Gabrielle Morgan

Elevated serum interferon-α activity in juvenile dermatomyositis: Associations with disease activity at diagnosis and after thirty-six months of 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.

Mycophenolate Mofetil: A Possible Therapeutic Agent for Children With Juvenile Dermatomyositis

To determine if mycophenolate mofetil (MMF) diminishes skin and muscle disease activity in children with juvenile dermatomyositis (DM), thereby permitting a decrease in corticosteroid dose.

Pilot study of etanercept in patients with refractory juvenile dermatomyositis

To evaluate the efficacy of etanercept in patients with juvenile dermatomyositis (DM) refractory to standard treatment.

Familial Aggregation of Autoimmune Disease in Juvenile Dermatomyositis

OBJECTIVE: Familial aggregation of autoimmune diseases likely reflects shared pathogenic factors between different diseases. Familial aggregation of autoimmunity has not been examined in juvenile dermatomyositis. Interferon-α is thought to be a pathogenic factor in both systemic lupus erythematosus and juvenile dermatomyositis, and we have previously demonstrated familial aggregation of serum interferon-α. METHODS: Family histories were obtained from 304 families of children with juvenile dermatomyositis via 3-generation structured interviews performed by the same person. Rates of autoimmune disease in families of children with juvenile dermatomyositis were compared with published population rates. Serum interferon-α, tumor necrosis factor-α, and neopterin were measured using standard techniques. RESULTS: A total of 51% of families of children with juvenile dermatomyositis reported at least 1 additional member affected by an autoimmune disease. In particular, both type 1 diabetes and systemic lupus erythematosus were significantly more common than would be expected (odds ratio >5, P ≤ 1 × 10−7 for both). Pedigree analysis showed particularly strong familial clustering of systemic lupus erythematosus with little decrease in incidence across generations, suggesting the possibility of rare causal genes with large effect. Untreated subjects with juvenile dermatomyositis with a family history of systemic lupus erythematosus had higher serum interferon-α than those who did not (P = .047). CONCLUSIONS: We find strong familial aggregation of specific autoimmune diseases in families of children with juvenile dermatomyositis, suggesting that these conditions share pathogenic factors. Higher serum interferon-α in juvenile dermatomyositis patients with a family history of systemic lupus erythematosus suggesting that interferon-α is one such shared factor.

Serum Neopterin Levels as a Diagnostic Marker of Hemophagocytic Lymphohistiocytosis Syndrome

ABSTRACT The objective of this study was to retrospectively evaluate the utility of serum neopterin as a diagnostic marker of hemophagocytic lymphohistiocytosis (HLH). The medical records of patients diagnosed with HLH (familial and secondary) between January 2000 and May 2009 were reviewed retrospectively, and clinical and laboratory information related to HLH criteria, in addition to neopterin levels, was recorded. A group of 50 patients with active juvenile dermatomyositis (JDM) (who routinely have neopterin levels assessed) served as controls for the assessment of the accuracy, sensitivity, and specificity of neopterin as a diagnostic test for HLH. The Pearson correlation was used to measure the association between serum neopterin levels and established HLH-related laboratory data. Serum neopterin levels were measured using a competitive enzyme immunoassay. During the time frame of the study, 3 patients with familial HLH and 18 patients with secondary HLH were identified as having had serum neopterin measured (all HLH patients were grouped together). The mean neopterin levels were 84.9 nmol/liter (standard deviation [SD], 83.4 nmol/liter) for patients with HLH and 21.5 nmol/liter (SD, 10.13 nmol/liter) for patients with JDM. A cutoff value of 38.9 nmol/liter was 70% sensitive and 95% specific for HLH. For HLH patients, neopterin levels correlated significantly with ferritin levels (r = 0.76, P = 0.0007). In comparison to the level in a control group of JDM patients, elevated serum neopterin was a sensitive and specific marker for HLH. Serum neopterin has value as a diagnostic marker of HLH, and prospective studies are under way to further evaluate its role as a marker for early diagnosis and management of patients.

