Diagnostic accuracy and predictive value of extended autoantibody profile in systemic sclerosis

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.

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.

Quality of life in systemic sclerosis

Systemic sclerosis (SSc) is a chronic multi-system autoimmune disease associated with disability and reduced quality of life. There is no effective treatment or cure to SSc, so it is important improve global health of these patients and reduce morbidity and mortality associated with SSc. It was made a literature review about quality of life in patients with SSc, regarding the several factors that should be considered and evaluated when attending to SSc patients. It was also considered the validated scales and questionnaires used to measure outcomes in patients with SSc. We concluded that it is important to have an interdisciplinary approach to SSc patients considering the patient's cognitive representations of the disease and what they value most like mobility and hand function, pain, fatigue, sleep, depression and body image.

Hepatotoxicity of green tea: an update

Green tea (GT), obtained from the leaves of Camellia sinensis (L.) Kuntze (Fam. Theaceae), is largely used for its potential health benefits such as reduction in risk of cardiovascular diseases and weight loss. Nevertheless, it is suspected to induce liver damage. Present work reviews the hepatic adverse reactions associated with GT-based herbal supplements, published by the end of 2008 to March 2015. A systematic research was carried out on PubMed, MedlinePlus, Scopus and Google Scholar databases, without any language restriction. Moreover, some accessible databases on pharmacovigilance or phytovigilance were consulted. The causality assessment was performed using the CIOMS/RUCAM score. Nineteen cases of hepatotoxicity related to the consumption of herbal products containing GT were identified. The hepatic reactions involved mostly women (16/19); the kind of liver damage was generally classified as hepatocellular (16/19). The causality assessment between consumption of herbal preparation and hepatic reaction resulted as probable in eight cases and as possible in eleven cases. In seven cases, patients used preparations containing only GT, while twelve reactions involved patients who took multicomponent preparations (MC). The reactions induced by GT had a generally long latency (179.1 ± 58.95 days), and the outcome was always resolution, with recovery time of 64.6 ± 17.78 days. On the contrary, liver injury associated with MC had a shorter latency (44.7 ± 13.85 days) and was more serious in four cases that required liver transplantation and, when resolution occurred, the recovery time was longer (118.9 ± 38.79). MC preparations contained numerous other components, many of which are suspected to induce liver damage, so it is difficult to ascribe the toxicity to one specific component, e.g., GT. Present data confirm a certain safety concern with GT, even if the number of hepatic reactions reported is low considering the great extent of use of this supplement. The mechanism of GT hepatotoxicity remains unclear, but factors related to the patient are becoming predominant. A major safety concern exists when GT is associated with other ingredients that can interact between them and with GT, enhancing the risk of liver damage. Patients should be discouraged from using herbal or dietary supplements containing complex mixtures and should be encouraged to use herbal and dietary supplement possibly under supervision of healthcare professionals.

Autoantibodies in systemic sclerosis: unanswered questions

Systemic sclerosis (SSc) is an autoimmune disease characterized by vascular abnormalities, and cutaneous and visceral fibrosis. Serum autoantibodies directed to multiple intracellular antigens are present in more than 95% of patients and are considered a hallmark of SSc. They are helpful biomarkers for the early diagnosis of SSc and are associated with distinctive clinical manifestations. With the advent of more sensitive, multiplexed immunoassays, new and old questions about the relevance of autoantibodies in SSc are emerging. In this review, we discuss the clinical relevance of autoantibodies in SSc emphasizing the more recently published data. Moreover, we will summarize recent advances regarding the stability of SSc autoantibodies over the course of disease, whether they are mutually exclusive and their potential roles in the disease pathogenesis.

