Peripheral blood mononuclear cells (PBMCs) are stimulated by exercise and contribute not only to host defense, but also to growth, repair, and disease pathogenesis. Whether PBMC gene expression is altered by exercise in children is not known. 10 early pubertal boys (8-12 y) and 10 late pubertal boys (15-18 y) performed 10, 2-min bouts of strenuous, constant work rate exercise with 1-min rest intervals. PBMCs were isolated before and after exercise and microarray (Affymetrix U133+2 chips) analyzed. Statistical criterion to identify gene expression changes was less than 5% false discovery rate with 95% confidence. 1246 genes were altered in older boys (517 up, 729 down), but only 109 in the younger group (79 up, 30 down). In older boys, 13 gene pathways (using EASE p<0.05) were found (e.g., natural killer cell cytoxicity, apoptosis). Epiregulin gene expression (EREG, a growth factor involved in wound healing) increased in older boys. In older boys exercise altered genes such as TBX21, GZMA, PGTDR, and CCL5 that also play roles in pediatric inflammatory diseases like asthma. 66 genes changed significantly in both groups. The pattern of PBMC gene expression suggests the initiation of an immunological "danger" signal associated with a sudden change in energy expenditure.

ABSTRACT: Juvenile idiopathic arthritis (JIA) is a heterogeneous autoimmune disease characterized by chronic joint inflammation. Knowing which antigens drive the autoreactive T cell response in JIA is crucial for the understanding of disease pathogenesis and additionally may provide targets for antigen-specific immune therapy. In this study we tested 9 self-peptides derived from joint-related autoantigens for T cell recognition (T cell proliferative responses and cytokine production) in 36 JIA patients and 15 healthy controls. Positive T cell proliferative responses (SI>/=2) to one or more peptides were detected in PBMC of 69% JIA patients irrespective of MHC genotype. The peptides derived from aggrecan, fibrillin and mmp3 yielded the highest frequency of T cell proliferative responses in JIA patients. The aggrecan-peptide induced T cell proliferative responses in both the oligoarticular and polyarticular subtype of JIA that were inversely related with disease duration. The fibrillin-peptide, to our knowledge, is the first identified autoantigen that is primarily recognized in polyarticular JIA patients. Finally, the epitope derived from mmp3 elicited immune responses in both subtypes of JIA and healthy controls. Cytokine production in short-term peptide-specific T cell lines revealed production of IFN-gamma (aggrecan/mmp3), IL-17 (aggrecan) and inhibition of IL-10 production (aggrecan). Herewith we have identified a triplet of self-epitopes, each with distinct patterns of T cell recognition in JIA patients. Additional experiments need to be performed to explore their qualities and role in disease pathogenesis in further detail.

BACKGROUND: Juvenile idiopathic arthritis is a heterogeneous autoimmune disease characterised by chronic inflammation of one or more joints. In patients with this disease, T-cell reactivity to autologous heat-shock protein 60 (HSP60) is associated with a favourable prognosis. We sought to identify HSP60 T-cell epitopes to find potential targets for HSP60 immunotherapy and to assess whether immune responses to these epitopes contribute to the distinct clinical outcome of this disease. METHODS: We identified eight potential epitopes using a computer algorithm from both self and microbial HSP60 binding to many HLA-DR molecules. We analysed the pattern of T-cell responses induced by these HSP60 peptides in peripheral-blood mononuclear cells (PBMC) of 57 patients with juvenile idiopathic arthritis, 27 healthy controls, and 20 disease controls. We undertook in-vitro MHC binding studies with the identified peptides, and HLA class II typing of a subset of patients with juvenile idiopathic arthritis. FINDINGS: Five of the eight peptides identified yielded proliferative T-cell responses in 50-70% of PBMC from patients with juvenile idiopathic arthritis irrespective of MHC genotype, but not in PBMC from healthy or disease controls. Although PBMC from both patients with juvenile idiopathic arthritis and healthy controls produced interferon gamma in response to these peptides, only PBMC from patients with the disease produced interleukin 10. INTERPRETATION: The recorded T-cell-induction in juvenile idiopathic arthritis is tolerogenic. In patients with oligoarticular disease, the immune responses to the HSP60 epitopes identified could contribute to disease remission. RELEVANCE TO PRACTICE: The broad recognition of these HSP60 epitopes in a population of patients with polymorphic MHC genotypes opens the way for HSP60-peptide immunotherapy, representing a novel treatment option to specifically modulate the immune system in patients with juvenile idiopathic arthritis.

