Autoantibody evaluation in idiopathic inflammatory myopathies.

Idiopathic inflammatory myopathies (IIM), generally referred to as myositis is a heterogeneous group of diseases characterized by muscle inflammation and/or skin involvement, diverse extramuscular manifestations with variable risk for malignancy and response to treatment. Contemporary clinico-serologic categorization identifies 5 main clinical groups which can be further stratified based on age, specific clinical manifestations and/or risk for cancer. The serological biomarkers for this classification are generally known as myositis-specific (MSAs) and myositis-associated antibodies. Based on the use of these antibodies, IIM patients are classified into anti-synthetase syndrome, dermatomyositis, immune-mediated necrotizing myopathy, inclusion body myositis, and overlap myositis. The current classification criteria for IIM requires clinical findings, laboratory measurements, and histological findings of the muscles. However, the use MSAs and myositis-associated autoantibodies as an adjunct for disease evaluation is thought to provide a cost-effective personalized approach that may not only guide diagnosis but aid in stratification and/or prognosis of patients. This review provides a comprehensive overview of contemporary autoantibodies that are specific or associated myositis. In addition, it highlights possible pathways for the detection and interpretation of these antibodies with limitations for routine clinical use.

Using differential mobility spectrometry to improve the specificity of targeted measurements of 2,3-dinor 11ß-Prostaglandin F2α.

INTRODUCTION: 2,3-dinor 11ß-Prostaglandin F2α (BPG) is an arachidonic acid derivative and the most abundant metabolic byproduct of prostaglandin D2, which is released during mast cell activation. Therefore, measurements of BPG in urine using liquid chromatography-tandem mass spectrometry (LC-MS/MS) provide a noninvasive method for evaluation and management of mast cell disorders. Measurements obtained by LC-MS/MS exhibit a high prevalence of chromatographic interferences resulting in challenges with optimal determination of BGP. In this investigation, differential mobility spectrometry (DMS) is utilized to overcome the limitations of current testing. METHODS: Urine samples were extracted using an automated solid-phase extraction method. Samples were then analyzed with and without DMS devices installed on two commercially available mass spectrometry platforms to assess the benefits of DMS. Following promising results from a preliminary analytical evaluation, LC-DMS-MS/MS measurements of BPG in urine were fully validated to assess the analytical implications of using this technology. RESULTS AND DISCUSSION: The addition of DMS devices to the LC-MS/MS systems evaluated in this investigation significantly reduced interferences observed in the chromatograms. Concomitantly, DMS reduced the number of discordant quantifier/qualifier fragment ion results that significantly exceeded the ± 20 % limits, suggesting greater analytical specificity. The validation studies yielded low interday imprecision, with %CVs less than 6.5 % across 20 replicate measurements. Validation studies assessing other aspects of analytical performance also met acceptance criteria. CONCLUSIONS: Incorporating DMS devices greatly improved the specificity of BPG measurements by LC-MS/MS, as evidenced by the comparison of chromatograms and fragment ion results. Validation studies showed exceptional performance for established analytical metrics, indicating that this technology can be used to minimize the impact of interferences without adversely impacting other aspects of analytical or clinical performance.

Prevalence of tissue transglutaminase antibodies and IgA deficiency are not increased in juvenile idiopathic arthritis: a case-control study.

BACKGROUND: The prevalence of Celiac Disease (CD) in Juvenile Idiopathic Arthritis (JIA) has been reported to be 0.1-7% in various small studies. As a result of the limited number of research and their inconclusive results there are no clear recommendations for routine CD screening in asymptomatic patients with JIA. Our aim is to estimate the prevalence of IgA deficiency and tissue transglutaminase (tTG) IgA in a cohort of JIA followed in two large academic medical centers. METHODS: Serum was collected and stored from all subjects and analyzed in a reference laboratory for total IgA (Quantitative Nephelometry) and tTG IgA antibody levels (Semi-Quantitative Enzyme-Linked Immunosorbent Assay). Fisher's exact tests were performed for statistical significance. Risk estimates (odds ratios) with 95% confidence intervals were calculated. RESULTS: 808 JIA cases and 140 controls were analyzed. Majority were non-Hispanic whites (72% vs. 68% p = 0.309). A total of 1.2% of cases were IgA deficient compared to none of the controls (p = 0.373). After excluding IgA deficient subjects, 2% of cases had tTG IgA ≥ 4u/mL compared to 3.6% of controls (p = 0.216) (OR = 0.5; 95% C.I = 0.1-1.4); and 0.8% of cases had tTG IgA > 10u/mL compared to 1.4% of controls (p = 0.627) (OR = 0.5; 95%C.I = 0.1-2.9). CONCLUSIONS: Using the largest JIA cohort to date to investigate prevalence of celiac antibodies, the prevalence of positive tTG IgA was 0.8% and of IgA deficiency was 1.2%. The results did not demonstrate a higher prevalence of abnormal tTG IgA in JIA. The study did not support the routine screening of asymptomatic JIA patients for CD.

Reporting and Establishment of Reference Intervals for Antiphospholipid Antibody Immunoassays: A Survey of Participants in the College of American Pathologists Proficiency Testing Program.

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-ß2GPI) 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-ß2GPI (n = 354), and IgM anti-ß2GPI (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-ß2GPI, 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.

Diplomate in Medical Laboratory Immunology Certification Examination: A New Chapter for Medical Laboratory Immunology.

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.

Reduced quantity and function of pneumococcal antibodies are associated with exacerbations of COPD in SPIROMICS.

While hypogammaglobulinemia is associated with COPD exacerbations, it is unknown whether frequent exacerbators have specific defects in antibody production/function. We hypothesized that reduced quantity/function of serum pneumococcal antibodies correlate with exacerbation risk in the SPIROMICS cohort. We measured total pneumococcal IgG in n = 764 previously vaccinated participants with COPD. In a propensity-matched subset of n = 200 with vaccination within five years (n = 50 without exacerbations in the previous year; n = 75 with one, n = 75 with ≥2), we measured pneumococcal IgG for 23 individual serotypes, and pneumococcal antibody function for 4 serotypes. Higher total pneumococcal IgG, serotype-specific IgG (17/23 serotypes), and antibody function (3/4 serotypes) were independently associated with fewer prior exacerbations. Higher pneumococcal IgG (5/23 serotypes) predicted lower exacerbation risk in the following year. Pneumococcal antibodies are inversely associated with exacerbations, supporting the presence of immune defects in frequent exacerbators. With further study, pneumococcal antibodies may be useful biomarkers for immune dysfunction in COPD.

Clinical Significance of Anti-U1 Ribonucleoprotein Antibody Is Analyte Dependent: Implications for Laboratory Reporting, Interpretation, and Interassay Correlations.

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.

Presence of anti-gp210 or anti-sp100 antibodies in AMA-positive patients may help support a diagnosis of primary biliary cholangitis.

BACKGROUND: Anti-mitochondrial antibody (AMA) positivity is not always associated with primary biliary cholangitis (PBC). We aimed to determine the additional value of anti-sp100 or anti-gp210 antibody in AMA-positive patients for PBC. METHODS: Patients (n = 190) and healthy donors (n = 50) were evaluated for AMA, anti-gp210 and anti-sp100 antibodies by ELISA. Antibody frequencies in cohorts and performance characteristics in some patients categorized as 'definitive-', 'probable-', and 'no PBC' were determined following review of their charts. RESULTS: Of the patients (n = 190), 38.4% were AMA-positive (n = 73) and 61.6% AMA-negative (n = 117). Frequency of anti-sp100 or anti-gp210 antibody was 17.8%, 2.6%, and 0% in AMA-positive, AMA-negative and healthy controls, respectively. Clinical data was available for 63 of 73 AMA-positive patients with 28.6%, 22.2%, and 49.2% categorized as definite, probable, and no PBC, respectively. Patients with definite PBC had higher mean levels of AMA and frequencies of sp100 or gp210 antibody compared to other groups. Sensitivities were low (anti-sp100: 18.8% and anti-gp210: 16.7%) with specificities above 98.0% for both. CONCLUSION: AMA-positive patients positive for anti-sp100 or anti-gp210 antibody were more likely to have a diagnosis of definite or probable PBC than those with AMA alone. Use of all tests is likely to improve characterization of patients at-risk for PBC.

Reducing the burden of surveillance in pregnant women with no history of fetal atrioventricular block using the negative predictive value of anti-Ro/SSA antibody titers.

