Management of Autoimmune Encephalitis in a 7-Year-Old Child With CTLA-4 Haploinsufficiency and AMPA Receptor Antibodies: A Case Report.

OBJECTIVES: We report on the therapeutic management of early-onset severe neurologic symptoms in cytotoxic T lymphocyte antigen-4 haploinsufficiency (CTLA-4h) and the presence of antibodies to the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) as an important finding. METHODS: This is a case report from a Dutch academic hospital. Repeated clinical examinations, repeated brain MRI and extended diagnostics on serum and CSF were performed. We used the CARE checklist. RESULTS: A 7-year-old boy was diagnosed with CTLA-4h based on family screening. On diagnosis, he had mild chronic diarrhea and autism spectrum disorder, but no abnormalities in extensive laboratory screening. Six months later, he presented with sudden-onset autoimmune encephalitis. Repeated brain MRI revealed no abnormalities, but immunohistochemistry analysis on serum and CSF showed the presence of AMPAR antibodies. Treatment was initially focused on immunomodulation and targeted CTLA-4 replacement therapy. Because of the persistent fluctuating cerebellar and neuropsychiatric symptoms and the potential clinical significance of the AMPAR antibodies, treatment was intensified with repetition of first-line immunomodulation and rituximab. This combined therapy resulted in sustained clinical improvement and served as a bridge to curative hematopoietic stem cell transplantation. DISCUSSION: This case illustrates the rare early onset of autoimmune encephalitis and presence of AMPAR antibodies in CTLA-4h. Targeted CTLA-4 replacement therapy resulted in a partial response. However, awaiting its optimal therapeutic effect, refractory CNS symptoms required intensification of immunomodulation. The identification of AMPAR antibodies guided our treatment decisions. CLASSIFICATION OF EVIDENCE: This provides Class IV evidence. It is a single observational study without controls.

Neurological phenotype of adenosine deaminase 2 deficient patients: a cohort study.

BACKGROUND AND PURPOSE: Patients with adenosine deaminase 2 (ADA2) deficiency can present with various neurological manifestations due to vasculopathies and autoinflammation. These include ischaemic and hemorrhagic stroke, but less clearly defined neurological symptoms have also been reported. METHODS: In this cohort study, patients with confirmed ADA2 deficiency from seven university hospitals in the Netherlands were included. The frequency and recurrence rates of neurological manifestations before and after initiation of tumor necrosis factor α (TNF-α) inhibiting therapy were analyzed. RESULTS: Twenty-nine patients were included with a median age at presentation of 5 years (interquartile range 1-17). Neurological manifestations occurred in 19/29 (66%) patients and were the presenting symptom in 9/29 (31%) patients. Transient ischaemic attack (TIA)/ischaemic stroke occurred in 12/29 (41%) patients and was the presenting symptom in 8/29 (28%) patients. In total, 25 TIAs/ischaemic strokes occurred in 12 patients, one after initiation of TNF-α inhibiting therapy and one whilst switching between TNF-α inhibitors. None was large-vessel occlusion stroke. Two hemorrhagic strokes occurred: one aneurysmatic subarachnoid hemorrhage and one spontaneous intracerebral hemorrhage. Most neurological symptoms, including cranial nerve deficits, vertigo, ataxia and seizures, were caused by TIAs/ischaemic strokes and seldom recurred after initiation of TNF-α inhibiting therapy. CONCLUSIONS: Neurological manifestations, especially TIA/ischaemic stroke, are common in patients with ADA2 deficiency and frequently are the presenting symptom. Because it is a treatable cause of young stroke, for which antiplatelet and anticoagulant therapy are considered contraindicated, awareness amongst neurologists and pediatricians is important. Screening for ADA2 deficiency in young patients with small-vessel ischaemic stroke without an identified cause should be considered.

Clinical Symptoms, Laboratory Parameters and Long-Term Follow-up in a National DADA2 Cohort.

