PROTEIN AND RNA IMMUNOPRECIPITATION FOR THE IDENTIFICATION OF SPECIFIC SERUM AUTOANTIBODIES IN SYSTEMIC AUTOIMMUNE RHEUMATIC DISEASES.

Serum autoantibodies play a key role in systemic autoimmune rheumatic diseases for diagnostic, classification and prognostic purposes. Research of new autoantibodies has been very active in the last decade in rare connective tissue diseases such as systemic sclerosis and poly/dermatomyositis, with new biomarkers entering the clinical practice. Immunoprecipitation of protein and/or RNA components of the target autoantigens constitutes the gold standard method for the discovery of new autoantibodies in a screening setting but is considered time- and labor-intensive and, accordingly, is performed only in a few laboratories worldwide. As a result, alternative techniques such as ELISA and immunoblotting are often preferred for large-scale testing, despite the lack of standardization. The aims of the present project are (1) to set up protein- and RNA- immunoprecipitation in our laboratory and (2) to describe serum autoantibodies identified in our series of patients affected by systemic autoimmune rheumatic diseases. During the PhD program we were able to perform correctly protein-and RNA-immunoprecipitation in our laboratory as demonstrated by positive reference sera, and then by the identification of known but also new and rare autoantibodies, as represented by two new patterns immunoprecipitated in systemic sclerosis, corresponding to serum anti-hnRNP-L and anti-mitochondrial antibodies. In psoriatic arthritis we also analyzed the concentration of circulating levels of LL37, a recently established target of autoimmune response at the skin level, and we identified an increased production in a subset of patients. In conclusion, performing protein- and RNA-immunoprecipitation as a screening method in our laboratory allows a more complete and specific autoantibody analysis that cannot be performed by the commercial techniques available nowadays, and further analysis of the role of LL37 in psoriatic arthritis patients may help in the identification of a new biomarker in this condition

Recommendations for coronavirus infection in rheumatic diseases treated with biologic therapy.

The Coronavirus-associated disease, that was first identified in 2019 in China (CoViD-19), is a pandemic caused by a bat-derived beta-coronavirus, named SARS-CoV2. It shares homology with SARS and MERS-CoV, responsible for past outbreaks in China and in Middle East. SARS-CoV2 spread from China where the first infections were described in December 2019 and is responsible for the respiratory symptoms that can lead to acute respiratory distress syndrome. A cytokine storm has been shown in patients who develop fatal complications, as observed in past coronavirus infections. The management includes ventilatory support and broad-spectrum antiviral drugs, empirically utilized, as a targeted therapy and vaccines have not been developed. Based upon our limited knowledge on the pathogenesis of CoViD-19, a potential role of some anti-rheumatic drugs may be hypothesized, acting as direct antivirals or targeting host immune response. Antimalarial drugs, commonly used in rheumatology, may alter the lysosomal proteases that mediates the viral entry into the cell and have demonstrated efficacy in improving the infection. Anti-IL-1 and anti-IL-6 may interfere with the cytokine storm in severe cases and use of tocilizumab has shown good outcomes in a small cohort. Baricitinib has both antiviral and anti-inflammatory properties. Checkpoints inhibitors such as anti-CD200 and anti-PD1 could have a role in the treatment of CoViD-19. Rheumatic disease patients taking immunosuppressive drugs should be recommended to maintain the chronic therapy, prevent infection by avoiding social contacts and pausing immunosuppressants in case of infection. National and international registries are being created to collect data on rheumatic patients with CoViD-19

Severe rhabdomyolysis associated with pemetrexed-based chemotherapy

Pemetrexed is an antifolate metabolite that inhibits several enzymes involved in the folate pathway. It has activity against various solid tumours, and has been approved for treatment of malignant pleural mesothelioma on the basis of findings from a randomised phase III trial.1 The main toxic effects noted for pemetrexed have been rash, myelosuppression, diarrhoea, mucositis, and reversible elevation of liver enzymes—effects that are preventable partly by vitamin supplementation.

