Use of disease assessment tools to increase the value of case reports on Susac syndrome: two case reports

BACKGROUND

Susac syndrome is an immune-mediated, ischemia-producing, occlusive microvascular endotheliopathy that threatens the brain, retina, and inner ear. There is a need for disease assessment tools that can help clinicians and patients to more easily, accurately, and uniformly track the clinical course and outcome of Susac syndrome. Ideally, such tools should simultaneously facilitate the clinical care and study of Susac syndrome and improve the value of future case reports. To meet this need, two novel clinical assessment tools were developed: the Susac Symptoms Form and the Susac Disease Damage Score. The former is a comprehensive self-report form that is completed by patients/families to serially document the clinical status of a patient. The latter documents the extent of damage perceived by individual patients/families and their physicians. Both forms were initially trialed with two particularly representative and instructive patients. The results of this trial are shared in this report.

CASE PRESENTATION

Patient 1 is a 21-year-old Caucasian female who presented with an acute onset of headache, paresthesias, cognitive dysfunction, and emotional lability. Patient 2 is a 14-year-old Caucasian female who presented with an acute onset of headache, cognitive dysfunction, urinary incontinence, ataxia, and personality change. Both patients fulfilled criteria for a definite diagnosis of Susac syndrome: both eventually developed brain, retinal, and inner ear involvement, and both had typical "snowball lesions" on magnetic resonance imaging. The Susac Symptoms Form documented initial improvement in both patients, was sufficiently sensitive in detecting a subsequent relapse in the second patient, and succinctly documented the long-term clinical course in both patients. The Disease Damage Score documented minimal disease damage in the first patient and more significant damage in the second.

CONCLUSIONS

The Susac Symptoms Form and the Disease Damage Score are useful disease assessment tools, both for clinical care and research purposes. Their use could enhance the value of future case reports on Susac syndrome and could improve opportunities to learn from a series of such reports.

Neuropathological Findings in Susac Syndrome: An Autopsy Report

A 24-year-old woman developed encephalopathy, branch retinal artery occlusion, hearing loss, and had "snowball" lesions in the corpus callosum, classic findings of Susac syndrome (SuS). Despite intensive immunosuppressive therapy, she lapsed into a coma, and died 7 months after the onset of her illness. Neuropathological examination, revealed perivascular inflammation and vasculitis involving small vessels, associated with vascular narrowing and occlusion, and numerous microinfarcts diffusely throughout the brain. The findings establish SuS as a neuroinflammatory condition that can include vasculitis. This represents the most comprehensive report of the neuropathological findings in SuS.

Brain microvascular pathology in Susac syndrome: an electron microscopic study of five cases

Susac syndrome is a rare, immune-mediated disease characterized by encephalopathy, branch retinal artery occlusion, and hearing loss. Herein, we describe the electron microscopic findings of three brain biopsies and two brain autopsies performed on five patients whose working clinical diagnosis was Susac syndrome. In all five cases, the key findings were basement membrane thickening and collagen deposition in the perivascular space involving small vessels and leading to thickening of vessel walls, narrowing, and vascular occlusion. These findings indicate that Susac syndrome is a microvascular disease. Mononuclear cells were present in the perivascular space, underlining the inflammatory nature of the pathology. Though nonspecific, the changes can be distinguished from genetic and acquired small vessel diseases. The encephalopathy of Susac syndrome overlaps clinically with degenerative and infectious conditions, and brain biopsy may be used for its diagnosis. Its vascular etiology may not be obvious on light microscopy, and electron microscopy is important for its confirmation.

Guidelines for treatment of Susac syndrome - An update

Susac syndrome is an immune-mediated, pauci-inflammatory, ischemia-producing, occlusive microvascular endotheliopathy/basement membranopathy that affects the brain, retina, and inner ear. Treatment of Susac syndrome is particularly challenging. The organs involved can easily become irreversibly damaged, and the window of opportunity to protect them is often short. Optimal outcome requires rapid and complete disease suppression. Adding to the challenge is the absence of objective biomarkers of disease activity and the great variability in presentation, timing and extent of peak severity, duration of peak severity, and natural disease course. There have been no randomized controlled trials or prospective treatment studies. We offer treatment guidelines based on cumulative clinical experience and a large cohort of patients followed longitudinally in a comprehensive database project. These guidelines state our preferences but do allow flexibility and discuss other options. The guidelines also serve as an initial step in the planning of prospective treatment studies, future consensus-based recommendations, and future randomized controlled trials.

Pulmonary hypertension and other potentially fatal pulmonary complications in systemic juvenile idiopathic arthritis

OBJECTIVE

Systemic juvenile idiopathic arthritis (JIA) is characterized by fevers, rash, and arthritis, for which interleukin-1 (IL-1) and IL-6 inhibitors appear to be effective treatments. Pulmonary arterial hypertension (PAH), interstitial lung disease (ILD), and alveolar proteinosis (AP) have recently been reported with increased frequency in systemic JIA patients. Our aim was to characterize and compare systemic JIA patients with these complications to a larger cohort of systemic JIA patients.

METHODS

Systemic JIA patients who developed PAH, ILD, and/or AP were identified through an electronic Listserv and their demographic, systemic JIA, and pulmonary disease characteristics as well as their medication exposure information were collected. Patients with these features were compared to a cohort of systemic JIA patients enrolled in the Childhood Arthritis and Rheumatology Research Alliance (CARRA) registry.