Deficiency of adenosine deaminase-2 (DADA2) is an autosomal recessive autoinflammatory disease with an extremely variable disease presentation. This paper provides a comprehensive overview of the Dutch DADA2 cohort. We performed a retrospective cohort study in 29 ADA2-deficient patients from 23 families with a median age at inclusion of 26 years. All patients had biallelic pathogenic variants in the ADA2 gene. The most common clinical findings included cutaneous involvement (79.3%), (hepato)splenomegaly (70.8%) and recurrent infections (58.6%). Stroke was observed in 41.4% of the patients. The main laboratory abnormalities were hypogammaglobulinemia and various cytopenias. Patients presented most often with a mixed phenotype involving vasculopathy, immunodeficiency and hematologic manifestations (62.1%). In this cohort, malignancies were reported in eight patients (27.6%), of whom five presented with a hematologic malignancy and two with a basal cell carcinoma. Four patients developed hemophagocytic lymphohistiocytosis (HLH) or an HLH-like episode, of whom three passed away during or shortly after the occurrence of HLH. TNF-inhibitors (TNFi) were effective in treating vasculopathy-associated symptoms and preventing stroke, but were hardly effective in the treatment of hematologic manifestations. Three patients underwent hematopoietic cell transplantation and two of them are doing well with complete resolution of DADA2-related symptoms. The overall mortality in this cohort was 17.2%. In conclusion, this cohort describes the clinical, genetic and laboratory findings of 29 Dutch DADA2 patients. We describe the occurrence of HLH as a life-threatening disease complication and report a relatively high incidence of malignancies and mortality.

Trained Immunity in Primary Sjögren's Syndrome: Linking Type I Interferons to a Pro-Atherogenic Phenotype.

Background: Trained immunity - or innate immune memory - can be described as the long-term reprogramming of innate immune cells towards a hyperresponsive state which involves intracellular metabolic changes. Trained immunity has been linked to atherosclerosis. A subgroup of patients with primary Sjögren's syndrome (pSS) exhibits systemic type I interferon (IFN) pathway activation, indicating innate immune hyperactivation. Here, we studied the link between type I IFNs and trained immunity in an in vitro monocytic cell model and peripheral blood mononuclear cells (PBMCs) from pSS patients. Methods: The training stimuli heat killed Candida albicans, muramyl dipeptide, IFNß, and patient serum were added to THP-1 cells for 24 hours, after which the cells were washed, rested for 48 hours and subsequently re-stimulated with LPS, Pam3Cys, poly I:C, IFNß or oxLDL for 4-24 hours. PBMCs from pSS patients and healthy controls were stimulated with LPS, Pam3Cys, poly I:C or IFNß for 0.5-24 hours. Results: Training with IFNß induced elevated production of pro-atherogenic cytokines IL-6, TNFα and CCL2, differential cholesterol- and glycolysis-related gene expression, and increased glucose consumption and oxLDL uptake upon re-stimulation. Type I IFN production was increased in Candida albicans- and IFNß-trained cells after LPS re-stimulation, but was reduced after poly I:C re-stimulation. Training with muramyl dipeptide and IFNß, but not Candida albicans, affected the IFN-stimulated gene expression response to IFNß re-stimulation. PBMCs from pSS patients consumed more glucose compared with healthy control PBMCs and tended to produce more TNFα and type I IFNs upon LPS stimulation, but less type I IFNs upon poly I:C stimulation. Conclusions: Type I IFN is a trainer inducing a trained immunity phenotype with pro-atherogenic properties in monocytes. Conversely, trained immunity also affects the production of type I IFNs and transcriptional response to type I IFN receptor re-stimulation. The phenotype of pSS PBMCs is consistent with trained immunity. This connection between type I IFN, trained immunity and cholesterol metabolism may have important implications for pSS and the pathogenesis of (subclinical) atherosclerosis in these patients.

Anakinra in Patients With Systemic Juvenile Idiopathic Arthritis: Long-term Safety From the Pharmachild Registry.