Fecal calprotectin in systemic sclerosis and review of the literature

Fecal calprotectin (FC) is a simple, non-invasive and reproducible test, which has been described to be highly elevated in patients with active inflammatory bowel diseases. Recently, few authors have reported increased levels of FC in SSc patients, although the relationship between FC levels and the degree of gastrointestinal involvement has not yet been determined in patients with SSc. Thus, this prospective study aimed to: 1) determine the prevalence of increased fecal calprotectin (FC) levels in unselected patients with systemic sclerosis (SSc); 2) make prediction about which SSc patients exhibit increased levels of FC; and 3) evaluate the correlation between increased levels of FC and digestive symptoms, and gastrointestinal involvement, including the presence of small intestinal bacterial overgrowth (SIBO) using glucose H2/CH4 breath test. 125 consecutive patients with SSc underwent FC levels and glucose H2/CH4 breath test. All of the patients with SSc also completed a questionnaire on digestive symptoms, and a global symptom score (GSS) was calculated. 93 (74.4%) patients had abnormal levels of FC (>50 μg/g); 68 patients (54.4%) exhibited highly elevated levels of FC (>200 μg/g). A marked correlation was found between abnormal FC levels and GSS score of digestive symptoms, esophageal involvement and delayed gastric emptying. Moreover, we found a strong association between abnormal levels of FC and the presence of SIBO on glucose H2/CH4 breath test, with the higher correlation between the presence of SIBO and the level of FC ≥275 μg/g with an area under the receiver operating characteristic curve of 0.97 ± 0.001 (CI: 0.93-0.99; p<10(-6)); the sensitivity of FC level ≥275 μg/g for predicting SIBO was as high as 0.93, while the specificity was 0.95. Finally, eradication of SIBO was obtained in 52.4% of the SSc patients with a significant improvement of intestinal symptoms. Finally, after 3 months of rotating courses of alternative antibiotic therapy, eradication of SIBO was associated with significant decrease of FC levels in SSc patients. The current study underscores that abnormal FC levels were correlated with gastrointestinal impairment, especially SIBO. Because FC levels ≥275 μg/g were markedly associated with the presence of SIBO, our findings suggest that FC may be a helpful test in identifying the group of SSc patients at high risk for SIBO requiring glucose breath test to detect SIBO. Finally, we also suggest that FC levels may be helpful in SSc patients to assess SIBO eradication, as long-term antibiotic therapy is costly and carries risks such as the onset of pseudo-membranous colitis and SIBO-related antibiotic resistance.

Vascular biomarkers and correlation with peripheral vasculopathy in systemic sclerosis

Vascular disease is a hallmark of systemic sclerosis (SSc). It is present in every patient, being responsible both for the earliest clinical manifestations and the major life-threatening complications of the disease, and thus determining important morbidity and mortality. In SSc, progressive vascular injury leads to vascular tone dysfunction and reduced capillary blood flow, with consequent tissue ischemia and chronic hypoxia. These phenomena are often accompanied by abnormal levels of vascular factors. Microangiopathy in SSc may be easily assessed by nailfold videocapillaroscopy. The variety of derangements detected in the nailfold capillaries is accompanied by abnormal levels of different vascular mediators and appears to be the best evaluable predictor of the development of peripheral vascular complications, such as digital ulcers. The purpose of this review is to summarize in SSc the most relevant vascular biomarkers and the main associations between vascular biomarkers and capillaroscopic parameters and/or the presence of digital ulcers. Vascular biomarkers could become useful predictive factors of vascular damage in SSc, allowing an earlier management of vascular complications.

Undifferentiated Connective Tissue Disease at risk for systemic sclerosis (SSc) (so far referred to as very early/early SSc or pre-SSc)

In the last few years, a number of studies have been published on a condition characterized by Raynaud's phenomenon (RP) associated with systemic sclerosis (SSc) marker autoantibodies and/or scleroderma-type capillaroscopic abnormalities and referred to as very early/early SSc. The present review is devoted to analyze pathophysiologic, clinical, and evolutive aspects of the condition that would induce to label it as Undifferentiated Connective Tissue Disease at risk for SSc and to split it into 3 subsets (i.e. RP associated to marker autoantibodies and scleroderma-type capillaroscopic abnormalities; RP associated to marker autoantibodies in the absence of scleroderma-type capillaroscopic abnormalities; and RP associated to scleroderma-type capillaroscopic abnormalities without any detectable marker autoantibody), which have been shown to carry different degrees of risk, but not the certainty, to develop overt SSc over time. This nosographic approach is instrumental to plan future studies devoted to investigate validated biomarkers heralding the development of major vascular disease manifestations as well as skin and/or organ fibrosis in patients at risk.

Clinical differences between Thai systemic sclerosis patients with positive versus negative anti-topoisomerase I

BACKGROUND

Anti-topoisomerase I antibody (ATA) carries an increased risk of systemic sclerosis (SSc) internal organ involvement. There have been no published comparisons of the clinical characteristics of patients positive and negative for ATA in Thailand, where the positive rate for ATA is higher than among Caucasians.

OBJECTIVE

To define the clinical differences between SSc, positive versus negative, for ATA.

METHODS

A retrospective cohort study was performed among SSc patients over 18 at Srinagarind Hospital, Khon Kaen University, Thailand, during January 2006-December 2013. SSc-overlap syndrome was excluded.

RESULTS

Two hundred and ninety-four SSc patients were included (female : male 2.5 : 1). The majority (68.6%) were the diffuse cutaneous SSc subset (dcSSc). ATA was positive in 252 patients (85.7%), among whom 71.7% had dcSSc and 28.2% limited cutaneous SSc (lcSSc). Using a multivariate analysis, hand deformity had a significantly positive association with ATA (odds ratio [OR] 7.01; 95% CI 1.02-48.69), whereas being anti-centromere (ACA) positive had a negative association (OR 0.17; 95% CI 0.03-0.92). After doing a subgroup analysis of the SSc subset, the median duration of disease at time of pulmonary fibrosis detection among ATA positive dcSSc was significantly shorter than the ATA negative group (1.05 vs. 6.77 years, P = 0.01). Raynaud's phenomenon (RP) at onset was significantly more frequent in lcSSc sufferers who were ATA negative than those who were ATA positive (90.5% vs. 56.9%, P = 0.005).

CONCLUSIONS

A high prevalence of ATA positivity was found among Thai SSc patients and this was associated with a high frequency of hand deformity, ACA negativity, a short duration of pulmonary fibrosis in dcSSc and a lower frequency of RP in lcSSc.

Systemic sclerosis and prevalence of monoclonal immunoglobulin

INTRODUCTION

The purpose of this study was to estimate the prevalence of monoclonal immunoglobulin (MIg) among patients with systemic sclerosis (SSc) according to the capillary electrophoresis or immunofixation method of detection and to search for any related clinical correlations.

PATIENTS AND METHODS

Retrospective multicenter comparison of capillary electrophoresis and immunofixation results in SSc patients and of the characteristics of patients with and without MIg.

RESULTS

The study included 244 SSc patients (216 women and 28 men, mean age: 55±14 years). Median time since SSc diagnosis was 51 months [0-320]; disease was diffuse in 48% of cases. Ten percent of patients had cancer, including Waldenström macroglobulinemia (n=1) and multiple myeloma (n=3). Capillary electrophoresis showed a γ-globulin anomaly in 41% of cases, and immunofixation in 18%: MIg (13.5%) and restriction of heterogeneity (4.5%). Capillary electrophoresis failed to detect 60% of the 33 MIg patients. Measurable MIg concentrations were obtained from 7 patients. MIg patients were significantly older at SSc diagnosis than those without MIg (p=0.002), had a lower diffusing capacity (p=0.002), a higher prevalence of pulmonary hypertension and cancer (p=0.002) and were more frequently positive for anti-mitochondrial and anti-beta2-glycoprotein-I antibodies (p=0.03 and p=0.02, respectively). Multivariate analyses showed that only age at test [hazard ratio 1.03 (95% CI, 1.00-1.07, p=0.04)] and presence of cancer [hazard ratio 4.46 (95% CI, 1.6-12.4, p=0.004)] were associated with MIg.

CONCLUSION

Immunofixation detected a high prevalence of MIg among SSc patients especially in patients aged 50-years or older. MIg was not detected by the standard capillary electrophoresis in 60% of cases and was significantly associated with cancer.

Current status of systemic sclerosis biomarkers: applications for diagnosis, management and drug development

Systemic sclerosis (SSc) is a clinically heterogeneous orphan disease of unknown etiology and no effective therapy. It is characterized by protean manifestations, an unpredictable disease course and variable outcomes. Clinical manifestations reflect underlying autoimmunity, small vessel vasculopathy and progressive multi-organ fibrosis. Predicting disease progression, pattern and severity of complications and response to therapy in SSc remain major challenges both for the management of patients and for the development of effective disease-modifying therapies. This review summarizes contemporary understanding of novel and emerging biomarkers for SSc. We focus on the development of new classification criteria, the utility of SSc-specific autoantibodies as diagnostic and prognostic markers, and on biomarkers for skin and lung involvement. Finally, we review genome-wide expression analysis as a tool to predict therapeutic responses. We anticipate that the development, validation and application of these biomarkers, singly or more likely in combination, will have a transformative impact in SSc, informing early diagnosis, classification and management, as well as the design, execution and interpretation of clinical trials of novel therapeutic agents.

Coherent somatic mutation in autoimmune disease

BACKGROUND

Many aspects of autoimmune disease are not well understood, including the specificities of autoimmune targets, and patterns of co-morbidity and cross-heritability across diseases. Prior work has provided evidence that somatic mutation caused by gene conversion and deletion at segmentally duplicated loci is relevant to several diseases. Simple tandem repeat (STR) sequence is highly mutable, both somatically and in the germ-line, and somatic STR mutations are observed under inflammation.

RESULTS

Protein-coding genes spanning STRs having markers of mutability, including germ-line variability, high total length, repeat count and/or repeat similarity, are evaluated in the context of autoimmunity. For the initiation of autoimmune disease, antigens whose autoantibodies are the first observed in a disease, termed primary autoantigens, are informative. Three primary autoantigens, thyroid peroxidase (TPO), phogrin (PTPRN2) and filaggrin (FLG), include STRs that are among the eleven longest STRs spanned by protein-coding genes. This association of primary autoantigens with long STR sequence is highly significant (p<3.0x10(-7)). Long STRs occur within twenty genes that are associated with sixteen common autoimmune diseases and atherosclerosis. The repeat within the TTC34 gene is an outlier in terms of length and a link with systemic lupus erythematosus is proposed.

CONCLUSIONS

The results support the hypothesis that many autoimmune diseases are triggered by immune responses to proteins whose DNA sequence mutates somatically in a coherent, consistent fashion. Other autoimmune diseases may be caused by coherent somatic mutations in immune cells. The coherent somatic mutation hypothesis has the potential to be a comprehensive explanation for the initiation of many autoimmune diseases.

Autoantibodies to the Rpp25 component of the Th/To complex are the most common antibodies in patients with systemic sclerosis without antibodies detectable by widely available commercial tests

OBJECTIVE

Antinuclear antibodies (ANA) occur in up to 95% of patients with systemic sclerosis (SSc). In most, SSc-associated antibodies are detected (i.e., centromere, topoisomerase I, RNA polymerase III, PM/Scl, Ro52/TRIM21, and U1RNP). Ribonuclease P protein subunit p25, (Rpp25) is an autoantigenic component of the Th/To complex. The contribution of anti-Th/To and anti-Rpp25 antibodies to ANA positivity in patients with SSc remains unknown.

METHODS

Sera from 873 patients with SSc were tested for ANA, and SSc-associated antibodies were measured. Samples without antibodies to extractable nuclear antigens (ENA; n = 53, ANA+/ENA-), were analyzed by immunoprecipitation (IP) and metabolically labeled proteins and for anti-Rpp25 antibodies (n = 50) by a chemiluminescent immunoassay (CLIA) and Rpp25 ELISA.

RESULTS

Anti-Th/To antibodies occurred in 19/53 (36%), as determined by IP, and were the most common autoantibody in ANA+/ENA- SSc. Of those samples, 50/53 were available for additional testing by CLIA and ELISA. Anti-Rpp25 antibodies were detected in 12 (24% CLIA) or 10 (20% ELISA) of 50 patients. Receiver-operating characteristic curve analysis showed similar discrimination between Th/To IP-positive (n = 19) and -negative samples (n = 31) by CLIA and ELISA (area under the curve 0.90 vs 0.87; p = 0.6691). The positive percent agreement between IP and CLIA or ELISA was 12/19 (63.2%, 95% CI 38.4-83.7%) or 10/19 (52.6%, 95% CI 73.3-94.2%), respectively. Negative percent agreement was 100% for both assays.

CONCLUSION

Autoantibodies to the Th/To autoantigen are important in patients with SSc who have been considered negative for SSc-specific or SSc-associated antibodies by widely available commercial assays. Rpp25 can be considered a major target of anti-Th/To antibodies. Assays detecting anti-Th/To and anti-Rpp25 antibodies may be important in SSc.

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.

International recommendations for the assessment of autoantibodies to cellular antigens referred to as anti-nuclear antibodies

Anti-nuclear antibodies (ANA) are fundamental for the diagnosis of autoimmune diseases, and have been determined by indirect immunofluorescence assay (IIFA) for decades. As the demand for ANA testing increased, alternative techniques were developed challenging the classic IIFA. These alternative platforms differ in their antigen profiles, sensitivity and specificity, raising uncertainties regarding standardisation and interpretation of incongruent results. Therefore, an international group of experts has created recommendations for ANA testing by different methods. Two groups of experts participated in this initiative. The European autoimmunity standardization initiative representing 15 European countries and the International Union of Immunologic Societies/World Health Organization/Arthritis Foundation/Centers for Disease Control and Prevention autoantibody standardising committee. A three-step process followed by a Delphi exercise with closed voting was applied. Twenty-five recommendations for determining ANA (1-13), anti-double stranded DNA antibodies (14-18), specific antibodies (19-23) and validation of methods (24-25) were created. Significant differences between experts were observed regarding recommendations 24-25 (p<0.03). Here, we formulated recommendations for the assessment and interpretation of ANA and associated antibodies. Notably, the roles of IIFA as a reference method, and the importance of defining nuclear and cytoplasmic staining, were emphasised, while the need to incorporate alternative automated methods was acknowledged. Various approaches to overcome discrepancies between methods were suggested of which an improved bench-to-bedside communication is of the utmost importance. These recommendations are based on current knowledge and can enable harmonisation of local algorithms for testing and evaluation of ANA and related autoantibodies. Last but not least, new more appropriate terminologies have been suggested.

Prospective study to evaluate the association between systemic sclerosis and occupational exposure and review of the literature

INTRODUCTION

Systemic sclerosis (SSc) has complex pathogenesis and likely multifactorial causes. Environmental exposures have been suggested to play a role in SSc pathogenesis, including occupational exposure to pollutants and chemicals as well as use of drugs leading to modulation of immune response. Thus, this case-control study aimed to assess: the relationship between SSc and occupational exposure; and the risk of SSc related to occupational exposure in male and female patients.

METHODS

From 2005 to 2008, 100 patients with a definite diagnosis of SSc were included in the study; 3 age, gender, and smoking habits matched controls were selected for each patient. A committee of experts evaluated blindly occupational exposure to crystalline silica, white spirit, organic solvents, ketones, welding fumes, epoxy resins, and pesticides; an occupational exposure score was calculated for all subjects. Our findings were compared with previous data in the literature.

RESULTS

Increased ORs for SSc were found for: crystalline silica (p<0.0001), white spirit (p<0.0001), aromatic solvents (p=0.0002), chlorinated solvents (p=0.014), trichlorethylene (p=0.044), ketones (p=0.002) and welding fumes (p=0.021). Elevated risk associated with high final cumulative score in SSc was observed for: crystalline silica, white spirit, chlorinated solvents, trichlorethylene, aromatic solvents, any type of solvents, ketones and welding fumes. A marked association between SSc and occupational exposure was further found for: 1) crystalline silica, chlorinated solvents, trichloroethylene, white spirit, ketones and welding fumes in male patients; and 2) white spirit, aromatic solvents, any type of solvent and ketones in female patients. Finally, we did not find an association between SSc and: 1) the use of drugs that have been speculated to play a role in SSc onset (anorexigens, pentazocine, bromocriptine, l-tryptophan); 2) implants - that are prosthesis, silicone implants, and contact lenses; and 3) dyeing hair. In the literature, SSc has been associated with occupational exposure to silica and solvents, while the association between SSc and specific organic solvents and welding fumes has been anecdotally reported.

CONCLUSION

The following occupational factors have an impact in the development of SSc: crystalline silica, white spirit, aromatic solvents, chlorinated solvents, trichlorethylene, ketones and welding fumes. The risk of SSc appears to be markedly associated with high cumulative exposure. Finally, the association between SSc and occupational exposure may be variable according to gender.

Prospective study to evaluate the clinical and radiological outcome of patients with scleroderma of the face

INTRODUCTION

Scleroderma featuring rare connective tissue disease that manifests as skin sclerosis and variable systemic involvement. Two categories of scleroderma are known: systemic sclerosis, characterized by cutaneous sclerosis and visceral involvement and localized scleroderma or morphea which classically presents benign evolution and self-limited, confined to the skin and/or underlying tissue. Recent studies show that the localized form may possibly course with involvement of internal organs and variable morbidity. This study aimed to determine the demographic characteristics, the prevalence of systemic manifestations and laboratory findings, as well as the association with autoimmune diseases, and the evolution of neurological findings, both clinical as brain MRI in patients with scleroderma of the face and its relation with the activity skin.

METHODS

Patients with localized scleroderma with facial involvement were evaluated and underwent neurological examination, magnetic resonance imaging and ophthalmology evaluation. After 3years, the patients were subjected again to MRI.

RESULTS

We studied 12 patients with localized scleroderma of the face. Of this total, headache being the most frequent complaint found in 66.7% of patients, 33.3% had neurological changes possibly associated with scleroderma. As for ophthalmologic evaluation, 25% of patients showed abnormalities. The most frequent parenchymal finding was the presence of lesions with hyperintense or hypointense signal in 75% of patients, followed by ventricular asymmetry at 16.7%. Of the patients who had neurological deficits, 75% also had a change to MRI. In all patients, imaging findings after 3years were unchanged. During this interval of 3years, 25% of patients showed signs of activity of scleroderma.

CONCLUSION

Patients with localized scleroderma of the face have a high prevalence of neurological and ophthalmological changes. Based on these findings, we suggest that all cases of localized scleroderma of the face should be thoroughly examined for the presence of systemic changes.

Rpp25 is a major target of autoantibodies to the Th/To complex as measured by a novel chemiluminescent assay

Introduction

Autoantibodies to the Th/To antigen have been described in systemic sclerosis (SSc) and several proteins of the macromolecular Th/To complex have been reported to react with anti-Th/To antibodies. However, anti-Th/To has not been clinically utilized due to unavailability of commercial tests. The objective of the present study is to evaluate the newly developed ELISA and chemiluminescent immunoassay (CLIA) to measure autoantibodies to Rpp25 (a component of the Th/To complex) using immunoprecipitation (IP) as the reference method.

Methods

The first cohort consisted of 123 SSc patients including 7 anti-Th/To positive samples confirmed by IP. Additional seven anti-Th/To positive samples from non-SSc patients were also tested. For evaluation of the QUANTA Flash Rpp25 CLIA (research use only), 8 anti-Th/To IP positives, a cohort of 70 unselected SSc patients and sera from various disease controls (n = 357) and random healthy individuals (n = 10) were studied.

Results

Anti-Rpp25 antibodies determined by ELISA were found in 11/14 anti-Th/To IP positive but only in 1/156 (0.6%) negative samples resulting in a positive percent agreement of 78.6% (95% confidence interval [CI] 49.2, 95.3%) and a negative percent agreement of 99.4% (95% CI 96.4, 100.0%). To verify the results using a second method, 53 samples were tested by ELISA and CLIA for anti-Rpp25 reactivity and the results were highly correlated (rho = 0.71, 95% CI 0.56, 0.81; P < 0.0001). To define the cutoff of the CLIA, anti-Th/To IP positive and negative sera were tested using the anti-Rpp25 CLIA. At the cutoff selected by receiver operating characteristic (ROC) analysis 8/8 (100.0%) of the anti-Th/To positive sera but only 2/367 (0.5%) of the controls were positive for anti-Rpp25 antibodies. The positive and negative percent agreements were 100.0% (95% CI 63.1, 100.0%) and 99.5% (95% CI 98.0, 99.9%), respectively. In the disease cohorts 2/70 (2.9%) of the SSc patients were positive for anti-Rpp25 antibodies compared to 2/367 (0.5%) of the controls (P = 0.032). ROC analysis showed discrimination between SSc patients and controls with an area under the curve value of 0.732 (95% CI 0.655, 0.809).

Conclusion

Rpp25 is a major target of autoantibodies to the Th/To autoantigen complex. Further studies are needed to evaluate the clinical utility of the new assays.