This study investigates the role of CD4(+)CD25(+) regulatory T cells during the clinical course of juvenile idiopathic arthritis (JIA). Persistent oligoarticular JIA (pers-OA JIA) is a subtype of JIA with a relatively benign, self-remitting course while extended oligoarticular JIA (ext-OA JIA) is a subtype with a much less favorable prognosis. Our data show that patients with pers-OA JIA display a significantly higher frequency of CD4(+)CD25(bright) T cells with concomitant higher levels of mRNA FoxP3 in the peripheral blood than ext-OA JIA patients. Furthermore, while numbers of synovial fluid (SF) CD4(+)CD25(bright) T cells were equal in both patient groups, pers-OA JIA patients displayed a higher frequency of CD4(+)CD25(int) T cells and therefore of CD4(+)CD25(total) in the SF than ext-OA JIA patients. Analysis of FoxP3 mRNA levels revealed a high expression in SF CD4(+)CD25(bright) T cells of both patient groups and also significant expression of FoxP3 mRNA in the CD4(+)CD25(int) T cell population. The CD4(+)CD25(bright) cells of both patient groups and the CD4(+)CD25(int) cells of pers-OA JIA patients were able to suppress responses of CD25(neg) cells in vitro. A markedly higher expression of CTLA-4, glucocorticoid-induced TNFR, and HLA-DR on SF CD4(+)CD25(bright) T regulatory (Treg) cells compared with their peripheral counterparts suggests that the CD4(+)CD25(+) Treg cells may undergo maturation in the joint. In correlation with this mature phenotype, the SF CD4(+)CD25(bright) T cells showed an increased regulatory capacity in vitro compared with peripheral blood CD4(+)CD25(bright) T cells. These data suggest that CD4(+)CD25(bright) Treg cells play a role in determining the patient's fate toward either a favorable or unfavorable clinical course of disease.

OBJECTIVE: Human Hsp60 is expressed in the joints of patients with rheumatoid arthritis (RA) and can elicit a regulatory T cell response in the peripheral blood and synovial fluid. However, Hsp60 can also trigger strong proinflammatory pathways. Thus, to understand the nature of these Hsp60-directed responses in RA, it is necessary to study such responses at the molecular, epitope-specific level. This study was undertaken to characterize the disease specificity and function of pan-DR-binding Hsp60-derived epitopes as possible modulators of autoimmune inflammation in RA. METHODS: Lymphocyte proliferation assays (using (3)H-thymidine incorporation and carboxyfluorescein diacetate succinimidyl ester [CFSE] staining) and measurement of cytokine production (using multiplex immunoassay and intracellular staining) were performed after in vitro activation of peripheral blood mononuclear cells from patients with RA, compared with healthy controls. RESULTS: A disease (RA)-specific immune recognition, characterized by T cell proliferation as well as increased production of tumor necrosis factor alpha (TNFalpha), interleukin-1beta (IL-1beta), and IL-10, was found for 3 of the 8 selected peptides in patients with RA as compared with healthy controls (P < 0.05). Intracellular cytokine staining and CFSE labeling showed that CD4+ T cells were the subset primarily responsible for both the T cell proliferation and the cytokine production in RA. Interestingly, the human peptides had a remarkably different phenotype, with a 5-10-fold higher IL-10:TNFalpha ratio, compared with that of the microbial peptides. CONCLUSION: These results suggest a disease-specific immune-modulatory role of epitope-specific T cells in the inflammatory processes of RA. Therefore, these pan-DR-binding epitopes could be used as a tool to study the autoreactive T cell response in RA and might be suitable candidates for use in immunotherapy.