OBJECTIVE: To evaluate the long-term safety profile of anakinra in patients with systemic juvenile idiopathic arthritis (sJIA). METHODS: Data from patients with sJIA enrolled in the Pharmachild registry (ClinicalTrials.gov: NCT03932344) prior to September 30, 2018, and treated with anakinra were analyzed. The study endpoints were the occurrence of non-serious adverse events (SAEs) of at least moderate severity and SAEs, including macrophage activation syndrome (MAS), and the duration of anakinra treatment with reasons for discontinuation. All endpoints were analyzed overall by 6-month time windows, and in different treatment sets represented by those patients treated continuously with anakinra for at least 12, 18, and 24 months (set-12, -18, and -24, respectively). RESULTS: Three hundred six patients were enrolled. Of these patients, 46%, 34%, and 28% had been treated for at least 12, 18, and 24 months, respectively. Two hundred and one AEs, mostly represented by infections, were reported for 509.3 patient-years (PY) with an overall incidence rate (IR) of 39.5 per 100 PY. Among 56 SAEs (IR 11.0/100 PY), 23.2% were infections and 19.6% MAS episodes. The IR of AEs was higher during the first 6 months of anakinra treatment, followed by decreasing IRs in the long-term treatment sets. Treatment discontinuation occurred in 76% of patients, most frequently in the first 6 months, because of inefficacy (43%), remission (31%), or AEs/intolerance (15%). No deaths or malignancies occurred during anakinra treatment. CONCLUSION: The results of the present study confirm the long-term safety profile of anakinra in patients with sJIA and demonstrate an overall decreasing incidence of AEs over time. [ClinicalTrials.gov: NCT01399281 and NCT03932344].

Endothelial and Inflammation Biomarker Profiles at Diagnosis Reflecting Clinical Heterogeneity and Serving as a Prognostic Tool for Treatment Response in Two Independent Cohorts of Patients With Juvenile Dermatomyositis.

OBJECTIVE: Juvenile dermatomyositis (DM) is a heterogeneous systemic immune-mediated vasculopathy. This study was undertaken to 1) identify inflammation/endothelial dysfunction-related biomarker profiles reflecting disease severity at diagnosis, and 2) establish whether such biomarker profiles could be used for predicting the response to treatment in patients with juvenile DM. METHODS: In total, 39 biomarkers related to activation of endothelial cells, endothelial dysfunction, and inflammation were measured using multiplex technology in serum samples from treatment-naive patients with juvenile DM from 2 independent cohorts (n = 30 and n = 29). Data were analyzed by unsupervised hierarchical clustering, nonparametric tests with correction for multiple comparisons, and Kaplan-Meier tests with Cox proportional hazards models for analysis of treatment duration. Myositis-specific antibodies (MSAs) were measured in the patients' serum using line blot assays. RESULTS: Severe vasculopathy in patients with juvenile DM was associated with low serum levels of intercellular adhesion molecule 1 (Spearman's rho [rs ] = 0.465, P = 0.0111) and high serum levels of endoglin (rs = -0.67, P < 0.0001). In the discovery cohort, unsupervised hierarchical clustering analysis of the biomarker profiles yielded 2 distinct patient clusters, of which the smaller cluster (cluster 1; n = 8) exhibited high serum levels of CXCL13, CCL19, galectin-9, CXCL10, tumor necrosis factor receptor type II (TNFRII), and galectin-1 (false discovery rate <0.0001), and this cluster had greater severity of muscle disease and global disease activity (each P < 0.05 versus cluster 2). In the validation cohort, correlations between the serum levels of galectin-9, CXCL10, TNFRII, and galectin-1 and the severity of global disease activity were confirmed (rs = 0.40-0.52, P < 0.05). Stratification of patients according to the 4 confirmed biomarkers identified a cluster of patients with severe symptoms (comprising 64.7% of patients) who were considered at high risk of requiring more intensive treatment in the first 3 months after diagnosis (P = 0.0437 versus other cluster). Moreover, high serum levels of galectin-9, CXCL10, and TNFRII were predictive of a longer total treatment duration (P < 0.05). The biomarker-based clusters were not evidently correlated with patients' MSA serotypes. CONCLUSION: Results of this study confirm the heterogeneity of new-onset juvenile DM based on serum biomarker profiles. Patients with high serum levels of galectin-9, CXCL10, TNFRII, and galectin-1 may respond suboptimally to conventional treatment, and may therefore benefit from more intensive monitoring and/or treatment.

