Enzyme immunoassay for the qualitative screening of IgG antibodies against dsDNA, RNP, Sm, SS-A/Ro, SS-B/La, Scl-70, CENP-B and Jo-1 in human serum or plasma (EDTA, citrate).
Contents of Kit
1. MTP 1 Microtiter Plate, coated with a mixture of the above antigens, hermetically packed in a foil laminate pouch together with a desiccant bag. The plate consists of 12 strips, each of which can be broken into 8 individual wells. 2. SAMPLEDIL Sample Diluent, 100 mL, ready-to-use, orange coloured. Contains Tris-buffered saline (TBS), bovine serum albumin (BSA), Tween and Na-azide. 3. WASHBUF CONC Wash buffer, 100 mL, 10x-concentrate, blue coloured. Contains TBS, Tween and bromonitrodioxane. 4. CONTROL + CONTROL - Negative and Positive Control, 3,0 mL each, ready-to-use, green and red coloured, respectively. Contain TBS, BSA, Tween and Na-azide. 5. ENZCONJ IgG Enzyme Conjugate, 14 mL, ready-to-use, red coloured. Buffered solution containing stabilising protein, methylisothiazolone and bromonitrodioxane. 6. TMB SUBS TMB Substrate Solution, 14 mL, ready-to-use, colourless. Contains a buffered solution of TMB and H2O2. Contained in a vial impermeable to light. 7. STOP TMB Stop Solution (0,2 M H2SO4), 14 mL, colourless, ready-to-use. Caution: sulfuric acid is corrosive. 8. Instructions for Use 9. Lot-specific certificate of analysis
Storage
Store kit at 2 - 8°C, do not freeze. It is stable up to the expiry date stated on the label of the box. Do not use kit beyond its expiry date.
Performance Characteristics
1. Standardisation The test is standardised with a purified serum preparation containing IgG antibodies directed at each of the immobilised autoantigens. It constitutes the stock material for both controls of the test. The proportion of the antibodies is adjusted in such a manner that each one contributes approximately the same fraction to the overall signal. The stock preparation is calibrated against a set of monospecifically positive sera solely reserved for this purpose. The degree of sample reactivity is expressed as summary ratio, as outlined above. 2. Analytical specificity The test permits the specific determination of human IgG antibodies, directed at the autoantigens quoted in article 1. The following results (ratio values) are typical: Remark: The corresponding ANA Profile 8 IgG ELISA which differentiates between the antigens revealed that serum # 6 shows ratio values ≤ 1 towards all single antigens. Interference with anticoagulants (EDTA, Citrat, Heparin) in samples has been tested and no interference effects have been observed. 3. Detection limit (analytical sensitivity) The detection limit is defined as that concentration of analyte that corresponds to the mean absorbance of sample buffer plus 3-fold standard deviation (s). It was determined as < 0,3 (ratio; n = 24). Recommended measuring range: 0,4 < ratio < 6 4. Dose-response relationship In order to assess this feature of the ELISA, several pools of individual sera with heterogeneous reactivity were measured in serial 2-fold dilution. A typical result is depicted below. An approximately linear relationship between sample concentration and resulting ratio is restricted to ratio values < 2. This is due to the qualitative evaluation manner and contrasts ELISAs which are evaluated quantitatively by means of a standard curve.
Precision
For the assessment of the test precision, the variability of results under the following conditions was determined: a. within 1 assay and between 3 assays, b. between 3 operators and c. between 2 kit lots. a. Intra- and inter-assay variability (n = 24 and 72, respectively) b. Operator to operator variability (n = 12) c. Variability between 2 kit lots (n = 6)
General Description
The test is designed for the qualitative, summary determination of the respective autoantibodies (IgG) in human serum or plasma, without the ability to discriminate between them. The test is fast (incubation time 30 / 30 / 30 minutes) and flexible (divisible solid phase, ready-to-use reagents). A negative and a positive control check the assay performance. The positive control also serves as calibrator for assay evaluation. ANA Screen 8 IgG ELISA is an enzyme-linked immunosorbent assay (ELISA) intended for the qualitative, summary determination of IgG class antibodies directed against double-stranded DNA, U1-RNP complexes (proteins A, C, 68kDa), Sm, SS-A/Ro 60, SS-B/La, Scl-70 (DNA-topoisomerase 1), CENP-B (centromereprotein B) and Jo-1 (Histidyl-tRNA synthetase) in human serum or plasma samples. This product is intended for manual professional research use only. Not for use in diagnostic procedures.
