The Florida Scoring System for stratifying children with suspected Sjögren's disease: a cross-sectional machine learning study.

BACKGROUND: Childhood Sjögren's disease is a rare, underdiagnosed, and poorly-understood condition. By integrating machine learning models on a paediatric cohort in the USA, we aimed to develop a novel system (the Florida Scoring System) for stratifying symptomatic paediatric patients with suspected Sjögren's disease. METHODS: This cross-sectional study was done in symptomatic patients who visited the Department of Pediatric Rheumatology at the University of Florida, FL, USA. Eligible patients were younger than 18 years or had symptom onset before 18 years of age. Patients with confirmed diagnosis of another autoimmune condition or infection with a clear aetiological microorganism were excluded. Eligible patients underwent comprehensive examinations to rule out or diagnose childhood Sjögren's disease. We used latent class analysis with clinical and laboratory variables to detect heterogeneous patient classes. Machine learning models, including random forest, gradient-boosted decision tree, partial least square discriminatory analysis, least absolute shrinkage and selection operator-penalised ordinal regression, artificial neural network, and super learner were used to predict patient classes and rank the importance of variables. Causal graph learning selected key features to build the final Florida Scoring System. The predictors for all models were the clinical and laboratory variables and the outcome was the definition of patient classes. FINDINGS: Between Jan 16, 2018, and April 28, 2022, we screened 448 patients for inclusion. After excluding 205 patients due to symptom onset later than 18 years of age, we recruited 243 patients into our cohort. 26 patients were excluded because of confirmed diagnosis of a disorder other than Sjögren's disease, and 217 patients were included in the final analysis. Median age at diagnosis was 15 years (IQR 11-17). 155 (72%) of 216 patients were female and 61 (28%) were male, 167 (79%) of 212 were White, and 20 (9%) of 213 were Hispanic, Latino, or Spanish. The latent class analysis identified three distinct patient classes: class I (dryness dominant with positive tests, n=27), class II (high symptoms with negative tests, n=98), and class III (low symptoms with negative tests, n=92). Machine learning models accurately predicted patient class and ranked variable importance consistently. The causal graphical model discovered key features for constructing the Florida Scoring System. INTERPRETATION: The Florida Scoring System is a paediatrician-friendly tool that can be used to assist classification and long-term monitoring of suspected childhood Sjögren's disease. The resulting stratification has important implications for clinical management, trial design, and pathobiological research. We found a highly symptomatic patient group with negative serology and diagnostic profiles, which warrants clinical attention. We further revealed that salivary gland ultrasonography can be a non-invasive alternative to minor salivary gland biopsy in children. The Florida Scoring System requires validation in larger prospective paediatric cohorts. FUNDING: National Institute of Dental and Craniofacial Research, National Institute of Arthritis, Musculoskeletal and Skin Diseases, National Heart, Lung, and Blood Institute, and Sjögren's Foundation.

Bortezomib is efficacious in the treatment of severe childhood-onset neuropsychiatric systemic lupus erythematosus with psychosis: a case series and mini-review of B-cell immunomodulation in antibody-mediated diseases.

Childhood-onset neuropsychiatric systemic lupus erythematosus (cNPSLE) with psychosis is a challenging manifestation of SLE. Pathogenic long-lived plasma cells (LLPCs) are not specifically targeted by standard immunosuppression and their persistence contributes to chronic autoimmunity. Bortezomib is approved for the treatment of multiple myeloma and has shown benefits in a variety of other antibody-mediated diseases. Bortezomib may be efficacious for severe or treatment-refractory cNPSLE through eradication of LLPCs, decreasing autoantibody production. We describe the first pediatric case series of five patients with unrelenting cNPSLE with psychosis who were treated safely and effectively with bortezomib between 2011 and 2017. Most patients had persistent cNPSLE with psychosis despite aggressive immunosuppression with methylprednisolone, cyclophosphamide, rituximab, and usually plasmapheresis. All patients demonstrated rapid clinical improvement in their psychotic manifestations with the ability to quickly taper immunosuppression after the introduction of bortezomib. No patient had a recurrence of overt psychosis during a follow-up period of 1-10 years. Secondary hypogammaglobulinemia developed in all five patients and required immunoglobulin replacement. No other severe side effects or adverse events were observed. Bortezomib-mediated LLPC depletion is a promising therapy for severe recalcitrant cNPSLE with psychosis when used as adjunctive therapy to conventional immunosuppression, B-cell, and antibody-depleting therapies. After initiation of bortezomib, patients had rapid, demonstrable improvement in psychosis as well as reduction in glucocorticoids and antipsychotics. Further investigation is needed to determine the therapeutic role of bortezomib in severe cNPSLE and cSLE. We present a mini-review of the rationale for bortezomib use and novel B-cell immunomodulation in rheumatic disease.