Juvenile idiopathic arthritis (JIA) consists of a heterogeneous group of disorders with, for the most part, an unknown immunopathogenesis. Although onset and disease course differ, the subtypes of JIA share the occurrence of chronic inflammation of the joints, with infiltrations of immune competent cells that secrete inflammatory mediators. We undertook the present study to identify a panel of cytokines that is specifically related to the inflammatory process in JIA. Using a novel technology, the multiplex immunoassay we measured 30 cytokines in plasma from 65 JIA patients, of which 34 were paired with synovial fluid. We compared these data with plasma of 20 healthy controls and 9 patients with type I diabetes, a chronic inflammatory disease. JIA patients have, irrespective of their subclassification, significant higher levels of TNFa, MIF, CCL2, CCL3, CCL11, CCL22 and CXCL9 in plasma compared with healthy controls. In paired plasma and synovial fluid samples of JIA patients significant higher levels IL6, IL15, CCL2, CCL3, CXCL8, CXCL9 and CXCL10 are present in synovial fluid. Cluster analysis within all JIA patients reveals a pre dominant pro inflammatory cytokine cluster during active disease whereas a regulatory / anti-inflammatory related cytokine cluster is observed during remission. Furthermore we tested if a discrimination profile of various cytokines could be helpful in determination of disease classification. We suggest several cytokines (IL18, MIF, CCL2, CCL3, CCL11, CXCL9 and CXCL10) may correspond to the activation status during inflammation in JIA and could be instrumental to monitor disease activity, and therapy outcome of (new) immuno-therapies.

Adenovirus can cause fatal infections in the immunocompromised host. To date, no effective anti-viral therapy is available. Adoptive therapy with adenovirus-specific T cells could be a promising treatment, but requires the identification of such T cells. Aim of this study was to identify conserved adenoviral T cell epitopes recognized in a majority of healthy individuals. By using a computer algorithm designed to predict pan-HLA-DR-binding T cell epitopes, we selected 19 peptides of adenovirus serotype 5. PBMCs from 26 healthy subjects were isolated and incubated with these peptides to test epitope-specific T cell proliferation. Six epitopes derived from E1B protein, hexon protein (two epitopes), DNA polymerase, E3A glycoprotein and fiber protein induced a proliferative T cell response in the majority of healthy controls. In vitro MHC binding assays confirmed the potential capacity of the adenovirus epitopes to bind multiple MHC alleles. The cytokine and chemokine profile induced by these epitopes was determined with a multiplex immunoassay and revealed a predominant pro-inflammatory pattern. Based on the broad recognition and the induced cytokine and chemokine profile, the detected epitopes can be regarded as potential candidates to select adenovirus-specific T cells for immune intervention in the immunocompromised host.

Objective. Macrophage activation syndrome (MAS) in systemic onset juvenile idiopathic arthritis (SoJIA) is considered to be an acquired form of familial haemophagocytic lymphohistiocytosis (fHLH). FHLH is an autosomal recessive disorder, characterized by diminished NK cell function and caused by mutations in the perforin gene (PRF1) in 20-50% of patients. Interestingly, SoJIA patients display decreased levels of perforin in NK cells and diminished NK cell function as well. Here, we analysed PRF1 and its putative promoter in SoJIA patients with or without a history of MAS. Methods. DNA of 56 SoJIA patients (41 Italian and 15 Dutch) was isolated. Of these, 15 (27%) had a confirmed history of MAS. We sequenced PRF1 and 1.5 kb of the 5'-upstream region. DNA sequence variations in the promoter region were functionally tested in transfection experiments using a human NK cell line. Results. We detected a previously undescribed sequence variation (-499 C > T) in the promoter of PRF1 in 18% of the SoJIA patients. However, transfection experiments did not show functional implications of this variation. Secondly, we found that 11 of 56 (20%) SoJIA patients were heterozygous for missense mutations in PRF1. In particular, we found a high prevalence of the Ala91Val mutation, a variant known to result in defective function of perforin. Interestingly, the prevalence of Ala91Val in SoJIA patients with a history of MAS (20%) was increased compared with SoJIA patients without MAS (9.8%). One SoJIA patient, heterozygous for Ala91Val, showed profound decreased perforin levels at the time of MAS. Conclusions. These findings suggest that PRF1 mutations play a role in the development of MAS in SoJIA patients.