European consensus-based recommendations for diagnosis and treatment of immunoglobulin A vasculitis-the SHARE initiative.

OBJECTIVES: IgA vasculitis (IgAV, formerly known as Henoch-Schönlein purpura) is the most common cause of systemic vasculitis in childhood. To date, there are no internationally agreed, evidence-based guidelines concerning the appropriate diagnosis and treatment of IgAV in children. Accordingly, treatment regimens differ widely. The European initiative SHARE (Single Hub and Access point for paediatric Rheumatology in Europe) aims to optimize care for children with rheumatic diseases. The aim therefore was to provide internationally agreed consensus recommendations for diagnosis and treatment for children with IgAV. METHODS: Recommendations were developed by a consensus process in accordance with the EULAR standard operating procedures. An extensive systematic literature review was performed, and evidence-based recommendations were extrapolated from the included papers. These were evaluated by a panel of 16 international experts via online surveys and subsequent consensus meeting, using nominal group technique. Recommendations were accepted when ⩾80% of experts agreed. RESULTS: In total, 7 recommendations for diagnosis and 19 for treatment of paediatric IgAV were accepted. Diagnostic recommendations included: appropriate use of skin and renal biopsy, renal work-up and imaging. Treatment recommendations included: the importance of appropriate analgesia and angiotensin-converting enzyme inhibitor use and non-renal indications for CS use, as well as a structured approach to treating IgAV nephritis, including appropriate use of CS and second-line agents in mild, moderate and severe disease along with use of angiotensin-converting enzyme inhibitors and maintenance therapy. CONCLUSION: The SHARE initiative provides international, evidence-based recommendations for the diagnosis and treatment of IgAV that will facilitate improvement and uniformity of care.

European consensus-based recommendations for the diagnosis and treatment of rare paediatric vasculitides - the SHARE initiative.

OBJECTIVES: The European initiative Single Hub and Access point for paediatric Rheumatology in Europe (SHARE) aimed to optimize care for children with rheumatic diseases. Systemic vasculitides are very rare in children. Consequently, despite recent advances, paediatric-specific information is sparse. The lack of evidence-based recommendations is an important, unmet need. This study aimed to provide recommendations for diagnosing and treating children with rare forms of childhood systemic vasculitis. METHODS: Recommendations were developed by a consensus process in accordance with the European League Against Rheumatism standard operating procedures. A systematic literature review informed the recommendations, which were devised and evaluated by a panel of experts via an online survey, and two consensus meetings using nominal group technique. Recommendations were accepted when ⩾ 80% of experts agreed. RESULTS: Ninety-three relevant articles were found, and 78 recommendations were accepted in the two consensus meetings. General, cross-cutting recommendations and disease-specific statements regarding the diagnosis and treatment of childhood-onset PAN, granulomatosis with polyangiitis, microscopic polyangiitis, eosinophilic granulomatosis with polyangiitis, and Takayasu arteritis are provided. CONCLUSION: These Single Hub and Access point for paediatric Rheumatology in Europe recommendations were formulated through an evidence-based consensus process to support uniform, high-quality standard of care for children with rare forms of paediatric systemic vasculitis.

Type I IFN signature in childhood-onset systemic lupus erythematosus: a conspiracy of DNA- and RNA-sensing receptors?