RESULTS

The patients (n = 25) were significantly (P < 0.05) more likely than the CARRA registry cohort (n = 389) to be female; have more systemic features; and have been exposed to an IL-1 inhibitor, tocilizumab, corticosteroids, intravenous immunoglobulin, cyclosporine, and cyclophosphamide. Twenty patients (80%) were diagnosed with pulmonary disease after 2004. Twenty patients (80%) had macrophage activation syndrome (MAS) during their disease course and 15 patients (60%) had MAS at pulmonary diagnosis. Sixteen patients had PAH, 5 had AP, and 7 had ILD. Seventeen patients (68%) were taking or recently discontinued (<1 month) a biologic agent at pulmonary symptom onset; 12 patients (48%) were taking anti-IL-1 therapy (primarily anakinra). Seventeen patients (68%) died at a mean of 10.2 months from the diagnosis of pulmonary complications.

CONCLUSION

PAH, AP, and ILD are underrecognized complications of systemic JIA that are frequently fatal. These complications may be the result of severe uncontrolled systemic disease activity and may be influenced by medication exposure.

Ultrasound-guided corticosteroid injection therapy for juvenile idiopathic arthritis: 12-year care experience

BACKGROUND

Intra-articular corticosteroid injections are a safe and effective treatment for patients with juvenile idiopathic arthritis. The potential scope of care in ultrasound-guided corticosteroid therapy in children and a joint-based corticosteroid dose protocol designed to optimize interdisciplinary care are not found in the current literature.

OBJECTIVE

The purpose of this study was to report the spectrum of care, technique and safety of ultrasound-guided corticosteroid injection therapy in patients with juvenile idiopathic arthritis and to propose an age-weight-joint-based corticosteroid dose protocol.

MATERIALS AND METHODS

A retrospective analysis was performed of 198 patients (ages 21 months to 28 years) referred for treatment of juvenile idiopathic arthritis with corticosteroid therapy. Symptomatic joints and tendon sheaths were treated as prescribed by the referring rheumatologist. An age-weight-joint-based dose protocol was developed and utilized for corticosteroid dose prescription.

RESULTS

A total of 1,444 corticosteroid injections (1,340 joints, 104 tendon sheaths) were performed under US guidance. Injection sites included small, medium and large appendicular skeletal joints (upper extremity 497, lower extremity 837) and six temporomandibular joints. For patients with recurrent symptoms, 414 repeat injections were performed, with an average time interval of 17.7 months (range, 0.5-101.5 months) between injections. Complications occurred in 2.6% of injections and included subcutaneous tissue atrophy, skin hypopigmentation, erythema and pruritis.

CONCLUSION

US-guided corticosteroid injection therapy provides dynamic, precise and safe treatment of a broad spectrum of joints and tendon sheaths throughout the entire pediatric musculoskeletal system. An age-weight-joint-based corticosteroid dose protocol is effective and integral to interdisciplinary care of patients with juvenile idiopathic arthritis.

Protocols for the initial treatment of moderately severe juvenile dermatomyositis: results of a Children's Arthritis and Rheumatology Research Alliance Consensus Conference

OBJECTIVE

To use juvenile dermatomyositis (DM) survey data and expert opinion to develop a small number of consensus treatment protocols, which reflect current initial treatment of moderately severe juvenile DM.

METHODS

A consensus meeting was held in Toronto, Ontario, Canada on December 1-2, 2007. Nominal group technique was used to achieve consensus on treatment protocols, which represented typical management of moderately severe juvenile DM. Consensus was also reached as to which patients these protocols would be applicable (inclusion and exclusion criteria), which initial investigations should be done prior to initiating one of these protocols, which data should be collected to evaluate these protocols, and the concomitant interventions required or recommended.

RESULTS

Three protocols that described the first 2 months of treatment were developed. All protocols included corticosteroids and methotrexate. One protocol also included intravenous gamma globulin. Consensus was achieved for all issues that were addressed by conference participants, although there were some areas of controversy.

CONCLUSION

Despite considerable variation in clinical practice, it is possible to achieve consensus on the initial treatment of juvenile DM. Once these protocols are extended beyond 2 months, these protocols will be available for clinical use. By using methods that account for differences between patients (confounding by indication), the comparative effectiveness of the protocols will be evaluated. In the future, the goal will be to identify the optimal treatment of moderately severe juvenile DM.

Damage extent and predictors in adult and juvenile dermatomyositis and polymyositis as determined with the myositis damage index

OBJECTIVE

We undertook this study to validate the Myositis Damage Index (MDI) in juvenile and adult myositis, to describe the degree and types of damage and to develop predictors of damage.

METHODS

Retrospective MDI evaluations and prospective assessment of disease activity and illness features were conducted. Patients with juvenile-onset disease (n = 143) were evaluated a median of 18 months after diagnosis; 135 patients were assessed 7-9 months later, and 121 were last assessed a median of 82 months after diagnosis. Ninety-six patients with adult-onset dermatomyositis or polymyositis had a baseline assessment a median of 30 months after diagnosis; 77 patients had a 6-month followup evaluation, and 55 had a final assessment a median of 60 months after diagnosis.

RESULTS

Damage was present in 79% of juvenile patients and in 97% of adult patients. In juveniles, scarring, contractures, persistent weakness, muscle dysfunction, and calcinosis were most frequent (23-30%) at the last evaluation. In adults, muscle atrophy, muscle dysfunction, and muscle weakness were most frequent (74-84%). MDI severity correlated with physician-assessed global damage, serum creatinine, and muscle atrophy on magnetic resonance imaging, and in juveniles also with functional disability and weakness. MDI damage scores and frequency were highest in patients with a chronic illness course and in adult patients who died. Predictors of damage included functional disability, duration of active disease, disease severity at diagnosis, physician-assessed global disease activity, and illness features, including ulcerations in children and pericarditis in adults.

