Evidence‐based guidelines for the use of immunologic tests: Antinuclear antibody testing

Abstract

IntroductionThis article is part of a series on immunologic testing guidelines. The series introduction, published in this issue, outlines the full methodology for obtaining data, grading the literature, combining the information from multiple sources, and developing recommendations. Briefly, MEDLINE and Healthstar were searched using a variety of search terms, and all relevant available literature was reviewed. All articles were critically reviewed using published standards for studies of diagnostic tests. Test use was categorized as primarily diagnostic or prognostic (which also included monitoring). Information was extracted from each article to allow for calculation of a weighted average for sensitivity and specificity; likelihood ratios (LRs) were then derived from these values (positive LR ϭ sensitivity / [1-specificity]; negative LR ϭ [1-sensitivity] / specificity). Recommendations for use of tests were based on the LRs, where a test was considered to be "very useful" for a given disease if the weighted average positive LR was Ͼ 5 or negative LR was Ͻ 0.2. A test was considered "useful" if the weighted average positive LR was Ͼ 2 and Յ 5 or negative LR was Ͼ 0.2 and Յ 0.5. A test was considered "not useful" if the positive LR was Յ 2 or the negative LR was Ͼ 0.5. DefinitionAntinuclear antibodies (ANA) directed against a variety of nuclear antigens have been detected in the serum of patients with many rheumatic and nonrheumatic diseases, as well as in patients with no definable clinical syndrome. These antibodies can be detected using a variety of substrates and staining techniques as described below and are directed against many different nuclear antigens.

An official European Respiratory Society/American Thoracic Society research statement: interstitial pneumonia with autoimmune features

“…In accordance with current guidelines for ANA testing, the preferred method for the ANA assay is by indirect immunofluorescence [41], which allows for reporting of ANA titre and staining pattern. The ELISA assay for ANA testing is less reliable [42], has been shown to be falsely negative in subsets of patients with systemic sclerosis [42], does not allow for staining pattern reporting and does not provide a titre.…”

C-X-C Motif Chemokine 13 (CXCL13) Is a Prognostic Biomarker of Idiopathic Pulmonary Fibrosis

“…Enhanced B-cell differentiation caused by repetitive antigen stimulation is another classic feature of systemic lupus erythematosus, rheumatoid arthritis, and many other autoantibody syndromes, and is also present in and clinically associated with IPF (5). The production of autoantibodies with specificities for varied autoantigens is a common feature of immunologic diseases (15). Several selfreactive antibodies have also been identified in IPF cohorts (12,14,(16)(17)(18)(19)(20)(21)(22)(23)(24).…”

Choosing Wisely: The Canadian Rheumatology Association’s List of 5 Items Physicians and Patients Should Question

“…Five items were selected to advance for literature review. Other items included rheumatoid factor, antineutrophil cytoplasmic antibodies, anticyclic citrullinated peptide antibodies, extractable nuclear antigen (ENA) testing, radiographs, magnetic resonance imaging (MRI) tests, and nonsteroidal 12 , and the Italian Society of Laboratory Medicine Guidelines 13 .…”