Tebo, Anne E.

Objective Antinuclear antibody (ANA) indirect immunofluorescence (IIF) is the reference standard but depends on subjective pattern interpretation. We tested whether artificial intelligence (AI) applied to ANA IIF images could identify specific autoantibodies. Methods We assembled a cohort of ANA‐positive patients (human epithelial type 2 IIF titer ≥1:80) with anti–double‐stranded DNA (dsDNA), anti‐Smith (Sm) antibody, ribonucleoprotein (RNP), anti‐Sjögren's disease‐related antigen A (SSA), anti‐Sjögren's disease‐related antigen B (SSB), anti‐topoisomerase I (Scl‐70), or centromere antibody (CMA) testing within 90 days. The development cohort (December 12, 2016–December 31, 2022) included the first ANA test per patient. Two AI architectures were trained for each autoantibody. Performance was assessed using area under the receiver operating characteristic curve (AUROC), sensitivity, specificity, and accuracy; comparisons with IIF patterns were summarized as pattern‐antibody agreement. A prospective cohort (January 1, 2023–August 20, 2024), including a dsDNA assay transition, provided temporal validation. Results Among 512,959 patients, 47,890 met inclusion criteria (mean age 55 [SD 17.6], 78% female). Models for CMA, dsDNA, Sm, SSA, and SSB achieved AUROC ≥0.80 (CMA highest: AUROC 0.95, accuracy 94.2%, specificity 95.3%). Compared with associated IIF patterns, dsDNA and Sm models more often classified antibody‐negative cases as negative (dsDNA 88.2% vs 54.7%; Sm 82.6% vs 60.3%) while similarly classifying antibody‐positive cases. Performance for RNP (AUROC 0.68) and Scl‐70 (AUROC 0.59) was lower. In the prospective cohort (n = 21,427), performance was similar; dsDNA discrimination remained stable across assays (AUROC ~0.85). Conclusion AI applied to ANA IIF images identified specific autoantibodies and often improved classification of antibody‐negative cases versus simplified pattern‐based comparators. These findings support its potential to standardize ANA interpretation and triage or reduce confirmatory testing. image

Abstract The Africa Working Group, under the auspices of the Global Laboratory Quality Initiative of the Association for Diagnostics & Laboratory Medicine (ADLM), conducted several educational workshops in Africa to promote laboratory quality in the region. The challenges faced in maintaining quality in clinical laboratories in low-resource countries may differ from region to region and country to country. To better understand current gaps and inform our engagement with partners in Africa, a needs assessment survey was distributed to 1427 ADLM members in Africa and further disseminated through local partners, resulting in 121 responses from participants across 8 countries in the region. Additionally, interviews were conducted with laboratory professionals from the countries surveyed. The surveys primarily focused on quality management, continuing education, budgeting, infrastructure and funding, supplies, and staffing issues. The data collected from the surveys and interviews strongly indicate that respondents face major challenges in all areas assessed, including lack of funding, lack of equipment, lack of quality control (QC) and external quality assessment (EQA) materials, gaps in quality management, lack of appropriate budgeting, staffing issues, and lack of accessible training/continuing education. Consistent with the primary focus of ADLM;s Global Quality Initiative, improved access to continuing education was identified as the primary need by the participants (58%). The assessment highlights that while a strong role for educational workshops in mitigating some of the challenges continues to exist, there is also an opportunity to broaden the scope of the working groups beyond education.