CONCLUSION

Damage is common in myositis after a median duration of 5 years in patients with adult-onset disease and 6.8 years in patients with juvenile-onset disease. The MDI has good content, construct, and predictive validity in juvenile and adult myositis.

The Cutaneous Assessment Tool: development and reliability in juvenile idiopathic inflammatory myopathy

OBJECTIVES

Clinical care and therapeutic trials in idiopathic inflammatory myopathies (IIM) require accurate and consistent assessment of cutaneous involvement. The Cutaneous Assessment Tool (CAT) was designed to measure skin activity and damage in IIM. We describe the development and inter-rater reliability of the CAT, and the frequency of lesions endorsed in a large population of juvenile IIM patients.

METHODS

The CAT includes 10 activity, 4 damage and 7 combined lesions. Thirty-two photographic slides depicting IIM skin lesions were assessed by 11 raters. One hundred and twenty-three children were assessed by 11 paediatric rheumatologists at 10 centres. Inter-rater reliability was assessed using simple agreements and intra-class correlation coefficients (ICC).

RESULTS

Simple agreements in recognizing lesions as present or absent were generally high (0.5-1.0). ICCs for CAT lesions were moderate (0.4-0.75) in both slides and real patients. ICCs for the CAT activity and damage scores were 0.71 and 0.81, respectively. CAT activity scores ranged from 0 to 44 (median 7, potential range 0-96) and CAT damage scores ranged from 0 to 13 (median 1, potential range 0-22). The most common cutaneous lesions endorsed were periungual capillary loop changes (63%), Gottron's papules/sign (53%), heliotrope rash (49%) and malar/facial erythema (49%).

CONCLUSIONS

Total CAT activity and damage scores have moderate to good reliability. Assessors generally agree on the presence of a variety of cutaneous lesions. The CAT is a promising, semi-quantitative tool to comprehensively assess skin disease activity and damage in IIM.

Preliminary validation and clinical meaning of the Cutaneous Assessment Tool in juvenile dermatomyositis

OBJECTIVE

To provide preliminary validation of the Cutaneous Assessment Tool (CAT), a new tool to assess cutaneous manifestations of juvenile dermatomyositis (DM), and to explore the clinical meaning of CAT scores.

METHODS

Children with juvenile DM (n = 113) were assessed at baseline and 7-9 months later (n = 94). Internal consistency, redundancy, construct validity, and responsiveness of the CAT were examined. CAT scores corresponding to ordinal global assessments were determined.

RESULTS

Item-total correlations ranged from 0.27-0.67 for activity lesions present in > or =10% of patients; item-domain and domain-total correlations ranged from 0.25-0.99. Cronbach's alpha was 0.79 for the CAT activity score and 0.74 for the CAT damage score. As predicted, the CAT activity score correlated strongly with both global disease activity and skin disease activity and moderately with the Childhood Myositis Assessment Scale, whereas the CAT damage score correlated moderately with the physician global disease and skin disease damage scores. Median CAT activity scores of 1, 7, 13, 18, and 31 corresponded to absent, mild, moderate, severe, and extremely severe skin disease activity, respectively. Median CAT damage scores of 0, 1, 2, and 5 correlated with the same descriptions of damage (severe and extremely severe combined).

CONCLUSION

Preliminary validation of the CAT demonstrated good internal consistency, nonredundancy, good construct validity, and appropriate responsiveness. The CAT is a comprehensive, semiquantitative assessment tool for skin disease in juvenile DM.

Aggressive immunosuppressive treatment of Susac's syndrome in an adolescent: using treatment of dermatomyositis as a model

We describe aggressive immunosuppressive treatment of an adolescent with Susac's syndrome (SS), a disease of the microvasculature in the brain, retina, and inner ear. Because the immunopathogenesis of SS appears to have much in common with that of juvenile dermatomyositis (JDM), the patient was treated with an approach that has been effective for severe JDM. The patient's outcome provides evidence for the importance of prompt, aggressive, and sustained immunosuppressive treatment of encephalopathic SS.

Susac's syndrome: 1975–2005 microangiopathy/autoimmune endotheliopathy

Susac's syndrome (SS) consists of the clinical triad of encephalopathy, branch retinal artery occlusions (BRAO) and hearing loss. It is due to a microangiopathy affecting the precapillary arterioles of the brain, retina, and inner ear (cochlea and semicircular canals). Women are more commonly affected than men (3:1); the age of onset ranges from 9 to 58 years; but young women between the ages of 20 and 40 are most vulnerable. The encephalopathy is almost always accompanied by headache which may be the presenting feature. Multifocal neurological signs and symptoms, psychiatric disturbances, cognitive changes, memory loss, and confusion may rapidly progress to dementia. The MRI shows a distinctive white matter disturbance that always affects the corpus callosum. The central callosal fibers are particularly vulnerable and central callosal holes develop as the active lesions resolve. Linear defects (spokes) and rather large round lesions (snowballs) sometime dominate the MRI findings, which include cortical, deep gray (70%) and leptomeningeal involvement (33%). Frequently, the lesions enhance and may be evident on diffusion weighted imaging (DWI). The BRAO are best evaluated with fluorescein angiography, which may show the pathognomonic multifocal fluorescence. Gass plaques are frequently present and reflect endothelial damage. Brain biopsy shows microinfarction to be the basic pathology, but more recent pathological studies have shown endothelial changes that are typical for an antiendothelial cell injury syndrome. Elevated levels of Factor VIII and von Willebrand Factor Antigen reflect the endothelial perturbation. Despite extensive evaluations, a procoagulant state has never been demonstrated. SS is an autoimmune endotheliopathy that requires treatment with immunosuppressants: steroids, cyclophosphamide, and intravenous immunoglobulin, usually in combination. Aspirin is a useful adjunct.

