Ro52, Myositis, and Interstitial Lung Disease

Ro52 is a member of the tripartite motif-containing (TRIM) family and, hence, is also known as TRIM21. Ro52 is distinct, with no structural homology to Ro60 (also known as TROVE2), 1 although both are major targets of autoantibody responses in several autoimmune connective tissue diseases (CTDs). </p

Verna Wright Lecture:Psoriatic Arthritis: The Need for Early Intervention

About 30% of individuals with skin psoriasis will develop an inflammatory disease of the peripheral or axial skeleton involving synovial and/or entheseal tissue termed psoriatic arthritis (PsA). In most cases psoriasis will precede PsA by several years. Hence skin psoriasis provides an opportune model to investigate genetic and environmental factors that interact and contribute to the development of a common form of inflammatory arthritis. Further, the preexisting presence of psoriasis represents a unique opportunity for the early detection of arthritis and the potential for more effective intervention. However, despite the presence of psoriasis, there may be delay in the diagnosis of PsA that is associated with adverse longterm outcome. Undiagnosed disease is not uncommon, as demonstrated by studies applying screening questionnaires to primary care and dermatology clinic populations. Other potential risk factors, such as obesity and smoking, the presence of certain genetic and biomarker profiles, combined with accurate imaging modalities, offer the potential for more targeted screening. So in future it should be possible to detect PsA at a much earlier stage and prevent significant joint damage and associated disability before it happens.</p

Novel autoantibodies and clinical phenotypes in adult and juvenile myositis

Autoantibodies targeting intracellular proteins involved in key processes are detected in patients with idiopathic inflammatory myopathies. These myositisspecific autoantibodies have been increasingly demonstrated to correlate with distinct clinical phenotypes within the myositis spectrum. This review highlights the clinical associations of the myositisspecific autoantibodies, with particular attention to the recently identified and characterized novel myositis autoantibodies: p155/140, p140 (MJ), CADM-140 (MDA5), SAE, and 200/100

The reliability of immunoassays to detect autoantibodies in patients with myositis is dependent on autoantibody specificity

OBJECTIVES: In order to address the reliability of commercial assays to identify myositis-specific and -associated autoantibodies, we aimed to compare the results of two commercial immunoassays with the results obtained by protein immunoprecipitation.METHODS: Autoantibody status was determined using radio-labelled protein immunoprecipitation for patients referred to our laboratory for myositis autoantibody characterization. For each autoantibody of interest, the sera from 25 different patients were analysed by line blot (Euroline Myositis Antigen Profile 4, EuroImmun, Lübeck, Germany) and dot blot (D-Tek BlueDiver, Diagnostic Technology, Belrose, NSW, Australia). Sera from 134 adult healthy controls were analysed.RESULTS: Overall commercial assays performed reasonably well, with high agreement (Cohen's κ &gt;0.8). Notable exceptions were the detection of rarer anti-synthetases with κ &lt; 0.2 and detection of anti-TIF1γ, where κ was 0.70 for the line blot and 0.31 for dot blot. Further analysis suggested that the proportion of patients with anti-TIF1γ may recognize a conformational epitope, limiting the ability of blotting-based assays that utilize denatured antigen to detect this clinically important autoantibody. A false-positive result occurred in 13.7% of samples analysed by line blot and 12.1% analysed by dot blot.CONCLUSION: The assays analysed do not perform well for all myositis-specific and -associated autoantibodies and overall false positives are relatively common. It is crucial that clinicians are aware of the limitations of the methods used by their local laboratory. Results must be interpreted within the clinical context and immunoprecipitation should still be considered in selected cases, such as apparently autoantibody-negative patients where anti-synthetase syndrome is suspected.</p

Serological subsets of juvenile idiopathic inflammatory myopathies - an update

In this review we explore the different characteristics of the serological phenotypes identified in juvenile-onset myositis and consider how the serological sub-classification of patients with juvenile myositis can be advantageous both in terms of reaching what can be a difficult diagnosis and informing on prognosis. Recent studies have described the autoantibody associated disease phenotypes and outcome for those with juvenile-onset disease and include analyses of large juvenile-onset myositis cohorts. Here we describe the autoantibody associated disease features for patients within juvenile-onset myositis in detail and discuss the expanding opportunities and strategies for myositis specific autoantibody testing in clinical practice.</p