Monogenic early-onset lymphoproliferation and autoimmunity: Natural history of STAT3 gain-of-function syndrome.

BACKGROUND: In 2014, germline signal transducer and activator of transcription (STAT) 3 gain-of-function (GOF) mutations were first described to cause a novel multisystem disease of early-onset lymphoproliferation and autoimmunity. OBJECTIVE: This pivotal cohort study defines the scope, natural history, treatment, and overall survival of a large global cohort of patients with pathogenic STAT3 GOF variants. METHODS: We identified 191 patients from 33 countries with 72 unique mutations. Inclusion criteria included symptoms of immune dysregulation and a biochemically confirmed germline heterozygous GOF variant in STAT3. RESULTS: Overall survival was 88%, median age at onset of symptoms was 2.3 years, and median age at diagnosis was 12 years. Immune dysregulatory features were present in all patients: lymphoproliferation was the most common manifestation (73%); increased frequencies of double-negative (CD4-CD8-) T cells were found in 83% of patients tested. Autoimmune cytopenias were the second most common clinical manifestation (67%), followed by growth delay, enteropathy, skin disease, pulmonary disease, endocrinopathy, arthritis, autoimmune hepatitis, neurologic disease, vasculopathy, renal disease, and malignancy. Infections were reported in 72% of the cohort. A cellular and humoral immunodeficiency was observed in 37% and 51% of patients, respectively. Clinical symptoms dramatically improved in patients treated with JAK inhibitors, while a variety of other immunomodulatory treatment modalities were less efficacious. Thus far, 23 patients have undergone bone marrow transplantation, with a 62% survival rate. CONCLUSION: STAT3 GOF patients present with a wide array of immune-mediated disease including lymphoproliferation, autoimmune cytopenias, and multisystem autoimmunity. Patient care tends to be siloed, without a clear treatment strategy. Thus, early identification and prompt treatment implementation are lifesaving for STAT3 GOF syndrome.

An ELF4 hypomorphic variant results in NK cell deficiency.

NK cell deficiencies (NKD) are a type of primary immune deficiency in which the major immunologic abnormality affects NK cell number, maturity, or function. Since NK cells contribute to immune defense against virally infected cells, patients with NKD experience higher susceptibility to chronic, recurrent, and fatal viral infections. An individual with recurrent viral infections and mild hypogammaglobulinemia was identified to have an X-linked damaging variant in the transcription factor gene ELF4. The variant does not decrease expression but disrupts ELF4 protein interactions and DNA binding, reducing transcriptional activation of target genes and selectively impairing ELF4 function. Corroborating previous murine models of ELF4 deficiency (Elf4-/-) and using a knockdown human NK cell line, we determined that ELF4 is necessary for normal NK cell development, terminal maturation, and function. Through characterization of the NK cells of the proband, expression of the proband's variant in Elf4-/- mouse hematopoietic precursor cells, and a human in vitro NK cell maturation model, we established this ELF4 variant as a potentially novel cause of NKD.

A human STAT3 gain-of-function variant confers T cell dysregulation without predominant Treg dysfunction in mice.

