Increased T Cell Plasticity With Dysregulation of Follicular Helper T, Peripheral Helper T, and Treg Cell Responses in Children With Juvenile Idiopathic Arthritis and Down Syndrome-Associated Arthritis.

OBJECTIVE: Juvenile idiopathic arthritis (JIA) is the most common inflammatory arthritis in children; however, an aggressive, erosive arthritis of little-known immunologic mechanism occurs 20 times more frequently in children with Down syndrome. This study was undertaken to characterize T cell and B cell polyreactivity, follicular helper T (Tfh) cell, peripheral helper T (Tph) cell, and Treg cell responses, and synovial inflammation in Down syndrome-associated arthritis (DA). METHODS: Multiparametric flow cytometric analysis and Simplified Presentation of Incredibly Complex Evaluations (SPICE) software were used to examine peripheral blood B cell populations and T cell cytokine responses in patients with DA, JIA, Down syndrome (trisomy 21 [T21]), and in healthy controls. Tfh and Tph cell frequency and origin, in addition to Treg cell frequency, were also evaluated. Synovial inflammation was assessed by immunohistology. RESULTS: Expansion of IgM-only memory B cells was demonstrated in DA compared to JIA (mean ± SEM 22.48 ± 3.278 versus 9.011 ± 1.317; P = 0.005), paralleled by decreased frequency of transitional B cells. T cell responses in DA were characterized by marked functional plasticity, as was evident from the increased frequency of polyfunctional CD8+ Th cells (P < 0.05), CD161+ Th cells (P < 0.05), and CD8- Th cells (P < 0.001), and positivity for tumor necrosis factor, interferon-γ, interleukin-17A, or granulocyte-macrophage colony-stimulating factor, compared to all other groups. Significant expansion of CXCR3+CCR6+ (Th1/Th17) Tfh cells (P = 0.003) and CXCR3+CCR6+ Tph cells (P = 0.01), paralleled by a decrease in CXCR3-CCR6- (Th2) Tfh cells was observed in DA compared to T21. Treg cells were significantly reduced in DA compared to T21 (mean ± SEM 7.111 ± 0.9518 versus 11.96 ± 1.055 versus; P = 0.0028), with a specific reduction in the naive:memory Treg cell ratio. Marked synovial tissue inflammation and increased T cell and B cell infiltrations were demonstrated in DA compared to JIA. CONCLUSION: DA is more common and more aggressive than JIA. It is characterized by increased polyreactive Th, Tfh, and Tph cell responses, reduced Treg cell frequency, and evidence of increased synovial inflammation, all of which are potentially distinct from JIA and T21.

Juvenile systemic lupus erythematosus presenting as pancarditis.

BACKGROUND: Systemic lupus erythematosus (SLE) is a chronic autoimmune disease with marked variation in its clinical presentation. Juvenile SLE (jSLE) accounts for 15-20% of all cases and is diagnosed when SLE manifests before 18 years of age. Pancarditis is a rare complication of SLE, regardless of age of disease onset. CASE PRESENTATION: We report a case of jSLE in a 15 year old Caucasian female presenting with an acute episode of pancarditis and multiorgan dysfunction who was successfully treated with systemic corticosteroids and cyclophosphamide. CONCLUSION: Pancarditis can be a presenting feature of jSLE which was previously unreported. A high index of suspicion for severe cardiac involvement is required at all stages of disease.

Defining consensus opinion to develop randomised controlled trials in rare diseases using Bayesian design: An example of a proposed trial of adalimumab versus pamidronate for children with CNO/CRMO.

INTRODUCTION: Chronic nonbacterial osteomyelitis (CNO) is a rare autoinflammatory bone disorder primarily affecting children and adolescents. It can lead to chronic pain, bony deformities and fractures. The pathophysiology of CNO is incompletely understood. Scientific evidence suggests dysregulated expression of pro- and anti-inflammatory cytokines to be centrally involved. Currently, treatment is largely based on retrospective observational studies and expert opinion. Treatment usually includes nonsteroidal anti-inflammatory drugs and/or glucocorticoids, followed by a range of drugs in unresponsive cases. While randomised clinical trials are lacking, retrospective and prospective non-controlled studies suggest effectiveness of TNF inhibitors and bisphosphonates. The objective of the Bayesian consensus meeting was to quantify prior expert opinion. METHODS: Twelve international CNO experts were randomly chosen to be invited to a Bayesian prior elicitation meeting. RESULTS: Results showed that a typical new patient treated with pamidronate would have an 84% chance of improvement in their pain score relative to baseline at 26 weeks and an 83% chance on adalimumab. Experts thought there was a 50% chance that a new typical patient would record a pain score of 28mm (pamidronate) to 30mm (adalimumab) or better at 26 weeks. There was a modest trend in prior opinion to indicate an advantage of pamidronate vs adalimumab, with a 68% prior chance that pamidronate is superior to adalimumab by some margin. However, it is clear that there is considerable uncertainty about the precise relative merits of the two treatments. CONCLUSIONS: The rarity of CNO leads to challenges in conducting randomised controlled trials with sufficient power to provide a definitive outcome. We address this using a Bayesian design, and here describe the process and outcome of the elicitation exercise to establish expert prior opinion. This opinion will be tested in the planned prospective CNO study. The process for establishing expert consensus opinion in CNO will be helpful for developing studies in other rare paediatric diseases.

The value of the perinatal and neonatal autopsy.

The postmortem historically has been considered a valuable diagnostic exercise which contributes to medical knowledge. Despite this, there has been a significant reduction in autopsy rates throughout the developed world. This audit was a retrospective study of autopsy reports of stillbirths and neonates [corrected] greater than 500 grams over a five year period from 1995 to 1999. The audit was performed to assess the impact of autopsy on the current practice of perinatal medicine. The audit compared the final pathological diagnosis to the clinical diagnosis. The pathological diagnosis was categorised as (I) diagnostic, (II) confirmative, (III) unexplained. The recurrence risk estimates as a result of necropsy were also identified, as were any additional findings that were felt to be relevant but did not belong to any of the above categories. A total of 262 perinatal deaths (including stillbirths) and neonatal deaths greater than 500 grams birth weight were recorded during this period. The autopsy rate was 81%. The 213 autopsies performed were assessed, of which 76 (36%) were found to be diagnostic, 108 (51%) confirmatory, and 29 (13%) were unexplained or revealed no new findings. Change in recurrence risk estimates was identified in 24 (11%) and additional relevant information was obtained in 38 (18%). There were a number of cases where an unexpected diagnosis was made as a result of autopsy; these diagnoses included a respiratory chain disorder in a twenty nine week infant, and an occult necrotising enterocolitis presenting with severe haemolysis post transfusion in a preterm infant. The perinatal post mortem examination remains an indispensable part of clinical management. It contributes to medical education and quality assurance. It can aid in the identification of inheritable diseases and provide information for accurate parental counseling.