Search

Purpose Mendelian susceptibility to mycobacterial disease (MSMD) is caused by inborn errors of IFN-γ immunity. The most frequent genetic defects are found in IL12 or a subunit of its receptor. IL23R deficiency in MSMD has only been reported once, in two pediatric patients from the same kindred with isolated disseminated Bacille Calmette-Guérin disease. We evaluated the impact of a homozygous stop mutation in IL23R (R381X), identified by whole exome sequencing, in an adult patient with disseminated non-tuberculous mycobacterial disease. Methods We performed functional validation of the R381X mutation by evaluating IL23R expression and IL-23 signaling (STAT3 phosphorylation, IFN-γ production) in primary cells (PBMCs, EBV-B cells) and cell lines (HeLa) with or without back-complementation of wild-type IL23R. Results We report on a 48-year-old male with disseminated non-tuberculous mycobacterial disease. We identified and characterized a homozygous loss-of-function stop mutation underlying IL23R deficiency, resulting in near absent expression of membrane bound IL23R. IL23R deficiency was characterized by impaired IL-23-mediated IFN-γ secretion in CD4+, CD8+ T, and mucosal-associated invariant T (MAIT) cells, and low frequencies of circulating Th17 (CD3+CD45RA−CCR4+CXCR3−RORγT+), Th1* (CD45RA−CCR4−CXCR3+RORγT+), and MAIT (CD3+CD8+Vα7.2+CD161+) cells. Although the patient did not have a history of recurrent fungal infections, impaired Th17 differentiation and blunted IL-23-mediated IL-17 secretion in PBMCs were observed. Conclusion We demonstrate that impaired IL-23 immunity caused by a homozygous R381X mutation in IL23R underlies MSMD, corroborating earlier findings with a homozygous p.C115Y IL23R mutation. Our report further supports a model of redundant contribution of IL-23- to IL-17-mediated anti-fungal immunity.1

Encephalitis and encephalopathy in children represent a diagnostic challenge. We describe a patient with relapsing encephalitis in whom the differential diagnosis included acute disseminated encephalomyelitis (ADEM), human herpesvirus 6 (HHV-6) encephalitis, and hemophagocytic lymphohistiocytosis (HLH). Because of its rarity, HLH is often overlooked as a differential diagnosis in encephalitis, especially in the isolated central nervous system (CNS) forms. As this case illustrates, inborn errors of immunity (IEIs) can underlie isolated encephalitis and should be included in the differential diagnosis of these presentations.

An international consensus on antineutrophil cytoplasm antibodies (ANCA) testing in eosinophilic granulomatosis with polyangiitis (EGPA) is presented. ANCA, specific for myeloperoxidase (MPO), can be detected in 30-35% of patients with EGPA. MPO-ANCA should be tested with antigen-specific immunoassays in any patient with eosinophilic asthma and clinical features suggesting EGPA, including constitutional symptoms; purpura; polyneuropathy; unexplained heart, gastrointestinal, or kidney disease; and/or pulmonary infiltrates or hemorrhage. A positive MPO-ANCA result contributes to the diagnostic workup for EGPA. Patients with MPO-ANCA-associated EGPA have vasculitis features, such as glomerulonephritis, neuropathy, and skin manifestations, more frequently than patients with ANCA-negative EGPA. However, the presence of MPO-ANCA is neither sensitive nor specific enough to identify whether a patient should be subclassified as having "vasculitic" or eosinophilic" EGPA. At present, ANCA status cannot guide treatment decisions, that is, whether cyclophosphamide, rituximab, or mepolizumab should be added to conventional glucocorticoid treatment. In EGPA, monitoring of ANCA is only useful when MPO-ANCA was tested positive at disease onset.

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).

INTRODUCTION: Quantification of serum-free light chains (FLCs) is important in the diagnosis and monitoring of paraprotein-related diseases. There are currently 2 FLC assays available: the Freelite assay (Binding Site) and the N Latex assay (Siemens). There is emerging evidence that these assays give different results, but it is not established how kidney dysfunction affects these assays differently. METHODS: In this study, we measured and compared serum FLCs in patients with mild-to-moderate chronic kidney disease (CKD) using both assays. RESULTS: Although κ FLCs are higher by Freelite, λ FLCs are higher by N Latex. Both κ and λ FLCs correlate inversely with estimated glomerular filtration rate (eGFR) in the 2 assays, but this effect is more pronounced in λ-free light-chain measurement by N Latex. Consequently, although the κ/λ ratio by Freelite is inversely correlated by eGFR, the κ/λ ratio by N Latex is positively correlated with eGFR. CONCLUSION: Our results clearly demonstrate that the 2 available FLC assays cannot be used interchangeably in patients with CKD. ispartof: KIDNEY INTERNATIONAL REPORTS vol:5 issue:5 pages:627-631 ispartof: location:United States status: published

Background Both enzyme-linked immunosorbent assays (ELISAs) and indirect immunofluorescence (IIF) are available for the diagnosis of autoimmune bullous diseases (AIBD). Many studies have reported on the performance of ELISAs and concluded that ELISAs could replace IIF. This study compares the diagnostic accuracy of ELISA and IIF for the detection of autoantibodies to desmoglein 1 (DSG1), desmoglein 3 (DSG3), bullous pemphigoid antigen 2 (BP180) and bullous pemphigoid antigen 1 (BP230) to support the diagnosis of pemphigus vulgaris (PV), pemphigus foliaceus (PF) and bullous pemphigoid (BP). Methods A literature search was performed in the PubMed database. The meta-analysis was performed using summary values and a bivariate random effect model. Results The five included studies on PV did not demonstrate significant differences between IIF and DSG3-ELISA (sensitivity 82.3% vs. 81.6%, p = 0.9284; specificity 95.6% vs. 93.9%, p = 0.5318; diagnostic odds ratio [DOR] 101.60 vs. 67.760, p = 0.6206). The three included studies on PF did not demonstrate significant differences between IIF and DSG1-ELISA (sensitivity 80.6% vs. 83.1%, p = 0.8501; specificity 97.5% vs. 93.9%, p = 0.3614; DOR 160.72 vs. 75.615, p = 0.5381). The eight included studies on BP showed that BP230-ELISA differed significantly from both IIF on monkey esophagus (MO) and BP180-ELISA with regard to DOR (11.384 vs. 68.349, p = 0.0008; 11.384 vs. 41.699, p = 0.0125, respectively) Conclusions Our meta-analysis shows that ELISA performs as well as IIF for diagnosing PV, PF and BP.