Primary immune regulatory disorders (PIRD) represent a group of disorders characterized by immune dysregulation, presenting with a wide range of clinical disease, including autoimmunity, autoinflammation, or lymphoproliferation. Autosomal dominant germline gain-of-function (GOF) variants in STAT3 result in a PIRD with a broad clinical spectrum. Studies in patients have documented a decreased frequency of FOXP3+ Tregs and an increased frequency of Th17 cells in some patients with active disease. However, the mechanisms of disease pathogenesis in STAT3 GOF syndrome remain largely unknown, and treatment is challenging. We developed a knock-in mouse model harboring a de novo pathogenic human STAT3 variant (p.G421R) and found these mice developed T cell dysregulation, lymphoproliferation, and CD4+ Th1 cell skewing. Surprisingly, Treg numbers, phenotype, and function remained largely intact; however, mice had a selective deficiency in the generation of iTregs. In parallel, we performed single-cell RNA-Seq on T cells from STAT3 GOF patients. We demonstrate only minor changes in the Treg transcriptional signature and an expanded, effector CD8+ T cell population. Together, these findings suggest that Tregs are not the primary driver of disease and highlight the importance of preclinical models in the study of disease mechanisms in rare PIRD.

The Diagnostic Performance of Early Sjögren's Syndrome Autoantibodies in Juvenile Sjögren's Syndrome: The University of Florida Pediatric Cohort Study.

Objectives: The aim of this study was to evaluate the clinical validity of early Sjögren's syndrome (SS) autoantibodies (eSjA), which were originally marketed for early diagnosis of SS, for juvenile SS (JSS) in a recently identified pediatric cohort. Methods: A total of 105 symptomatic subjects with eSjA results available were evaluated at the Center for Orphaned Autoimmune Disorders at the University of Florida and enrolled for this study. JSS diagnosis was based on the 2016 ACR/EULAR SS criteria. Demographic/clinical/laboratory parameters were compared between JSS (n = 27) and non-JSS (n = 78) for % positivity, sensitivity, and specificity of eSjA (SP1, anti-salivary protein; CA6, anti-carbonic anhydrase VI; PSP, anti-parotid secretory protein) and classic SS-autoantibodies (cSjA; ANA, SSA/SSB, RF, and others) either alone or in combination. Associations between eSjA and diagnostic/glandular parameters were also determined by Fisher's exact test. Results: Compared to non-JSS, JSS patients exhibited sicca symptoms demonstrating reduced unstimulated salivary flow rate (USFR) and abnormal glandular features revealed by salivary gland ultrasound (SGUS). Among cSjA, ANA demonstrated the highest sensitivity of 69.2%, while SSA, SSB, and RF showed around 95% specificities for JSS diagnosis. The % positive-SSA was notably higher in JSS than non-JSS (56% vs. 5%). Of eSjA, anti-CA6 IgG was the most prevalent without differentiating JSS (37%) from non-JSS (32%). Sensitivity and specificity of eSjA were 55.6 and 26.9%, respectively. Autoantibodies with potentially applicable specificity/sensitivity for JSS were seen only in cSjA without a single eSjA included. There were no associations detected between eSjA and focus score (FS), USFR, SSA, SGUS, and parotitis/glandular swelling analyzed in the entire cohort, JSS, and non-JSS. However, a negative association between anti-PSP and parotitis/glandular swelling was found in a small group of positive-SSA (n = 19, p = 0.02) whereas no such association was found between anti-PSP-positive compared to anti-PSP-negative. JSS and non-JSS groups differed in FS, USFR, and EULAR SS Patient Reported Index Dryness/Mean in CA6/PSP/ANA, SP1, and SSA-positive groups, respectively. Additionally, a higher FS was found in RF-positive than RF-negative individuals. Conclusions: eSjA underperformed cSjS in differentiating JSS from non-JSS. The discovery of clinical impact of eSjA on early diagnosis of JSS necessitates a longitudinal study.

S100A12 and S100A8/9 proteins are biomarkers of articular disease activity in Blau syndrome.

OBJECTIVE: To identify biomarkers of articular and ocular disease activity in patients with Blau syndrome (BS). METHODS: Multiplex plasma protein arrays were performed in five BS patients and eight normal healthy volunteers (NHVs). Plasma S100A12 and S100A8/9 were subsequently measured by ELISA at baseline and 1-year follow-up in all patients from a prospective multicentre cohort study. CRP was measured using Meso Scale Discovery immunoassay. Active joint counts, standardization uveitis nomenclature for anterior uveitis cells and vitreous haze by Nussenblatt scale were the clinical parameters. RESULTS: Multiplex Luminex arrays identified S100A12 as the most significantly elevated protein in five selected BS vs eight NHVs and this was confirmed by ELISA on additional samples from the same five BS patients. In the patient cohort, S100A12 (n = 39) and S100A8/9 (n = 33) were significantly higher compared with NHVs (n = 44 for S100A12, n = 40 for S100A8/9) (P = 0.0000004 and P = 0.0003, respectively). Positive correlations between active joint counts and S100 levels were significant for S100A12 (P = 0.0008) and S100A8/9 (P = 0.015). CRP levels did not correlate with active joint count. Subgroup analysis showed significant association of S100 proteins with active arthritis (S100A12 P = 0.01, S100A8/9 P = 0.008). Active uveitis was not associated with increased S100 levels. CONCLUSION: S100 proteins are biomarkers of articular disease activity in BS and potential outcome measures in future clinical trials. As secreted neutrophil and macrophage products, S100 proteins may reflect the burden of granulomatous tissue in BS.

Rituximab: a promising therapy in systemic lupus erythematosus.

Several trials of new immunologic agents in systemic lupus erythematosus (SLE) have recently been undertaken. Rituximab, a chimeric antibody directed against CD20 on B lymphocytes, has emerged as a promising therapy. Based upon preliminary data, clinical efficacy of rituximab has been documented in both pediatric and adult-onset SLE patients. The specific manifestations reported to be beneficially affected include lupus nephritis, arthralgia/arthritis, serositis, cutaneous vasculitis, mucositis, rashes, fatigue and neurologic symptoms. Although rituximab's mechanisms of action are incompletely understood, the effects of rituximab are likely mediated by antibody-dependent cell-mediated cytotoxicity and the induction of apoptosis. The resultant repopulation of B cells, alteration of abnormal B cell homeostasis and down-regulation of co-stimulatory molecules on both B and T cells all likely contribute to clinical efficacy. Good tolerability of rituximab is reported with rare serious side effects. The positive response to rituximab verifies a central role for B cells in SLE. This article highlights the clinical experience of rituximab therapy in both pediatric and adult-onset SLE. These data suggest a promising role for rituximab in the treatment of SLE. Further controlled trials and long-term outcome studies are imperative to further define its clinical application and to improve the care of patients.

Infliximab treatment for severe granulomatous disease in common variable immunodeficiency: a case report and review of the literature.

BACKGROUND: Granulomatous disease resembling sarcoidosis is a well-described condition associated with common variable immunodeficiency (CVID). Its treatment remains problematic, and new therapeutic options are needed. OBJECTIVES: To report the efficacy of treatment with infliximab, a chimeric anti-tumor necrosis factor alpha monoclonal antibody, in a patient with granulomatous CVID and to review the literature on the treatment of patients with granulomatous CVID. METHODS: A 22-year-old white man with CVID developed acute multiorgan failure, with granulomatous inflammation on lung and liver biopsy specimens. He was initially treated with antibiotics, intravenous immunoglobulin, and corticosteroids for 5 weeks without improvement. High-dose infliximab was then infused weekly for 6 weeks and then monthly for 9 months. The response to infliximab was determined by changes on clinical examination, imaging studies, and histologic studies. RESULTS: The patient's condition dramatically improved after 1 dose of infliximab infusion, with decreasing hepatosplenomegaly, ventilatory support requirements, and pulmonary infiltrates. Ventilatory support was successfully discontinued within 3 weeks. The corticosteroid dose was tapered without reactivation of the disease. After 9 months of therapy, follow-up imaging studies showed resolution of pulmonary infiltrates, no hepatosplenomegaly, and no portal hypertension, and a percutaneous liver biopsy revealed no granulomas; then, infliximab use was discontinued. The patient remains free of granulomatous disease after 18 months of follow-up. CONCLUSIONS: To our knowledge, this is the first report of severe visceral granulomatous CVID successfully treated with infliximab. Infliximab may be an effective therapy for granulomas in CVID. Further studies of infliximab and other tumor necrosis factor a antagonist therapies in granulomatous CVID are warranted.