Predictive value of antinuclear autoantibodies: The lessons of the systemic sclerosis autoantibodies

Autoantibodies against the NineTeen complex and U5 RNP in systemic sclerosis

ObjectiveMultiple spliceosome components are known autoantigens in systemic sclerosis (SSc). Here we aim to identify new and characterize rare anti-spliceosomal autoantibodies in patients with SSc without known autoantibody specificity. MethodsSera that precipitated spliceosome subcomplexes, as detected by immunoprecipitation-mass spectrometry (IP-MS), were identified from a database of 106 patients with SSc without known autoantibody specificity. New autoantibody specificities were confirmed with immunoprecipitation-western blot. The IP-MS pattern of new anti-spliceosomal autoantibodies was compared with anti-U1 RNP-positive sera of patients with different systemic autoimmune rheumatic diseases and anti-SmD-positive sera of patients with systemic lupus erythematosus (n = 24). ResultsThe NineTeen Complex (NTC) was identified and confirmed as new spliceosomal autoantigen in one patient with SSc. U5 RNP, as well as additional splicing factors, were precipitated by the serum of another patient with SSc. The IP-MS patterns of anti-NTC and anti-U5 RNP autoantibodies were distinct from those of anti-U1 RNP- and anti-SmD-positive sera. Furthermore, there was no difference in IP-MS patterns between a limited number of anti-U1 RNP-positive sera of patients with different systemic autoimmune rheumatic diseases. ConclusionAnti-NTC autoantibodies are a new anti-spliceosomal autoantibody specificity, here first identified in a patient with SSc. Anti-U5 RNP autoantibodies are a distinct but rare anti-spliceosomal autoantibody specificity. All major spliceosomal subcomplexes have now been described as target of autoantibodies in systemic autoimmune diseases.

Anti-U11/U12 Antibodies as a Rare but Important Biomarker in Patients with Systemic Sclerosis: A Narrative Review

Anti-nuclear (ANA) are present in approximately 90% of systemic sclerosis (SSc) patients and are key biomarkers in supporting the diagnosis and determining the prognosis of this disease. In addition to the classification criteria autoantibodies for SSc [i.e., anti-centromere, anti-topoisomerase I (Scl-70), anti-RNA polymerase III], other autoantibodies have been associated with important SSc phenotypes. Among them, anti-U11/U12 ribonucleoprotein (RNP) antibodies, also known as anti-RNPC-3, were first reported in a patient with SSc, but very little is known about their association and clinical utility. The U11/U12 RNP macromolecular complex consists of several proteins involved in alternative mRNA splicing. More recent studies demonstrated associations of anti-anti-U11/U12 antibodies with SSc and severe pulmonary fibrosis as well as with moderate to severe gastrointestinal dysmotility. Lastly, anti-U11/U12 autoantibodies have been strongly associated with malignancy in SSc patients. Here, we aimed to summarize the knowledge of anti-U11/U12/RNPC-3 antibodies in SSc, including their seroclinical associations in a narrative literature review.

A Rare Case of Polymyositis and Systemic Sclerosis Overlap Syndrome: Diagnosis and Treatment

Diffuse scleroderma is a kind of scleroderma in which the immune system malfunctions, leading to excessive production of collagen in the skin and a variety of organ abnormalities. Based on previously recognized criteria, overlap syndrome is a disorder in which two or more medical illnesses are documented in a single patient. These syndromes are significantly more prevalent in illnesses with mixed connective tissue. In this case report, we present a patient with overlapping systemic sclerosis and polymyositis symptoms. The treatment and diagnosis of this extremely uncommon condition are discussed in further detail.

Identification of new telomere- and telomerase-associated autoantigens in systemic sclerosis

PURPOSE

In up to 20% of patients with systemic sclerosis (SSc) no known autoantibody specificity can be identified. Recently discovered autoantigens, such as telomeric repeat binding factor 1 (TERF1), as well as established autoantigens, like RuvBL1/2, are associated with telomere and telomerase biology. We aimed to identify new telomere- and telomerase-associated autoantigens in patients with SSc without known autoantibody specificity.

METHODS

Unlabelled protein immunoprecipitation combined with gel-free liquid chromatography-tandem mass spectrometry (IP-MS) was performed with sera of 106 patients with SSc from two tertiary referral centres that had a nuclear pattern on HEp-2 indirect immunofluorescence without previously identified autoantibody. Telomere- or telomerase-associated proteins or protein complexes precipitated by individual sera were identified. Candidate autoantigens were confirmed through immunoprecipitation-western blot (IP-WB). A custom Luminex xMAP assay for 5 proteins was evaluated with sera from persons with SSc (n = 467), other systemic autoimmune rheumatic diseases (n = 923), non-rheumatic disease controls (n = 187) and healthy controls (n = 199).

RESULTS

Eight telomere- and telomerase-associated autoantigens were identified in a total of 11 index patients, including the THO complex (n = 3, all with interstitial lung disease and two with cardiac involvement), telomeric repeat-binding factor 2 (TERF2, n = 1), homeobox-containing protein 1 (HMBOX1, n = 2), regulator of chromosome condensation 1 (RCC1, n = 1), nucleolar and coiled-body phosphoprotein 1 (NOLC1, n = 1), dyskerin (DKC1, n = 1), probable 28S rRNA (cytosine(4447)-C(5))-methyltransferase (NOP2, n = 1) and nuclear valosin-containing protein-like (NVL, n = 2). A Luminex xMAP assay for THO complex subunit 1 (THOC1), TERF2, NOLC1, NOP2 and NVL revealed high reactivity in all index patients, but also in other patients with SSc and disease controls. However, the reactivity by xMAP assay in these other patients was not confirmed by IP-WB.

CONCLUSION

IP-MS revealed key telomere- and telomerase-associated proteins and protein complexes as autoantigens in patients with SSc.

Effects of Immunoglobulins G From Systemic Sclerosis Patients in Normal Dermal Fibroblasts: A Multi-Omics Study

Autoantibodies (Aabs) are frequent in systemic sclerosis (SSc). Although recognized as potent biomarkers, their pathogenic role is debated. This study explored the effect of purified immunoglobulin G (IgG) from SSc patients on protein and mRNA expression of dermal fibroblasts (FBs) using an innovative multi-omics approach. Dermal FBs were cultured in the presence of sera or purified IgG from patients with diffuse cutaneous SSc (dcSSc), limited cutaneous SSc or healthy controls (HCs). The FB proteome and transcriptome were explored using liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) and microarray assays, respectively. Proteomic analysis identified 3,310 proteins. SSc sera and purified IgG induced singular protein profile patterns. These FB proteome changes depended on the Aab serotype, with a singular effect observed with purified IgG from anti-topoisomerase-I autoantibody (ATA) positive patients compared to HC or other SSc serotypes. IgG from ATA positive SSc patients induced enrichment in proteins involved in focal adhesion, cadherin binding, cytosolic part, or lytic vacuole. Multi-omics analysis was performed in two ways: first by restricting the analysis of the transcriptomic data to differentially expressed proteins; and secondly, by performing a global statistical analysis integrating proteomics and transcriptomics. Transcriptomic analysis distinguished 764 differentially expressed genes and revealed that IgG from dcSSc can induce extracellular matrix (ECM) remodeling changes in gene expression profiles in FB. Global statistical analysis integrating proteomics and transcriptomics confirmed that IgG from SSc can induce ECM remodeling and activate FB profiles. This effect depended on the serotype of the patient, suggesting that SSc Aab might play a pathogenic role in some SSc subsets.