OBJECTIVE: Systemic-onset juvenile idiopathic arthritis (JIA) is an autoimmune disease characterized by arthritis and systemic features. Its pathogenesis is still largely unknown. It is characterized immunologically by natural killer (NK) cell dysfunction and cytokine signatures that predominantly feature interleukin-1 (IL-1), IL-6, and IL-18. Since IL-18 can drive NK cell function, we examined how the high plasma levels of this cytokine are related to the documented NK cell failure in these patients. METHODS: The phenotype and function of NK cells from 10 healthy control subjects, 15 patients with polyarticular JIA, and 15 patients with systemic-onset JIA were characterized by staining and functional assays in vitro. IL-18 ligand binding was visualized by fluorescence microscopy. Phosphorylation of several MAP kinases and the IL-18 receptor beta (IL-18Rbeta) were visualized by Western blotting. RESULTS: IL-18 from the plasma of systemic-onset JIA patients stimulated the activation of NK cells from healthy controls and bound its cognate receptor. However, NK cells from systemic-onset JIA patients failed to up-regulate cell-mediated killing molecules, such as perforin and interferon-gamma, after IL-18 stimulation. Furthermore, treatment with IL-18 did not induce the phosphorylation of receptor-activated MAP kinases in NK cells. Alternate activation of NK cells by IL-12 induced NK cell cytotoxicity. We observed no additive effect of IL-18 in combination with IL-12 in systemic-onset JIA patients. Immunoprecipitation of IL-18Rbeta showed that NK cells from systemic-onset JIA could not phosphorylate this receptor after IL-18 stimulation. CONCLUSION: The mechanism of the impaired NK cell function in systemic-onset JIA involves a defect in IL-18Rbeta phosphorylation. This observation has major implications for the understanding and, ultimately, the treatment of systemic-onset JIA.

In health, immune responses to self are abundantly available, but under strict control of mechanisms of peripheral tolerance. Occasionally the immune system loses control and an autoimmune disease develops. At present, treatment of autoimmune disease is based on generalised suppression of all immune responses, and is often needed to be lifelong, leading to long-term toxicities and suppression of protective immune responses against pathogens. A more targeted approach would be to reset the immune system via restoration of failing regulatory mechanisms, and redirect the immune system to a state of tolerance. Over the past decade there have been enormous advances in the understanding of basic processes that control immune tolerance, pushing regulatory T cells forward as targets for novel therapeutic strategies. This review describes the development of antigen-specific immunotherapy that targets the antigen-specific induction of regulatory T cells as a means to treat autoimmune disease. The 'holy grail' for autoimmunity is not the disease-causing antigen, but the disease-curing antigen.

Cytokines, chemokines and soluble adhesion molecules interact in a complex network within the immune system. Fingerprinting of these proteins may allow the use of these proteins as biomarkers for identification of disease, disease subtyping and monitoring therapeutic interventions. We developed a multiplex immunoassay (MIA) for the detection of 30 proteins in a variety of human body fluids such as plasma and synovial fluid (SF). The measurement of these proteins is hampered by the presence of human (auto-) antibodies, which can cause non-specific binding. We have validated a novel approach for the removal of interfering immunoglobulins using pre-absorption with protein-L. Interfering (auto-) antibodies, such as rheumatoid factor (RF), were removed using three methods; polyethylene glycol (PEG) precipitation, pre-absorption with human gamma-globulin or pre-absorption with protein-L. A significant decrease of RF was observed after a 2 h incubation with protein-L. RF IgM levels were reduced by 89% whereas total IgM, IgG and IgA levels were reduced by 60%. Residual immunoglobulins were blocked with rodent serum and did not interfere with the multiplex immunoassay. Comparing the MIA with a conventional enzyme-linked immunosorbent assay (ELISA) using a panel of spiked plasma samples resulted in correlation coefficients for all mediators between R2 = 0.88 and R2 = 0.99. Intra-assay variance was less than 10% whereas inter-assay variance ranged between 6% and 16%. Pathological samples with heterophilic antibodies hamper immunoassays such as ELISA and MIA. We show that pre-absorption with protein-L is a powerful tool for removal of interfering immunoglobulins from human bodily fluids to be used in immunoassays for studying changes in protein patterns.