Citations
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Background
The classification and diagnosis of systemic autoimmune diseases is usually based on a series of criteria consisting of clinical, laboratory, imaging, and pathologic elements that are closely related to the corresponding disease. Autoantibodies are a unique marker that figures prominently in the classification criteria for many autoimmune diseases. The HEp-2 indirect cellular immunofluorescence assay (HEp-2 IFA), historically known as an antinuclear antibody (ANA) assay, detects a wide range of autoantibodies. HEp-2 IFA test results were included in the classification criteria for systemic lupus erythematosus (SLE) and juvenile idiopathic arthritis (JIA), as well as in the diagnostic criteria for autoimmune hepatitis (AIH) and primary biliary cholangitis (PBC).
Systemic lupus erythematosus (SLE) is a multisystem chronic inflammatory disease with multiple immune abnormalities and an excess of circulating autoantibodies. The diagnosis of SLE relies on validated clinical and laboratory elements, most of which are not specific to SLE, making the diagnosis of SLE challenging and requiring specialized knowledge and careful consideration of other diagnoses. Therefore, since the 1970s, diagnostic criteria have been established to categorize SLE, and all versions of the diagnostic criteria include ANA and SLE-specific autoantibodies. The ANA test is extremely sensitive for the diagnosis of SLE, with most studies reporting that 92-99% of patients test positive at some point during the course of the disease.
The first set of SLE classification criteria contained two separate criteria related to autoantibodies: a LE cell test and a false-positive serologic test for syphilis (VDRL), which can be considered indirect evidence of the presence of autoantibodies to deoxyribonucleoprotein and phospholipids, respectively. Subsequent classification criteria added anti-double-stranded DNA and anti-Sm and combined the LE cell test and the false-positive syphilis test. Thus, any of these four serologic variables can be considered as a single criterion. In addition, the ANA IFA test was included as a separate immunologic criterion. The 1997 revised SLE classification criteria eliminated the LE cell test and included three tests as evidence of antiphospholipid antibodies: a false-positive serologic test for syphilis, a test for lupus anticoagulant, and a test for anticardiolipin antibodies. These antibodies, along with anti-dsDNA and anti-Sm, are considered a single immunologic criterion, whereas the ANA test remains a separate immunologic criterion.
Figure 1. Historical perspective on the classification criteria for systemic lupus erythematosus (Source: Andrade LEC, et al. 2022)
Alternative Names
antinuclear antibody-8-Screen Antibody ELISA Kit
References
1. Damoiseaux J, et al. Clinical relevance of HEp-2 indirect immunofluorescent patterns: the International Consensus on ANA patterns (ICAP) perspective. Ann Rheum Dis. 2019 Jul;78(7):879-889.
2. Andrade LEC, et al. Antinuclear antibodies (ANA) as a criterion for classification and diagnosis of systemic autoimmune diseases. J Transl Autoimmun. 2022 Jan 19;5:100145.