BACKGROUND: Childhood-onset systemic lupus erythematosus (cSLE) is an incurable multi-systemic autoimmune disease. Interferon type I (IFN-I) plays a pivotal role in the pathogenesis of SLE. The objective of this study was to assess the prevalence of the IFN-I signature and the contribution of cytosolic nucleic acid receptors to IFN-I activation in a cohort of primarily white cSLE patients. METHODS: The IFN-I score (positive or negative), as a measure of IFN-I activation, was assessed using real-time quantitative PCR (RT-PCR) expression values of IFN-I signature genes (IFI44, IFI44L, IFIT1, Ly6e, MxA, IFITM1) in CD14+ monocytes of cSLE patients and healthy controls (HCs). Innate immune receptor expression was determined by RT-PCR and flow cytometry. To clarify the contribution of RNA-binding RIG-like receptors (RLRs) and DNA-binding receptors (DBRs) to IFN-I activation, peripheral blood mononuclear cells (PBMCs) from patients were treated with BX795, a TANK-binding kinase 1 (TBK1) inhibitor blocking RLR and DBR pathways. RESULTS: The IFN-I signature was positive in 57% of cSLE patients and 15% of the HCs. Upregulated gene expression of TLR7, RLRs (IFIH1, DDX58, DDX60, DHX58) and DBRs (ZBP-1, IFI16) was observed in CD14+ monocytes of the IFN-I-positive cSLE patients. Additionally, RIG-I and ZBP-1 protein expression was upregulated in these cells. Spontaneous IFN-I stimulated gene (ISG) expression in PBMCs from cSLE patients was inhibited by a TBK1-blocker. CONCLUSIONS: IFN-I activation, assessed as ISG expression, in cSLE is associated with increased expression of TLR7, and RNA and DNA binding receptors, and these receptors contribute to IFN-I activation via TBK1 signaling. TBK1-blockers may therefore be a promising treatment target for SLE.

Trends in prescription of biological agents and outcomes of juvenile idiopathic arthritis: results of the Dutch national Arthritis and Biologics in Children Register.

BACKGROUND: Treatment of juvenile idiopathic arthritis (JIA) has changed dramatically since the introduction of biological agents in 1999. OBJECTIVE: To evaluate trends in prescription patterns of biological agents and the subsequent outcome of JIA. METHODS: The Arthritis and Biologics in Children register (multicentre prospective observational study) aimed to include all consecutive patients with JIA in the Netherlands who had started biological agents since 1999. Patients were divided according to year of introduction of first biological agent. Patient characteristics at introduction of the first biological agent and its effectiveness were analysed over 12 years. RESULTS: 335 patients with non-systemic JIA and 86 patients with systemic JIA started a biological agent between 1999 and 2010. Etanercept remained the most often prescribed biological agent for non-systemic JIA; anakinra became first choice for systemic JIA. The use of systemic glucocorticoids and synthetic disease-modifying antirheumatic drugs before biological agents decreased. During these 12 years of observation, biological agents were prescribed earlier in the disease course and to patients with lower baseline JADAS (Juvenile Arthritis Disease Activity Score) disease activity. All baseline disease activity parameters were lowered in patients with non-systemic JIA. In systemic JIA, prescription patterns changed towards very early introduction of biological agents (median 0.4 years of disease duration) in patients with a low number of joints with active arthritis and high erythrocyte sedimentation rates. These changes for both systemic and non-systemic JIA resulted in more patients with inactive disease after 3 and 15 months of treatment. CONCLUSIONS: Biological agents are increasingly prescribed, earlier in the disease and in patients with JIA with lower disease activity. These changes are accompanied by better short-term disease outcomes.

Treatment choices of paediatric rheumatologists for juvenile idiopathic arthritis: etanercept or adalimumab?