Gene copy-number variation and associated polymorphisms of complement component C4 in human systemic lupus erythematosus (SLE): low copy number is a risk factor for and high copy number is a protective factor against SLE susceptibility in European Americans

Interindividual gene copy-number variation (CNV) of complement component C4 and its associated polymorphisms in gene size (long and short) and protein isotypes (C4A and C4B) probably lead to different susceptibilities to autoimmune disease. We investigated the C4 gene CNV in 1,241 European Americans, including patients with systemic lupus erythematosus (SLE), their first-degree relatives, and unrelated healthy subjects, by definitive genotyping and phenotyping techniques. The gene copy number (GCN) varied from 2 to 6 for total C4, from 0 to 5 for C4A, and from 0 to 4 for C4B. Four copies of total C4, two copies of C4A, and two copies of C4B were the most common GCN counts, but each constituted only between one-half and three-quarters of the study populations. Long C4 genes were strongly correlated with C4A (R=0.695; P<.0001). Short C4 genes were correlated with C4B (R=0.437; P<.0001). In comparison with healthy subjects, patients with SLE clearly had the GCN of total C4 and C4A shifting to the lower side. The risk of SLE disease susceptibility significantly increased among subjects with only two copies of total C4 (patients 9.3%; unrelated controls 1.5%; odds ratio [OR] = 6.514; P=.00002) but decreased in those with > or =5 copies of C4 (patients 5.79%; controls 12%; OR=0.466; P=.016). Both zero copies (OR=5.267; P=.001) and one copy (OR=1.613; P=.022) of C4A were risk factors for SLE, whereas > or =3 copies of C4A appeared to be protective (OR=0.574; P=.012). Family-based association tests suggested that a specific haplotype with a single short C4B in tight linkage disequilibrium with the -308A allele of TNFA was more likely to be transmitted to patients with SLE. This work demonstrates how gene CNV and its related polymorphisms are associated with the susceptibility to a human complex disease.

Treatment of Susac's syndrome

Susac's syndrome (SS) is an immune-mediated endotheliopathy that affects the microvasculature of the brain, retina, and inner ear. SS responds well to immunosuppressive therapies when treatment is prompt, aggressive, and sustained. Striking similarities exist between SS and dermatomyositis (DM), regarding immunopathogenesis, natural history, and treatment needs. We apply lessons learned from study of DM to SS, and offer our current treatment protocol for SS. Since these treatment guidelines are based mainly on anecdotal evidence, they represent only preliminary recommendations.

Three distinct profiles of serum complement C4 proteins in pediatric systemic lupus erythematosus (SLE) patients: tight associations of complement C4 and C3 protein levels in SLE but not in healthy subjects

The serial changes of serum complement proteins C4 and C3 in SLE were characterized in 33 pediatric SLE patients with defined C4 genotypes. Three distinct groups of C4 protein profiles were observed. The first group was characterized by persistently low C4 levels (<10 mg/dL) throughout the course of the study. Patients with this profile had mild disease manifestations and low to medium copy numbers of C4 genes. The second group featured periodic fluctuations of serum C4 protein concentrations above and below 10 mg/dL, paralleled with ups and downs of SLE disease activities. Most patients with the second profile had unequal copy numbers of C4A and C4B genes and relatively severe disease. The third group had normal serum C4 levels (>15 mg/dL) most of the time and occasionally low C4 and C3 levels that were mostly coincident with disease flares prior to effective medical treatment. Most patients in this group

Pulmonary hyalinizing granuloma and retroperitoneal fibrosis in an adolescent

We describe a 15-year-old boy who developed pulmonary hyalinizing granuloma (PHG) and retroperitoneal fibrosis (RPF). His PHG and RPF were not associated with histoplasmosis or tuberculosis and appeared to represent idiopathic autoimmune phenomena. This is the first reported case of PHG in a pediatric patient and the fourth reported co-occurrence of PHG and RPF. The use of F-18 fluorodeoxyglucose positron emission tomography in the diagnostic and follow-up evaluation of PHG is reported.

Pediatric-Onset Mixed Connective Tissue Disease

This article discusses the literature on pediatric-onset mixed connective tissue disease (MCTD) and adds 34 new cases. Although not benign, pediatric-onset MCTD carries less mortality than adult-onset disease.

Muscle metabolites, detected in urine by proton spectroscopy, correlate with disease damage in juvenile idiopathic inflammatory myopathies

OBJECTIVE

To assess for novel markers of muscle damage using urinary muscle metabolites by 1H magnetic resonance spectroscopy in patients with juvenile idiopathic inflammatory myopathy (IIM).

METHODS

Creatine (Cr), choline (Cho), betaine (Bet), glycine (Gly), trimethylamine oxide (TMAO), and several other metabolites were measured in first morning void urine samples from 45 patients with juvenile IIM and from 35 healthy age-matched controls, and correlated with measures of myositis disease activity and damage. Urinary metabolite to age-adjusted creatinine (Cn) ratios were examined.