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References
Challenges and potential improvements in hospital patient flow: the contribution of frontline, top and middle management professionals
Purpose This study aims to describe and understand the contributions of frontline, middle and top management healthcare professionals in detecting areas of potential improvement in hospital patient flow and proposing solutions. Design/methodology/approach This is a qualitative interview study. Semistructured interviews were conducted with 22 professionals in the orthopedic department of a 250-bed academic teaching hospital. Data were analyzed through a thematic framework analytical approach by using ana prioriframework. The Consolidated Criteria for Reporting Qualitative (COREQ) checklist for qualitative studies was followed. Findings When dealing with a hospital-wide process, the involvement of all professionals, including nonhealth professionals, can reveal priority areas for improvement and for services integration. The improvements identified by the professionals largely focus on covering major gaps detected in the technical and administrative quality. Research limitations/implications This study focused on the professional viewpoint and the connections between services and further studies should explore the role of patient involvement. The study design could limit the generalizability of findings. Practical implications Improving high-quality, efficient hospital patient flow cannot be accomplished without learning the perspective of the healthcare professionals on the process of service delivery. Originality/value Few qualitative studies explore professionals' perspectives on patient needs in hospital flow management. This study provides insights into what produces value for the patient within a complex process by analyzing the contribution of professionals from their particular role in the organization.
Clinical and laboratory characteristics in juvenile-onset systemic lupus erythematosus across age groups
LUPUS
Authors: Massias, J. S.; Smith, E. M. D.; Al-Abadi, E.; Armon, K.; Bailey, K.; Ciurtin, C.; Davidson, J.; Gardner-Medwin, J.; Haslam, K.; Hawley, D. P.; Leahy, A.; Leone, V; McErlane, F.; Mewar, D.; Modgil, G.; Moots, R.; Pilkington, C.; Ramanan, A., V; Rangaraj, S.; Riley, P.; Sridhar, A.; Wilkinson, N.; Beresford, M. W.; Hedrich, C. M.
Background Systemic lupus erythematous (SLE) is a systemic autoimmune/inflammatory condition. Approximately 15-20% of patients develop symptoms before their 18th birthday and are diagnosed with juvenile-onset SLE (JSLE). Gender distribution, clinical presentation, disease courses and outcomes vary significantly between JSLE patients and individuals with adult-onset SLE. This study aimed to identify age-specific clinical and/or serological patterns in JSLE patients enrolled to the UK JSLE Cohort Study. Methods Patient records were accessed and grouped based on age at disease-onset: pre-pubertal (<= 7 years), peri-pubertal (8-13 years) and adolescent (14-18 years). The presence of American College of Rheumatology (ACR) classification criteria, laboratory results, disease activity [British Isles Lupus Assessment Group (BILAG) and Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2 K) scores] and damage [Systemic Lupus International Collaborating Clinics (SLICC) damage index] were evaluated at diagnosis and last follow up. Results A total of 418 JSLE patients were included in this study: 43 (10.3%) with pre-pubertal disease onset; 240 (57.4%) with peri-pubertal onset and 135 (32.3%) were diagnosed during adolescence. At diagnosis, adolescent JSLE patients presented with a higher number of ACR criteria when compared with pre-pubertal and peri-pubertal patients [pBILAG2004 scores: 9(4-20] vs. 7(3-13] vs. 7(3-14], respectively, p = 0.015] with increased activity in the following BILAG domains: mucocutaneous (p = 0.025), musculoskeletal (p = 0.029), renal (p = 0.027) and cardiorespiratory (p = 0.001). Furthermore, adolescent JSLE patients were more frequently ANA-positive (p = 0.034) and exhibited higher anti-dsDNA titres (p = 0.001). Pre-pubertal individuals less frequently presented with leukopenia (p = 0.002), thrombocytopenia (p = 0.004) or low complement (p = 0.002) when compared with other age groups. No differences were identified in disease activity (pBILAG2004 score), damage (SLICC damage index) and the number of ACR criteria fulfilled at last follow up. Conclusions Disease presentations and laboratory findings vary significantly between age groups within a national cohort of JSLE patients. Patients diagnosed during adolescence exhibit greater disease activity and "classic" autoantibody, immune cell and complement patterns when compared with younger patients. This supports the hypothesis that pathomechanisms may vary between patient age groups.
COA
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Figure 1. Historical perspective on the classification criteria for systemic lupus erythematosus