Objective Despite the reported clinical significance of anti-C1q immunoglobulin G autoantibodies (anti-C1q) for SLE and the development of anti-C1q commercial kits, their performance characteristics in routine patient evaluation remain poorly defined. Methods In this cross-sectional study, an unselected cohort of 107 patients with suspicion of a systemic autoimmune disease and 102 controls were included and evaluated for anti-C1q autoantibodies with three kits (Bühlmann, Orgentec and Werfen). Patients in the unselected cohort were classified as having SLE or a mimicker condition. Disease activity was assessed using Systemic Lupus Erythematosus Disease Activity Index (SLEDAI)-2K and SLE patients were subclassified based on the presence of lupus nephritis (LN) (history/active). Each kit was assessed for diagnostic performance. The degree of association between anti-C1q and SLEDAI/complement levels was assessed using the Spearman correlation coefficient (rho). Between-kit agreement was evaluated using Fleiss Ƙ. Results Werfen had the best performance in discriminating patients with SLE from non-SLE (area under the curve (AUC)=0.76), whereas for the SLE versus mimicker comparison Bühlmann (AUC=0.71) and Werfen (AUC=0.71) exhibited adequate discrimination. Among patients with SLE, all kits exhibited poor discrimination of patients with history of LN versus non-renal SLE, but Orgentec displayed good discrimination for patients with active LN from non-active LN (AUC=0.74). A positive correlation was observed between anti-C1q and SLEDAI scores, whereas a negative correlation was found between anti-C1q and complement C3 and C4 across all kits. Agreement for SLE between the three kits was moderate (Ƙ=0.42). Conclusion Anti-C1q can identify patients with SLE and correlate with global and renal disease activity, highlighting their potential to function as follow-up markers in SLE. Agreement with commercial anti-C1q kits is variable. Further studies are required to harmonise anti-C1q kits for optimal routine patient evaluation.

Abstract Background Duplicate measurements can be used to characterize assay imprecision, identify outliers, and estimate error rates. The benefits of duplicate analysis, however, need to be balanced against the increased financial cost. The objective of this study was to evaluate the need for continued replicate measurement in a laboratory developed assay measuring anti-drug antibodies to infliximab (ATI). To this end, duplicate patient sample measurements from the ATI assay over a two-year period were analyzed to calculate outlier and error frequencies. Methods ATI were measured by electrochemiluminescence (ECL) on the MesoScale Discovery (MSD) platform, with a standard curve from 20–1250 U/mL using commercially available monoclonal ATIs. All patient samples tested for ATI over a 27-month period of time (n = 9582) were subject to inclusion in this study. Only patient samples with ATI levels within the analytical measuring range (AMR) of the assay, however, were selected for further analysis. Samples were divided equally into 7 bins across the measuring range based on mean replicate concentration. Within-run imprecision was determined for each bin using the standard deviation (combined from all replicates using sum of squares) and mean concentration derived from all replicates. Outliers were defined as replicate measurements with a percent difference greater than ±3 SD of the calculated assay imprecision. Errors were defined as samples which had replicate values on opposite sides of the clinical cutoff of positive ATI (≥50 U/mL) and a percent difference greater than 3SD of the assay imprecision. Results Of the 9582 total patient samples analyzed, 2467 had ATI values within the AMR and 1655 had levels over the clinical cut-off of 50 U/mL (17.3% positivity rate). Within-run imprecision determined from the mean and combined SD of the duplicate measurements ranged from 15.7% at the lowest concentration bin (20–27.5 U/mL) to 10.0% at the highest concentration bin (358–1243 U/mL). The mean percentage of outliers in each bin ranged from 0.8%–3.4% resulting in an overall outlier frequency of 2.1% when considering all samples within the AMR. There were 66 samples within the AMR which demonstrated qualitative discrepancies between the replicates. However, only 21 (31.8%) of these samples, had a percent agreement greater than 3SD of the assay imprecision resulting in an overall error rate of 0.2% when considering all 9582 samples. Conclusion In this study, the analysis of replicate patient samples enabled the establishment of a precision profile and estimation of error rates for a laboratory developed test measuring ATI. The calculated error rate of 0.2%, however, is well within the reported range of most clinical assays indicating that the continued practice of duplicate measurement may not be necessary. Additionally, updating the laboratory protocol to eliminate replicate testing would have positive impact in laboratory workflow, cost, and turn-around-time for results.