RESULTS

Age-adjusted initial Cr:Cn, Cho:Cn, Bet:Cn, Gly:Cn, and TMAO:Cn ratios were higher in patients with juvenile IIM than controls (P < 0.01). Cr:Cn ratios showed significant correlations with physician-assessed global disease damage (Spearman rs = 0.37; P = 0.01), Steinbrocker functional class (rs = 0.35; P = 0.02), serum Cr (rs = 0.72; P = 0.001), and lactate dehydrogenase (rs = 0.34; P = 0.03) levels. Cho:Cn (rs = 0.3; P = 0.05), Gly:Cn (rs = 0.33; P = 0.03), and TMAO:Cn (rs = 0.36; P = 0.02) ratios showed a significant correlation with serum aldolase levels. Cho:Cn ratios also showed a significant correlation with aspartate aminotransferase levels (rs = 0.35; P = 0.02). A linear regression model was used to evaluate the factors influencing urinary Cr:Cn ratios in the 43 patients with data sets available at the initial visit. The regression model explained 73% of the variation in Cr:Cn ratios. The most significant factor was the physician-assessed global disease damage (R2 = 0.50, P = 0.015).

CONCLUSION

Urinary Cr:Cn, Cho:Cn, Bet:Cn, Gly:Cn, and TMAO:Cn ratios are elevated in juvenile IIM and Cr:Cn correlates strongly with global disease damage. The Cr:Cn ratio may have potential utility as a marker of myositis disease damage.

Normal scores for nine maneuvers of the Childhood Myositis Assessment Scale

OBJECTIVE

To document and evaluate the scores that normal, healthy children achieve when performing 9 maneuvers of the Childhood Myositis Assessment Scale (CMAS).

METHODS

A total of 303 healthy children, 4-9 years of age, were scored as they performed 9 CMAS maneuvers. The data were then evaluated to determine whether normal scores for some maneuvers are age and sex dependent.

RESULTS

All children were able to achieve maximum possible scores for the supine to prone, supine to sit, floor sit, floor rise, and chair rise maneuvers. All but 2 4-year-olds achieved a maximum possible score for the arm raise/duration maneuver. Performance of the head lift and sit-up maneuvers varied significantly, depending primarily on age. Children in all age groups had less difficulty performing the leg lift than the head lift or sit-up.

CONCLUSION

The normative data generated by this study are of value for interpreting the serial CMAS scores of children with idiopathic inflammatory myopathies.

Validation and clinical significance of the Childhood Myositis Assessment Scale for assessment of muscle function in the juvenile idiopathic inflammatory myopathies

OBJECTIVE

To examine the measurement characteristics of the Childhood Myositis Assessment Scale (CMAS) in children with juvenile idiopathic inflammatory myopathy (juvenile IIM), and to obtain preliminary data on the clinical significance of CMAS scores.

METHODS

One hundred eight children with juvenile IIM were evaluated on 2 occasions, 7-9 months apart, using various measures of physical function, strength, and disease activity. Interrater reliability, construct validity, and responsiveness of the CMAS were examined. The minimum clinically important difference (MID) and CMAS scores corresponding to various degrees of physical disability were estimated.

RESULTS

The intraclass correlation coefficient for 26 patients assessed by 2 examiners was 0.89, indicating very good interrater reliability. The CMAS score correlated highly with the Childhood Health Assessment Questionnaire (C-HAQ) score and with findings on manual muscle testing (MMT) (r(s) = -0.73 and 0.73, respectively) and moderately with physician-assessed global disease activity and skin activity, parent-assessed global disease severity, and muscle magnetic resonance imaging (r(s) = -0.44 to -0.61), thereby demonstrating good construct validity. The standardized response mean was 0.81 (95% confidence interval 0.53, 1.09) in patients with at least 0.8 cm improvement on a 10-cm visual analog scale for physician-assessed global disease activity, indicating strong responsiveness. In bivariate regression models predicting physician-assessed global disease activity, MMT remained significant in models containing the CMAS (P = 0.03) while the C-HAQ did not (P = 0.4). Estimates of the MID ranged from 1.5 to 3.0 points on a 0-52-point scale. CMAS scores corresponding to no, mild, mild-to-moderate, and moderate physical disability, respectively, were 48, 45, 39, and 30.

CONCLUSION

The CMAS exhibits good reliability, construct validity, and responsiveness, and is therefore a valid instrument for the assessment of physical function, muscle strength, and endurance in children with juvenile IIM. Preliminary data on MID and corresponding levels of disability should aid in the clinical interpretation of CMAS scores when assessing patients with juvenile IIM.

Determining the one, two, three, or four long and short loci of human complement C4 in a major histocompatibility complex haplotype encoding C4A or C4B proteins

The complex genetics of human complement C4 with unusually frequent variations in the size and number of C4A and C4B, as well as their neighboring genes, in the major histocompatibility complex has been a hurdle for accurate epidemiological studies of diseases associated with C4. A comprehensive series of novel or improved techniques has been developed to determine the total gene number of C4 and the relative dosages of C4A and C4B in a diploid genome. These techniques include (1) definitive genomic restriction-fragment-length polymorphisms (RFLPs) based on the discrete duplication patterns of the RCCX (RP-C4-CYP21-TNX) modules and on the specific nucleotide changes for C4A and C4B isotypes; (2) module-specific PCR to give information on the total number of C4 genes by comparing the relative quantities of RP1- or TNXB-specific fragments with TNXA-RP2 fragments; (3) labeled-primer single-cycle DNA polymerization procedure of amplified C4d genomic DNA for diagnostic RFLP analysis of C4A and C4B; and (4) a highly reproducible long-range-mapping method that employs PmeI-digested genomic DNA for pulsed-field gel electrophoresis, to yield precise information on the number of long and short C4 genes in a haplotype. Applications of these vigorously tested techniques may clarify the roles that human C4A and C4B gene-dosage variations play in infectious and autoimmune diseases.