BackgroundSevere acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the cause of the ongoing COVID-19 pandemic. To prevent the massive COVID-19 burden, several vaccination campaigns were initiated. We performed a single center observational trial to evaluate adaptive immunity in naive healthcare workers upon BNT162b2 vaccination.MethodsSerological analysis was performed through conventional immunoassays. Antibody functionality was analyzed via in vitro neutralization assays. Circulating receptor-binding domain (RBD) specific B cells were assessed via flowcytometry. The induction of SARS-CoV-2 specific T cells was investigated through interferon-γ release assay combined with flowcytometric profiling of activated CD4 and CD8 T cells.ResultsThree months after vaccination, all but one of the subjects (N = 31) displayed vaccine-induced neutralizing antibodies. In 10 out of 31 subjects, circulating RBD specific B cells were found of which the rate showed moderate correlation to serological parameters. Specific interferon-γ release was present in all subjects and correlated with the significant upregulation of CD69 on CD4+ and CD8+ T cells and CD40L on CD4+ T cells. Interestingly, no relation was found between B and T cell parameters. In addition, one symptomatic breakthrough infection with the SARS-CoV-2 alpha variant of concern was reported.ConclusionThree months post vaccination, both humoral and cellular immune responses are detectable in all but one participant. No correlation was found between the magnitude of both B and T cell responses.

Objectives Rheumatoid factor (RF) is a well-established marker for the diagnosis and classification of rheumatoid arthritis (RA). Most studies evaluated IgM RF or isotype-nonspecific total RF assays. We evaluated the added value of IgA RF in this context. Methods An international sample cohort consisting of samples from 398 RA patients and 1073 controls was tested for IgA RF with 3 commercial assays. For all RA patients and 100 controls essential clinical and serological data for ACR/EULAR classification were available. Results The sensitivity of IgA RF for diagnosing RA was lower than the sensitivity of IgM RF. Differences in numerical values between IgA RF assays were observed. With all assays, the highest IgA RF values were found in patients with primary Sjögren’s syndrome. Double positivity for IgM RF and IgA RF had a higher specificity for RA than either IgM RF or IgA RF. The sensitivity of double positivity was lower than the sensitivity of either IgA RF or IgM RF. Single positivity for IgA RF was at least as prevalent in controls than in RA patients. Adding IgA RF to IgM RF and anti-citrullinated protein antibodies (ACPA) did not affect RA classification. However, combined positivity for IgA RF, IgM RF and IgG ACPA had a higher specificity and lower sensitivity for RA classification than positivity for either of the antibodies. Conclusions IgA RF showed a lower sensitivity than IgM RF. Combining IgA RF with IgM RF and ACPA did not improve sensitivity of RA classification. Combined positivity (IgA-RF/IgM-RF/ACPA) increased specificity.

Contains fulltext : 287807.pdf (Publisher’s version ) (Closed access)

A multiplex assay for the quantitation of immunoglobulin G (IgG) serum antibodies directed against Clostridium tetani toxin (TT), Corynebacterium diphtheriae toxoid (DTxd), and the Bordetella pertussis antigens pertussis toxin (PT), filamentous hemagglutinin (FHA) and pertactin (Prn) was developed on an Evalution® platform to enhance the evaluation of the specific antibody response towards protein antigens in suspected humoral immunodeficiencies. Evalution® is a microfluidic and microparticle-based platform with the possibility to analyse single samples and to perform real-time kinetic measurements of antibody binding. All individual antigens were covalently linked to the carboxylated microparticles after which samples and fluorescently labelled detection antibodies were flowed over the microparticles in the microfluidic channels of the assay cartridges of the system. The developed assay showed very good sensitivity, specificity, and intra- and inter-assay coefficients of variation (CVs for the different antigens between 1.72-3.53% and 3.54‐5.79%, respectively). Furthermore, the correlation of the Evalution pentaplex with a Luminex pentaplex using a panel of 48 human serum samples was excellent, with Spearman correlation coefficients between 0.936 for PT and 0.982 for DTxd (p < 0.0001 for all). Finally, we showed in a proof-of-concept experiment the potential of the Evalution® platform to simultaneously measure concentrations and binding kinetics (as a surrogate for avidity) of the IgG antibodies to the selected protein antigens. Overall, these findings show that this new Evalution pentaplex can accurately measure the antibody response to TT, DTxd, PT, FHA and Prn. It also has the potential to measure antibody binding and dissociation kinetics. ispartof: Journal Of Immunological Methods vol:503 ispartof: location:Netherlands status: Published online

Background There is a need for additional biomarkers to assist in the diagnosis and prognosis of rheumatoid arthritis (RA). The aim of our study was to evaluate the (pre-analytical, analytical and clinical) performance of serum calprotectin as a marker of inflammation in RA. Methods The study population included 463 rheumatologic patients (including 111 RA patients and 352 controls) who for the first time consulted a rheumatologist, 20 healthy controls and 27 patients with an infectious disease. Calprotectin was measured (using four different assays) in serum or in serum and EDTA plasma (healthy controls and infectious disease group). For rheumatologic patients, results for C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), rheumatoid factor (RF) and anti-cyclic citrullinated peptide antibody (ACPA) were available. Results Results for blood calprotectin were assay- and matrix-dependent, with higher values found in serum than in plasma. Serum calprotectin was higher in RA patients than in rheumatologic diseased controls and in healthy controls. Serum calprotectin was lower in RA patients than in patients with an infectious disease. Serum calprotectin was associated with disease activity (DAS score). The area under the curve (AUC) to discriminate RA from controls was 0.756 for CRP, 0.714 for ESR and 0.726–0.783 for calprotectin. Conclusions Our data document that calprotectin measurement is assay- and matrix-dependent. Serum calprotectin is associated with disease activity. Additional (prospective) studies are warranted to further evaluate the prognostic and diagnostic value of blood calprotectin measurements.