Systemic Sclerosis-Specific Antibodies: Novel and Classical Biomarkers

Disease-specific autoantibodies are considered the most important biomarkers for systemic sclerosis (SSc), due to their ability to stratify patients with different severity and prognosis. Anti-nuclear antibodies (ANA), occurring in subjects with isolated Raynuad's phenomenon, are considered the strongest independent predictors of definite SSc and digital microvascular damage, as observed by nailfold videocapillaroscopy. ANA are present in more than 90% of SSc, but ANA negativity does not exclude SSc diagnosis: a little rate of SSc ANA negative exists and shows a distinct subtype of disease, with less vasculopathy, but more frequent lower gastrointestinal involvement and severe disease course. Anti-centromere, anti-Th/To, and anti-Topoisomerase I antibodies could be considered as classical biomarkers, covering about 60% of SSc and defining patients with well-described cardio-pulmonary complications. In particular, anti-Topoisomerase I represent a risk factor for development of diffuse cutaneous involvement and digital ulcers in the first 3 years of disease, as well as severe interstitial lung disease (ILD). Anti-RNA polymerase III is a biomarker with new clinical implications: very rapid skin thickness progression, gastric antral vascular ectasia, the occurrence of synchronous cancers, and possible association with silicone breast implants rupture. Moreover, novel SSc specific autoantibodies have been globally described in about 10% of "seronegative" SSc patients: anti-elF2B, anti-RuvBL1/2 complex, anti-U11/U12 RNP, and anti-BICD2 depict specific SSc subtypes with severe organ complications. Many autoantibodies could be considered markers of overlap syndromes, including SSc. Anti-Ku are found in 2-7% of SSc, strictly defining the PM/SSc overlap. They are associated with synovitis, joint contractures, myositis, and negatively associated with vascular manifestation of disease. Anti-U3RNP are associated with a well-defined clinical phenotype: Afro-Caribbean male patients, younger at diagnosis, and higher risk of pulmonary hypertension and gastrointestinal involvement. Anti-PM/Scl define SSc patients with high frequency of ILD, calcinosis, dermatomyositis skin changes, and severe myositis. The accurate detection of autoantibodies SSc specific and associated with overlap syndromes is crucial for patients' stratification. ANA should be correctly identified using indirect immunofluorescent assay and a standardized way of patterns' interpretation. The gold-standard technique for autoantibodies' identification in SSc is still considered immunoprecipitation, for its high sensitivity and specificity, but other assays have been widely used in routine practice. The identification of SSc autoantibodies with high diagnostic specificity and high predictive value is mandatory for early diagnosis, a specific follow-up and the possible definition of the best therapy for every SSc subsets. In addition, the validation of novel autoantibodies is mandatory in wider cohorts in order to restrict the gap of so-called seronegative SSc patients.

Capillaroscopy and Immunological Profile in Systemic Sclerosis

Introduction: Data on the associations between capillaroscopic changes and diagnostic systemic-sclerosis (SSc)-related antibodies are scarce. Presence of such correlation would improve current knowledge about the disease’s pathogenesis by revealing the mechanisms of microangiopathy. The microvascular pathology of SSc is a hallmark of the disease, and immunological abnormalities probably contribute to its development. Patients and methods: 19 patients with definite diagnosis of SSc were included in the current pilot study; 16 had limited and 3 had diffuse cutaneous involvement; their mean age was 51.56 ± 15.07 years. All patients exhibited symptoms of Raynaud’s phenomenon of the fingers. A “scleroderma” type capillaroscopic pattern was classified according to the staging suggested by Cutolo et al. (2000): “early”, “active” or ”late” phase. In the presence of different degrees of capillaroscopic changes in different fingers, the most-advanced microvascular pathology was chosen for classification. In cases without capillaroscopic features of microangiopathy, the findings were categorized as normal or nonspecific (dilated, tortuous capillaries, and/or hemorrhages). Indirect immunofluorescence on HEp-2 cells was performed as the gold-standard screening method for the detection of antinuclear autoantibodies (ANA), and determination of the immunofluorescent staining pattern (anti-cell pattern) was in accordance with the International Consensus on ANA Patterns. Scleroderma-associated autoantibodies in the patients’ serum were assessed using line immunoblot assay for detection of autoantibodies to 13 scleroderma-associated autoantigens: Scl-70, CENP A, CENP B, RP11/RNAP-III, RP155/RNAP-III, fibrillarin, NOR-90, Th/To, PM-Scl100, PM-Scl75, Ku, PDGFR, and Ro-52. Results: In 73.7% (n = 14) of the examined patients, “scleroderma” type capillaroscopic changes were found, and in 26.3% (n = 5), capillaroscopic features of microangiopathy were absent (nonspecific changes, n = 3; normal findings, n = 2). In SSc patients with positive anti-Scl-70 (n = 7) antibodies, significantly lower mean capillary density was observed along with a higher frequency of “active” and “late” phase capillaroscopic changes as compared to the anti-Scl-70-negative patients (p < 0.05). Anti-RNAP III−155 positive patients (n = 4) had significantly higher mean capillary density than anti-RNAP III−155 negative patients (n = 15). In three of the anti-RNAP III−155-positive cases, capillaroscopic features of microangiopathy were not detected, and in one case there was an “early” phase “scleroderma” pattern. Conclusion: In the current pilot study, the association between more advanced capillaroscopic changes and the presence of anti-Scl-70 autoantibodies was confirmed. As a novel observation, positive anti-RNAP III−155 antibodies were found in SSc patients with or without early microangiopathy. The question of associations between microvascular changes in SSc and other SSc-related autoantibodies requires further research.

Clinical characteristics associated with small airways disease in systemic sclerosis

Objective:

Pulmonary manifestations of systemic sclerosis are a major cause of morbidity and mortality. Small airways disease can cause dyspnea and pulmonary function test abnormalities. We aimed to determine the prevalence of small airways disease and describe the characteristics associated with small airways disease in a cohort of systemic sclerosis patients.

Methods:

We performed a retrospective cohort study of adults with systemic sclerosis who met American College of Rheumatology/European League Against Rheumatism 2013 classification criteria and were evaluated at our institution between November 2000 and November 2015. Patients with prior lung transplantation were excluded. Small airways disease was defined as the presence of one or more of the following: airway-centered fibrosis on surgical lung biopsy, forced expiratory volume at 25–75% ⩽ 50% on pulmonary function tests, and/or high-resolution computed tomography scan of the chest with bronchiolitis, mosaic attenuation, or air trapping on expiratory views. The primary outcome was small airways disease diagnosis. We performed multivariable logistic regression to determine the association of clinical variables with small airways disease.

Results:

One-hundred thirty-six systemic sclerosis patients were included; 55 (40%) had small airways disease. Compared to those without small airways disease, a significantly greater proportion of those with small airways disease had interstitial lung disease, chronic obstructive pulmonary disease, pulmonary hypertension, and gastroesophageal reflux disease. On multivariable analysis, pulmonary hypertension (odds ratio = 2.91, 95% confidence interval = 1.11–7.65, p-value = 0.03), gastroesophageal reflux disease (odds ratio = 2.70, 95% confidence interval = 1.08–6.79, p-value = 0.034), and anti-topoisomerase I (anti-Scl-70) antibody positivity (odds ratio = 0.42, 95% confidence interval = 0.19–0.93, p-value = 0.033) were associated with diagnosis of small airways disease.

Conclusion:

Small airways disease is prevalent among systemic sclerosis patients; those with pulmonary hypertension or gastroesophageal reflux disease may have a higher risk of small airways disease.