Genetic sophistication of human complement components C4A and C4B and RP-C4-CYP21-TNX (RCCX) modules in the major histocompatibility complex

Human populations are endowed with a sophisticated genetic diversity of complement C4 and its flanking genes RP, CYP21, and TNX in the RCCX modules of the major histocompatibility complex class III region. We applied definitive techniques to elucidate (a) the complement C4 polymorphisms in gene sizes, gene numbers, and protein isotypes and (b) their gene orders. Several intriguing features are unraveled, including (1) a trimodular RCCX haplotype with three long C4 genes expressing C4A protein only, (2) two trimodular haplotypes with two long (L) and one short (S) C4 genes organized in LSL configurations, (3) a quadrimodular haplotype with four C4 genes organized in a SLSL configuration, and (4) another quadrimodular structure, with four long C4 genes (LLLL), that has the human leukocyte antigen haplotype that is identical to ancestral haplotype 7.2 in the Japanese population. Long-range PCR and PshAI-RFLP analyses conclusively revealed that the short genes from the LSL and SLSL haplotypes are C4A. In four informative families, an astonishingly complex pattern of genetic diversity for RCCX haplotypes with one, two, three and four C4 genes is demonstrated; each C4 gene may be long or short, encoding a C4A or C4B protein. Such diversity may be related to different intrinsic strengths among humans to defend against infections and susceptibilities to autoimmune diseases.

Neopterin and quinolinic acid are surrogate measures of disease activity in the juvenile idiopathic inflammatory myopathies

OBJECTIVE

We evaluated the utility of neopterin and quinolinic acid (QUIN) as surrogate measures of disease activity in juvenile idiopathic inflammatory myopathies (IIMs).

METHODS

Plasma and first morning void urine samples were measured for neopterin and QUIN using commercial ELISA, HPLC, or gas chromatography-mass spectrometry in 45 juvenile IIM patients and 79 healthy controls. Myositis disease activity assessments were obtained.

RESULTS

Plasma and urine neopterin and QUIN concentrations were increased in juvenile IIM patients compared with healthy controls (P <0.017). Urine neopterin and QUIN highly correlated with each other (r(s) = 0.73; P <0.0001). Urine neopterin and QUIN correlated moderately with myositis disease activity assessments, including physician and parent global activity assessments, muscle strength testing, functional assessments (Childhood Myositis Assessment Scale, Childhood Health Assessment Questionnaire), skin global activity, and edema on magnetic resonance imaging (r(s) = 0.42-0.62; P <0.05), but generally not with muscle-associated enzymes in serum. Urine neopterin or QUIN, in combination with either serum lactate dehydrogenase (LD) or aspartate aminotransferase (AST), significantly predicted global disease activity (R(2) =0.40-0.56; P <0.002), and both were more sensitive to change than these serum enzymes (standardized response means, -0.41 to -0.48).

CONCLUSIONS

Urinary neopterin and QUIN are candidate measures of disease activity in juvenile IIM patients and add significantly to the prediction of global disease activity in combination with serum LD or AST values. Measurement of these markers in first morning void urine specimens appears to be as good as, or possibly better than, measurements of their concentrations in plasma.

Validation of the Childhood Health Assessment Questionnaire in the juvenile idiopathic myopathies. Juvenile Dermatomyositis Disease Activity Collaborative Study Group

OBJECTIVE

To examine the validity of the Childhood Health Assessment Questionnaire (CHAQ) in patients with juvenile idiopathic inflammatory myopathy (IIM).

METHODS

One hundred fifteen patients were enrolled in a multicenter collaborative study, during which subjects were assessed twice, 7-9 months apart. Physical function was measured using the CHAQ. Internal reliability was assessed using adjusted item-total correlations and item endorsement rates. Construct validity was assessed by comparing predicted and actual correlations of the CHAQ with other measures of physical function and disease activity. Responsiveness was assessed by calculating effect size (ES) and standardized response mean (SRM) in a group of a priori defined "improvers."

RESULTS

Item-total correlations were high (rs range = 0.35-0.81), suggesting all items were related to overall physical function. Manual muscle testing and the Childhood Myositis Assessment Scale correlated moderate to strongly with the CHAQ (r = -0.64 and -0.75, both p < 0.001). Moderate correlations were also seen with the physician global assessment of disease activity (rs = 0.58, p < 0.001), parent global assessment of overall health (rs = -0.65, p < 0.001), Steinbrocker function class (rs = 0.69, p < 0.001), and global skin activity (rs = 0.40, p < 0.001), while global disease damage and skin damage had low correlations (rs = 0.13 and 0.07, p > or =0.17). Responsiveness of the CHAQ was high, with ES = 1.05 and SRM = 1.20.

CONCLUSION

In this large cohort of patients with juvenile IIM, the CHAQ exhibited internal reliability, construct validity, and strong responsiveness. We conclude that the CHAQ is a valid measure of physical function in juvenile IIM, appropriate for use in therapeutic trials, and potentially in the clinical care of these patients.