Gene-Gene-Sex Interaction in Cytokine Gene Polymorphisms Revealed by Serum Interferon Alpha Phenotype in Juvenile Dermatomyositis

OBJECTIVE To detect genetic polymorphisms associated with high serum interferon alpha (IFN-alpha) levels in juvenile dermatomyositis (JDM) and explore interactions in associated polymorphisms. STUDY DESIGN Eighty-five children of European ancestry with definite/probable JDM were studied. Selected genetic polymorphisms that were associated with high IFN-alpha levels in 12 untreated patients with newly diagnosed JDM were genotyped in a validation cohort of 73 children with JDM and analyzed for gene-gene and gene-sex interactions. RESULTS Untreated children with newly diagnosed JDM carrying both the osteopontin (OPN) rs28357094G and tumor necrosis factor alpha (TNF-alpha)-308 A alleles had significantly increased serum IFN-alpha levels. These 2 polymorphisms were genotyped in the validation cohort, and the OPN rs28357094G allele was more common in female subjects with JDM (odds ratio=3.97, P=.012). This OPN allele was most strongly enriched in female carriers of TNF-alpha-308A as compared with male carriers of TNF-alpha-308A (odds ratio>9.0; P=7.2x10(-3)). CONCLUSION These data support a complex gene-gene-sex interaction between the OPN and TNF-alpha promoter regions in JDM, defining a high serum IFN-alpha subgroup within JDM. This suggests pathogenic synergy between the OPN and TNF-alpha loci in female subjects with JDM, which may underlie some of the increased incidence of this condition in girls.

Interferon-α induction and detection of anti-ro, anti-la, anti-sm, and anti-rnp autoantibodies by autoantigen microarray analysis in juvenile dermatomyositis.

OBJECTIVE To evaluate serum interferon-α (IFNα) activity in the context of autoantibody profiles in patients with juvenile dermatomyositis (JDM). METHODS Sera from 36 patients with JDM were analyzed. Autoantibody profiles were determined by probing microarrays, which were fabricated with ∼80 distinct autoantigens, with serum and a Cy3-conjugated secondary antibody. Arrays were scanned and analyzed to determine antigen reactivity. Serum IFNα activity was measured using a functional reporter cell assay. Sera were assayed alone or in combination with cellular material released from necrotic U937 cells to stimulate peripheral blood mononuclear cells from healthy donors in vitro, and IFNα production in culture was measured by a dissociation-enhanced lanthanide fluoroimmunoassay (DELFIA). RESULTS Reactivity against at least 1 of 41 autoantigens on the microarray, including Ro 52, Ro 60, La, Sm, and RNP, was observed in 75% of the serum samples from patients with JDM. IFNα activity was detected in 7 samples by reporter cell assay. The reporter cell assay showed a significant association of reactivity against Ro, La, Sm, and proliferating cell nuclear antigen with serum IFNα activity (P = 0.005). Significance Analysis of Microarrays (SAM) identified increased reactivity against Sm, RNP, Ro 52, U1-C, and Mi-2 in these sera. Sixteen samples induced IFNα production as measured by DELFIA, and there was a significant association of reactivity against Ro, La, Sm, and RNP with the induction of IFNα by serum and necrotic cell material (P = 0.034). SAM identified increased reactivity against Ro 60 in these sera. CONCLUSION These data support the hypothesis that nucleic acid-associated autoantibodies, including the Ro/La and Sm/RNP complexes, may stimulate the production of active IFNα in children with JDM.

Increased expression of vascular cell adhesion molecule 1 in muscle biopsy samples from juvenile dermatomyositis patients with short duration of untreated disease is regulated by miR-126.