We describe two unrelated patients with inherited IFNAR1 deficiency who suffered from life-threatening infections following measles or yellow fever virus vaccination and were otherwise healthy., Vaccination against measles, mumps, and rubella (MMR) and yellow fever (YF) with live attenuated viruses can rarely cause life-threatening disease. Severe illness by MMR vaccines can be caused by inborn errors of type I and/or III interferon (IFN) immunity (mutations in IFNAR2, STAT1, or STAT2). Adverse reactions to the YF vaccine have remained unexplained. We report two otherwise healthy patients, a 9-yr-old boy in Iran with severe measles vaccine disease at 1 yr and a 14-yr-old girl in Brazil with viscerotropic disease caused by the YF vaccine at 12 yr. The Iranian patient is homozygous and the Brazilian patient compound heterozygous for loss-of-function IFNAR1 variations. Patient-derived fibroblasts are susceptible to viruses, including the YF and measles virus vaccine strains, in the absence or presence of exogenous type I IFN. The patients’ fibroblast phenotypes are rescued with WT IFNAR1. Autosomal recessive, complete IFNAR1 deficiency can result in life-threatening complications of vaccination with live attenuated measles and YF viruses in previously healthy individuals.

Idiopathic inflammatory myopathies (IIM) are a group of diseases characterized by immune-mediated muscular lesions that may be associated with extra-muscular manifestations involving skin, lungs, heart or joints. Four main groups of IIM can be distinguished: dermatomyositis (DM), overlap myositis including mainly anti-synthetase syndrome (ASS), immune mediated necrotizing myopathy (IMNM), and inclusion body myositis (IBM). Myositis-specific autoantibodies (MSA) are increasingly recognized as valuable tools for diagnosis, classification and prognosis of IIM. For example, ASS is associated with anti-aminoacyl tRNA synthetase antibodies (anti-Jo-1, PL-7, PL-12, …), IMNM with anti-SRP and anti-HMGCR; IBM with anti-cytosolic 5'nucleotidase 1A (cN1A), and DM with anti-Mi-2, anti-MDA-5, anti-TIF-1γ, anti-NXP-2 and anti-SAE. Moreover, anti-MDA-5 is associated with amyopathic myositis and interstitial lung disease and anti-TIF-1γ and anti-NXP-2 with juvenile DM as well as malignancy in patients >40 years. Most MSA have initially been discovered by immunoprecipitation. In routine laboratories, however, MSA are screened for by indirect immunofluorescence and identified by (automated) monospecific immunoassays or by multispecific immunoassays (mainly line/dot immunoassays). Validation of these (multispecific) assays is a challenge as the antibodies are rare and the assays diverse. In this review, we give an overview of the (clinical) performance characteristics of monospecific assays as well as of multispecific assays for detection of MSA. Although most assays are clinically useful, there are differences between techniques and between manufacturers. We discuss that efforts are needed to harmonize and standardize detection of MSA. ispartof: AUTOIMMUNITY REVIEWS vol:18 issue:3 pages:293-305 ispartof: location:Netherlands status: published

Background Isolated antibodies to DFS70 have been described in healthy individuals and are rarely found in patients with antinuclear antibody-associated autoimmune rheumatic diseases (AARD). However, no data is available on geographic differences in the prevalence of anti-DFS70 antibodies. We aimed to study the prevalence of anti-DFS70 antibodies in blood donor samples from several countries representing various ethnical backgrounds and geographic regions in the world. Methods Sera from apparently healthy blood donors (n≥300 per site) were collected in seven countries (USA, Italy, Spain, Germany, UK, Belgium and Brazil). All samples (n=2628) were tested for anti-DFS70 antibodies by QUANTA Flash DFS70 (Inova Diagnostics, Inc., San Diego, CA, USA). Results The prevalence of anti-DFS70 antibodies varied from 4/321 (1.2%, Italy) to 42/497 (8.5%, USA). Consequently, the prevalence of the antibodies was significantly higher in USA compared to all other countries (p Conclusions This is the first study to analyze the prevalence of anti-DFS70 antibodies in different geographic areas using a standardized assay. Our findings show that the antibodies are most prevalent in young females.

Background The introduction of automated anti-nuclear antibody (ANA) indirect immunofluorescence (IIF) analysis may allow for more harmonized ANA IIF reporting, provided that a thorough quality assurance program controls this process. The aim of this study was to evaluate various quality indicators used for ANA IIF analysis with the final goal of optimizing the iQC program. Methods In an experimental setup, we introduced artificial errors, mimicking plausible problems during routine practice on a QUANTA-Lyser-NOVA View® system (Inova Diagnostics, San Diego, CA, USA). Predetermined quality indicators were evaluated against predefined acceptance criteria. In addition, we retrospectively investigated the applicability of the selected quality indicators in the daily routine practice during three pre-defined periods. Results Both the experimental as the retrospective study revealed that pre-analytical, analytical and post-analytical errors were not highlighted by company internal quality control (iQC) materials. The use of patient derived iQC samples, median fluorescence intensity results per run and the percentage of positive ANA IIF results as additional quality indicators ensured a more adequate ANA IIF quality assurance. Furthermore, negative and moderate positive sample iQC materials merit clinical validation, as titer changes of >1 correspond to clinically important shifts. Traditional Westgard rules, including a clinically defined stop limit, revealed to be useful in monitoring of the supplemental quality indicators. Conclusions A thorough ANA IIF quality assurance for daily routine practice necessitates the addition of supplemental quality indicators in combination with well-defined acceptance criteria.

