METHODS:: RESULTS:: Patients randomized to opt-in agreed to participate 23.1% of the time, and only 2.5% of those in opt-out chose not to participate. FIT kits were mailed to 22.4% and 93% of ...patients in opt-in and opt-out arms, respectively. In intention-to-screen analysis, patients in the opt-out arm had a higher FIT completion rate (29.1%) than in the opt-in arm (9.6%) (absolute difference 19.5%; 95% confidence interval, 10.9-27.9%; P < .001). Results were similar in subgroup analysis of those sent initial messaging through the EHR portal (9.5% opt-in versus 37.5% in opt-out).
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In an article reviewing the status of gastrointestinal allergy in the New England Journal of Medicine in 1949, Ingelfinger et al1 decried the reliance on patients' "incrimination" of specific foods, ...outcome of trial diets, or association of abdominal complaints with symptoms believed to be allergic in making the diagnosis of food allergy. Recently, the National Institutes of Health-sponsored expert panel "Guidelines for the diagnosis and management of food allergy," reaffirmed the utility of the DBPCFC for diagnosing food allergy after an extensive review of the current literature.11 However, the expert panel noted that open or single-blind challenges could also be acceptable when the challenge outcome is negative or when objective symptoms are elicited that exactly recapitulate the history of the reaction.
Antinuclear antibodies (ANAs) are valuable laboratory markers to screen for and support the diagnosis of various rheumatic diseases (known as ANA-associated rheumatic diseases). The importance of ANA ...testing has been reinforced by the inclusion of ANA positivity as an entry criterion in the 2019 systemic lupus erythematosus classification criteria. In addition, specific ANAs (such as antibodies to Sm, double-stranded DNA (dsDNA), SSA/Ro60, U1RNP, topoisomerase I, centromere protein B (CENPB), RNA polymerase III and Jo1) are included in classification criteria for other rheumatic diseases. A number of techniques are available for detecting antibodies to a selection of clinically relevant antigens (such as indirect immunofluorescence and solid phase assays). In this Review, we discuss the advantages and limitations of these techniques, as well as the clinical relevance of the differences between the techniques, to provide guidance in understanding and interpreting ANA test results. Such understanding not only necessitates insight into the sensitivity and specificity of each assay, but also into the importance of the disease context and antibody level. We also highlight the value of titre-specific information (such as likelihood ratios).
The impact of autoimmune diseases is growing from both a clinical and a laboratory point of view. Diagnostic assays are now being transferred from dedicated specialised laboratories into ...high-throughput service laboratories. The increasing number of available methods has raised the variability among the laboratories, making their reproducibility a critical problem. On the other hand, reliable tests are needed for early diagnosis and prompt treatment, and the cost of repeated confirmatory tests should be reduced and unnecessary further investigations avoided. New methodologies, particularly for antinuclear antibodies (ANAs), have been applied to autoantibody detection in order to screen and process larger volumes of clinical specimens more quickly and at less cost than the traditional methods. However, because of the lack of their sensitivity to detect all ANAs and standardisation, inaccuracies (including false positives and negatives) in the results have been reported. A committee of the American College of Rheumatology was formed to address this issue. Specific recommendations have been suggested that represent a realistic first step in the standardisation of diagnostic tests for autoimmune diseases.
Until recently, the tuberculin skin test was the only test for detecting latent tuberculosis (TB) infection, but 2 ex vivo interferon-gamma release assays (IGRAs) are now commercially licensed.
To ...estimate sensitivity, specificity, and reproducibility of IGRAs (commercial or research versions of QuantiFERON QFT and Elispot) for diagnosing latent TB infection in healthy and immune-suppressed persons.
The authors searched MEDLINE and reviewed citations of all original articles and reviews for studies published in English.