OBJECTIVE To evaluate the effect of duration of untreated disease on vascular cell adhesion molecule 1 (VCAM-1) and microRNA (miRNA) expression in muscle biopsy samples from children with juvenile dermatomyositis (DM) as well as its effect on soluble VCAM-1 (sVCAM-1) and tumor necrosis factor α (TNFα) concentrations in sera from these children. METHODS We enrolled 28 untreated children with juvenile DM and 8 pediatric controls. Eleven children with juvenile DM had short duration of untreated disease (symptoms for ≤2 months before muscle biopsy), and 17 had long duration of untreated disease (symptoms for >2 months before muscle biopsy). Vascular structures, characterized by immunofluorescence using antibodies against von Willebrand factor, VCAM-1, and α-smooth muscle actin, were measured for total area and intensity. Circulating sVCAM-1 and TNFα levels were determined in patients with short duration of untreated disease, patients with long duration of untreated disease, and controls. Differential expression of microRNA-126 (miR-126) in muscle biopsy samples from the 2 patient groups and the control group was detected by miRNA expression profiling and confirmed by quantitative reverse transcription-polymerase chain reaction in muscle biopsy samples from the 3 groups. RESULTS Juvenile DM patients with short duration of untreated disease had significantly higher total positive area and intensity/high power field of VCAM-1 expression than did juvenile DM patients with long duration of untreated disease (P = 0.043 and P = 0.015, respectively) or controls (P = 0.004 and P = 0.001, respectively). Von Willebrand factor antigen-positive vasculature displayed greater VCAM-1 intensity in patients with short duration of untreated disease than in patients with long duration of untreated disease (P = 0.001). Circulating levels of sVCAM-1 and TNFα were significantly higher in patients with short duration of untreated disease than in controls (P = 0.013 and P = 0.048, respectively). The miRNA miR-126, a negative regulator of VCAM-1 expression, was significantly decreased (3.39-fold; P < 0.006) in patients with short duration of untreated disease compared to controls, while miR-126 expression in patients with long duration of untreated disease did not differ significantly compared to controls. CONCLUSION In patients with short duration of untreated disease, miR-126 down-regulation is associated with increased VCAM-1 in both muscle and blood, suggesting that VCAM-1 plays a critical role early in juvenile DM disease pathophysiology, augmented by TNFα.

Association of normal nailfold end row loop numbers with a shorter duration of untreated disease in children with juvenile dermatomyositis.

OBJECTIVE To determine the association of normal numbers of end row loops (ERLs) in nailfold capillaries at the time of diagnosis of juvenile dermatomyositis (DM) with clinical findings in untreated children with the disease and to identify predictors of the development of decreased numbers of ERLs. METHODS Clinical and laboratory data from 80 untreated children with juvenile DM were collected. ERL numbers were recorded at the time of diagnosis and at 24 months and 36 months thereafter. The 12 children who had normal ERLs at diagnosis were compared with the remaining 68 children. Outcomes included the duration of untreated disease, the duration of treatment with immunosuppressive medications, family medical history, Disease Activity Score (DAS) for juvenile DM, creatinine phosphokinase level, aldolase level, absolute number of CD3-CD56+/16+ natural killer cells, and von Willebrand factor antigen level. Cross-sectional and longitudinal analyses were performed. RESULTS At diagnosis, children with normal ERLs had a shorter duration of untreated disease (P = 0.03) and a lower skin DAS (P = 0.045). Over time, an increased likelihood of having decreased numbers of ERLs was associated with a longer duration of untreated disease and with a higher skin DAS. CONCLUSION The presence of a normal number of ERLs in juvenile DM appears to be associated with a shorter duration of symptoms and may be a useful indicator of disease chronicity in the newly diagnosed child. Normal ERLs is also associated with a lower skin DAS. The lack of association between normal ERLs and other variables indicates that normal findings on nailfold capillaroscopy should not be used as justification to delay immunosuppressive therapy in children with typical symptoms of juvenile DM.

Double trouble: therapeutic challenges in patients with both juvenile dermatomyositis and psoriasis.

BACKGROUND Juvenile dermatomyositis (JDM) and psoriasis are inflammatory disorders that share interferon-α induced responses and dysregulation of cytokines, including tumor necrosis factor alpha. Although 13% of patients with JDM have a family history of psoriasis there is little information concerning children with JDM and psoriasis. OBSERVATIONS We identified 3 children with both JDM and psoriasis. In 2 cases, psoriatic lesions occurred after the childs JDM symptoms had diminished following effective immunosuppressive therapy (high-dose intermittent intravenous methylprednisolone, methotrexate, and low dose oral corticosteroids). Patient 2, initially diagnosed as having psoriasis, was treated with prednisone and methotrexate but then developed classic JDM, which worsened following use of tumor necrosis factor alpha inhibitor and reduction of prednisone and methotrexate dosage. For each child, their history of JDM complicated the choice of therapy for psoriasis. CONCLUSIONS Two therapies commonly used to treat psoriasis-phototherapy and tumor necrosis factor-alpha antagonists-must be used with caution in patients with both JDM and psoriasis owing to their potential to exacerbate clinical manifestations of JDM. We discuss the implications affecting treatment of children with these dual diagnoses and consider the pathophysiology linking these 2 conditions.