Chronic inflammatory demyelinating polyneuropathy is a neuroinflammatory disorder with considerable variation in clinical phenotype, disease progression and therapy response among patients. Recently, paranodal antibodies associated with poor response to intravenous immunoglobulin therapy and more aggressive disease course have been described in small subsets of patients, but reliable serum-based prognostic biomarkers are not yet available for the general population. In current retrospective longitudinal study, we utilized logistic regression models to investigate the associations of serum neurofilament light chain levels with 1-year disease progression and therapy response during follow-up in chronic inflammatory demyelinating polyneuropathy. One-year disease progression was defined as a decrease of four or more points (the minimal clinically important difference) on an 80-point Medical Research Council sum-score scale 1 year after sampling. Patients who, compared to treatment received at time of sampling, required therapy switch during follow-up due to insufficient effect were classified as non-responders. Serum neurofilament light chain was measured by electrochemiluminescence assay in clinical residual serum samples of 76 patients diagnosed with probable (13 patients) or definite (63 patients) chronic inflammatory demyelinating polyneuropathy according to European Federation of Neurological Societies/Peripheral Nerve Society diagnostic criteria. Eleven (15%) patients were female, and the mean (standard deviation) cohort age was 61.5 (11.7) years. In both univariate and multivariable (including demographics) models, elevated serum neurofilament light chain harboured increased odds for 1-year disease progression (respectively odds ratio, 1.049; 95% confidence interval, 1.022–1.084 and odds ratio, 1.097; 95% confidence interval, 1.045–1.169; both P = 0.001). Patients with levels above the median cohort neurofilament light chain level (28.3 pg/ml) had largely increased odds of 1-year disease progression (univariate: odds ratio, 5.597; 95% confidence interval, 1.590–26.457; P = 0.01; multivariable: odds ratio, 6.572; 95% confidence interval, 1.495–39.702; P = 0.02) and of insufficient treatment response (univariate: odds ratio, 4.800; 95% confidence interval, 1.622–16.442; P = 0.007; multivariable: odds ratio, 6.441; 95% confidence interval, 1.749–29.357; P = 0.009). In a combined approach analysis, patients with levels above median cohort serum neurofilament light chain level reported strongly increased odds of demonstrating 1-year disease progression and/or therapy non-response during follow-up (univariate: odds ratio, 6.337; 95% confidence interval, 2.276–19.469; P < 0.001; multivariable: odds ratio, 10.138; 95% confidence interval, 2.801–46.404; P = 0.001). These results show that in various logistic regression models, serum neurofilament light chain was associated with both 1-year disease progression and therapy response during follow-up in chronic inflammatory demyelinating polyneuropathy. Hence, our findings warrant further prospective research regarding the value of neurofilament light chain as potential prognostic biomarker in chronic inflammatory demyelinating polyneuropathy., Godelaine et al. investigated the prognostic value of serum neurofilament light chain in chronic inflammatory demyelinating polyneuropathy and showed in various logistic regression models that elevated serum neurofilament light chain levels were significantly associated with increased odds of 1-year disease progression, not responding to therapy during follow-up or both., Graphical Abstract Graphical Abstract

Objectives To compare indirect immunofluorescence (IIF) for antinuclear antibodies (ANA) against immunoassays (IAs) as an initial screening test for connective tissue diseases (CTDs). Methods A systematic literature review identified cross-sectional or case-control studies reporting test accuracy data for IIF and enzyme-linked immunosorbent assays (ELISA), fluorescence enzyme immunoassay (FEIA), chemiluminescent immunoassay (CLIA) or multiplex immunoassay (MIA). The meta-analysis used hierarchical, bivariate, mixed-effect models with random-effects by test. Results Direct comparisons of IIF with ELISA showed that both tests had good sensitivity (five studies, 2321 patients: ELISA: 90.3% [95% confidence interval (CI): 80.5%, 95.5%] vs. IIF at a cut-off of 1:80: 86.8% [95% CI: 81.8%, 90.6%]; p = 0.4) but low specificity, with considerable variance across assays (ELISA: 56.9% [95% CI: 40.9%, 71.5%] vs. IIF 1:80: 68.0% [95% CI: 39.5%, 87.4%]; p = 0.5). FEIA sensitivity was lower than IIF sensitivity (1:80: p = 0.005; 1:160: p = 0.051); however, FEIA specificity was higher (seven studies, n = 12,311, FEIA 93.6% [95% CI: 89.9%, 96.0%] vs. IIF 1:80 72.4% [95% CI: 62.2%, 80.7%]; p Conclusions FEIA and CLIA have good specificity compared to IIF. A positive FEIA or CLIA test is useful to support the diagnosis of a CTD. A negative IIF test is useful to exclude a CTD.

Detectie van autoantilichamen is relevant voor de diagnose, prognose, classificatie en stratificatie van systemische auto-immune reumatische aandoeningen (SARD). De belangrijke detectiemethodes zijn indirecte immunofluorescentie bij HEp-2-cellen (HEp-2-IIF) en solid-phase assays (SPA). Bij HEp-2-IIF kunnen een fluorescentie-intensiteit en een patroon gerapporteerd worden. De laatste jaren wordt volop ingezet op automatisatie en standaardisatie van HEp-2-IIF. Meer en meer worden ook solid-phase assays gebruikt, waarbij recombinante, synthetische of opgezuiverde antigenen op een vast substraat worden geplaatst. Daarbij is er een evolutie naar het gebruiken van multiplextesten, waarbij meerdere autoantilichamen in één test opgespoord kunnen worden. In dit artikel worden de eigenschappen van die detectiemethodes en de implicaties voor de klinische praktijk besproken.