Studies had evaluated IGRAs using Mycobacterium tuberculosis-specific antigens (RD1 antigens) and overnight (16- to 24-h) incubation times. Reference standards had to be clearly defined without knowledge of test results. DATA EXTRACTION AND QUALITY ASSESSMENT: Specific criteria for quality assessment were developed for sensitivity, specificity, and reproducibility.
When newly diagnosed active TB was used as a surrogate for latent TB infection, sensitivity of all tests was suboptimal, although it was higher with Elispot. No test distinguishes active TB from latent TB. Sensitivity of the tuberculin skin test and IGRAs was similar in persons who were categorized into clinical gradients of exposure. Pooled specificity was 97.7% (95% CI, 96% to 99%) and 92.5% (CI, 86% to 99%) for QFT and for Elispot, respectively. Both assays were more specific than the tuberculin skin test in samples vaccinated with bacille Calmette-Guérin. Elispot was more sensitive than the tuberculin skin test in 3 studies of immune-compromised samples. Discordant tuberculin skin test and IGRA reactions were frequent and largely unexplained, although some may be related to varied definitions of positive test results. Reversion of IGRA results from positive to negative was common in 2 studies in which it was assessed.
Most studies used cross-sectional designs with the inherent limitation of no gold standard for latent TB infection, and most involved small samples with a widely varying likelihood of true-positive and false-positive test results. There is insufficient evidence on IGRA performance in children, immune-compromised persons, and the elderly.
New IGRAs show considerable promise and have excellent specificity. Additional studies are needed to better define their performance in high-risk populations and in serial testing. Longitudinal studies are needed to define the predictive value of IGRAs.
Background
Perioperative allergic reactions to chlorhexidine are often severe and easily overlooked. Although rare, the prevalence remains unknown. Correct diagnosis is crucial, but no validated ...provocation model exists, and other diagnostic tests have never been evaluated. The aims were to estimate (i) the prevalence of chlorhexidine allergy in perioperative allergy and (ii) the specificity and sensitivity for diagnostic tests for chlorhexidine allergy.
Methods
We included all patients investigated for suspected perioperative allergic reactions in the Danish Anaesthesia Allergy Centre during 2004–2012. The following tests were performed: specific IgE (Immunocap®; Phadia AB, Sweden), histamine release test (HR) (RefLab ApS, Denmark), skin prick test (SPT) and intradermal test (IDT). Positivity criteria were as follows: specific IgE >0.35 kUA/l; HR class 1–12; SPT mean wheal diameter ≥3 mm; IDT mean wheal diameter ≥ twice the diameter of negative control. Chlorhexidine allergy was post hoc defined as a relevant clinical reaction to chlorhexidine combined with two or more positive tests. Based on this definition, sensitivity and specificity were estimated for each test.
Results
In total, 22 of 228 patients (9.6%) met the definition of allergy to chlorhexidine. Estimated sensitivity and specificity were as follows: specific IgE (sensitivity 100% and specificity 97%), HR (sensitivity 55% and specificity 99%), SPT (sensitivity 95% and specificity 97%) and IDT (sensitivity 68% and specificity 100%).
Conclusions
In patients investigated for suspected perioperative allergic reactions, 9.6% were diagnosed with allergy to chlorhexidine. Using our definition of chlorhexidine allergy, the highest combined estimated sensitivity and specificity was found for specific IgE and SPT.
Well-Based Antibody Arrays Matson, Robert S
Methods in molecular biology (Clifton, N.J.),
2021, Volume:
2237
Journal Article
Multiplex immunoassays are important tools in basic research and diagnostics. The ability to accurately quantify the presence of several antigens within an individual sample all at once has been ...useful in developing a proteomics view of biology. This in turn has enabled the development of disease-associated immunodiagnostic panels for better prognosis and well-being. Moreover, it is well understood that such multiplexing approaches lend themselves to automation, thereby reducing labor while providing the ability to dramatically conserve both reagent and sample all of which will reduce the cost per test. Here we describe various methods to create and use multiplex immunoassays in the wells of microtiter plates or similar formats.
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