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- Damoiseaux, Jan, et al.
(författare)
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An international survey on anti-neutrophil cytoplasmic antibodies (ANCA) testing in daily clinical practice
- 2018
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Ingår i: Clinical Chemistry and Laboratory Medicine. - : Walter de Gruyter. - 1434-6621 .- 1437-4331. ; 56:10, s. 1759-1770
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Tidskriftsartikel (refereegranskat)abstract
- Background: Detection of anti-neutrophil cytoplasmic antibodies (ANCA) is important for the diagnosis of the ANCA-associated vasculitides (AAV). For AAV, especially ANCA directed against myeloperoxidase (MPO) and proteinase 3 (PR3) are most relevant. ANCA with less well-defined specificities may, however, also be detected in other inflammatory and non-inflammatory conditions.Methods: A questionnaire, initiated by the European Autoimmunity Standardisation Initiative (EASI), was used to gather information on methods and testing algorithms used for ANCA in clinical laboratories of 12 European countries (EASI survey).Results: Four hundred and twenty-nine responses were included in the EASI survey analysis which revealed differences within countries and between countries. Laboratories overall were poor in adherence to international consensus on ANCA testing. Substantial variation was observed with respect to the use of ANCA indirect immunofluorescence (IIF) in the algorithm, application of distinct methods for MPO- and PR3-ANCA, the daily availability of new ANCA results, and interpretation of test results.Conclusions: Awareness of these differences may stimulate further harmonization and standardization of ANCA testing. This may be promoted by an update of the international ANCA consensus and the introduction of international standards.
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| 2. |
- Erlandsson, Malin, 1972, et al.
(författare)
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Survivin improves the early recognition of rheumatoid arthritis among patients with arthralgia : A population-based study within two university cities of Sweden
- 2018
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Ingår i: Seminars in Arthritis & Rheumatism. - : Saunders Elsevier. - 0049-0172 .- 1532-866X. ; 47:6, s. 778-785
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Forskningsöversikt (refereegranskat)abstract
- Objectives: The aim of this study was to validate the use of survivin for preclinical recognition of rheumatoid arthritis (RA) among patients with unexplained arthralgia.Methods: Serum levels of survivin and the arthritis-specific autoantibodies RF and ACPA were measured in total of 5046 patients with musculoskeletal complains during 12 consecutive months in Gothenburg and in Umea. Among them, 303 arthralgia patients were identified and prospectively followed.Results: After 48 months, 12.2% of the arthralgia patients developed RA. Most of RA cases had high serum survivin, which increased the relative risk for RA (RR = 5.90,p = 3 x 10(-7)). Combination of survivin with autoantibodies was present in only 4.6% of the arthralgia patients and increased further the risk of RA and shortened time to RA development. Presence of any single autoantibody in the survivin-negative patients was associated with a minor risk for RA and had RA-free survival similar to the reference group.Conclusion: This study shows that measurement of survivin in serum improves estimation of RA risk and prospectively predicts RA development in patients with arthralgia. Survivin may indicate a phase preceding autoantibody production.
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| 3. |
- Siljehult, Filip, et al.
(författare)
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Concentrations of infliximab and anti-drug antibodies in relation to clinical response in patients with rheumatoid arthritis
- 2018
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Ingår i: Scandinavian Journal of Rheumatology. - : Taylor & Francis Group. - 0300-9742 .- 1502-7732. ; 47:5, s. 345-350
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Tidskriftsartikel (refereegranskat)abstract
- Objective: The efficacy of anti-tumour necrosis factor-α (anti-TNF-α) treatment with infliximab (IFX) may be reduced by the development of anti-drug antibodies (ADAs). This study evaluated drug concentration and the presence of ADAs, relative to response, in rheumatoid arthritis (RA) patients treated with IFX.Method: Ninety-four RA patients were consecutively included and assessed for disease activity at baseline, and after 14, and 30 or 52 weeks. Serum IFX concentration and ADAs were analysed using in-house enzyme-linked immunosorbent assays. ADA analysis was based on binding to TNF-α-coated plates, with the lower detection limit set at mean + 2 sd of controls.Results: At 14 and 52 weeks, 74.5% of the patients had moderate to good response. Good responders had significantly higher IFX concentrations than moderate and poor responders at 52 weeks (6.6 ± 1.4 µg/mL vs 3.6 ± 1.3 µg/mL and 2.6 ± 1.6 µg/mL, respectively). An IFX concentration ≥4.66 µg/mL at 14 weeks yielded a moderate to good response at 30/52 weeks, with 91.3% specificity and 39.3% sensitivity. Eleven patients dropped out owing to lack of efficacy and eight owing to side effects; three with IFX concentration ≤ 0.5 µg/mL were ADA positive. At an IFX concentration ≤ 0.5 µg/mL, 43.8% and 30.1% at 14 and 52 weeks, respectively, were ADA positive. None of the good responders had ADAs.Conclusion: One-quarter of patients had an IFX concentration ≤ 0.5 µg/mL but only 11.7% had ADAs. High IFX concentration was related to a good response, suggesting that the lack of response could be due to a lack of IFX, rather than to the presence of ADAs.
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