Myositis-specific autoantibodies (MSAs) are thought to be mutually exclusive in patients with idiopathic inflammatory myopathies (IIM) based on studies with immunoprecipitation-based (IP) detection methods. Recently, detection of multiple MSAs in unique patients is increasingly reported, but the extent of this phenomenon remains unclear.At our centre, we reviewed results from two line immunoassays and one dot immunoassay in 145 IIM patients and 240 controls for the presence of multiple MSAs. Pubmed and Embase were systematically searched for articles mentioning detection of multiple MSAs in IIM patients, published until February 2019. We assessed the frequency, detection method, the precise combinations and clinical phenotypes of participants with multiple MSAs.At our centre, detection of multiple MSAs occurred in 3.4-8.3% of patients with IIM, depending on the assay. However, no cases with full concordance across all three assays were identified. Forty-four articles reported detection of multiple MSAs, representing a total of 133 cases, including four patients with a connective tissue disease other than IIM and two healthy controls. In 101 cases all MSAs were detected using only one detection method: 40 cases with IP-based methods (most frequently used technique) and 61 cases with other assay types. In most cases the phenotype of patients with multiple MSAs matched the predicted presentation associated with one MSA and in few cases the phenotype matched with both MSAs.Detection of multiple MSAs in unique IIM patients is less rare than commonly accepted. Specificity issues of the commercially available multiplex immunoassays may, at least partly, explain the higher frequency compared to IP-based methods. 'True multiple MSA-positive' patients may exist, though they are most likely rare.

Background The International Consensus on Antinuclear Antibody (ANA) Patterns (ICAP) has recently proposed nomenclature in order to harmonize ANA indirect immunofluorescence (IIF) pattern reporting. ICAP distinguishes competent-level from expert-level patterns. A survey was organized to evaluate reporting, familiarity, and considered clinical value of ANA IIF patterns. Methods Two surveys were distributed by European Autoimmunity Standardization Initiative (EASI) working groups, the International Consensus on ANA Patterns (ICAP) and UK NEQAS to laboratory professionals and clinicians. Results 438 laboratory professionals and 248 clinicians from 67 countries responded. Except for dense fine speckled (DFS), the nuclear competent patterns were reported by > 85% of the laboratories. Except for rods and rings, the cytoplasmic competent patterns were reported by > 72% of laboratories. Cytoplasmic IIF staining was considered ANA positive by 55% of clinicians and 62% of laboratory professionals, with geographical and expertise-related differences. Quantification of fluorescence intensity was considered clinically relevant for nuclear patterns, but less so for cytoplasmic and mitotic patterns. Combining IIF with specific extractable nuclear antigens (ENA)/dsDNA antibody testing was considered most informative. Of the nuclear competent patterns, the centromere and homogeneous pattern obtained the highest scores for clinical relevance and the DFS pattern the lowest. Of the cytoplasmic patterns, the reticular/mitochondria-like pattern obtained the highest scores for clinical relevance and the polar/Golgi-like and rods and rings patterns the lowest. Conclusion This survey confirms that the major nuclear and cytoplasmic ANA IIF patterns are considered clinically important. There is no unanimity on classifying DFS, rods and rings and polar/Golgi-like as a competent pattern and on reporting cytoplasmic patterns as ANA IIF positive.

Antineutrophil cytoplasmic antibodies (ANCAs) are important laboratory markers to support the diagnosis of ANCA-associated vasculitis. A 2017 international consensus states that high-quality immunoassays for proteinase-3 (PR3)-ANCA and myeloperoxidase (MPO)-ANCA can be used as the primary screening method for patients suspected of having granulomatosis with polyangiitis or microscopic polyangiitis.1 Efforts have been undertaken to standardise PR3-ANCA and MPO-ANCA measurements. More than 10 years ago, PR3-ANCA and MPO-ANCA reference standards have been prepared (from single patients) under the umbrella of the International Union of Immunological Societies (IUIS) and are available through the Autoantibody Standardization Committee (www.AutoAb.org). Several companies are using these reference standards (assigned value: 100 IU/mL) to calibrate their assays, such as Svar Life Science (ELISA), Thermo Fisher Scientific (fluoroenzyme immunoassay (FEIA)), Medipan (CytoBead assay) and Inova Diagnostics (chemiluminescence assay (CLIA)). The Institute for Reference Materials and Measurements (IRMM) recently released certified reference materials for MPO-ANCA (ERM-DA476/IFCC) and for PR3-ANCA (ERM-DA483/IFCC).2 3 Both reference materials are based on plasmapheresis samples from single patients. We evaluated whether using the IRMM-certified reference materials aligns results for PR3-ANCA and MPO-ANCA across assays. A random selection of 98 serum samples covering low, medium and high PR3-ANCA or MPO-ANCA levels from the Leuven and the Maastricht cohort included in the international EUVAS study4 were distributed to five manufacturers, together with the PR3-ANCA and …

BackgroundThe International Consensus on Antinuclear Antibody (ANA) Patterns (ICAP) has recently proposed nomenclature in order to harmonize ANA indirect immunofluorescence (IIF) pattern reporting. ICAP distinguishes competent-level from expert-level patterns. A survey was organized to evaluate reporting, familiarity, and considered clinical value of ANA IIF patterns. MethodsTwo surveys were distributed by European Autoimmunity Standardization Initiative (EASI) working groups, the International Consensus on ANA Patterns (ICAP) and UK NEQAS to laboratory professionals and clinicians. Results438 laboratory professionals and 248 clinicians from 67 countries responded. Except for dense fine speckled (DFS), the nuclear competent patterns were reported by >85% of the laboratories. Except for rods and rings, the cytoplasmic competent patterns were reported by >72% of laboratories. Cytoplasmic IIF staining was considered ANA positive by 55% of clinicians and 62% of laboratory professionals, with geographical and expertise-related differences. Quantification of fluorescence intensity was considered clinically relevant for nuclear patterns, but less so for cytoplasmic and mitotic patterns. Combining IIF with specific extractable nuclear antigens (ENA)/dsDNA antibody testing was considered most informative. Of the nuclear competent patterns, the centromere and homogeneous pattern obtained the highest scores for clinical relevance and the DFS pattern the lowest. Of the cytoplasmic patterns, the reticular/mitochondria-like pattern obtained the highest scores for clinical relevance and the polar/Golgi-like and rods and rings patterns the lowest. ConclusionThis survey confirms that the major nuclear and cytoplasmic ANA IIF patterns are considered clinically important. There is no unanimity on classifying DFS, rods and rings and polar/Golgi-like as a competent pattern and on reporting cytoplasmic patterns as ANA IIF positive.

