The clinical phenotype of systemic sclerosis patients with anti-PM/Scl antibodies: results from the EUSTAR cohort.

OBJECTIVE: To evaluate clinical associations of anti-PM/Scl antibodies in patients with SSc in a multicentre international cohort, with particular focus on unresolved issues, including scleroderma renal crisis (RC), malignancies, and functional outcome of interstitial lung disease (ILD). METHODS: (1) Analysis of SSc patients from the EUSTAR database: 144 anti-PM/Scl+ without SSc-specific autoantibodies were compared with 7202 anti-PM/Scl-, and then to 155 anti-Pm/Scl+ with SSc-specific antibodies. (2) Case-control study: additional data were collected for 165 anti-PM/Scl+ SSc patients (85 from the EUSTAR registry) and compared with 257 anti-PM/Scl- SSc controls, matched for sex, cutaneous subset, disease duration and age at SSc onset. RESULTS: Patients with isolated anti-PM/Scl+, as compared with anti-Pm/Scl-, had higher frequency of muscle involvement, ILD, calcinosis and cutaneous signs of DM, but similar frequency of SRC and malignancies (either synchronous with SSc onset or not). The presence of muscle involvement was associated with a more severe disease phenotype. Although very frequent, ILD had a better functional outcome in cases than in controls. In patients with both anti-PM/Scl and SSc-specific antibodies, a higher frequency of typical SSc features than in those with isolated anti-PM/Scl was observed. CONCLUSION: The analysis of the largest series of anti-PM/Scl+ SSc patients so far reported helps to delineate a specific clinical subset with muscle involvement, cutaneous DM, calcinosis and ILD characterized by a good functional outcome. SRC and malignancies do not seem to be part of this syndrome.

An Anti-PM/Scl-75 Antibody-positive Japanese Woman Who Developed Inflammatory Myopathy.

A 69-year-old Japanese woman presented with mild muscle weakness of the neck and symmetrical proximal parts of the upper and lower limbs. Laboratory tests, needle electromyography, and a muscle biopsy revealed inflammatory myopathy with an apparent clinical classification of polymyositis and positive findings for anti-PM/Scl-75 antibody. This antibody is rare among Japanese populations, and most Japanese patients with the antibody are not classified with the inflammatory myopathy seen in polymyositis. The muscle biopsy also showed marked necrotic and regenerative fibers. We need to collectively investigate patients with the potential to develop this disease, and to identify any unique characteristics for Asian populations, including Japanese.

Clinical significance of autoantibodies in dermatomyositis and systemic sclerosis.

Autoimmune connective tissue diseases, including dermatomyositis and systemic sclerosis, have a heterogeneous clinical presentation and prognosis; moreover, their clinical features are often incomplete and overlap with other rheumatic disorders, which can make diagnosis and prognostic stratification challenging. Specific autoantibodies have been associated with certain clinical findings as well as prognostic implications, and many new associations have been made over the last decade. Although patient populations manifest considerable heterogeneity, autoantibodies can be used to help predict clinical features, prognosis, and response to therapy. In this review, the clinical and prognostic implications associated with disease-specific autoantibodies in dermatomyositis and scleroderma are summarized with an emphasis on how the clinician can use this information for patient care.

[Regulation of immune responses by exosomes derived from antigen presenting cells]. / Los exosomas de las células presentadoras de antígeno y su papel en la regulación de las respuestas inmunológicas.

Cells release several biomolecules to the extracellular environment using them as a communication alternative with neighbor cells. Besides these molecules, cells also release more complex elements, like vesicles; structures composed of a lipidic bilayer with transmembrane proteins that protect a hydrophilic content. Exosomes are a small subtype of vesicles (30-150 nm), produced by many cell types, such as tumor cells, neurons, epithelial cells and immune cells. Included in this last group, antigen presenting cells produce exosomes that contain different types of molecules depending on their activation and/or maturation state. In recent years there has been an exponential interest in exosomes due to the recent evidences that show the immunomodulatory properties of these vesicles and therefore, their great potential in diagnostic approaches and development of therapies for different inflammation-associated pathologies.