Pediatric Crohn's disease is a chronic auto inflammatory bowel disorder affecting children under the age of 17 years. A putative etiopathogenesis of Crohn's disease (CD) is associated with disregulation of immune response to antigens commonly present in the gut microenvironment. Heat shock proteins (HSP) have been identified as ubiquitous antigens with the ability to modulate inflammatory responses associated with several autoimmune diseases. The present study tested the contribution of immune responses to HSP in the amplification of autoimmune inflammation in chronically inflamed mucosa of pediatric CD patients. Colonic biopsies obtained from normal and CD mucosa were stimulated with pairs of Pan HLA-DR binder HSP60-derived peptides (human/bacterial homologues). The modulation of RNA and protein levels of induced proinflammatory cytokines were measured. We identified two epitopes capable of sustaining proinflammatory responses, specifically TNF and IFN(c) induction, in the inflamed intestinal mucosa in CD patients. The responses correlated positively with clinical and histological measurements of disease activity, thus suggesting a contribution of immune responses to HSP in pediatric CD site-specific mucosal inflammation.

OBJECTIVE: Up-regulation of whole blood type I interferon (IFN)-driven transcripts and chemokines has been described in a number of autoimmune diseases. An IFN gene expression "signature" is a candidate biomarker in patients with dermatomyositis (DM). This study was performed to evaluate the capacity of IFN-dependent peripheral blood gene and chemokine signatures and levels of proinflammatory cytokines to serve as biomarkers for disease activity in adult and juvenile DM. METHODS: Peripheral blood samples and clinical data were obtained from 56 patients with adult or juvenile DM. The type I IFN gene signature in the whole blood of patients with DM was defined by determining the expression levels of 3 IFN-regulated genes (IFIT1, G1P2, and IRF7) using quantitative real-time reverse transcription-polymerase chain reaction. Multiplexed immunoassays were used to quantify the serum levels of 4 type I IFN-regulated chemokines (IFN-inducible T cell alpha chemoattractant, IFNgamma-inducible 10-kd protein, monocyte chemotactic protein 1 [MCP-1], and MCP-2) and the serum levels of other proinflammatory cytokines, including interleukin-6 (IL-6). RESULTS: DM disease activity correlated significantly with the type I IFN gene signature (r = 0.41, P = 0.007) and with the type I IFN chemokine signature (r = 0.61, P < 0.0001). Furthermore, the serum levels of IL-6 were significantly correlated with disease activity (r = 0.45, P = 0.001). In addition, correlations between the serum levels of IL-6 and both the type I IFN gene signature (r = 0.47, P < 0.01) and the type I IFN chemokine signature (r = 0.71, P < 0.0001) were detected in patients with DM. CONCLUSION: These results suggest that serum IL-6 production and the type I IFN gene signature are candidate biomarkers for disease activity in adult and juvenile DM. Coregulation of the expression of IFN-driven chemokines and IL-6 suggests a novel pathogenic linkage in DM.

Juvenile idiopathic arthritis (JIA) is a heterogeneous, multi-factorial disease. The ability to distinguish various subtypes of JIA has enabled more directed and uniform clinical care. Possible triggers of the disease include genetic and environmental factors such as infections and vaccinations. Autoreactive T cells responding to unknown antigens are among the mechanisms that perpetuate the cycle of autoimmune inflammation once established. There are two groups of candidate auto-antigens that are thought to play a role in induction or modulation of T-cell responses. The first group is derived from cartilage and other joint-related tissue and the second group is derived from stress proteins. Several molecules have been implicated in the quest to restore immune homeostasis and tolerance, such as regulatory T cells, FoxP3, heat shock proteins, cytokines, chemokines and other key mediators of inflammation. Treatment strategies might focus on the induction of regulation in a more specific fashion.