Acknowledgments: We thank Ingrid Zegers and Evanthia Monogioudi (European Commission, Joint Research Centre, Geel, Belgium) for providing the reference materials and for helpful discussions.

The prevalence of primary immunodeficiency (PID) is rather high in Iran compared to the world average, mainly due to the high rate of consanguineous marriage. Despite that, little genetic information is available about primary immunodeficiencies in Iran. Autosomal recessive hyper IgE syndrome (AR-HIES) is a severe type of immunodeficiency, mainly caused by mutations in the dedicator of cytokinesis 8 (DOCK8). Rapid and precise diagnoses of patients suffering from AR-HIES can help to manage the patients and reach properly the treatment decision. However, in regions with low financial resources and limited expertise, deep phenotyping is uncommon. Therefore, an exome-first approach is helpful to make a genetic-based diagnosis. In the present study, whole-exome sequencing (WES) was applied to detect causative mutations in three unrelated primary immunodeficient patients with poor clinical information. One of the cases was a deceased patient with suspected hyper IgE syndrome (HIES) whose parents were subjected to WES. As a result, three novel pathogenic variants were detected in the DOCK8 gene, including two splicing sites (c.4241+1G>T and c.4886+1G>T) and one-stop-gain (c.4201G>T, p.Glu1401Ter) variants. Sanger sequencing confirmed the mutations' segregation in corresponding families. Further immunological investigations confirmed that HIES in the studied probands. The presence of frontal bossing and broad nose in one of the studied cases, in addition to the typical clinical presentation of DOCK8-AR-HIES, is notable. This work suggests that an exome-first approach can be a valuable alternative strategy for precise diagnosis of primary immunodeficiency patients. ispartof: IRANIAN JOURNAL OF ALLERGY ASTHMA AND IMMUNOLOGY vol:19 issue:2 pages:193-199 ispartof: location:Iran status: published

Anti-transcription intermediary factor 1 (TIF1)-γ autoantibodies are robustly linked with cancer-associated DM in adults. This review aims to give an overview of the physiological context of TIF1-γ and to determine whether there is a pathophysiological link between anti-TIF1-γ autoantibodies and the occurrence of cancer. Detection of anti-TIF1-γ autoantibodies has a high sensitivity and specificity for cancer-associated DM in adults and is therefore useful for both diagnosis and cancer risk stratification. The function of the autoantigen, TIF1-γ, may provide insight into the mechanism behind this association. TIF1-γ is a ubiquitously present protein involved in various biological pathways, including TGF-β signalling. In cancer, it can act either as a tumour suppressor or promoter, depending on the cellular context and cancer stage. Evolving data provide pathophysiological insights, linking anti-TIF1-γ autoantibodies to both the anti-tumour response and to muscle and skin damage. TIF1-γ expression is increased in muscle and skin tissue of patients with DM. Mutations or loss-of-heterozygosity in TIF1-γ alleles in malignant tissue may result in the expression of tumour-specific neo-antigens stimulating autoantibody production. The newly formed autoantibodies are hypothesized to cross-react with antigens in muscle and skin, driving the development of DM. Based on the current evidence, anti-TIF1-γ autoantibodies should be considered warning lights of a potential tumour autoantigen and should alert the physician to the possibility of an underlying cancer. ispartof: RHEUMATOLOGY vol:59 issue:3 pages:469-477 ispartof: location:England status: published

Severe combined immunodeficiency (SCID) comprises a heterogeneous group of genetic disorders caused by early defects in the development and function of T cells. Other lymphocyte lineages (B and/or natural killer cells) are variably affected. With a worldwide frequency of approximately 1:50,000 live births, SCID may result from diverse mutations in over 16 genes. Whole-exome sequencing (WES) provides an opportunity for parallel screening of all those genes. This approach is also useful for genetic diagnosis in parents whose infant expired before genetic testing. Here, we describe a heterozygous novel non-frameshift deletion (c.587_598del p.196_199del) in the adenosine deaminase (ADA) gene identified by WES in healthy parents of an expired child with SCID. The mutation was subsequently confirmed to be homozygous in the deceased baby whose left-over blood sample volume was insufficient for direct WES analysis. In conclusion, we here describe a novel mutation in ADA, a well-known SCID gene. ispartof: IRANIAN JOURNAL OF ALLERGY ASTHMA AND IMMUNOLOGY vol:19 issue:1 pages:94-101 ispartof: location:Iran status: published

This document follows up on a 2017 revised international consensus on anti-neutrophil cytoplasm antibodies (ANCA) testing in granulomatosis with polyangiitis and microscopic polyangiitis and focuses on the clinical and diagnostic value of ANCA detection in patients with connective tissue diseases, idiopathic interstitial pneumonia, autoimmune liver diseases, inflammatory bowel diseases, anti-glomerular basement membrane (GBM) disease, infections, malignancy, and during drug treatment. Current evidence suggests that in certain settings beyond systemic vasculitis, ANCA may have clinical, pathogenic and/or diagnostic relevance. Antigen-specific ANCA targeting proteinase-3 and myeloperoxidase should be tested by solid phase immunoassays in any patient with clinical features suggesting ANCA-associated vasculitis and in all patients with anti-GBM disease, idiopathic interstitial pneumonia, and infective endocarditis associated with nephritis, whereas in patients with other aforementioned disorders routine ANCA testing is not recommended. Among patients with autoimmune liver diseases or inflammatory bowel diseases, ANCA testing may be justified in patients with suspected autoimmune hepatitis type 1 who do not have conventional autoantibodies or in case of diagnostic uncertainty to discriminate ulcerative colitis from Crohn's disease. In these cases, ANCA should be tested by indirect immunofluorescence as the target antigens are not yet well characterized. Many questions concerning the optimal use of ANCA testing in patients without ANCA-associated vasculitis remain to be answered.

Background:ANCA can be detected in sera from patients with autoimmune, inflammatory, infectious or neoplastic diseases.Objectives:To issue a Consensus Statement on ANCA testing and interpretation beyond systemic vasculitis.Methods:This Statement was prepared by a group of experts, based on the results of a comprehensive search in PubMed.Results:In certain settings beyond systemic vasculitis, ANCA may have diagnostic, clinical, and/or prognostic relevance. Testing for PR3- and MPO-ANCA by specific immunoassays should be performed in any patient with clinical features suggesting ANCA-associated vasculitis and in patients with anti-GBM disease and idiopathic interstitial pneumonia. Routine ANCA testing is not recommended in patients with connective tissue diseases (CTD), autoimmune liver diseases, inflammatory bowel diseases, infections, and/or malignancy unless there is evidence for small vessel vasculitis. ANCA testing by specific immunoassays may be useful in patients with rheumatoid arthritis, systemic sclerosis or primary Sjögren’s syndrome who have kidney disease with a nephritic sediment or in patients with systemic lupus erythematosus if a kidney biopsy shows prominent necrotizing and crescentic lesions or proliferative lupus nephritis. ANCA testing may be justified in patients with suspected autoimmune hepatitis type 1, who do not have conventional disease-related autoantibodies, or in patients with inflammatory bowel diseases in case of diagnostic uncertainty to discriminate ulcerative colitis from Crohn’s disease. In these cases, ANCA should be tested by indirect immunofluorescence since target antigens are not well characterized. ANCA against bactericidal/permeability-increasing protein may be a biomarker for deteriorating lung function and a poor prognosis in patients with cystic fibrosis.Conclusion:ANCA testing is clinically relevant not only in patients with manifestations suggesting systemic vasculitis, but also in patients with certain other disorders, particularly in patients with anti-GBM disease or idiopathic interstitial pneumonia.Disclosure of Interests:Sergey Moiseev Grant/research support from: This work was supported by the 5-100 Project, Sechenov University, Moscow, Jan Willem Cohen Tervaert: None declared, Yoshihiro Arimura: None declared, Dimitrios Bogdanos: None declared, Csernok Elena: None declared, Jan Damoiseaux: None declared, Marc Ferrante: None declared, Luis Felipe Flores-Suárez: None declared, Marvin Fritzler: None declared, Pietro Invernizzi: None declared, David Jayne Grant/research support from: ChemoCentryx, GSK, Roche/Genentech, Sanofi-Genzyme, Consultant of: Astra-Zeneca, ChemoCentryx, GSK, InflaRx, Takeda, Insmed, Chugai, Boehringer-Ingelheim, J. Charles Jennette: None declared, Mark Little: None declared, Stephen P. McAdoo: None declared, Pavel Novikov Grant/research support from: This work was supported by the 5-100 Project, Sechenov University, Moscow, Charles D. Pusey: None declared, Antonella Radice: None declared, Alan D. Salama: None declared, Judith Savige: None declared, Mårten Segelmark: None declared, Yehuda Shoenfeld: None declared, Renato Alberto Sinico: None declared, Maria Jose Rego de Sousa: None declared, Ulrich Specks: None declared, Benjamin Terrier: None declared, Athanasios Tzioufas: None declared, Severine Vermeire: None declared, Ming-hui Zhao: None declared, Xavier Bossuyt: None declared

Special conditions associated with laboratory autoimmune testing are not well compatible with recent developments in regulatory frameworks such as EN/ISO 15189 accreditation or in vitro diagnostic medical device regulation (IVD-R). In addition, international recommendations, guidelines and disease criteria are poorly defined with respect to requirements on autoantibody testing. Laboratory specialists from Austria, Belgium, Croatia, Estonia, Finland, France, Germany, Greece, Hungary, Italy, Norway, Poland, Portugal, South Africa, Spain, Sweden, Switzerland, and The Netherlands collected information, reported national experience, and identified quality issues in relation to autoantibody testing that require consensus on interpretation of the regulatory frameworks and guidelines. This process has been organized by the European Autoimmunity Standardisation Initiative (EASI). By identifying the critical items and looking for a consensus, our objective was to define a framework for, in particular, EN/ISO accreditation purposes. Here, we present a review of current publications and guidelines in this field to unify national guidelines and deliver in this way a European handout on quality control and accreditation for laboratories involved in autoantibody testing. We focus on quality items that can be checked during accreditation visits. Despite various local varieties, we encountered an overwhelming dedication to quality assurance in all contributing countries. ispartof: AUTOIMMUNITY HIGHLIGHTS vol:11 issue:1 ispartof: location:England status: published

We report IgG anti-spike levels up to 3 months after vaccination with 2 doses of BNT162b2 mRNA vaccine in healthcare workers (HCW). The antibody response was significantly stronger in previously infected vaccinated HCW compared to uninfected HCW, and stronger after vaccination compared to (mostly) mild natural infection.

ispartof: CLINICAL CHEMISTRY AND LABORATORY MEDICINE vol:56 issue:11 pages:E258-E261 ispartof: location:Germany status: published

The aim was to compare indirect immunofluorescence (IIF) and fluorescence enzyme immunoassay (FEIA) for initial screening of connective tissue diseases (CTDs) and to evaluate whether combining IIF with FEIA adds value. A comprehensive systematic literature review was conducted to identify fully paired, cross-sectional or case-control studies on ANA screening of CTD reporting results for IIF and FEIA. Study quality was assessed using the QUADAS-2 checklist. The reference standard was assessed against established classification criteria. The meta-analysis used hierarchical, bivariate and mixed-effects models to allow test results to vary within and across studies. Eighteen studies of good to fair quality were included in the review. IIF had a higher sensitivity than FEIA [cut-off 1:160, 7 studies, 3251 patients, 0.83 (95% CI 0.75-0.89) versus 0.73 (95% CI 0.64-0.80); cut-off 1:80, 7 studies, 12,311 patients, 0.89 (95% CI 0.84-0.93) versus 0.78 (95% CI 0.71-0.84)] but lower specificity [1:160, 0.81 (95% CI 0.73-0.87) versus 0.94 (95% CI 0.91-0.95); 1:80, 0.72 (95% CI 0.62-0.81) versus 0.94 (95% CI 0.90-0.96)]. A double-positive test had a higher likelihood ratio (LR) for CTD (26.2 (95% CI 23.0-29.9)) than a single positive test (14.4 (95% CI 13.1-15.9) FEIA+, 5.1 (95% CI 4.8-5.4) IIF+). A double-negative test result had more clinical value for ruling out CTD than a single negative test (LR 0.15 (95% CI 0.12-0.18) versus 0.21 (95% CI 0.18-0.25) IIF; 0.33 (95% CI 0.29-0.37) FEIA-). A FEIA+/IIF- discordant result had a higher LR than an IIF+/FEIA- discordant result (LR 2.4 (95% CI 1.7-3.4) versus 1.4 (95% CI 1.2-1.7)). Because of the comparatively higher specificity of FEIA and higher sensitivity of IIF, the combination of FEIA and IIF increases the diagnostic value. Clinicians should be acquainted with the clinical presentation of CTD and aware of the advantages and disadvantages of FEIA and IIF to avoid misinterpretation. ispartof: BEST PRACTICE & RESEARCH IN CLINICAL RHEUMATOLOGY vol:32 issue:4 pages:521-534 ispartof: location:Netherlands status: published