Las células liberan biomoléculas de diversa naturaleza a su entorno para comunicarse con las células vecinas. Además de dichas moléculas, secretan también elementos más complejos como las vesículas; estructuras compuestas por bicapas lipídicas con proteínas transmembranales que encierran un contenido hidrofílico. Los exosomas son un subtipo pequeño de estas vesículas (de 30 a 150 nm), producidos por una amplia variedad de tipos celulares incluyendo las neuronas, células tumorales, células epiteliales y células del sistema inmunológico. De entre estas últimas, las células presentadoras de antígeno se han caracterizado como productoras de exosomas con contenido variable, tanto en condiciones de reposo como en aquellas que derivan de su estimulación o maduración. En los últimos años, el estudio de los exosomas ha aumentado debido a que se ha demostrado que dichas vesículas poseen propiedades inmunomoduladoras, razón por la que ostentan un gran potencial en aplicaciones de diagnóstico y desarrollo de terapias en diferentes patologías con componentes inflamatorios.

Calcinosis in poly-dermatomyositis: clinical and laboratory predictors and treatment options.

OBJECTIVES: We aimed to identify the possible clinical and laboratory predictors of calcinosis in a cohort of patients with a diagnosis of polymyositis (PM) and dermatomyositis (DM). METHODS: We carried out a retrospective analysis of a cohort of myositis patients attending our clinic between January 2013 and May 2014. RESULTS: 74 patients (58 females, 16 males) with PM (30 cases), DM (30 cases), overlap syndrome (13 cases) and inclusion body myositis (1 case) were enrolled. Sixteen patients (21.6%) had calcinosis that occurred a mean of 43.7 months after diagnosis of PDM. At multivariate analysis, patients with calcinosis experienced longer follow-up duration (p=0.006), anti-PM/Scl (p=0.033) and anti-NXP2 (p=0.024) positivity compared to patients without calcinosis. Furthermore, anti-NXP-2 positive C+ showed a diffuse form of calcinosis from the beginning and lower frequency of respiratory tract involvement. No single drug or associations of drugs was found effective in the treatment of calcinosis. CONCLUSIONS: A longer follow-up period of time, DM diagnosis and positivity for PM/Scl and NXP-2 could all be considered risk factors which foresee the development of calcinosis. Moreover, the positivity for antibodies to NXP-2 depicts a distinct phenotype of calcinosis with an early onset and quick widespread dissemination.

Clinical correlates of monospecific anti-PM75 and anti-PM100 antibodies in a tri-nation cohort of 1574 systemic sclerosis subjects.

OBJECTIVE: Autoantibodies directed against the two principal antigens of the human exosome complex, PM75 and PM100, are present in systemic sclerosis (SSc) sera and have been associated with myositis and calcinosis. However, there is a paucity of data on the clinical correlates of these autoantibodies separately and in the absence of other SSc-specific antibodies. The aim of this study was to assess the clinical correlates of monospecific anti-PM75 and anti-PM100 in SSc. METHODS: A tri-nation cohort of 1574 SSc subjects was formed, clinical variables were harmonized and sera were tested for anti-PM75 and anti-PM100 antibodies using a line immunoassay. RESULTS: Forty-eight (3.0%) subjects had antibodies against PM75 and 18 (1.1%) against PM100. However, only 16 (1%) had monospecific anti-PM75 antibodies and 11 (0.7%) monospecific anti-PM100 antibodies (i.e. in isolation of each other and other SSc-specific antibodies). Monospecific profiles of each autoantibody included more calcinosis. An increased frequency of myositis was only seen in subjects positive for both anti-PM75 and anti-PM100 antibodies. Lung disease was only associated with anti-PM75 and subjects with anti-PM100 antibodies had better survival compared to other antibody subsets. CONCLUSION: The prevalence of monospecific anti-PM75 and anti-PM100 antibodies in this large SSc cohort was low. Disease features associated with anti-PM/Scl antibodies may depend on particular and possibly multiple antigen specificities. However, due to the small samples, these results need to be interpreted with caution. International collaborations are key to understanding the clinical correlates of uncommon serological profiles in SSc.

Interpretation of an Extended Autoantibody Profile in a Well-Characterized Australian Systemic Sclerosis (Scleroderma) Cohort Using Principal Components Analysis.

