade in lupus model mice restores LC ADAM17 sheddase activity, all without consistent effects on LC ADAM17 protein expression or LC numbers. Anti-IFNAR-mediated LC ADAM17 sheddase function restoration is associated with reduced photosensitive responses that are dependent on EGFR signaling and LC ADAM17. Reactive oxygen species (ROS) is a known mediator of ADAM17 activity; we show that UVR-induced LC ROS production is reduced in lupus model mice, restored by anti-IFNAR, and is cytoplasmic in origin. Our findings suggest that IFN-I promotes photosensitivity at least in part by inhibiting UVR-induced LC ADAM17 sheddase function and raise the possibility that anifrolumab ameliorates lupus skin disease in part by restoring this function. This work provides insight into IFN-I-mediated disease mechanisms, LC regulation, and a potential mechanism of action for anifrolumab in lupus.

PROMIS Computer Adaptive Tests and Their Correlation With Disease Activity in Juvenile Idiopathic Arthritis.

BACKGROUND/OBJECTIVE: The importance of patient-reported outcomes, like the Patient-Reported Outcomes Measurement Information System (PROMIS) measures, is increasingly recognized both in clinical care and in research. While "short forms" have been studied in juvenile idiopathic arthritis (JIA), study of PROMIS computer adaptive tests (CATs) in JIA is limited. This cross-sectional study evaluates whether PROMIS CATs correlate with disease activity in patients with JIA. METHODS: A convenience sample of patients with JIA (N = 44) was recruited from a single center. Patients and parents completed pediatric and parent proxy PROMIS CATs. Disease activity was evaluated using the Juvenile Arthritis Disease Activity Score in 71 joints (JADAS-71) and the Childhood Health Assessment Questionnaire (CHAQ). Correlation of the CAT T scores with disease activity was assessed using Spearman correlation coefficients. RESULTS: Forty-four of 80 eligible subjects (29 patients and 15 parents) completed all or some PROMIS CATs. Pain interference and mobility CATs correlated moderately with JADAS-71. Nearly all correlations with the JADAS-71 were weakened when the patient global was removed. Pain interference, mobility, and fatigue were strongly correlated with the CHAQ. Among parent proxy CATs, only mobility and depressive symptoms correlated strongly with the CHAQ. CONCLUSIONS: Only pain interference and mobility PROMIS CATs showed strong correlation with standard disease activity measures in JIA, and nearly all correlations were weakened when the patient global was removed. Correlations of the CATs with the CHAQ were stronger than correlations with the JADAS-71, indicating that although the CHAQ is no longer routinely used it may be a better measure of health-related quality of life in routine clinical care.

Immunopathogenesis of Juvenile Systemic Sclerosis.

Juvenile-onset systemic sclerosis (jSSc) is a rare and severe autoimmune disease with associated life-threatening organ inflammation and evidence of fibrosis. The organ manifestations of jSSc resemble adult SSc, but with better outcomes and survival. The etiology of jSSc appears to reflect adult-onset SSc, with similar inflammatory mediators and autoantibodies, but with a significant population of children with uncharacterized anti-nuclear antibodies. The genetics of patients with jSSc differ from women with SSc, resembling instead the genes of adult males with SSc, with additional HLA genes uniquely associated with childhood-onset disease. Current treatments are aimed at inhibiting the inflammatory aspect of disease, but important mechanisms of fibrosis regulated by dermal white adipose tissue dendritic cells may provide an avenue for targeting and potentially reversing the fibrotic stage.

Immunopathogenesis of Pediatric Localized Scleroderma.

Localized scleroderma (LS) is a complex disease characterized by a mixture of inflammation and fibrosis of the skin that, especially in the pediatric population, also affects extracutaneous tissues ranging from muscle to the central nervous system. Although developmental origins have been hypothesized, evidence points to LS as a systemic autoimmune disorder, as there is a strong correlation to family history of autoimmune disease, the presence of shared HLA types with rheumatoid arthritis, high frequency of auto-antibodies, and elevated circulating chemokines and cytokines associated with T-helper cell, IFNγ, and other inflammatory pathways. This inflammatory phenotype of the peripheral blood is reflected in the skin via microarray, RNA Sequencing and tissue staining. Research is underway to identify the key players in the pathogenesis of LS, but close approximation of inflammatory lymphocytic and macrophage infiltrate with collagen and fibroblasts deposition supports the notion that LS is a disease of inflammatory driven fibrosis. The immune system is dynamic and undergoes changes during childhood, and we speculate on how the unique features of the immune system in childhood could potentially contribute to some of the differences in LS between children and adults. Interestingly, the immune phenotype in pediatric LS resembles to some extent the healthy adult cellular phenotype, possibly supporting accelerated maturation of the immune system in LS. We discuss future directions in better understanding the pathophysiology of and how to better treat pediatric LS.

Sturge-Weber syndrome: soft-tissue and skeletal overgrowth.

Sturge-Weber syndrome (SWS) is characterized by capillary malformation, glaucoma, leptomeningeal vascular anomalies, and variable facial overgrowth. The purpose of this study was to document the prevalence and morbidity of facial hypertrophy in 2 cohorts: group 1, surveyed patients registered in the SWS Foundation, and group 2, patients treated at our Vascular Anomalies Center. Predictive variables included age, sex, region of capillary stain, and ocular or cerebral involvement. Outcome variables were soft-tissue and bony overgrowth, as well as the type of operative correction. In group 1, the response rate to our questionnaire was 29.3% (108/368). Facial overgrowth was documented in 60.0% of patients. Soft-tissue hypertrophy was present in 55.0%; the lip (81.0%) was the most commonly affected site. Skeletal hypertrophy was reported in 22% of patients; the maxilla (83.0%) was the most frequently overgrown bone. Overall, 23.0% of patients (36.5% with overgrowth) had an operation: 34.0% of patients with soft tissue hypertrophy and 9.0% with skeletal enlargement. In group 2, 47 patients with SWS were treated at our center: 83% had facial overgrowth, either a localized cutaneous lesion (18.0%), soft-tissue enlargement (70.0%), or bony hypertrophy (45.0%). As in group 1, the lip (75.0%) and maxilla (94.0%) were the most commonly enlarged structures. Operations were necessary for localized cutaneous lesions (86.0%), soft-tissue hypertrophy (53.0%), or skeletal overgrowth (11.0%). In conclusion, facial hypertrophy is a major component of SWS; these patients should be counseled about the risk of overgrowth and about the types of possible operative correction.