Deficiencies of human complement component C4A and C4B and heterozygosity in length variants of RP-C4-CYP21-TNX (RCCX) modules in caucasians. The load of RCCX genetic diversity on major histocompatibility complex-associated disease

The complement component C4 genes located in the major histocompatibility complex (MHC) class III region exhibit an unusually complex pattern of variations in gene number, gene size, and nucleotide polymorphism. Duplication or deletion of a C4 gene always concurs with its neighboring genes serine/threonine nuclear protein kinase RP, steroid 21-hydroxylase (CYP21), and tenascin (TNX), which together form a genetic unit termed the RCCX module. A detailed molecular genetic analysis of C4A and C4B and RCCX modular arrangements was correlated with immunochemical studies of C4A and C4B protein polymorphism in 150 normal Caucasians. The results show that bimodular RCCX has a frequency of 69%, whereas monomodular and trimodular RCCX structures account for 17.0 and 14.0%, respectively. Three quarters of C4 genes harbor the endogenous retrovirus HERV-K(C4). Partial deficiencies of C4A and C4B, primarily due to gene deletions and homoexpression of C4A proteins, have a combined frequency of 31.6%. This is probably the most common variation of gene dosage and gene size in human genomes. The seven RCCX physical variants create a great repertoire of haplotypes and diploid combinations, and a heterozygosity frequency of 69.4%. This phenomenon promotes the exchange of genetic information among RCCX constituents that is important in homogenizing the structural and functional diversities of C4A and C4B proteins. However, such length variants may cause unequal, interchromosomal crossovers leading to MHC-associated diseases. An analyses of the RCCX structures in 22 salt-losing, congenital adrenal hyperplasia patients revealed a significant increase in the monomodular structure with a long C4 gene linked to the pseudogene CYP21A, and bimodular structures with two CYP21A, which are likely generated by recombinations between heterozygous RCCX length variants.

Development of validated disease activity and damage indices for the juvenile idiopathic inflammatory myopathies. II. The Childhood Myositis Assessment Scale (CMAS): a quantitative tool for the evaluation of muscle function. The Juvenile Dermatomyositis Disease Activity Collaborative Study Group

OBJECTIVE

To develop, validate, and determine the measurement characteristics of a quantitative tool for assessing the severity of muscle involvement in children with idiopathic inflammatory myopathies.

METHODS

The Childhood Myositis Assessment Scale (CMAS) was developed from 2 existing observational functional assessment tools to assess muscle function in the areas of strength and endurance across a wide range of ability and ages. The 14 ordinal items included were chosen to assess primarily axial and proximal muscle groups and are ranked with standard performance and scoring methods. Following the development of the CMAS, a training video and written instructions were developed and reviewed by the physicians participating in this study. Subsequently, utilizing a randomized block design, 12 physicians independently scored 10 children (9 with dermatomyositis, 1 with polymyositis; ages 4-15 years) twice in one day (morning and afternoon) on the CMAS. A pediatric physical therapist performed quantitative manual muscle strength testing (MMT) twice on each child (morning and afternoon), including the neck, trunk, and proximal and distal extremity muscle groups.

RESULTS

The CMAS has a potential range of 0-51, with higher scores indicating greater muscle strength and endurance. The observed mean for the 10 patients was 36.4 (median 44, SD 14.1, observed range 5-51). The total score for the CMAS correlated with the physician's global assessment (by visual analog scale) of disease activity, the MMT score, serum creatine kinase level, and the Juvenile Arthritis Functional Assessment Report score. The score on the CMAS was not correlated with patient age. Interrater reliability (Kendall's coefficient of concordance) ranged from 0.77 to 1.0 for individual items (all P < 0.001), and overall, it was 0.95 (P < 0.001). Intrarater reliability for the individual physicians was measured by correlation of the CMAS scores for each patient on 2 separate evaluations and ranged from 0.97 to 0.99, with an overall correlation for all physicians of 0.98 (all P < 0.001).

CONCLUSION

The CMAS demonstrated an acceptable range of observed scores, excellent convergent validity, and excellent inter- and intrarater reliability. The CMAS is validated to quantitatively assess muscle function in the areas of strength and endurance in children with idiopathic inflammatory myopathies. It can be used in routine clinical care as well as therapeutic trials.

An unequal crossover between the RCCX modules of the human MHC leading to the presence of a CYP21B gene and a tenascin TNXB/TNXA-RP2 recombinant between C4A and C4B genes in a patient with juvenile rheumatoid arthritis

The RCCX module of the human MHC class III region is comprised of four genes arranged in tandem: RP, complement C4, steroid 21-hydroxylase (CYP21), and tenascin X (TNX). Variations in the number and genes of the RCCX modules may lead to genetic and/or autoimmune diseases. Restriction fragment length polymorphism (RFLP) analysis was utilized to determine the RCCX modular variation in patients with juvenile rheumatoid arthritis (JRA). In JRA patient L1, RFLP analysis suggested the presence of a bimodular RCCX structure containing both C4A long and C4B short genes, yet missing the markers for the CYP21A and TNXA genes usually located between the C4A and C4B genes. The 7.5-kb genomic fragment spanning the CYP21-TNX-RP2 genes was cloned and sequenced, revealing that a genetic recombination occurred between TNXA of a bimodular RCCX chromosome and TNXB of a monomodular RCCX chromosome. This recombination results in a new MHC haplotype with a CYP21B gene and a TNXB/TNXA-RP2 recombinant between the two C4 genes. Elucidation of the breakpoint region provides further evidence for the instability of the MHC class III gene region as a result of the RCCX modular variation.