OBJECTIVE: To determine the relationships between systemic sclerosis (SSc)-related autoantibodies, as well as their clinical associations, in a well-characterized Australian patient cohort. METHODS: Serum from 505 Australian SSc patients were analyzed with a commercial line immunoassay (EuroLine; Euroimmun) for autoantibodies to centromere proteins CENP-A and CENP-B, RNA polymerase III (RNAP III; epitopes 11 and 155), the 90-kd nucleolar protein NOR-90, fibrillarin, Th/To, PM/Scl-75, PM/Scl-100, Ku, topoisomerase I (topo I), tripartite motif-containing protein 21/Ro 52, and platelet-derived growth factor receptor. Patient subgroups were identified by hierarchical clustering of the first 2 dimensions of a principal components analysis of quantitative autoantibody scores. Results were compared with detailed clinical data. RESULTS: A total of 449 of the 505 patients were positive for at least 1 autoantibody by immunoblotting. Heatmap visualization of autoantibody scores, along with principal components analysis clustering, demonstrated strong, mutually exclusive relationships between CENP, RNAP III, and topo I. Five patient clusters were identified: CENP, RNAP III strong, RNAP III weak, topo I, and other. Clinical features associated with CENP, RNAP III, and topo I were consistent with previously published reports concerning limited cutaneous and diffuse cutaneous SSc. A novel finding was the statistical separation of RNAP III into 2 clusters. Patients in the RNAP III strong cluster had an increased risk of gastric antral vascular ectasia, but a lower risk of esophageal dysmotility. Patients in the other cluster were more likely to be male and to have a history of smoking and a history of malignancy, but were less likely to have telangiectasia, Raynaud's phenomenon, and joint contractures. CONCLUSION: Five major autoantibody clusters with specific clinical and serologic associations were identified in Australian SSc patients. Subclassification and disease stratification using autoantibodies may have clinical utility, particularly in early disease.

[Expression and purification of GST-CML28 fusion protein and preparation of its polyclonal antibody].

This study was aimed to investigate the expression of GST-CML28 in Escherichia Coli and to prepare its antibody. The constructed recombinant expression vectors CML28-pGEX-3X were transformed into Escherichia Coli BL21 under IPTG induction. The protein was abstracted from the transformers, and purified by a GSTrap FF column. The rabbits were immunized by the purified fusion protein to produce serum with anti-CML28 antibody. The serum was purified by chromatographic column stuffed with glutathione Sephamse 4B to get the antibody. The specific antibody against CML28 was further identified by ELISA, Western blot, immunohistochemistry and quantum dot luminescence. The results indicated that GST-CML28 fusion protein was expressed in Escherichia coli and its specific polyclonal antibody was obtained. It is concluded that the anti-CML28 polyclonal antibodies with high titer and specificity are successfully prepared. These antibodies provide an useful experimental tool to profoundly research the physiological significance and biological function of the CML28 gene.

Fluoroenzymeimmunoassay to detect systemic sclerosis-associated antibodies: diagnostic performance and correlation with conventional techniques.

OBJECTIVES: Detection of systemic sclerosis-associated antibodies (SSc-Ab) in routine clinical practice is mostly restricted to anti-centromere and anti-Scl-70 antibodies. However, also other antinuclear antibodies have been shown to be valuable diagnostic and prognostic markers for the disease. The aim of this study was to evaluate the diagnostic performance of measuring the most prevalent SSc-Ab with fluoroenzymeimmunoassay (FEIA) as an alternative for the combined conventional techniques (CCT). METHODS: Sera from 144 consecutive systemic sclerosis (SSc) patients previously tested by CCT (indirect immunofluorescence on HEp-2000, western blotting, protein radio immunoprecipitation and a well-documented line immunoassay) and an additional group of 266 disease controls (80 rheumatoid arthritis, 58 systemic lupus erythematosus, 50 spondyloarthropathy, 48 osteoarthritis, 18 polymyalgia rheumatica and 12 ANCA-associated vasculitis) were retrospectively evaluated. Anti-centromere-B, anti-Scl-70, anti-RNA polymerase III and anti-PM/Scl antibodies were measured using FEIA. RESULTS: Using cut-off values corresponding with likelihood ratios larger than 10 FEIA obtained the following sensitivities: 45.1% for anti-centromere-B, 15.3% for anti-Scl-70, 5.6% for anti-RNA polymerase III and 2.1% for anti-PM/Scl. The overall agreement between combined conventional techniques and FEIA was good for all individual reactivities (kappa>0.800). The overall diagnostic sensitivity of 68.1% and diagnostic specificity of 98.1% were comparable to those obtained by CCT. CONCLUSIONS: FEIA testing for anti-centromere-B, anti-Scl-70, anti-RNA polymerase III and anti-PM/Scl-100 shows good performance and represents an accurate alternative for the time-consuming combined conventional techniques.