OBJECTIVE:To assess MHC I and II expressions in muscle fibres of juvenile dermatomyositis (JDM) and compare with the expression in polymyositis (PM), dermatomyositis (DM) and dystrophy. PATIENTS AND METHODS: Forty-eight JDM patients and 17 controls (8 PM, 5 DM and 4 dystrophy) were studied. The mean age at disease onset was 7.1+/-3.0 years and the mean duration of weakness before biopsy was 9.4+/-12.9 months. Routinehistochemistry and immunohistochemistry (StreptABComplex/HRP) for MHC I and II (Dakopatts) were performed on serial frozen muscle sections in all patients. Mann-Whitney, Kruskal Wallis, chi-square and Fisher's exact statistical methods were used.RESULTS:MHC I expression was positive in 47 (97.9%) JDM cases. This expression was observed independent of time of disease, corticotherapy previous to muscle biopsy and to the grading of inflammation observed in clinical, laboratorial and histological parameters. The expression of MHC I was similar on JDM, PM and DM, and lower in dystrophy. On the other hand, MHC II expression was positive in just 28.2% of JDM cases and was correlated to histological features as inflammatory infiltrate, increased connective tissue and VAS for global degree of abnormality (p<0.05). MHC II expression was similar in DM/PM and lower in JDM and dystrophy, and it was based on the frequency of positive staining rather than to the degree of the MCH II expression.CONCLUSIONS:: MHC I expression in muscle fibres is a premature and late marker of JDM patient independent to corticotherapy, and MHC II expression was lower in JDM than in PM and DM.

Juvenile dermatomyositis (JDM) is a rare systemic disease of unknown etiology characterized by inflammation of the muscle, skin and digestive tract, with variable outcome. The diagnostic criteria include proximal symmetrical muscular weakness, characteristic skin rashes, elevation of skeletal muscle enzymes and specific electromyographic and muscle biopsy abnormalities. Pulmonary and gastro-intestinal involvements, calcinosis and generalized edema usually indicate severe disease. Recent data suggest an association between the genotype -308 AA of the Tumour Necrosis Factor (TNF) gene and disease chronicity. We present a case of a 14 year-old female with JDM and generalized oedema which is a rare manifestation of the disease and it is associated to a poor outcome.

OBJECTIVE: Human Hsp60 is expressed in the joints of patients with rheumatoid arthritis (RA) and can elicit a regulatory T cell response in the peripheral blood and synovial fluid. However, Hsp60 can also trigger strong proinflammatory pathways. Thus, to understand the nature of these Hsp60-directed responses in RA, it is necessary to study such responses at the molecular, epitope-specific level. This study was undertaken to characterize the disease specificity and function of pan-DR-binding Hsp60-derived epitopes as possible modulators of autoimmune inflammation in RA. METHODS: Lymphocyte proliferation assays (using (3)H-thymidine incorporation and carboxyfluorescein diacetate succinimidyl ester [CFSE] staining) and measurement of cytokine production (using multiplex immunoassay and intracellular staining) were performed after in vitro activation of peripheral blood mononuclear cells from patients with RA, compared with healthy controls. RESULTS: A disease (RA)-specific immune recognition, characterized by T cell proliferation as well as increased production of tumor necrosis factor alpha (TNFalpha), interleukin-1beta (IL-1beta), and IL-10, was found for 3 of the 8 selected peptides in patients with RA as compared with healthy controls (P < 0.05). Intracellular cytokine staining and CFSE labeling showed that CD4+ T cells were the subset primarily responsible for both the T cell proliferation and the cytokine production in RA. Interestingly, the human peptides had a remarkably different phenotype, with a 5-10-fold higher IL-10:TNFalpha ratio, compared with that of the microbial peptides. CONCLUSION: These results suggest a disease-specific immune-modulatory role of epitope-specific T cells in the inflammatory processes of RA. Therefore, these pan-DR-binding epitopes could be used as a tool to study the autoreactive T cell response in RA and might be suitable candidates for use in immunotherapy.