Role of environmental factors in autoantibody production-importance of a detailed analysis in a small cohort

In the previous issue of Arthritis Research & Therapy, Muro and colleagues reported a detailed epidemiologic analysis in central Japan on one of the new myositis-specific autoantibodies to MDA-5 (melanoma differentiation-associated gene 5), which is associated with clinically amyopathic dermatomyositis accompanying interstitial lung disease. The increasing prevalence of anti-MDA-5, higher prevalence in small rural towns, and geographical clustering in two areas along the Kiso River suggest a role of environmental factors associated with rural communities or the river/water system or both. A detailed analysis of a small cohort may offer clues, which is ignored in multi-center studies, to the pathogenesis of systemic rheumatic diseases and autoantibody production. \ua9 2012 BioMed Central Ltd

MicroRNAs in systemic rheumatic diseases

MicroRNAs (miRNAs) are endogenous, non-coding, single-stranded RNAs about 21 nucleotides in length. miRNAs have been shown to regulate gene expression and thus influence a wide range of physiological and pathological processes. Moreover, they are detected in a variety of sources, including tissues, serum, and other body fluids, such as saliva. The role of miRNAs is evident in various malignant and nonmalignant diseases, and there is accumulating evidence also for an important role of miRNAs in systemic rheumatic diseases. Abnormal expression of miRNAs has been reported in autoimmune diseases, mainly in systemic lupus erythematosus and rheumatoid arthritis. miRNAs can be aberrantly expressed even in the different stages of disease progression, allowing miRNAs to be important biomarkers, to help understand the pathogenesis of the disease, and to monitor disease activity and effects of treatment. Different groups have demonstrated a link between miRNA expression and disease activity, as in the case of renal flares in lupus patients. Moreover, miRNAs are emerging as potential targets for new therapeutic strategies of autoimmune disorders. Taken together, recent data demonstrate that miRNAs can influence mechanisms involved in the pathogenesis, relapse, and specific organ involvement of autoimmune diseases. The ultimate goal is the identification of a miRNA target or targets that could be manipulated through specific therapies, aiming at activation or inhibition of specific miRNAs responsible for the development of disease

The Th17 axis in psoriatic disease : pathogenetic and therapeutic implications

Psoriasis and psoriatic arthritis represent two paradigmatic conditions characterized by chronic inflammation and possibly autoimmunity, despite the absence of known serum autoantibodies. The two diseases, albeit strongly correlated from clinical, genetic, and epidemiogical standpoints, manifest significant differences in terms of etiology and pathogenetic mechanisms. Nonetheless, Th17 cells appear crucial to both diseases, and IL23 is the cytokine involved in determining the fate of naive CD4+ cells to differentiate into a pathogenic phenotype. This basic experimental observation led to a clear understanding of the immune dysfunction causing psoriasis and psoriatic arthritis but, more importantly, also led to new therapeutic approaches. In recent years, monoclonal antibodies directed to IL12/IL23 (ustekinumab) or IL17 (secukinumab, ixekizumab, brodalumab) are being investigated or have proven to be beneficial for patients with psoriatic disease, thus further supporting the view that Th17 cells play a pivotal role in disease onset and perpetuation. These most recent reports indeed represent significant developments that may allow overcoming the TNF\u3b1 pathway as the major therapeutic target in chronic inflammation

MicroRNAs in rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic and severe autoimmune disease that affects joint tissues, bone, and cartilage. However, the pathogenesis of RA is still unclear. Autoantibodies such as rheumatoid factor and anti-cyclic citrullinated peptide are useful tools for early diagnosis, monitoring disease activity, and predicting prognosis. Recently, many groups have focused their attention on the role of microRNAs in the pathogenesis of RA, as well as a potential biomarker to monitor RA. In fact, the expression of some microRNAs, such as miR-146a, is upregulated in different cell types and tissues in RA patients. MicroRNAs in RA could also be considered as possible future targets for new therapeutic approaches. \ua9 2011 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved