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S J Adelstein - One of the best experts on this subject based on the ideXlab platform.
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modification of thresholds for detection of Extractable Nuclear Antigens ena using a commercial elisa
Pathology, 2012Co-Authors: Louise Wienholt, S J AdelsteinAbstract:The identification of antibodies to Extractable Nuclear Antigens (ENA) is important in the diagnosis of connective tissue diseases. Traditional gel based methods of detection such as counterimmu-noelectrophoresis (CIEP) have been replaced in recent years by more automated semi-quantitative systems such as ELISA and multiplex based assays. However the sensitivity and specificity of these assays have been shown to be variable. A review of 3000 patient samples showed that by decreasing the cut-off for positive confirmation by 25% on the Euroimmun screening ELISA [ANA Screen 11-ELISA (IgG)], an additional 28 patients (0.9%) were referred for confirmatory testing by the Euroimmun line blot [Euroline ANA Proflie 3 (IgG)]. Of these 20 (71%) showed positivity to a variety of Nuclear Antigens while 8/28 (29%) were negative. Clinical information was available on 14/20 (70%); the identification of an ENA was consistent with a connective tissue disease in 8/14 (57%) of patients, while 10/14 (71%) patients were already on immunosuppressive therapy. Decreasing the threshold value for confirmatory testing to 75% of the kit calibrator, reflective of the uncertainty of measurement (UOM) of the assay, increased the diagnostic sensitivity of the assay in detecting true positive samples that would not have had additional testing using the threshold recommended by the manufacturer.
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minireviews autoantibodies to Extractable Nuclear Antigens making detection and interpretation more meaningful
2002Co-Authors: Tri Giang Phan, Richard C W Wong, S J AdelsteinAbstract:The diagnosis of autoimmune connective tissue diseases (CTDs) depends not only on the identification of patients manifesting disease-associated groups of clinical symptoms and signs but also on the detection of autoantibodies directed against Nuclear or cytoplasmic Antigens. Clinicians, however, often do not fully understand the appropriate application and limitations of these tests (10, 25). Over the last decade, new methods of performing immunology tests have been introduced into laboratory practice, principally to facilitate the processing of large numbers of samples. This rapid change has compounded the problems that result when requesting clinicians are unaware of the performance characteristics of laboratory tests. Testing for autoantibodies to Extractable Nuclear Antigens (ENAs) provides a cogent example. Interpretation of the clinical significance and role of these antibodies in the diagnosis and management of CTDs is based on information gained by using gel-based techniques, such as double immunodiffusion (DID) and counterimmunoelectrophoresis (CIEP) (11). The disease associations linked to the findings may no longer hold true with newer techniques, such as enzyme-linked immunosorbent assays (ELISAs) and immunoblotting (IB) assays. For example, anti-Sm antibodies detected by gel-based techniques are highly specific for systemic lupus erythematosus (SLE) and form part of the revised American Rheumatism Association criteria for the classification of SLE (26). However, the detection of anti-Sm antibodies by ELISAs in some patients who do not have SLE has diluted the strength of this formerly very powerful clinical association (12). Clinicians not aware of this subtle difference in the performance characteristics of the ELISA method may overdiagnose SLE. In this minireview, we examine the role of anti-ENA antibody testing in the diagnosis of CTDs, compare the performance of tests that are commonly used in the diagnostic immunology laboratory to measure anti-ENA antibodies, and discuss ways in which the laboratory can improve its anti-ENA antibody testing and reporting to make the results more meaningful for clinicians.
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autoantibodies to Extractable Nuclear Antigens making detection and interpretation more meaningful
Clinical and Vaccine Immunology, 2002Co-Authors: Tri Giang Phan, Richard C W Wong, S J AdelsteinAbstract:The diagnosis of autoimmune connective tissue diseases (CTDs) depends not only on the identification of patients manifesting disease-associated groups of clinical symptoms and signs but also on the detection of autoantibodies directed against Nuclear or cytoplasmic Antigens. Clinicians, however,
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high quality cost effective strategy for detection of autoantibodies to Extractable Nuclear Antigens
Clinical and Vaccine Immunology, 2001Co-Authors: Tri Giang Phan, Dana Bird, Kara Smithers, Vicky Wong, Kerri Gallagher, Andrew Williams, S J AdelsteinAbstract:We evaluated methods for the detection of autoantibodies to Extractable Nuclear Antigens (ENAs) to determine the strategy that yielded the most cost effective and clinically meaningful result. We prospectively compared counterimmunoelectrophoresis (CIEP) with and without serum prediffusion (SPD) and found that SPD significantly improved the quality of precipitation lines. This resulted in a decreased requirement for repeat testing and, consequently, was associated with a significant decrease in reagent costs and specimen turnaround time. We also retrospectively compared reactivity by CIEP, CIEP plus SPD, enzyme-linked immunosorbent assay (ELISA), and line immunoassay (LIA) of 52 serum samples that were previously determined to be positive for ENAs, and we correlated the results with clinical diagnoses. There was significant agreement among CIEP, CIEP plus SPD, ELISA, and LIA for the detection of anti-SS-A, anti-SS-B and anti-RNP. In general, CIEP, CIEP plus SPD, and LIA correlated better with the clinical diagnoses than ELISA, even though ELISA detected anti-ENAs more often than the other methods. CIEP plus SPD is therefore the most cost effective method for the identification of clinically meaningful ENAs. Based on our experience, we now screen for ENAs by CIEP, and positive samples are then typed by CIEP plus SPD. Samples that are difficult to interpret are then further assessed by an alternative method.
P D W Kiely - One of the best experts on this subject based on the ideXlab platform.
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PAPER Concentration of antibodies to Extractable Nuclear Antigens and disease activity in systemic lupus erythematosus
2016Co-Authors: S Agarwal, J Harper, P D W KielyAbstract:A hallmark of systemic lupus erythematosus (SLE) is the production of autoantibodies directed against intracellular Antigens. Antibodies to double stranded DNA (dsDNA) are most closely associated with the clinical manifestations of the condition and appear to have a direct role in pathogenesis. On the contrary, the relationship between disease activity in SLE and anti-Extractable Nuclear antigen (ENA) antibodies has not been well demonstrated. Despite this, commercial assays for the quantification of anti-ENA antibodies are now widely available, although their usefulness in clinical practice is not known. The aim of this study was to investigate whether there is an association between disease activity in SLE and concentrations of individual anti-ENA antibodies. A prospective 2-year study of 45 patients with SLE, known to be positive for at least one anti-ENA antibody, was performed. Disease activity was assessed using the SLE Disease Activity Index (SLEDAI). Anti-ENA antibodies were quantified using a commercial antibody detection system. A total of 45 patients were studied over a 2-year period (median number of assessments 5, range 2–9). Of them 29 patients were positive for Ro, 8 for La, 9 for Sm and 27 for RNP antibodies. In the population as a whole, there was a weak relationship between peak SLEDAI score and anti-Sm concentration (r = 0.57, NS), but no relation with the othe
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concentration of antibodies to Extractable Nuclear Antigens and disease activity in systemic lupus erythematosus
Lupus, 2009Co-Authors: S Agarwal, J Harper, P D W KielyAbstract:A hallmark of systemic lupus erythematosus (SLE) is the production of autoantibodies directed against intracellular Antigens. Antibodies to double stranded DNA (dsDNA) are most closely associated with the clinical manifestations of the condition and appear to have a direct role in pathogenesis. On the contrary, the relationship between disease activity in SLE and anti-Extractable Nuclear antigen (ENA) antibodies has not been well demonstrated. Despite this, commercial assays for the quantification of anti-ENA antibodies are now widely available, although their usefulness in clinical practice is not known. The aim of this study was to investigate whether there is an association between disease activity in SLE and concentrations of individual anti-ENA antibodies. A prospective 2-year study of 45 patients with SLE, known to be positive for at least one anti-ENA antibody, was performed. Disease activity was assessed using the SLE Disease Activity Index (SLEDAI). Anti-ENA antibodies were quantified using a com...