Context.— Misdiagnosis of antiphospholipid syndrome can occur owing to the wide diversity of antiphospholipid (aPL) assays and a lack of international calibrators and harmonized reference intervals. Objective.— To assess laboratory practices regarding reporting and establishing reference intervals for immunoglobulin (Ig) G/IgM anti-cardiolipin (aCL) and anti–beta-2 glycoprotein I (anti-β2GPI) assays. Design.— Supplemental questions related to reporting and establishing reference ranges for aPL assays were sent as part of the Antiphospholipid Antibody (ACL)-B 2019 College of American Pathologists (CAP) proficiency testing survey. The response rate and methods assessment details were determined, as well as qualitative and quantitative results for 3 test samples. Results.— The number of participants reporting results for IgG aCL (n = 489), IgM aCL (n = 476), IgG anti-β2GPI (n = 354), and IgM anti-β2GPI (n = 331) varied by antibody type. The enzyme-linked immunosorbent assay (ELISA) (up to 58.6%, 260 of 444) was the most used method; others included multiplex (from 18.9% to 23.9%), fluorescence enzyme immunoassay (14.4%–17.6%), and chemiluminescence immunoassay (6.5%–9.0%). More respondents reported quantitative than qualitative results, and manufacturer cutoff ranges were used by 92.9% and 94.2% of respondents for aCL and anti-β2GPI, respectively. Despite variation in the use of semiquantitative ranges, qualitative negative/positive reporting of the test samples achieved almost 100% consensus. Qualitative consensus was met in contrast to the wide range of quantitative results obtained for each analyte across different kits. Conclusions.— ELISA remains the most used method for detecting aPL antibodies, with most laboratories reporting quantitative results based on manufacturers' suggested reference ranges. The categorization of quantitative results as equivocal, weak positive, or positive for responders using kits from the same manufacturer was variable.

Abstract It is indeed a privilege to be an immunologist in what is arguably the golden age of immunology. From astounding advances in fundamental knowledge to groundbreaking immunotherapeutic offerings, immunology has carved out an enviable niche for itself in basic science and clinical medicine. The need and the vital importance of appropriate education, training, and certification in clinical immunology was recognized by the World Health Organization as far back as 1972. In the United States, Ph.D. scientists with board certification in medical laboratory immunology have served as directors of high-complexity Clinical Laboratory Improvement Amendments– and College of American Pathologists–certified clinical immunology laboratories since 1977. From 1977 to 2017, board certification for medical laboratory immunology was administered by the American Society for Microbiology through the American Board of Medical Laboratory Immunology examination. The American Board of Medical Laboratory Immunology examination was phased out in 2017, and in the fall of 2019, the American Society for Clinical Pathology (ASCP) Board of Certification (BOC) examination committee took on the responsibility of developing a new doctoral-level certification examination for medical laboratory immunology. This transition to the ASCP BOC represents a well-deserved and much-needed recognition of the rapid advances in and the highly specialized nature of medical laboratory immunology and its ever-increasing relevance to patient care. This new ASCP BOC certification is called the Diplomate in Medical Laboratory Immunology, and, as of April 1, 2023, it is now available to potential examinees. In this report, we describe the examination, eligibility routes, and potential career pathways for successful diplomates.

Context.— Antibodies to U1 ribonucleoprotein (U1RNP) were first described more than 50 years ago, and although clinically relevant for antinuclear antibody–associated connective tissue disease (ANA-CTD), test results are challenging to interpret. Objective.— To evaluate the impact of anti-U1RNP analyte diversity in the assessment of patients at risk for ANA-CTD. Design.— Two multiplex assays for U1RNP (Smith [Sm]/RNP and RNP68/A) were used to test serum specimens from consecutive patients (n = 498) under evaluation for CTD in a single academic center. Discrepant specimens were further tested for Sm/RNP antibody by enzyme-linked immunosorbent assay and the BioPlex multiplex assay. Data were evaluated for antibody positivity per analyte and their method of detection, correlations between analytes, and impact on clinical diagnoses through retrospective chart review. Results.— Of the 498 patients tested, 47 (9.4%) were positive in the RNP68/A (BioPlex) and 15 (3.0%) were positive in the Sm/RNP (Theradiag) immunoassays. U1RNP-CTD, other ANA-CTD, and no ANA-CTD were diagnosed in 34% (16 of 47), 12.8% (6 of 47), and 53.2% (25 of 47) of the cases, respectively. The prevalence of antibody by method in patients with U1RNP-CTD was 100.0% (16 of 16), 85.7% (12 of 14), 81.5% (13 of 16), and 87.5% (14 of 16) for RNP68/A, Sm/RNP BioPlex, Sm/RNP Theradiag, and Sm/RNP Inova, respectively. For other ANA-CTD and no ANA-CTD, the highest prevalence was observed with RNP68/A; all others had comparable performance. Conclusions.— In this study, the overall performance characteristics of Sm/RNP antibody assays were comparable; however, the RNP68/A immunoassay was very sensitive but less specific. In the absence of harmonization, reporting the type of U1RNP analyte in clinical testing may be useful in guiding interpretation and interassay correlations.