ABSTRACT: Juvenile idiopathic arthritis (JIA) is a disease characterized by chronic joint inflammation, caused by a deregulated immune response. In patients with JIA, heat shock proteins (HSPs) are highly expressed in the synovial lining tissues of inflamed joints. HSPs are endogenous proteins that are expressed upon cellular stress and are able to modulate immune responses. In this review, we concentrate on the role of HSPs, especially HSP60, in modulating immune responses in both experimental and human arthritis, with a focus on JIA. We will mainly discuss the tolerogenic immune responses induced by HSPs, which could have a beneficial effect in JIA. Overall, we will discuss the immune modulatory capacity of HSPs, and the underlying mechanisms of HSP60-mediated immune regulation in JIA, and how this can be translated into therapy.

OBJECTIVE: Interferon-alpha (IFNalpha) has been implicated in the pathogenesis of juvenile dermatomyositis (DM). The aim of this study was to examine serum IFNalpha activity in a cohort of children with juvenile DM to determine relationships between IFNalpha and indicators of disease activity and severity. METHODS: Thirty-nine children with definite/probable juvenile DM were included in the study. Serum samples were obtained at the time of diagnosis from 18 untreated patients with juvenile DM. Second samples from 11 of these patients were obtained at 24 months, while they were receiving treatment, and third samples were obtained from 7 of these patients at 36 months. The remaining 21 children were studied 36 months after their initial diagnosis. Serum IFNalpha activity was measured using a functional reporter cell assay. RESULTS: Patients with juvenile DM had higher serum IFNalpha activity than both pediatric and adult healthy control subjects. In untreated patients, serum IFNalpha activity was positively correlated with serum muscle enzyme levels (P < 0.05 for creatine kinase, aspartate aminotransferase, and aldolase) and inversely correlated with the duration of untreated disease (P = 0.017). The tumor necrosis factor alpha -308A allele was associated with higher serum IFNalpha levels only in untreated patients (P = 0.030). At 36 months, serum IFNalpha levels were inversely correlated with muscle enzyme levels in those patients still requiring therapy and with the skin Disease Activity Score in those patients who had completed therapy (P = 0.002). CONCLUSION: Serum IFNalpha activity was associated with higher serum levels of muscle-derived enzymes and a shorter duration of untreated disease in patients with newly diagnosed juvenile DM and was inversely correlated with measures of chronic disease activity at 36 months postdiagnosis. These data suggest that IFNalpha could play a role in disease initiation in juvenile DM.

OBJECTIVE: To assess the time needed to achieve sustained, medication-free remission in a cohort of patients with juvenile dermatomyositis (DM) receiving a stepwise, aggressive treatment protocol. METHODS: Between 1994 and 2004, a cohort of 49 children with juvenile DM who were followed up at a single tertiary care children's hospital using disease activity measures according to a specific protocol received standardized therapy with steroids and methotrexate. If a patient's strength or muscle enzyme levels did not normalize with this initial therapy, additional medications were added in rapid succession to the treatment regimen. The primary outcome measure was time to complete remission. Additional outcome measures were onset of calcinosis, effect of treatment on height, and complications resulting from medications. RESULTS: Forty-nine patients were followed up for a mean +/- SD of 48 +/- 30 months. All but 1 patient received 2 or more medications simultaneously. Transient localized calcifications occurred in 4 patients (8%), and 2 additional patients (4%) had persistent calcinosis. Despite the aggressive therapy, complications associated with treatment were mild and were primarily attributable to steroids. No persistent effect on longitudinal growth was observed. A complete, medication-free remission was achieved in 28 patients; the median time to achievement of complete remission was 38 months (95% confidence interval 32-44 months). None of these patients experienced a disease flare that required resumption of medications during the subsequent period of observation (mean +/- SD 36 +/- 19.7 months). CONCLUSION: Our findings suggest that aggressive treatment of juvenile DM aimed at achieving rapid, complete control of muscle weakness and inflammation improves outcomes and reduces disease-related complications. In more than one-half of the children whose disease was treated in this manner (28 of 49), a prolonged, medication-free remission was attained within a median of 38 months from the time of diagnosis.