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concentration of antibodies to Extractable Nuclear Antigens and disease activity in systemic lupus erythematosus
Lupus, 2009Co-Authors: S Agarwal, J Harper, P D W KielyAbstract:A hallmark of systemic lupus erythematosus (SLE) is the production of autoantibodies directed against intracellular Antigens. Antibodies to double stranded DNA (dsDNA) are most closely associated with the clinical manifestations of the condition and appear to have a direct role in pathogenesis. On the contrary, the relationship between disease activity in SLE and anti-Extractable Nuclear antigen (ENA) antibodies has not been well demonstrated. Despite this, commercial assays for the quantification of anti-ENA antibodies are now widely available, although their usefulness in clinical practice is not known. The aim of this study was to investigate whether there is an association between disease activity in SLE and concentrations of individual anti-ENA antibodies. A prospective 2-year study of 45 patients with SLE, known to be positive for at least one anti-ENA antibody, was performed. Disease activity was assessed using the SLE Disease Activity Index (SLEDAI). Anti-ENA antibodies were quantified using a commercial antibody detection system. A total of 45 patients were studied over a 2-year period (median number of assessments 5, range 2-9). Of them 29 patients were positive for Ro, 8 for La, 9 for Sm and 27 for RNP antibodies. In the population as a whole, there was a weak relationship between peak SLEDAI score and anti-Sm concentration (r = 0.57, NS), but no relation with the other anti-ENA antibodies. In a small number of patients, there appeared to be either a positive (Ro, Sm) or negative (La, Sm, RNP) association between ENA antibody concentration and disease activity over time; however, this was not apparent for the majority of individuals. These results show that in SLE, clinically significant changes in disease activity do not correlate well with concentrations of anti-ENA antibodies, either within the population as a whole or on an individual basis. Repeated quantitative measurement of anti-ENA antibodies does not therefore appear to provide useful additional information in assessing disease activity in SLE. The widespread application of commercial quantitative assays to routine clinical practice is not recommended.
X Bossuyt - One of the best experts on this subject based on the ideXlab platform.
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antibodies to Extractable Nuclear Antigens in antiNuclear antibody negative samples
Clinical Chemistry, 2005Co-Authors: X Bossuyt, Ariane LuyckxAbstract:Antibodies to Extractable Nuclear Antigens (ENAs)—SSA, SSB, U1RNP, Sm, Scl-70, and Jo-1—are clinically important in patients with systemic rheumatic diseases. Indirect immunofluorescence (IIF) with HEp-2 cells is a common initial screening test for detection of antiNuclear antibodies (ANAs) and antibodies to ENAs. IIF-positive samples are further screened with more specific assays, but few studies have addressed the value of this cascade testing (1)(2). Although screening with conventional HEp-2 cells may miss some Antigens, such as SSA (3) and Jo-1(4), false-negative ANA results are infrequent (1)(2). SSA-transfected cells in particular, which overexpress SSA (60 kDa), are considered highly sensitive for detection of anti-SSA antibodies (5). Some antibodies to ENAs can be missed by IIF, however (6). Hoffman et al. (6) found that of 291 ANA-negative samples, 12 were positive for antibodies to ENAs, including antibodies to SSA (Ro52 and Ro60), SSB, RNP-A, RNP-C, RNP-70, SmD, Scl-70, and Jo-1. We performed a prospective study to …
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Evaluation of a Dot-Blot Method for Identification of Antibodies against Extractable Nuclear Antigens and Anti-Cytoplasmic Antibodies
Clinical Chemistry, 1999Co-Authors: Alex Mewis, Godelieve Mariën, Norbert Blanckaert, X BossuytAbstract:Antibodies against Extractable Nuclear Antigens (ENAs) are useful diagnostic markers for various autoimmune diseases. Anti-SSA and anti-SSB antibodies are found in Sjogren Syndrome (SS), anti-Sm antibodies are found in systemic lupus erythematosus (SLE), anti-RNP antibodies are found in mixed connective tissue disease (MCTD), and anti-Scl-70 antibodies are found in scleroderma. Antibodies against cytoplasmic Jo-1 and M2 are helpful markers for the diagnosis of, respectively, polymyositis and primary biliary cirrhosis. The antibodies can be identified by either counter immunoelectrophoresis (CIE) or immunoblotting. These techniques, however, are time-consuming, technically demanding, and do not provide for fast turnaround times. Over the last few years, alternative …
Anthony A M Ermens - One of the best experts on this subject based on the ideXlab platform.
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a comparison of elisa assays as routine diagnostic test for detection of autoantibodies against Extractable Nuclear Antigens
Clinical Biochemistry, 1999Co-Authors: Hans L P Van Duijnhoven, Frencia J M Van De Warenburg, Ryan J W P Willems, Anthony A M ErmensAbstract:Abstract Objective: In an analytical evaluation, commercially available ELISA test kits for detection of antibodies directed against Extractable Nuclear Antigens (ENA) were compared with the currently used combination of counterimmunoelectrophoresis and immunoblotting. Design: Three screening ELISAs and two typing ELISAs were tested. These methods were fairly simple, easy to perform and “user friendly,” because most of the reagents were ready to use. Results: The agreement with the current methods was good, but the screening as well as typing ELISAs proved to be more sensitive, especially with regard to detection of SS-A auto-antibodies. The cut-off range of one screening assay was not well established and one typing assay suffered from problems with inaccuracy of package insert, purity of antigen and standardisation of reactivity (possibly caused by differences in amount of coated antigen). The other three ELISAs were reliable and sensitive for detection of ENA auto-antibodies. Conclusions: The ELISA ENA screen assays ENA-LISA™ polyvalent and Milenia ENA screen and typing assays ENA-LISA™ are reliable and sensitive for detection of autoantibodies in clinical specimens without substantial false negatives.
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simple dot blot method evaluated for detection of antibodies against Extractable Nuclear Antigens
Clinical Chemistry, 1997Co-Authors: Anthony A M Ermens, Angelique J M Bayens, Anita C M Van Gemert, Johannes L P Van DuijnhovenAbstract:Detection of antiNuclear antibodies (ANA), usually by indirect immunofluorescence, is generally regarded as an important test in the diagnosis of systemic autoimmune diseases. If ANA are present, the subsequent identification of autoantibody specificity contributes to the final diagnosis and may also be helpful in disease management. ANA, which show many different serologic specificities, are partly directed against Extractable Nuclear Antigens (ENA). The most common ENAs are SSA, SSB, Sm, RNP, and Scl-70. The presence of these specific ENA antibodies is related to certain autoimmune diseases such as Sjogren syndrome (SSA, SSB), mixed connective tissue disease (RNP), systemic lupus erythematosus (Sm), and scleroderma (Scl-70) (1). ENA antibodies can be detected in several ways. Double immunodiffusion, often in combination with immunoblotting (IB), is widely used but is time-consuming and requires well-trained and experienced technicians (2). A few years ago several ELISAs were introduced which have proven to be both sensitive and specific for detection of ENA antibodies (2)(3)(4). However, they are expensive and require the availability of an ELISA reader. Recently, a simple dot-blot method (DB) for the detection of ENA antibodies [Biomedical Diagnostics (BMD)] has become available. In the present study we compared this DB with the currently used combination of counterimmunoelectrophoresis and immunoblotting (CIE/IB) for the detection of antibodies against ENA. Sera from 146 patients were selected for the evaluation of detection of antibodies directed against SSA, SSB, Sm, and RNP. Besides samples with CIE/IB-proven ENA antibodies, samples with negative results were included to check for cross-reactivity and purity of the Antigens used in the DB …
S Agarwal - One of the best experts on this subject based on the ideXlab platform.
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PAPER Concentration of antibodies to Extractable Nuclear Antigens and disease activity in systemic lupus erythematosus
2016Co-Authors: S Agarwal, J Harper, P D W KielyAbstract:A hallmark of systemic lupus erythematosus (SLE) is the production of autoantibodies directed against intracellular Antigens. Antibodies to double stranded DNA (dsDNA) are most closely associated with the clinical manifestations of the condition and appear to have a direct role in pathogenesis. On the contrary, the relationship between disease activity in SLE and anti-Extractable Nuclear antigen (ENA) antibodies has not been well demonstrated. Despite this, commercial assays for the quantification of anti-ENA antibodies are now widely available, although their usefulness in clinical practice is not known. The aim of this study was to investigate whether there is an association between disease activity in SLE and concentrations of individual anti-ENA antibodies. A prospective 2-year study of 45 patients with SLE, known to be positive for at least one anti-ENA antibody, was performed. Disease activity was assessed using the SLE Disease Activity Index (SLEDAI). Anti-ENA antibodies were quantified using a commercial antibody detection system. A total of 45 patients were studied over a 2-year period (median number of assessments 5, range 2–9). Of them 29 patients were positive for Ro, 8 for La, 9 for Sm and 27 for RNP antibodies. In the population as a whole, there was a weak relationship between peak SLEDAI score and anti-Sm concentration (r = 0.57, NS), but no relation with the othe
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concentration of antibodies to Extractable Nuclear Antigens and disease activity in systemic lupus erythematosus
Lupus, 2009Co-Authors: S Agarwal, J Harper, P D W KielyAbstract:A hallmark of systemic lupus erythematosus (SLE) is the production of autoantibodies directed against intracellular Antigens. Antibodies to double stranded DNA (dsDNA) are most closely associated with the clinical manifestations of the condition and appear to have a direct role in pathogenesis. On the contrary, the relationship between disease activity in SLE and anti-Extractable Nuclear antigen (ENA) antibodies has not been well demonstrated. Despite this, commercial assays for the quantification of anti-ENA antibodies are now widely available, although their usefulness in clinical practice is not known. The aim of this study was to investigate whether there is an association between disease activity in SLE and concentrations of individual anti-ENA antibodies. A prospective 2-year study of 45 patients with SLE, known to be positive for at least one anti-ENA antibody, was performed. Disease activity was assessed using the SLE Disease Activity Index (SLEDAI). Anti-ENA antibodies were quantified using a com...
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concentration of antibodies to Extractable Nuclear Antigens and disease activity in systemic lupus erythematosus
Lupus, 2009Co-Authors: S Agarwal, J Harper, P D W KielyAbstract:A hallmark of systemic lupus erythematosus (SLE) is the production of autoantibodies directed against intracellular Antigens. Antibodies to double stranded DNA (dsDNA) are most closely associated with the clinical manifestations of the condition and appear to have a direct role in pathogenesis. On the contrary, the relationship between disease activity in SLE and anti-Extractable Nuclear antigen (ENA) antibodies has not been well demonstrated. Despite this, commercial assays for the quantification of anti-ENA antibodies are now widely available, although their usefulness in clinical practice is not known. The aim of this study was to investigate whether there is an association between disease activity in SLE and concentrations of individual anti-ENA antibodies. A prospective 2-year study of 45 patients with SLE, known to be positive for at least one anti-ENA antibody, was performed. Disease activity was assessed using the SLE Disease Activity Index (SLEDAI). Anti-ENA antibodies were quantified using a commercial antibody detection system. A total of 45 patients were studied over a 2-year period (median number of assessments 5, range 2-9). Of them 29 patients were positive for Ro, 8 for La, 9 for Sm and 27 for RNP antibodies. In the population as a whole, there was a weak relationship between peak SLEDAI score and anti-Sm concentration (r = 0.57, NS), but no relation with the other anti-ENA antibodies. In a small number of patients, there appeared to be either a positive (Ro, Sm) or negative (La, Sm, RNP) association between ENA antibody concentration and disease activity over time; however, this was not apparent for the majority of individuals. These results show that in SLE, clinically significant changes in disease activity do not correlate well with concentrations of anti-ENA antibodies, either within the population as a whole or on an individual basis. Repeated quantitative measurement of anti-ENA antibodies does not therefore appear to provide useful additional information in assessing disease activity in SLE. The widespread application of commercial quantitative assays to routine clinical practice is not recommended.