Development of validated disease activity and damage indices for the juvenile idiopathic inflammatory myopathies: I. Physician, parent, and patient global assessments. Juvenile Dermatomyositis Disease Activity Collaborative Study Group

OBJECTIVE

To determine the reliability, content validity, and responsiveness of physician global assessments of disease activity and damage in the juvenile idiopathic inflammatory myopathies (IIM), and to investigate concordance among physician, parent, and patient global ratings.

METHODS

Sixteen pediatric rheumatologists rated 10 juvenile IIM paper patient cases for global disease activity and damage, and assessed the importance of 51 clinical and laboratory parameters in formulating their global assessments. Then, 117 juvenile IIM patients were enrolled in a protocol to examine the relationship between Likert and visual analog scale global assessments, their sensitivity to change, and the comparability of physician, parent, and patient global ratings.

RESULTS

Pediatric rheumatologists demonstrated excellent interrater reliability in their global assessments of juvenile IIM disease activity and damage (97.7% and 94.7% agreement among raters, respectively), and agreed on a core set of clinical parameters in formulating their judgments. Likert scale ratings correlated with those on a visual analog scale, and both were comparable in responsiveness (standardized response means -0.56 for disease activity, 0.02 [Likert] and 0.14 [visual analog] for damage, measured over 8 months). Parent global ratings of disease activity correlated with physician assessments, but were not colinear (Spearman's correlation [r] = 0.41-0.45). Patient global disease activity assessments correlated with those done by parents (r = 0.57-0.84) and physicians (r = 0.37-0.63), but demonstrated less responsiveness (standardized response means -0.21 and -0.12, respectively, over 8 months).

CONCLUSION

Physician global assessments of juvenile IIM disease activity and damage demonstrated high interrater reliability and were shown to be comprehensive measures. Both physician and parent disease activity assessments should be considered valuable as quantitative measures for evaluating therapeutic responses in juvenile IIM patients.

Clinical pharmacology and use of nonsteroidal anti-inflammatory drugs

This review informs clinicians about current clinical usage and pharmacokinetics of newer NSAIDs and aspirin. To understand the effects of these drugs, a review of prostaglandin synthesis and actions is provided.

Reye syndrome in children receiving salicylate therapy for connective tissue disease

Concern that salicylates may play a role in the pathogenesis of Reye syndrome has raised the question of whether children receiving salicylate therapy for connective tissue disease are at risk for development of Reye syndrome. Of 176 patients with biopsy-confirmed Reye syndrome studied between January 1969 and June 1983, six had connective tissue disease at the time of development of Reye syndrome, and all six were receiving salicylates. Compared with the general population, children receiving salicylate therapy for connective tissue disease may be at increased risk for the development of Reye syndrome.

Infantile multisystem inflammatory disease: a specific syndrome?

We report two patients with infantile onset of evanescent rash, fever, arthropathy with severe deformities, periosteal changes, chronic meningitis, hydrocephalus, convulsions, developmental delay, papilledema, unusual uveitis, and lymphadenopathy. A few patients with similar findings have been previously reported. Although some similarity exists between findings in these patients and in others with systemic juvenile rheumatoid arthritis, they appear to differ both in regard to the nature and severity of the clinical and pathologic features. We suggest that this group of patients has a separate rheumatic disorder not yet included in the standard classifications of the childhood rheumatic diseases.

Juvenile gouty arthritis. Two cases associated with mild renal insufficiency

Two patients had onset of juvenile gouty arthritis at ages 16 and 1 1/2 years, respectively. Both had mild renal insufficiency, with creatinine clearances of 46 and 54 mL/min/1.73 sq m, respectively. Their presenting hyperuricemia (13.8 and 11 mg/dL, respectively) was out of proportion to the degree of renal insufficiency. Clinical and laboratory studies did not suggest an inborn error of purine metabolism, glycogen storage disease type I, or any myeloproliferative disorder. Neither patient had a family history of gout or inherited renal disease. Although juvenile gouty arthritis is rare, it must be considered in the differential diagnosis of episodic arthritis in children, especially if renal impairment, even mild, is present.

Eye involvement in Kawasaki disease

Kawasaki disease or mucocutaneous lymph node syndrome is an acute febrile illness primarily affecting children. The principal signs and symptoms recognizable during the acute phase of the illness are described. Kawasaki disease is fatal in up to 3% of cases due to cardiac complications secondary to a systemic vasculitis. In a prospective series, ophthalmologic examinations on 10 children with Kawasaki disease showed that eight had anterior uveitis during the acute phase of the illness. All cases resolved within two to eight weeks. Because of these findings, 15 patients who had had Kawasaki disease with documented bilateral conjunctival injection, but who had never undergone slit-lamp examinations, were recalled for ophthalmologic evaluation. Results of these follow-up examinations were normal in all 15 children.

Follow-up ophthalmologic examinations in children with Kawasaki's disease

We recalled 15 patients who had had Kawasaki's disease with documented bilateral conjunctival injection but who had not undergone slit-lamp examinations during the acute phase of the illness. Although anterior uveitis has been found in the acute phase of Kawasaki's disease, results of the follow-up studies (including slit-lamp examination, visual acuity testing, and assessment of pupillary reaction, muscle balance, and intraocular pressure) were normal in all 14 children.

Anterior uveitis in Kawasaki's disease

Kawasaki's disease (mucocutaneous lymph node syndrome) is an acute febrile illness primarily affecting children. Slit-lamp examinations of six children with kawasaki's disease, ranging in age from 22 months to 16 years, showed that five had anterior uveitis during the acute phase of the illness. Two of the children were treated with corticosteroids and cycloplegic drugs and three received no treatment. In all five, the anterior uveitis resolved completely within a few weeks.