Anti-RNA polymerase III antibodies in systemic sclerosis: Multicentric study from Argentina

OBJECTIVE

To describe the frequency of anti-RNA polymerase III antibody in patients with Systemic Sclerosis (SSc) of a group of healthcare centres from Argentina and to explore differences among patients with positive and negative anti-RNA polymerase III antibody.

PATIENTS AND METHODS

Data from clinical records, anamnesis and physical examination were collected from 135 patients with SSc (ACR/EULAR 2013). A serum sample from each patient was obtained for the detection of anti-RNA polymerase III IgG antibodies by ELISA.

RESULTS

In all, 97.8% were women and the median age at diagnosis was 53 years (range 12-87), 77.7% had limited cutaneous SSc (lcSSC), 19,3% patients had diffuse cutaneous SSc (dcSSC) and 2.9% had scleroderma sine scleroderma. The 67.5% of the patients were from a Mestizos or Amerindian ethnic group. Anti-RNA polymerase III was positive in 5.9% of the patients. In 36 patients, the anticentromere (ACA) and anti-Scl70 antibodies were negative; anti-RNA polymerase III was positive in 16.7% of these 36 patients. Pitting scars and pulmonary artery hypertension were more frequent in anti-RNA polymerase III positive patients who were also older at diagnosis. No association with gastric antral vascular ectasia was found. The only patient with scleroderma renal crisis was anti-RNA polymerase III positive.

CONCLUSIONS

Anti-RNA polymerase III frequency found in this study was one of the lowest reported, which could be related to the predominance of the Amerindian and Mestizo ethnic group. It is possible that the detection of anti RNA polymerase III allows better classification of SSc patients, to know their prognosis and to improve their follow-up, therefore more studies are needed.

Recent advances in the diagnosis and management of interstitial pneumonia with autoimmune features: the perspective of rheumatologists

Interstitial pneumonia with autoimmune feature (IPAF) is a recently established disease entity that is comprised of interstitial lung diseases with evidence of autoimmune features but that does not fulfill the criteria for definite autoimmune rheumatic diseases. The classification criteria for IPAF were defined by the European Respiratory Society and American Thoracic Society in 2015. However, further studies to establish IPAF subgroups and treatment modalities for each subgroup are still needed. In this review, we discuss recent advances regarding IPAF and raise critical points for the diagnosis and management of patients with IPAF from the perspective of rheumatologists.

Anti-RNA Polymerase III Antibodies in Systemic Sclerosis: Multicentric Study from Argentina

OBJECTIVE

To describe the frequency of anti-RNA polymerase III antibody in patients with Systemic Sclerosis (SSc) of a group of healthcare centres from Argentina and to explore differences among patients with positive and negative anti-RNA polymerase III antibody.

PATIENTS AND METHODS

Data from clinical records, anamnesis and physical examination were collected from 135 patients with SSc (ACR/EULAR 2013). A serum sample from each patient was obtained for the detection of anti-RNA polymerase III IgG antibodies by ELISA.

RESULTS

In all, 97.8% were women and the median age at diagnosis was 53 years (range: 12-87), 77.7% had limited cutaneous SSc (lcSSC), 19,3% patients had diffuse cutaneous SSc (dcSSC) and 2.9% had scleroderma sine scleroderma. The 67.5% of the patients were from a Mestizos or Amerindian ethnic group. Anti-RNA polymerase III was positive in 5.9% of the patients. In 36 patients, the anticentromere (ACA) and anti-Scl70 antibodies were negative; anti-RNA polymerase III was positive in 16.7% of these 36 patients. Pitting scars and pulmonary artery hypertension were more frequent in anti-RNA polymerase III positive patients who were also older at diagnosis. No association with gastric antral vascular ectasia was found. The only patient with scleroderma renal crisis was anti-RNA polymerase III positive.

CONCLUSIONS

Anti-RNA polymerase III frequency found in this study was one of the lowest reported, which could be related to the predominance of the Amerindian and Mestizo ethnic group. It is possible that the detection of anti-RNA polymerase III allows better classification of SSc patients, to know their prognosis and to improve their follow-up, therefore more studies are needed.

Putative functional pathogenic autoantibodies in systemic sclerosis

Systemic sclerosis (scleroderma, SSc) is a systemic disease characterized by vascular lesions, fibrosis, and circulating autoantibodies. A complex interplay between innate and adaptive immunity, and with regard to the latter, between humoral and cellular immunity, is believed to be involved in SSc pathogenesis. Lately, close attention has been paid to the role of B cells which, once activated, release profibrotic cytokines, promote profibrotic Th2 differentiation, and produce autoantibodies. Several novel interesting autoantibodies, targeting antigens within the extracellular matrix or on the cell surface, rather than the nuclear antigens of canonical SSc-autoantibodies, have been recently described in patients with SSc. As they show stimulatory or inhibitory activity or react with structures involved in the pathogenesis of SSc lesions, they can be considered as potentially pathogenic. In this paper, we will review those which have been better characterized.

Detection of Autoantibodies in Bronchoalveolar Lavage in Patients with Diffuse Interstitial Lung Disease

INTRODUCTION

Serum autoantibodies support the diagnosis of interstitial lung disease (ILD) related to systemic autoimmune diseases (SAD-ILD). Nevertheless, their presence in the bronchoalveolar lavage (BAL) has not been explored.

OBJECTIVES

To demonstrate the presence of autoantibodies in the BAL of ILD patients at onset of clinical evaluation, its relation with serum autoantibodies and to analyze clinical features of patients with autoantibodies in BAL.

METHODS

Autoantibodies against extractable nuclear antigens (ENAs) were analyzed by immunoblot in the BAL of 155 patient with suspected diagnosis of ILD and 10 controls.

RESULTS

Seven ENAs were detected in the BAL of 19 patients (Anti-Ro52, Anti-Ro60, CENP-B, Anti-La, Jo-1, Sm/RNP and Anti-SL70). The most frequent ENA was anti-Ro52 (13 patients; 68,4% of positives ones). Seven patients presented more than one ENAs. Fourteen were diagnosed of SAD-ILD, 3 of interstitial pneumonia with autoimmune features, one of non-specific idiopathic pneumonia and other of silicosis. In 10 cases (52%) IgA autoantibodies were also detected. The autoantibodies observed in BAL were also detected in the serum of 17 patients (90%). There were no significant clinical differences with the patients with SAD-ILD or interstitial pneumonia with autoimmune features with patients with negative BAL.

CONCLUSION

The study of ENAs in BAL is feasible and can be a useful tool in the ILD initial algorithm, specifically sustaining the suspected diagnosis of SAD-ILD.

Urinary Metals Concentrations and Biomarkers of Autoimmunity among Navajo and Nicaraguan Men

Metals are suspected contributors of autoimmune disease among indigenous Americans. However, the association between metals exposure and biomarkers of autoimmunity is under-studied. In Nicaragua, environmental exposure to metals is also largely unexamined with regard to autoimmunity. We analyzed pooled and stratified exposure and outcome data from Navajo (n = 68) and Nicaraguan (n = 47) men of similar age and health status in order to characterize urinary concentrations of metals, compare concentrations with the US National Health and Nutrition Examination Survey (NHANES) male population, and examine the associations with biomarkers of autoimmunity. Urine samples were analyzed for metals via inductively coupled plasma mass spectrometry (ICP-MS) at the US Centers for Disease Control and Prevention. Serum samples were examined for antinuclear antibodies (ANA) at 1:160 and 1:40 dilutions, using an indirect immunofluorescence assay and for specific autoantibodies using enzyme-linked immunosorbent assay (ELISA). Logistic regression analyses evaluated associations of urinary metals with autoimmune biomarkers, adjusted for group (Navajo or Nicaraguan), age, and seafood consumption. The Nicaraguan men had higher urinary metal concentrations compared with both NHANES and the Navajo for most metals; however, tin was highest among the Navajo, and uranium was much higher in both populations compared with NHANES. Upper tertile associations with ANA positivity at the 1:160 dilution were observed for barium, cesium, lead, strontium and tungsten.

The importance of skin manifestations, serology and nailfold (video)capillaroscopy in morphea and systemic sclerosis: current understanding and new insights

Since the field around morphea and systemic sclerosis (SSc) is evolving rapidly, this review approaches conventional as well as more recent clinical developments from a dermatological point of view. Skin manifestations are critical in sub-classifying these diseases ensuring a correct prognosis for these patients. They can be discretely present, and therefore, diagnosis can be challenging sometimes, implicating a thorough dermatological examination is mandatory. Furthermore, a growing amount of dermatologists perform nailfold videocapillaroscopy (NVC), a more recent reliable non-invasive imaging technique used for in vivo assessment of the microcirculation at the nailfold. After all, specific NVC-changes are present in a majority of patients with SSc. This way, dermatologists not only take part in the diagnosis process through clinical investigation but also through the use of a modern state of the art imaging technique that is becoming the golden standard in SSc multidisciplinary workup. In this review, current understandings for NVC in morphea and SSc are revised. So far, the role of NVC in the diagnosis/prognosis/classification of morphea patients has not been thoroughly investigated to make proper conclusions. As for SSc, it is well known that NVC contributes to the diagnosis and can make a fundamental difference especially when obvious clinical SSc signs are absent. This review emphasizes the (somewhat underestimated) role of dermatologists in the process of diagnosis and follow-up, and thus, the difference we can make for our patients and fellow colleagues in the multidisciplinary workup of SSc and morphea.

Pathogenic roles of autoantibodies in systemic sclerosis: Current understandings in pathogenesis

The potential pathogenic role for autoantibodies in systemic sclerosis has captivated researchers for the past 40 years. This review answers the question whether there is yet sufficient knowledge to conclude that certain serum autoantibodies associated with systemic sclerosis contribute to its pathogenesis. Definitions for pathogenic, pathogenetic and functional autoantibodies are formulated, and the need to differentiate these autoantibodies from natural autoantibodies is emphasized. In addition, seven criteria for the identification of pathogenic autoantibodies are proposed. Experimental evidence is reviewed relevant to the classic systemic sclerosis antinuclear autoantibodies, anti-topoisomerase I and anticentromere, and to functional autoantibodies to endothelin 1 type A receptor, angiotensin II type 1 receptor, muscarinic receptor 3, platelet-derived growth factor receptor, chemokine receptors CXCR3 and CXCR4, estrogen receptor α, and CD22. Pathogenic evidence is also reviewed for anti-matrix metalloproteinases 1 and 3, anti-fibrillin 1, anti-IFI16, anti-eIF2B, anti-ICAM-1, and anti-RuvBL1/RuvBL2 autoantibodies. For each autoantibody, objective evidence for a pathogenic role is scored qualitatively according to the seven pathogenicity criteria. It is concluded that anti-topoisomerase I is the single autoantibody specificity with the most evidence in favor of a pathogenic role in systemic sclerosis, followed by anticentromere. However, these autoantibodies have not been demonstrated yet to fulfill completely the seven proposed criteria for pathogenicity. Their contributory roles to the pathogenesis of systemic sclerosis remain possible but not yet conclusively demonstrated. With respect to functional autoantibodies and other autoantibodies, only a few criteria for pathogenicity are fulfilled. Their common presence in healthy and disease controls suggests that major subsets of these immunoglobulins are natural autoantibodies. While some of these autoantibodies may be pathogenetic in systemic sclerosis, establishing that they are truly pathogenic is a work in progress. Experimental data are difficult to interpret because high serum autoantibody levels may be due to polyclonal B-cell activation. Other limitations in experimental design are the use of total serum immunoglobulin G rather than affinity-purified autoantibodies, the confounding effect of other systemic sclerosis autoantibodies present in total immunoglobulin G and the lack of longitudinal studies to determine if autoantibody titers fluctuate with systemic sclerosis activity and severity. These intriguing new specificities expand the spectrum of autoantibodies observed in systemic sclerosis. Continuing elucidation of their potential mechanistic roles raises hope of a better understanding of systemic sclerosis pathogenesis leading to improved therapies.

Autoantibodies as biomarkers for interstitial lung disease in idiopathic inflammatory myositis and systemic sclerosis: The case of anti-eIF2B antibodies

Objectives

Serum autoantibodies are pivotal for the early detection of systemic autoimmune rheumatic diseases such as Systemic Sclerosis (SSc) and Poly/Dermatomyositis (PM/DM), and in some cases are associated with organ complications such as interstitial lung disease (ILD). A paradigmatic example is provided by the autoantibody against the Eukaryotic Initiation Factor 2B (eIF2B) that has been recently detected in SSc.

Methods

Sera from 118 patients with SSc, 8 Poly/Dermatomyositis, 2 overlap SSc/Polymyositis, 4 undifferentiated connective tissue disease-UCTD and 3 healthy controls were tested first by indirect immunofluorescence for anti-nuclear antibodies-ANA pattern. Further, we employed protein-radioimmunoprecipitation (IP) and IP- Western Blot for the detection and confirmation of anti-eIF2B antibodies. Serum findings were further correlated with the clinical features of patients.

Results

We identified 3 SSc cases (2.5%) positive for anti-eIF2B antibodies while this autoantibody was not detected in control sera. Using protein-IP all three patients manifested the 38kD protein which is the antigenic target of anti-eIF2B antibodies, and this was associated with a cytoplasmic pattern at indirect immunofluorescence. The presence of anti-eIF2B was associated with ILD and a diffuse SSc variant, in one case in association with anti-Scl70/topoI.

Conclusions

Our data confirm that a small subgroup (2.5%) of patients with SSc have detectable anti-eIF2B with cytoplasmic-positive staining at immunofluorescence and this reactivity is associated with ILD.

Analysis of anti-RNA polymerase III antibodies in Chinese Han systemic sclerosis patients

OBJECTIVES

This study aimed to assess the prevalence and clinical correlation of anti-RNA polymerase III antibodies (anti-RNAP III) in Chinese Han systemic sclerosis (SSc) patients.

METHODS

Serum samples from 236 patients with SSc, 125 patients with connective tissue diseases (CTD), and 166 healthy controls (HCs), recruited from Peking Union Medical College Hospital and 21 other medical centers in China, were tested for antibodies to RNA polymerase III by means of a line immunoassay (LIA) or an enzyme-linked immunosorbent assay (ELISA) kit.

RESULTS

Anti-RNAP III antibodies were found in 14/236 SSc patients (5.93%), 1/125 (0.80%) CTD patients, and 0/166 (0.00%) HCs. The prevalence of anti-RNAP III was higher in SSc patients than in the CTD and HC groups (p = 0.02, p = 0.001, respectively). Renal crisis was significantly more common in patients with anti-RNAP III than patients without anti-RNAP III (42.9 vs. 4.1%, p < 0.0001). Gastrointestinal involvement was significantly more common in patients without anti-RNAP III than patients with anti-RNAP III (53.6 vs. 21.4%, p = 0.039). There was good agreement between the ELISA and line immunoassay (LIA) detection capabilities for anti-RNAP III.

CONCLUSIONS

The anti-RNAP III antibody, which was detected by ELISA, has diagnostic value for SSc and predictive value for SSc-related renal crisis. Both ELISA and LIA are very reliable methods for anti-RNAP III.Key Points• The prevalence of anti-RNAP III antibody was determined in Chinese SSc patients and performed ethnic differences.• The clinical association between anti-RNAP III antibody and Chinese SSc patients was evaluated in this research.• Methodological consistency of detection of anti-RNAP III antibody using commercial ELISA and LIA methods was evaluated in this research.

Positive effect of ozonotherapy on serum concentration of soluble interleukin-2 receptor and neopterin in patients with systemic sclerosis

Introduction

Systemic sclerosis (SSc) is a chronic systemic autoimmune disease of unknown aetiology. No curative therapy exists, thus management includes controlling of symptoms and prevention of complications. Ozonotherapy has multiple beneficial therapeutic effects which can translate into improving prognostic factors for SSc.

Aim

To evaluate the effect of ozone on selected factors of inflammation: serum concentration of the soluble receptor of interleukin-2 (IL-2 sR), neopterin as well as the peripheral blood smear in patients with SSc.

Material and methods

Forty-two patients with SSc underwent two series of 10-minute baths in water with a mixture of air and ozone separated by a 10-day period without treatment. Examinations were performed at baseline and 10 days after completing the last treatment.

Results

The mean concentration of IL-2 sR decreased significantly from 1563.73 to 1249.86 pg/ml. The mean concentration of neopterin decreased significantly from 12.06 to 10.9 nmol/ml. Absolute monocytosis decreased insignificantly from 1.694 to 1.480 G/l. Correlations between the disease duration and concentration of IL-2 sR were weak and negative, while between the disease duration and concentration of neopterin were weak and positive.

Conclusions

Ozonotherapy had a beneficial influence on the immune response in patients with scleroderma. Balneotherapy may be considered as an additional therapeutic option, but further research is required.

Predictive autoimmunity using autoantibodies: screening for anti-nuclear antibodies

Background:

Early detection of antinuclear antibodies (ANA) in asymptomatic subjects is useful to predict autoimmune diseases years before diagnosis. ANA have been determined by indirect immunofluorescence (IIF) using human epithelial type 2 (HEp-2) cells, which is considered the gold standard technique. Multiplex technology (BioPlex ANA Screen) has been introduced for ANA evaluation in recent years. Nevertheless, concordance between BioPlex and IIF is low and there is no harmonization between both methods for detection of autoantibodies. This study has aimed to clarify the clinical significance of autoantibodies detected by BioPlex ANA Screen in subjects with undiagnosed clinical suspicion of autoimmune disease and to determine the predictive value of autoantibodies detected by BioPlex ANA Screen.

Methods:

A 3-year follow-up study was performed of 411 subjects without a clear diagnosis of autoimmune diseases in whom autoantibodies were detected by BioPlex ANA Screen that were negative by IIF on HEp-2 cells.

Results:

At 3 years of follow-up, 312 (76%) subjects were positive for autoantibodies by IIF and 99 subjects continued to be negative. A diagnosis of autoimmune disease was found in most of the subjects (87%).

Conclusions:

BioPlex ANA Screen has greater sensitivity than IIF on HEp-2 cells for autoantibodies detection. Early detection of these antibodies by BioPlex can predict possible development of autoimmune diseases.

Autoantibodies to a novel Rpp38 (Th/To) derived B-cell epitope are specific for systemic sclerosis and associate with a distinct clinical phenotype

Objective

Detection of antinuclear antibodies and specific autoantibodies is important in the diagnosis and classification of SSc. Several proteins of the Th/To complex, including Rpp25, Rpp38 and hPop1 are the target of autoantibodies in SSc patients. However, very little is known about the epitope distribution of this autoantigen. Consequently, we screened Rpp25, Rpp38 and hPop1 for B cell epitopes and evaluated their clinical relevance.

Methods

Serum pools with (n = 2) and without (n = 1) anti-Th/To autoantibodies were generated and used for epitope discovery. Identified biomarker candidate sequences were then utilized to synthesize synthetic, biotinylated, soluble peptides. The peptides were tested to determine reactivity with sera from SSc cohorts (n = 202) and controls (n = 159) using a chemiluminescence immunoassay. Additionally, samples were also tested for antibodies to full-length recombinant Rpp25 antibodies by chemiluminescence immunoassay.

Results

Several immunodominant regions were found on the three proteins. The strongest reactivity was observed with an Rpp38 peptide (aa 229–243). Autoantibodies to the Rpp38 peptide were detected in 8/149 (5.4%) limited cutaneous SSc patients, but not in any of 159 controls (P = 0.003 by two-sided Fisher's exact probability test). Although reactivity to the novel antigenic peptide was correlated with the binding to Rpp25 (rho = 0.44; P < 0.0001), subsets of patient sera either reacted strongly with Rpp25 or with the novel Rpp38-derived peptide.

Conclusion

A novel Rpp38 epitope holds promise to increase the sensitivity in the detection of anti-Th/To autoantibodies, thus enhancing the serological diagnosis of SSc.

Multiparametric autoantibody profiling of patients with systemic sclerosis in Greece

Background:

Systemic sclerosis (SSc) is an autoimmune rheumatic disease characterized by a wide range of disease-specific and disease-related autoantibodies (autoAbs). Profile assays have been developed and are currently in use to meet the demand for better characterization of all autoAbs found in SSc patients.

Aim:

To assess the clinical relevance of SSc-related autoantibodies in 158 patients with SSc, all from Central Greece, taking advantage of a multiparametric SSc autoantibody line immunoassay.

Material and methods:

158 consecutive patients with SSc (137 females, mean age 53.2 ± 10 years; 63 patients with dcSSc and 95 with lcSSc) from central Greece were included in the study. Eighteen patients with morphea were also included. Serum samples were analyzed by a profile SSc nucleoli line assay (Euroimmun) to detect Abs against 13 autoantigens: Scl-70, Centromere (A, B), RNA polymerase III (subunits 11 & 155), fibrillarin, NOR90, Th/To, PM/Scl 100, PM/Scl75, Ku, PDGFR and Ro52. Antinuclear autoAbs (ANAs) were detected by indirect immunofluorescence.

Results:

ANAs were detected in 97.5% of SSc patients. Reactivities to specific autoantigens were as follows: Topo I, 40.5%; CENP, 32.9%; Ro52, 21.5%; RP11, 8.9%; RP155, 13.3%; NOR 90, 4.4%; Ku 3.8%; PM-Scl75, 3.2%; PM-Scl100, 1.3%; Th/To, 1.3%; Fibrillarin, 1.3%; PDGFR 0%; Ro52 21.5%. Twenty-one of SSc did not have any of the main autoAbs, namely anti-Topo I, anti-CENP, anti-RNA pol III Abs.

Conclusions:

Multiparametric autoAb test provides positive SSc-associated autoAb reactivities in SSc patients negative for the three main autoAbs and this may prove of significance in early disease diagnosis.

Systemic sclerosis phase III clinical trials: Hope on the horizon?

While significant progress has been made in treating systemic sclerosis, many patients still have an outcome that is far from satisfactory. For the first time in history, several drugs are now in phase III randomized controlled trials. Approaches tested include the anti-B cell antibody rituximab, the anti-interleukin-6 receptor antibody tocilizumab, the antifibrotic drugs nintedanib and pirfenidone, and the cannabinoid receptor mimetic lenabasum. That all these drugs are in advanced clinical trials despite the relatively low incidence of the disease therefore is good news. Not only is there realistic hope that at least some of the approaches will work, this also indicates growing industry interest, for most of the trials are company-sponsored. This review attempts to delineate the ongoing trials and to summarize the underlying evidence of these candidate systemic sclerosis drugs.

Serum Soluble Vascular Cell Adhesion Molecule-1 Overexpression Is a Disease Marker in Patients with First-Time Diagnosed Antinuclear Antibodies: A Prospective, Observational Pilot Study

Objective

Antinuclear antibodies (ANA) serve as screening tests for connective tissue diseases but have low specificity. In this pilot study, we aimed to identify patients with first-time positive ANA and musculoskeletal complaints and correlate serum soluble vascular adhesion molecules as biomarkers.

Methods

Prospective, observational study with 100 ANA-positive patients, comparing them to age- and gender-matched healthy controls (HC, n = 75), was conducted. Serum levels of soluble intercellular adhesion molecule-1 (sICAM-1), endothelial-leukocyte adhesion molecule-1 (sELAM-1), and vascular cell adhesion molecule-1 (sVCAM-1) were measured. A subgroup of patients with systemic sclerosis (SSc) treated with immunosuppressants was followed over 10 months.

Results

Patients belonged to three main entities: rheumatoid arthritis (RA, n = 32), collagen diseases (CD, n = 56) also including systemic sclerosis (SSc, n = 11), and other autoimmune diseases (n = 12). sICAM-1 was similar among groups. sELAM-1 was elevated by 1.9-fold in only in SSc. sVCAM-1 was elevated by 3.1-fold in RA and by 3.3-fold in CD and in other autoimmune diseases by 3.4-fold. Seven SSc patients with immunosuppression had a 2.7-fold increased sVCAM-1 at baseline and reached the levels of healthy controls after 5 months, while CRP, ESR, and clinical parameters remained unchanged.

Conclusion

Our study suggests that sVCAM-1 is a disease marker independent of standard serum parameters in several rheumatic diseases. This study is registered with EU PAS Register number: EUPAS22154.

Biomarkers in connective tissue diseases

Autoimmune connective tissue diseases are clinically variable, making biomarkers desirable for assessing future disease risk, supporting early and accurate diagnosis, monitoring disease activity and progression, selecting therapeutics, and assessing treatment response. Because of their correlations with specific clinical characteristics and often with disease progression, autoantibodies and other soluble mediators are considered potential biomarkers. Additional biomarkers might reflect downstream pathologic processes or appear because of ongoing inflammation and damage. Because of overlap between diseases, some biomarkers have limited specificity for a single autoimmune connective tissue disease. This review describes select current biomarkers that aid in the diagnosis and treatment of several major systemic autoimmune connective tissue disorders: systemic lupus erythematosus, rheumatoid arthritis, systemic sclerosis, and anti-neutrophil cytoplasmic antibody-associated vasculitides. Newly proposed biomarkers that target various stages in disease onset or progression are also discussed. Newer approaches to overcome the diversity observed in patients with these diseases and to facilitate personalized disease monitoring and treatment are also addressed.

Disease-related autoantibody profile in patients with systemic sclerosis

BACKGROUND

Autoantibodies (autoAbs) help in diagnosis and predicting clinical phenotypes in systemic sclerosis (SSc).

AIM OF THE STUDY

To determine the clinical utility of 13 SSc-related autoAbs in SSc patients.

MATERIAL AND METHODS

A total of 131 consecutive patients with SSc (111 female, mean age 58.1 ± 14 years; 49 with diffused cutaneous SSc [dcSSc] and 82 with limited cutaneous SSc [lcSSc]) were analysed by a multiplex line immunoassay (Euroimmun) for autoantibodies (autoAbs) against 13 SSc-related antigens. A total of 22 patients with primary Raynaud phenomenon (RP), and 22 healthy controls were also analysed.

RESULTS

ANA by indirect immunofluorescence was present in 128 (97.7%) patients with SSc. Excluding anti-Ro52, 113 (89.3%) SSc patients were positive for at least one autoAb: anti-Topoisomerase I (anti-Topo) I abs in 54 (41.2%), anti-centromere proteins (anti-CENP) in 37 (28.2%, all reactive with centromere protein-A (CENPA) and centromere protein B (CENPB)), anti-RNA polymerase III(RP11) in 19 (14.5%), anti-RNA polymerase III(RP155) in 13 (9.9%), anti-fibrillarin in 4 (3.1%), anti-Ku in 6 (4.6%), anti-nucleolus-organizing region (anti-NOR90) in 8 (6.1%), anti-PM-Scl100 in 2 (1.5%), and anti-PM-Scl75 in 4 (3.1%). There was no immunoreactivity for Th/To or platelet-derived growth factor receptor (PDGFR). Overall, 102 (77.9%) SSc patients had autoAbs against Topo I, CENPA or CENPB, RP11 or RP155. Anti-Topo I abs were strongly associated with dcSSc, interstitial lung disease (ILD) (p < .001), pulmonary hypertension (PH) (p = .019) and ILD-PH (p = .003). Anti-CENPB abs were associated with lcSSc, and negatively associated with ILD. Anti-RP11 and anti-NOR90 abs were associated with male gender, and anti-NOR90 associated with ILD.

CONCLUSIONS

Anti-Topo I, anti-CENP, and anti-RNA pol III are the most prevalent autoAbs in SSc. Anti-Topo I and anti-NOR90 abs are associated with ILD and/or PAH.

Role of Autoantibodies in the Diagnosis of Connective-Tissue Disease ILD (CTD-ILD) and Interstitial Pneumonia with Autoimmune Features (IPAF)

The diagnosis of interstitial lung disease (ILD) requires meticulous evaluation for an underlying connective tissue disease (CTD), with major implications for prognosis and management. CTD associated ILD (CTD-ILD) occurs most commonly in the context of an established CTD, but can be the first and/or only manifestation of an occult CTD or occur in patients who have features suggestive of an autoimmune process, but not meeting diagnostic criteria for a defined CTD-recently defined as "interstitial pneumonia with autoimmune features" (IPAF). The detection of specific autoantibodies serves a critical role in the diagnosis of CTD-ILD, but there remains a lack of data to guide clinical practice including which autoantibodies should be tested on initial assessment and when or in whom serial testing should be performed. The implications of detecting autoantibodies in patients with IPAF on disease behaviour and management remain unknown. The evaluation of CTD-ILD is challenging due to the heterogeneity of presentations and types of CTD and ILD that may be encountered, and thus it is imperative that immunologic tests are interpreted in conjunction with a detailed rheumatologic history and examination and multidisciplinary collaboration between respiratory physicians, rheumatologists, immunologists, radiologists and pathologists.

Systematic autoantigen analysis identifies a distinct subtype of scleroderma with coincident cancer

Scleroderma is a chronic autoimmune rheumatic disease associated with widespread tissue fibrosis and vasculopathy. Approximately two-thirds of all patients with scleroderma present with three dominant autoantibody subsets. Here, we used a pair of complementary high-throughput methods for antibody epitope discovery to examine patients with scleroderma with or without known autoantibody specificities. We identified a specificity for the minor spliceosome complex containing RNA Binding Region (RNP1, RNA recognition motif) Containing 3 (RNPC3) that is found in patients with scleroderma without known specificities and is absent in unrelated autoimmune diseases. We found strong evidence for both intra- and intermolecular epitope spreading in patients with RNA polymerase III (POLR3) and the minor spliceosome specificities. Our results demonstrate the utility of these technologies in rapidly identifying antibodies that can serve as biomarkers of disease subsets in the evolving precision medicine era.

Anti-centromere protein A antibodies in systemic sclerosis: Significance and origin

Systemic sclerosis (SSc) is systemic, autoimmune, connective tissue disorder characterized by vascular abnormalities, collagen deposition (fibrosis), and the production of autoantibodies to nuclear proteins. About 20%-40% of patients have antibodies to centromere protein (CENP)-A or -B. Despite the known association of anti-CENP antibodies with certain clinical features of SSc, the role of these antibodies in SSc physiopathology is still poorly understood. To better understand the clinical significance and origin of these antibodies, we and others have been studying the epitopic motifs (amino acid contact sites) on CENP-A with the aim of determining whether other proteins can prime or be targeted by them. Here, we review published and ongoing studies aimed at defining the fine specificity and origin of anti-CENP-A antibodies. We describe progress made in identifying the CENP-A epitopic motif amino acids, and the discovery of one of these motifs in forkhead box protein E3 (FOXE-3), a transcription factor previously studied only for its role in the development of lens fiber cells. Moreover, we discuss preliminary evidence for a possible role of FOXE-3 in SSc pathogenesis and for the association of different subsets of anti-CENP-A antibodies, heterogeneously expressed among SSc patients, with some clinical correlates.

Update on biomarkers in systemic sclerosis: tools for diagnosis and treatment

Systemic sclerosis (SSc) is a complex autoimmune disease in which immune activation, vasculopathy, and extensive fibrosis of the skin and internal organs are among the principal features. SSc is a heterogeneous disease with varying manifestations and clinical outcomes. Currently, patients’ clinical evaluation often relies on subjective measures, non-quantitative methods, or requires invasive procedures as markers able to predict disease trajectory or response to therapy are lacking. Therefore, current research is focusing on the discovery of useful biomarkers reflecting ongoing inflammatory or fibrotic activity in the skin and internal organs, as well as being predictive of future disease course. Recently, remarkable progress has been made towards a better understanding of numerous mechanisms involved in the pathogenesis of SSc. This has opened new possibilities for the development of novel biomarkers and therapy. However, current proposed biomarkers that could reliably describe various aspects of SSc still require further investigation. This review will summarize studies describing the commonly used and validated biomarkers, the newly emerging and promising SSc biomarkers identified to date, and consideration of future directions in this field.

Connective tissue disease-associated pulmonary arterial hypertension

Although rare in its idiopathic form, pulmonary arterial hypertension (PAH) is not uncommon in association with various associated medical conditions, most notably connective tissue disease (CTD). In particular, it develops in approximately 10% of patients with systemic sclerosis and so these patients are increasingly screened to enable early detection. The response of patients with systemic sclerosis to PAH-specific therapy appears to be worse than in other forms of PAH. Survival in systemic sclerosis-associated PAH is inferior to that observed in idiopathic PAH. Potential reasons for this include differences in age, the nature of the underlying pulmonary vasculopathy and the ability of the right ventricle to cope with increased afterload between patients with systemic sclerosis-associated PAH and idiopathic PAH, while coexisting cardiac and pulmonary disease is common in systemic sclerosis-associated PAH. Other forms of connective tissue-associated PAH have been less well studied, however PAH associated with systemic lupus erythematosus (SLE) has a better prognosis than systemic sclerosis-associated PAH and likely responds to immunosuppression.

An autoimmune myositis-overlap syndrome associated with autoantibodies to nuclear pore complexes: description and long-term follow-up of the anti-Nup syndrome

Autoimmune myositis encompasses various myositis-overlap syndromes, each being identified by the presence of serum marker autoantibodies. We describe a novel myositis-overlap syndrome in 4 patients characterized by the presence of a unique immunologic marker, autoantibodies to nuclear pore complexes. The clinical phenotype was characterized by prominent myositis in association with erosive, anti-CCP, and rheumatoid factor-positive arthritis, trigeminal neuralgia, mild interstitial lung disease, Raynaud phenomenon, and weight loss. The myositis was typically chronic, relapsing, and refractory to corticosteroids alone, but remitted with the addition of a second immunomodulating drug. There was no clinical or laboratory evidence for liver disease. The prognosis was good with 100% long-term survival (mean follow-up 19.5 yr).By indirect immunofluorescence on HEp-2 cells, sera from all 4 patients displayed a high titer of antinuclear autoantibodies (ANA) with a distinct punctate peripheral (rim) fluorescent pattern of the nuclear envelope characteristic of nuclear pore complexes. Reactivity with nuclear pore complexes was confirmed by immunoelectron microscopy. In a cohort of 100 French Canadian patients with autoimmune myositis, the nuclear pore complex fluorescent ANA pattern was restricted to these 4 patients (4%). It was not observed in sera from 393 adult patients with systemic sclerosis (n = 112), mixed connective tissue disease (n = 35), systemic lupus (n = 94), rheumatoid arthritis (n = 45), or other rheumatic diseases (n = 107), nor was it observed in 62 normal adults.Autoantibodies to nuclear pore complexes were predominantly of IgG isotype. No other IgG autoantibody markers for defined connective tissue diseases or overlap syndromes were present, indicating a selective and highly focused immune response. In 3 patients, anti-nuclear pore complex autoantibody titers varied in parallel with myositis activity, suggesting a pathogenic link to pathophysiology. The nuclear pore complex proteins, that is, nucleoporins (nup), recognized by these sera were heterogeneous and included Nup358/RanBP2 (n = 2 patients), Nup90 (n = 1), Nup62 (n = 1), and gp210 (n = 1). Taken together the data suggest that nup autoantigens themselves drive the anti-nup autoimmune response. Immunogenetically, the 4 patients shared the DQA1*0501 allele associated with an increased risk for autoimmune myositis.In conclusion, we report an apparent novel subset of autoimmune myositis in our population of French Canadian patients with connective tissue diseases. This syndrome is recognized by the presence of a unique immunologic marker, autoantibodies to nuclear pore complexes that react with nups, consistent with an "anti-nup syndrome."

A PRISMA-driven systematic review for predictive risk factors of digital ulcers in systemic sclerosis patients

Vasculopathy has a major role in the pathogenesis and tissue injury in systemic sclerosis (SSc). Raynaud's phenomenon (RP) is frequently the first clinical manifestation of SSc preceding by years other clinical manifestations. RP in SSc patients is frequent, often very severe and long lasting. The repeated bouts of RP lead to prolonged digital ischemia that may progress to digital ulceration or in extreme to critical digital ischemia with gangrene. Digital ulcers (DU) are a true burden for all patients. They are very painful, with a long and slow healing course, have high risk of infection and are extremely disabling. In adults, up to 40-50% of patients will experience at least one DU in the course of the disease and of these 31-71% will have recurrent ulcers. In order to try to identify predictive risk factors for DU in SSc patients, an extensive literature review was conducted, according to the guidelines proposed at the PRISMA statement. MEDLINE database (PubMed) and Thomson Reuters Web of Knowledge platform were searched for articles published in peer-reviewed journals since 1990 with the last search run on June 2014 and published in English language. The keyword search terms included: digital ulcer/s, systemic sclerosis, scleroderma, digital scars, ischemic complications, autoantibodies, biomarkers, endothelium dysfunction, endothelin-1, vascular endothelial growth factor (VEGF), endostatin, ADMA, endoglin, angiostatin, and capillaroscopy. The following criteria were included: (1) cohorts of SSc patients including patients with DU, (2) endothelium dysfunction and angiogenesis biomarkers compared with a healthy control group, (3) autoantibodies, capillary morphology and distribution, endothelium dysfunction and angiogenesis biomarkers compared between patients with and without digital ulcers, (4) detailed description of the statistical methods used to conclude for predictive factors, and (5) English language. Our search provided a total of 376 citations. Of these, 297 studies were discarded for not meeting the criteria proposed.

Systemic sclerosis evolution of disease pathomorphosis and survival. Our experience on Italian patients' population and review of the literature

The clinical spectrum and prognosis of systemic sclerosis (SSc) seem to vary among patients' populations recruited during different time periods. In order to verify this possible evolution we investigated the clinico-serological and survival rate in a large Italian SSc series (821 patients; 746 females, 75 males; mean age 53.7±13.9SD years) recruited between 2000 and 2011. The observed findings were compared with previous studies of the world literature.Compared to older Italian SSc series, the present patients' population showed a significantly increased prevalence of limited cutaneous SSc (from 72 to 87.5%; p ≤.0001) and serum anti-centromere antibodies (from 39 to 47,4%; p ≤.001), with a significant reduction of lung (from 81 to 63.7%; p ≤.0001), heart (from 35 to 20.5%; p ≤.0001), and renal involvement (from 10 to 3.8%; p ≤.0001), and skin ulcers (from 54 to 16.5%; p ≤.0001). Cumulative 10th-year survival showed a clear-cut increase (80.7%) compared to our previous series (69.2%). These findings were mirrored by the results of survival studies published during the last five decades, grouped according to the time periods of patients'' recruitment at the referral centers. A clear progression of 10th-year survival rates was detectable, from the 54% median survival of the oldest studies (1935-1974) to 74% and 83.5% of the more recent SSc series, 1976-1999 and after 1999, respectively. In conclusion, the favorable evolution of SSc pathomorphosis and prognosis during the last decades might be related to more diffuse physician/patient awareness of this harmful disease and availability of diagnostic tools, the consequent wider recruitment of patients in the early stages of the disease, as well as to the improved therapeutic strategies.

Prevalence of anti-RNA polymerase III antibodies in systemic sclerosis: New data from a French cohort and a systematic review and meta-analysis

OBJECTIVE

Studies assessing the prevalence of anti-RNA polymerase III (anti-RNAP III) antibodies in systemic sclerosis (SSc) have yielded a wide range of results. The aim of the present study was to describe a new SSc cohort tested for presence of anti-RNAP III and perform a systematic review and meta-analysis to assess the prevalence of anti-RNAP III in patients worldwide and the potential factors of variability.

METHODS

Seropositivity for anti-RNAP III was evaluated in a French cohort of SSc patients. A systematic review of the literature was carried out in PubMed and EMBase. Meta-analysis was performed using available data on prevalence, clinical characteristics of SSc patients, and the types of assays used for anti-RNAP III testing.

RESULTS

One hundred thirty-three French SSc patients were tested for anti-RNAP III, and a prevalence of 6-9% was found in these patients. Thirty studies representing a total population of 8,437 SSc patients were included in the meta-analysis. Prevalence of anti-RNAP III in this population was highly variable (range 0-41%). The overall pooled prevalence of anti-RNAP III was 11% (95% confidence interval 8-14), but heterogeneity was high among studies (I(2) = 93%, P < 0.0001). Geographic factors such as continent or country of study origin partially explained this heterogeneity and correlated with the prevalence. No other baseline SSc characteristics were significantly correlated with the prevalence of anti-RNAP III.

CONCLUSION

Data on our new cohort and our meta-analysis of the literature confirmed that anti-RNAP III prevalence in SSc varies among centers. Geographic factors were significantly associated with prevalence, which underscores the probable implication that genetic background and environmental factors play a role. Heterogeneity among studies remained largely unexplained.

Open questions in autoimmunity: discussions from the 2013 Controversies in Rheumatology and Autoimmunity Meeting

The recent CORA (Controversies in Rheumatology and Autoimmunity) meeting held in 2013 represented a unique opportunity for rheumatologists to address several topics. Among these, four topics include: (i) the role of epigenetic changes in the pathogenesis of rheumatoid arthritis (RA), as shown by studies in monozygotic twins; (ii) the cardiovascular and atherosclerotic risk in patients with RA treated with biologics; (iii) the use of new biomarkers for the diagnosis and follow-up of RA and other autoimmune diseases, as represented by the new automatic machines for anti-nuclear antibodies detection, or ultrasound imaging to follow RA progression; and (iv) the latest guidelines on how to use and manage biologic therapies in RA and other autoimmune diseases, such as lupus. In summary, we will herein present these topics of discussion and underline the conclusions obtained by rheumatologists during the 2013 CORA Meeting.

Automated tests of ANA immunofluorescence as throughput autoantibody detection technology: strengths and limitations

Anti-nuclear antibody (ANA) assay is a screening test used for almost all autoimmune rheumatic diseases, and in a number of these cases, it is a diagnostic/classification parameter. In addition, ANA is also a useful test for additional autoimmune disorders. The indirect immunofluorescence technique on monolayers of cultured epithelial cells is the current recommended method because it has higher sensitivity than solid phase assays. However, the technique is time-consuming and requires skilled operators. Automated ANA reading systems have recently been developed, which offer the advantage of faster and much easier performance as well as better harmonization in the interpretation of the results. Preliminary validation studies of these systems have given promising results in terms of analytical specificity and reproducibility. However, these techniques require further validation in clinical studies and need improvement in their recognition of mixed or less common staining patterns.

Raynaud's phenomenon: from molecular pathogenesis to therapy

Raynaud's phenomenon (RP) is a well defined clinical syndrome characterized by recurrent episodes of digital vasospasm triggered by exposure to physical/chemical or emotional stress. RP has been classified as primary or secondary, depending on whether it occurs as an isolated condition (pRP) or is associated to an underlying disease, mainly a connective tissue disease (CTD-RP). In both cases, it manifests with unique "triple" (pallor, cyanosis and erythema), or "double" color changes. pRP is usually a benign condition, while sRP can evolve and be complicated by acral digital ulcers and gangrene, which may require surgical treatment. The pathogenesis of RP has not yet been entirely clarified, nor is it known whether autoantibodies have a role in RP. Even so, recent advances in our understanding of the pathophysiology have highlighted novel potential therapeutic targets. The aim of this review is to discuss the etiology, epidemiology, risk factors, clinical manifestations, recently disclosed pathogenic mechanisms underlying RP and their correlation with the available therapeutic options, focusing primarily on pRP and CTD-RP.

Clinical significance of autoantibodies to the pericentromeric heterochromatin protein 1a protein

OBJECTIVE

The objective of the study is to determine the frequency and the clinical significance of autoantibodies to the pericentromeric heterochromatin protein 1 (HP1). So far this antinuclear antibody specificity has been mainly reported in patients with the CREST syndrome.

METHODS

We screened the sera of 199 individuals, including patients suffering from various autoimmune disorders (Group I, n=145) and non autoimmune diseases (Group II, n=44 patients) as well as healthy individuals (Group III, n=30). The sera were systematically tested by Western blot and ELISA using a GST-HP1α fusion protein as an antigen.

RESULTS

Anti-HP1 antibodies were detected in 32% of patients in Group I, 11.3% in Group II and 3.3% of individuals in Group III. They could be detected in sera containing or not antinuclear antibodies detectable by indirect immunofluorescence. Anti-HP1 antibodies were mostly associated with the CREST and Sjogren's syndromes (70% and 44.4%, respectively). They could also be detected in 22.2% of patients suffering from various other autoimmune diseases. However, their negative predictive value was 94% in the CREST syndrome.

CONCLUSION

Anti-HP1 autoantibodies are associated with a large spectrum of disorders. However, they have a diagnostic value in the CREST syndrome.