OBJECTIVES: To evaluate differences in baseline characteristics between etanercept- and adalimumab-treated JIA patients and to reveal factors that influence the choice between these TNF inhibitors, which are considered equally effective in the recent ACR recommendations for JIA treatment. METHODS: Biologic-naïve JIA patients with active arthritis who started treatment with adalimumab or etanercept between March 2008 and December 2011 were selected from the Dutch Arthritis and Biologicals in Children register. Baseline characteristics were compared. Focus group interviews with paediatric rheumatologists were performed to evaluate factors determining treatment choices. RESULTS: A total of 193 patients started treatment with etanercept and 21 with adalimumab. Adalimumab-treated patients had longer disease duration prior to the start of biologics (median 5.7 vs 2.0 years) and more often a history of uveitis (71% vs 4%). Etanercept-treated patients had more disability at baseline (median Childhood Health Assessment Questionnaire score 1.1 vs 0.4) and more active arthritis (median number of active joints 6 vs 4). The presence of uveitis was the most important factor directing the choice towards adalimumab. Factors specific for the paediatric population-such as painful adalimumab injections-as well as the physician's familiarity with the drug accounted for the preference for etanercept. CONCLUSION: Although the two TNF inhibitors are considered equally effective, in daily practice etanercept is most often prescribed; adalimumab is mainly preferred when uveitis is present. In choosing the most suitable biologic treatment, paediatric rheumatologists take into account drug and patient factors, considering newly published data and cautiously implementing this into daily care.

Tumour necrosis factor-blocking agents in persistent oligoarticular juvenile idiopathic arthritis: results from the Dutch Arthritis and Biologicals in Children Register.

OBJECTIVE: Because TNF inhibitors are not approved for persistent oligoarticular JIA (oJIA), although they are used off-label, we evaluated their effectiveness in patients in this category. METHODS: Persistent oJIA patients were selected from the Dutch Arthritis and Biologicals in Children (ABC) register, an ongoing multicentre prospective study that aims to include all Dutch children with JIA using biologic agents. Response was assessed by the JIA core-set disease activity variables and modified Wallace criteria for inactive disease. RESULTS: Until February 2011, 16 persistent oJIA patients (68.8% females) had been included in the register. Median age of onset was 8.4 years [interquartile range (IQR) 2.1-13.5 years]; history of uveitis in 18.8%; ANA-positive 56.3%. All had previously used MTX, and 81.3% had used IA CSs. Median follow-up after the introduction of biologic treatment was 13.7 months (IQR 8.3-16.7 months). Fourteen patients started etanercept and two patients who had active arthritis as well as uveitis started adalimumab. Although patients with persistent oJIA had few affected joints [median of two active joints at the start of biologic (IQR 1-3)], the patient/parent assessments of pain [median visual analogue score (VAS) 51 (IQR 1-64)] and well-being [median VAS 44 (IQR 6-66)] were high. Additionally, their physician evaluated the disease activity as moderately high [median VAS 36 (IQR 4-65)]. After 3 months this decreased to 0 (IQR 0-30) and 63% achieved inactive disease. After 15 months the disease was inactive in 9/10 observed patients. TNF inhibitors were tolerated well. CONCLUSION: TNF blocking agents seem an effective and justifiable option in persistent oJIA when treatment with IA CS injections and MTX has failed.

Effectiveness and safety of a second and third biological agent after failing etanercept in juvenile idiopathic arthritis: results from the Dutch National ABC Register.

OBJECTIVE: To evaluate the effectiveness and safety of switching to a second or third biological agent in juvenile idiopathic arthritis (JIA) after etanercept failure. METHODS: The Arthritis and Biologicals in Children Register aims to include all Dutch JIA patients who have used biological agents. Data on the disease course were used to estimate drug survival with Kaplan-Meier and calculate adverse event (AE) rates. RESULTS: Of 307 biologically naive JIA patients who started etanercept, 80 (26%) switched to a second and 22 (7%) to a third biological agent. During 1030 patient-years of follow-up after the introduction of etanercept, 49 switches to adalimumab, 28 infliximab, 17 anakinra, four abatacept and four trial drugs were evaluated. 84% (95% CI 80% to 88%) of patients who started etanercept as a first biological agent were, after 12 months, still on the drug, compared with 47% (95% CI 35% to 60%) who started a second and 51% (95% CI 26% to 76%) who started a third biological agent. Patients who switched because of primary ineffectiveness continued the second agent less often (32%, 95% CI 12% to 53%). After etanercept failure, drug continuation of adalimumab was similar to infliximab for patients with non-systemic JIA; anakinra was superior to a second TNF-blocker for systemic JIA. AE rates within first 12 months after initiation were comparable for each course and each biological agent. CONCLUSIONS: Switching to another biological agent is common, especially for systemic JIA patients. A second (and third) agent was less effective than the first. The choice of second biological agent by the physician mainly depends on availability and JIA category.

