Single-cell analysis reveals heterogeneity of juvenile idiopathic arthritis fibroblast-like synoviocytes with implications for disease subtype.

Background: Fibroblast-like synoviocytes (FLS) play a crucial role in JIA pathogenesis; however, the mechanisms by which they contribute to disease progression are not well described. Previous studies demonstrated that rheumatoid arthritis FLS are heterogeneous, and subpopulations with transformed, aggressive phenotypes cause invasive and destructive disease activity. We employ single-cell RNA-sequencing (scRNA-seq) to investigate JIA FLS heterogeneity and gene expression that distinguishes JIA subtypes.

Juvenile idiopathic arthritis fibroblast-like synoviocytes influence chondrocytes to alter BMP antagonist expression demonstrating an interaction between the two prominent cell types involved in endochondral bone formation.

Background: To examine critical interactions between juvenile idiopathic arthritis synovial fibroblasts (JFLS) and chondrocytes (Ch), and their role in bony overgrowth seen in patients with juvenile idiopathic arthritis (JIA).

Methods: Control (CFLS) and JFLS were cultured in synoviocyte media containing recombinant BMP4. Ch were cultured in either CFLS or JFLS conditioned-media without stimulation.

Distinct interferon signatures and cytokine patterns define additional systemic autoinflammatory diseases.

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.

Prior to extension, Transcriptomes of fibroblast-like Synoviocytes from extended and Polyarticular juvenile idiopathic arthritis are indistinguishable.

Background: Our intent was to identify differences between the transcriptome of fibroblast-like synoviocytes (FLS) in oligoarticular juvenile idiopathic arthritis (JIA) before extension when compared to persistent subtype of JIA, when the two are clinically indistinguishable. Additionally, we sought to determine if differences between the transcriptomes of FLS from extended-to-be and polyarticular course JIA could be detected. Our hypothesis was that intrinsic differences in the transcriptome of the FLS from extended-to-be JIA would distinguish them from persistent oligoarticular JIA, before the course is clinically apparent.

Secretion of pro-inflammatory cytokines and chemokines and loss of regulatory signals by fibroblast-like synoviocytes in juvenile idiopathic arthritis.

Purpose: The goal is to investigate the specific contribution of fibroblast-like synoviocytes (FLS) to the inflammatory milieu of the synovium in juvenile idiopathic arthritis (JIA) through detection of secreted proteins.

Experimental Design: Expression of 89 cytokines and chemokines is determined on unprocessed synovial fluid from controls and JIA patients using antibody arrays. Supernatants from pure cell cultures of FLS grown from synovial fluids or tissues from JIA and controls are also examined for protein expression.

The role of transforming growth factor β signaling in fibroblast-like synoviocytes from patients with oligoarticular juvenile idiopathic arthritis: dysregulation of transforming growth factor β signaling, including overexpression of bone morphogenetic protein 4, may lead to a chondrocyte phenotype and may contribute to bony hypertrophy.

Objective: This study was designed to investigate the pathogenic contributions of fibroblast-like synoviocytes (FLS) to juvenile idiopathic arthritis (JIA) by identifying pathways with dysregulated gene expression in FLS from patients with oligoarticular JIA.

Methods: FLS were derived from synovial fluid obtained by arthrocentesis from patients with JIA undergoing intraarticular steroid injections and from orthopedic control patients. Gene expression profiles of the JIA and control FLS were obtained using the Affymetrix platform, with application of Ingenuity Pathway Analysis and Gene Set Enrichment Analysis software to define gene sets in dysregulated pathways and networks of potential pathologic relevance in this disease.

Lyme chondritis presenting as painless ear erythema.

Erythema of the ear lobe in the context of Lyme disease is caused by either borrelial lymphocytoma or localized erythema migrans. Here we present a case of chondritis limited to the ear cartilage caused by Lyme disease. The patient was treated with ceftriaxone with complete resolution of symptoms.

Prolonged synovitis in pediatric Lyme arthritis cannot be predicted by clinical or laboratory parameters.

Ten percent of Lyme arthritis (LA) patients have continued synovitis despite antimicrobial therapy. The current study was designed to (1) investigate predictors of prolonged disease and (2) further define natural history of pediatric LA. Medical records of 94 children fulfilling Centers for Disease Control criteria for Lyme disease were reviewed, classified into groups according to duration of synovitis, and SPSS statistical software was used for analysis.

Steady improvement of prothrombin levels after cyclophosphamide therapy in pediatric lupus anticoagulant hypoprothrombinemia syndrome (LAHPS).

Lupus anticoagulant hypoprothrombinemia syndrome (LAHPS) is a rare acquired disorder associated with several different conditions but mostly with systemic lupus erythematosus (SLE). LAHPS probably results from the presence of anti-Factor II antibodies, which usually counterbalance the prothrombotic effect of the lupus anticoagulant (LAC). In fact, Factor II deficiency in SLE is invariably associated with the presence of LAC.