BACKGROUND: The risk of fetal atrioventricular block in anti-Ro/SSA antibody-exposed pregnancies with no previous affected offspring is approximately 2%. A high antibody titer is necessary but not sufficient for atrioventricular block, and specific antibody titers do not predict risk. However, there are no data on the negative predictive value of antibody titer to identify pregnancies at low risk of fetal atrioventricular block, and may not require surveillance. OBJECTIVE: This study aimed to define anti-Ro52 and anti-Ro60 antibody thresholds for the identification of fetuses unlikely to develop atrioventricular block using clinically validated and research laboratory tests. STUDY DESIGN: This study performed a multicenter review of pregnant subjects who tested positive in their local commercial laboratories for anti-Ro/SSA antibodies at the University of Colorado Children's Hospital (2014-2021) and Phoenix Children's Hospital (2014-2021) and enrolled in the Research Registry for Neonatal Lupus (RRNL) at New York University Langone Medical Center (2002-2021). The subjects were referred on the basis of rheumatologic symptoms or history of atrioventricular block in a previous pregnancy and were retrospectively grouped on the basis of pregnancy outcome. Group 1 indicated no fetal atrioventricular block in current or past pregnancies; group 2 indicated fetal atrioventricular block in the current pregnancy; and group 3 indicated normal current pregnancy but with fetal atrioventricular block in a previous pregnancy. Maternal sera were analyzed for anti-Ro52 and anti-Ro60 antibodies using a clinically validated multiplex bead assay (Associated Regional and University Pathologists Laboratories, Salt Lake City, UT) and a research enzyme-linked immunosorbent immunoassay (New York University). This study calculated the negative predictive value separately for anti-Ro52 and anti-Ro60 antibodies and for the 2 combined using a logistic regression model and a parallel testing strategy. RESULTS: This study recruited 270 subjects (141 in group 1, 66 in group 2, and 63 in group 3). Of note, 89 subjects in group 1 had data on hydroxychloroquine treatment: anti-Ro/SSA antibody titers were no different between those treated (n=46) and untreated (n=43). Mean anti-Ro52 and anti-Ro60 titers were the lowest in group 1 and not different between groups 2 and 3. No case of fetal atrioventricular block developed among subjects with anti-Ro52 and anti-Ro60 titers of <110 arbitrary units per milliliter using the multiplex bead assay of the Associated Regional and University Pathologists Laboratories (n=141). No case of fetal atrioventricular block developed among subjects with research laboratory anti-Ro52 titers of <650 and anti-Ro60 of <4060 enzyme-linked immunosorbent immunoassay units (n=94). Using these 100% negative predictive value thresholds, more than 50% of the anti-Ro/SSA antibody pregnancies that ultimately had no fetal atrioventricular block could be excluded from surveillance based on clinical and research titers, respectively. CONCLUSION: Study data suggested that there is a clinical immunoassay level of maternal anti-Ro/SSA antibodies below which the pregnancy is at low risk of fetal atrioventricular block. This study speculated that prospectively applying these data may avert the costly serial echocardiograms currently recommended for all anti-Ro/SSA-antibody positive pregnancies and guide future management.

Performance of MPO-ANCA and PR3-ANCA immunoassays for the stratification of specific ANCA-associated vasculitis: A systematic review and meta-analysis.

OBJECTIVE: To determine the impact of myeloperoxidase (MPO) and proteinase 3 (PR3) antigen-specific immunoassays in the stratification of patients at-risk for anti-neutrophil cytoplasmic antibodies (ANCA)-associated vasculitides (AAV) at diagnosis. METHODS: A Medline search was conducted to identify diagnostic accuracy studies using PR3-ANCA or MPO-ANCA for the evaluation of granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA), and eosinophilic granulomatosis with polyangiitis (EGPA). Studies estimates were pooled using the bivariate method. RESULTS: Diagnostic accuracy varied by analyte and AAV subtype. PR3-ANCA had greater sensitivity than MPO-ANCA for GPA (74% vs 11%, p < 0.001) and MPO-ANCA greater sensitivity for MPA (73% vs 7%, p < 0.001). Specificities of both MPO-ANCA and PR3-ANCA were consistently high (mean 97%, range: 93-99%) for both AAV subtypes. There was insufficient data to perform meta-analysis for the diagnostic accuracy of EPGA. CONCLUSION: These results validate the use of high quality MPO-ANCA and PR3-ANCA immunoassays to screen patients at-risk for AAV as well as to categorize disease as GPA or MPA subtype. However, caution must be exercised in doing so, since some assays may not have optimal performance. Each laboratory should validate appropriate algorithms based on the tests used and testing population.

Assessment of a Line Immunoassay for the Detection of Mi-2 Antibodies: Results From a Single Academic Center Investigation.

OBJECTIVES: To evaluate the performance characteristics of a line immunoassay (LIA) for the detection of Mi-2 antibodies associated with dermatomyositis (DM). METHODS: In total, 432 consecutive patient specimens were tested for Mi-2 antibodies concurrently by LIA (Mi-2α or Mi-2ß) or immunoprecipitation (IP) test and antinuclear antibody by indirect immunofluorescence assay using HEp-2 substrate. Following antibody evaluation, results for patients positive in any of the assays for Mi-2 antibody had a retrospective chart review for diagnostic categorization. The performance of all tests was evaluated based on the extracted clinical data. RESULTS: Forty patients were positive in at least one of the Mi-2 assays. The frequency of Mi-2ß antibody by LIA was highest (75.0%), followed by Mi-2 by IP (35.0%) and Mi-2α by LIA (20.0%), respectively. Mi-2 by IP had the best total percent agreement for DM (95.0%) compared with 70.0% and 25.0% for the LIA Mi-2α and Mi-2ß, respectively. Positivity of the Mi-2ß antibody was significantly associated with non-DM diagnosis. CONCLUSIONS: Agreement for DM with assays for detecting Mi-2 is variable. Additional studies are required to validate Mi-2 immunoassays for routine patient evaluation.

Performance evaluation of a radioimmunoprecipitation assay for the detection of N-type voltage-gated calcium channel antibodies.

BACKGROUND: In this study, we assessed the performance characteristics of a laboratory-developed radioimmunoassay (RIA) to detect N-type voltage-gated calcium channel (N-VGCC) antibodies found in several autoimmune neurologic diseases. METHODS: Four hundred and forty-five (n = 445) sera were evaluated, including 156 sera (50 positive and 106 negative for N-VGCC antibodies) previously tested at Mayo Clinic Laboratories (MCL) and 289 controls (n = 187 disease and n = 102 healthy). Specimens were analyzed with the RIA using N-VGCC labeled with 125I-ω-conotoxin GVIA. The RIA was compared to the predicate MCL assay using a tiered positive predictive value (PPV) approach. Other performance characteristics evaluated included specificity, precision, interference, and stability. RESULTS: Qualitative inter-laboratory agreement based on tiered PPVs was 100% for results >1.00 nmol/L (71% PPV), 48% for results of 0.10-0.99 nmol/L (24% PPV) and 22% for results of 0.04-0.10 nmol/L (19% PPV). Negative results showed 90% agreement (n = 106). Specificity in controls positive for other neural autoantibodies and healthy controls were 87% and 100%, respectively. Acceptable results were observed for other performance characteristics. CONCLUSIONS: Inter-laboratory correlations demonstrate equivalence between assays with some discrepancies between low positive results. Collaborative efforts aimed at assessing the clinical spectrum associated with these antibodies and consensus for harmonizing test performance are required for optimal categorization of patients.

Highlights of the 33rd annual scientific meeting of the Association of Medical Laboratory Immunologists (AMLI).

The annual meeting of the Association of Medical Laboratory Immunologists (AMLI) was convened virtually over the month of August. Prior to the emergence of the COVID-19 pandemic, AMLI's scientific committee had chosen the following topics as the focus of its 2020 meeting: Histocompatibility Testing and Transplant Immunology; Secondary Immunodeficiency and Immunotherapy Monitoring; ANA Update; and Emerging Infectious Diseases and New Algorithms for Testing. Given the central role of the discipline in the evaluation of the host response to infection, it was apt to add a separate session on antibody testing for SARS-CoV-2 infections to the original program. The current report provides an overview of the subjects discussed in the course of this meeting.

The antinuclear antibody HEp-2 indirect immunofluorescence assay: a survey of laboratory performance, pattern recognition and interpretation.

BACKGROUND: To evaluate the interpretation and reporting of antinuclear antibodies (ANA) by indirect immunofluorescence assay (IFA) using HEp-2 substrates based on common practice and guidance by the International Consensus on ANA patterns (ICAP). METHOD: Participants included two groups [16 clinical laboratories (CL) and 8 in vitro diagnostic manufacturers (IVD)] recruited via an email sent to the Association of Medical Laboratory Immunologists (AMLI) membership. Twelve (n = 12) pre-qualified specimens were distributed to participants for testing, interpretation and reporting HEp-2 IFA. Results obtained were analyzed for accuracy with the intended and consensus response for three main categorical patterns (nuclear, cytoplasmic and mitotic), common patterns and ICAP report nomenclatures. The distributions of antibody titers of specimens were also compared. RESULTS: Laboratories differed in the categorical patterns reported; 8 reporting all patterns, 3 reporting only nuclear patterns and 5 reporting nuclear patterns with various combinations of other patterns. For all participants, accuracy with the intended response for the categorical nuclear pattern was excellent at 99% [95% confidence interval (CI): 97-100%] compared to 78% [95% CI 67-88%] for the cytoplasmic, and 93% [95% CI 86%-100%] for mitotic patterns. The accuracy was 13% greater for the common nomenclature [87%, 95% CI 82-90%] compared to the ICAP nomenclature [74%, 95% CI 68-79%] for all participants. Participants reporting all three main categories demonstrated better performances compared to those reporting 2 or less categorical patterns. The average accuracies varied between participant groups, however, with the lowest and most variable performances for cytoplasmic pattern specimens. The reported titers for all specimens varied, with the least variability for nuclear patterns and most titer variability associated with cytoplasmic patterns. CONCLUSIONS: Our study demonstrated significant accuracy for all participants in identifying the categorical nuclear staining as well as traditional pattern assignments for nuclear patterns. However, there was less consistency in reporting cytoplasmic and mitotic patterns, with implications for assigning competencies and training for clinical laboratory personnel.

Assessment of antinuclear antibodies by indirect immunofluorescence assay: report from a survey by the American Association of Medical Laboratory Immunologists.

Background: The indirect immunofluorescence assay (IFA) using HEp-2 cell substrates is the preferred method by some for detecting antinuclear antibodies (ANA) as it demonstrates a number of characteristic staining patterns that reflect the cellular components bound as well as semi-quantitative results. Lack of harmonized nomenclature for HEp-2 IFA patterns, subjectivity in interpretation and variability in the number of patterns reported by different laboratories pose significant harmonization challenges. The main objectives of this study were to assess current practice in laboratory assessment of HEp-2 IFA, identify gaps and define strategies to improve reading, interpretation and reporting. Methods: We developed and administered a 24-item survey based on four domains: educational and professional background of participants, current practice of HEp-2 IFA testing and training, gap assessment and the perceived value of International Consensus on Antinuclear Antibody Patterns (ICAP) and other factors in HEp-2 IFA assessment. The Association of Medical Laboratory Immunologists (AMLI) and American Society for Clinical Pathology administered the survey from April 1 to June 30, 2018, to members involved in ANA testing. This report summarizes the survey results and discussion from a dry workshop held during the 2019 AMLI annual meeting. Results: One hundred and seventy-nine (n = 179) responses were obtained where a significant number were clinical laboratory scientists (46%), laboratory directors (24%), supervisors (13%) or others (17%). A majority of respondents agreed on the need to standardize nomenclature and reporting of HEp-2 IFA results. About 55% were aware of the ICAP initiative; however, among those aware, a significant majority thought its guidance on HEp-2 IFA nomenclature and reporting is of value to clinical laboratories. To improve ICAP awareness and further enhance HEp-2 IFA assessment, increased collaboration between ICAP and the clinical laboratory community was suggested with emphasis on education and availability of reference materials. Conclusions: Based on these suggestions, future efforts to optimize HEp-2 IFA reading, interpretation and reporting would benefit from more hands-on training of laboratory personnel as well as continuous collaboration between professional organizations, in vitro diagnostic manufacturers and clinical laboratories.

Laboratory Evaluation of Antiphospholipid Syndrome: An Update on Autoantibody Testing.

Antiphospholipid syndrome (APS) is as an autoimmune disease characterized by thrombosis and/or specific pregnancy-related morbidity associated with persistent antiphospholipid antibodies, namely, lupus anticoagulant and IgG and IgM antibodies to cardiolipin and beta2 glycoprotein I. Optimal antibody detection plays a central role in diagnosis and classification. This review discusses antiphospholipid antibodies helpful for diagnosing APS. It includes the criteria and noncriteria antiphospholipid antibodies, methods for their detection, and challenges for clinical reporting and interpretation. The significance of using specific noncriteria antiphospholipid tests in an integrated diagnostic approach with criteria antiphospholipid makers for the diagnosis and management of APS is also reviewed.