Delayed clinical response in patients with juvenile idiopathic arthritis treated with etanercept.

OBJECTIVE: To evaluate response in patients with juvenile idiopathic arthritis (JIA) who failed to meet response criteria after 3 months of etanercept treatment. METHODS: This was a prospective ongoing multicenter observational study of all Dutch patients with JIA using etanercept. Response according to American College of Rheumatology Pediatric 30 criteria was assessed at study start and at 3 and 15 months. RESULTS: In total we studied 179 patients of median age 5.8 years at disease onset; 70% were female. Thirty-four patients did not respond after 3 months, of which 20 continued etanercept and 11 achieved response thereafter. CONCLUSION: The delayed clinically relevant response in a substantial proportion of patients who initially did not respond justifies the consideration of continuing therapy to at least 6 months.

Hsp60 in inflamed muscle tissue is the target of regulatory autoreactive T cells in patients with juvenile dermatomyositis.

OBJECTIVE: Juvenile dermatomyositis (DM) is an autoimmune disease of unknown origin characterized by muscle weakness and skin manifestations. No definite autoantigen has yet been identified. Heat-shock proteins (HSPs) can be up-regulated at sites of inflammation, and immune reactivity to Hsp60 is suggested to play a regulatory role in various chronic inflammatory diseases. The purpose of this study was to determine whether Hsp60 could serve as an autoantigen in juvenile DM. METHODS: Muscle tissue from 4 patients with juvenile DM and 1 healthy control subject without evidence of muscle disease was stained for Hsp60. Peripheral blood mononuclear cells (PBMCs) from 22 patients and 10 healthy control subjects were tested for T cell proliferation induced by human and microbial Hsp60. Cytokine production in response to Hsp60 was examined in 15 patients and 6 healthy controls. T cell reactivity to Hsp60 was determined in muscle biopsy samples from 2 patients. RESULTS: We found significantly increased T cell proliferation to human Hsp60 in PBMCs from juvenile DM patients, which was higher during disease remission. Following in vitro activation with Hsp60, significant amounts of tumor necrosis factor alpha, interleukin-1beta (IL-1beta), and IL-10 were produced. In contrast to muscle biopsy samples from healthy controls, samples from juvenile DM patients showed up-regulation of Hsp60, induction of T cell proliferation, and production of cytokines. Production of proinflammatory cytokines by muscle-derived cells in response to Hsp60 was associated with a poor clinical prognosis, whereas human Hsp60-specific induction of IL-10 was followed by clinical remission. CONCLUSION: These findings suggest that human (self) Hsp60 is a disease-relevant autoantigen in juvenile DM. The difference in T cell response with regard to disease activity indicates an immune regulatory effect of Hsp60-specific T cells, opening up perspectives for antigen-specific immunotherapy.

Case report: severe central nervous system involvement in juvenile dermatomyositis.

We present 3 patients with juvenile dermatomyositis (JDM) and severe central nervous system (CNS) complications. All patients had at least 4 positive criteria of Bohan and Peter, which confirmed a definite diagnosis of JDM. They were all male, and had a relatively high creatinine kinase value at admission (1532-4260 U/l). Besides, progressive proximal muscle weakness and rash, one patient presented with rapid irreversible decline of vision. Ophthalmologic examination showed active vasculitis of the retina. After 2 weeks of treatment with immunosuppressive drugs and being in improved, relatively stable clinical condition, all 3 patients developed generalized tonic-clonic convulsions. Other causes of the neurological symptoms could be excluded. In all 3 patients, the course of JDM was fatal. The clinical symptoms and further investigations in our patients show CNS involvement in JDM. Although rarely reported, CNS vasculopathy can be a serious and life-threatening complication of JDM.