Although included in the serological domain of the 'interstitial pneumonia with auto-immune features' (IPAF) research statement, the search for myositis-specific antibodies (MSA) is not incorporated in routine clinical practice. The objective of the study was to evaluate MSA prevalence in an idiopathic interstitial pneumonia (IIP) cohort (n = 68) with suggestive morphological interstitial lung disease patterns. Twelve of 68 patients (17.6%) carried MSA, whereof only two were anti-nuclear antibody-positive. Besides female gender, no demographic or pulmonary function parameter was predictive for MSA positivity. MSA were present in 32.4% of IPAF patients (n = 37), being essential for IPAF diagnosis in four of them (10.8%).

ObjectivesRheumatoid factor (RF) and anti-cyclic citrullinated protein/peptide antibodies (ACPA) are integrated in the 2010 American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) classification criteria for rheumatoid arthritis (RA). The objectives of this study were to evaluate the technical and diagnostic performance of different RF and ACPA assays and to evaluate whether differences in performance impact RA classification.MethodsSamples from 594 consecutive patients who for the first time consulted a rheumatologist (44 of whom were diagnosed with RA) and 26 extra newly diagnosed patients with RA were analysed with six different RF assays (Menarini, Thermo Fisher, Inova, Roche, Abbott, Euroimmun) and seven different ACPA assays (Menarini, Thermo Fisher, Inova, Roche, Abbott, Euro Diagnostica, Euroimmun).ResultsWe found differences in analytical performance between assays. There was poor numerical agreement between the different RF and ACPA assays. For all assays, the likelihood ratio for RA increased with increasing antibody levels. The areas under the curve of receiver operating characteristic analysis of the RF (range 0.676–0.709) and ACPA assays (range 0.672–0.769) only differed between some ACPA assays. Nevertheless, using the cut-off proposed by the manufacturer, there was a large variation in sensitivity and specificity between assays (mainly for RF). Consequently, depending on the assay used, a subgroup of patients (13% for RF, 1% for ACPA and 9% for RF/ACPA) might or might not be classified as RA according to the 2010 ACR/EULAR criteria.ConclusionDue to poor harmonisation of RF and ACPA assays and of test result interpretation, RA classification according to 2010 ACR/EULAR criteria may vary when different assays are used.

Background: Antinuclear antibodies (ANAs) are useful for the diagnosis of ANA-associated systemic rheumatic disease (AASRD). The objective of this study was the evaluation of an immunoassay that detects antibodies to a mixture of 17 antigens as an alternative to indirect immunofluorescence (IIF). Methods: Nine thousand eight hundred and fifty-six consecutive patients tested for ANAs were tested by IIF and EliA connective tissue disease screen (Thermo-Fisher). Medical records were reviewed for 2475 patients, including all patients that tested positive/equivocal by either test and a selection of 500 patients that tested negative. Results: Concordance between IIF and EliA was 83.1%. AASRD was found in 12.8% of IIF-positive patients, 30.2% of EliA-positive patients and 0.4%, 46.6%, 5.8% and 3.0% of patients that tested, respectively, double negative, double positive, single positive for EliA and single positive for IIF. The association with AASRD increased with increasing antibody level. IIF and EliA were positive in, respectively, 90.4% and 69.9% of systemic lupus erythematosus (n=83), 100% and 84.1% of systemic sclerosis (n=63), 86.7% and 93.3% of Sjögren’s syndrome (n=45), 88.2% and 52.9% of polymyositis/dermatomyositis (n=17), and in all cases of mixed connective tissue disease (n=8). The specificity was projected to be 94%–96% for EliA and 86% for IIF. When all AASRDs were taken together, the areas under the curve of receiver operator curves were similar between IIF and EliA. Conclusions: The positive predictive value for AASRD was higher for EliA than for IIF, but, depending on the disease, EliA might fail to detect antibodies that are detected by IIF. Combining immunoassay with IIF adds value.

ispartof: Clinical Chemistry and Laboratory Medicine vol:56 issue:1 pages:E27-E30 ispartof: location:Germany status: published

Antinuclear antibodies (ANA) are important laboratory markers for the diagnosis and classification of systemic lupus erythematosus (SLE). In the 2019 European League Against Rheumatism (EULAR)/American College of Rheumatology (ACR) classification criteria for SLE, ANA with titre ≥1:80 are an entry criterion.1 Even though ANA 1:80 are highly sensitive for SLE, they have a low specificity. This has recently been reinforced by Aringer et al 2 who analysed the performance of the individual items included in the 2019 EULAR/ACR classification criteria for SLE on a large group of patients with SLE (n=1197) and non-SLE disease controls (n=1074), including patients with other connective tissue diseases (two-thirds of the controls). In this study, ANA with titre ≥1:80 were highly sensitive (99.5%), but only 19.4% specific for SLE.2 As ANA are an entry criterion for the 2019 EULAR/ACR classification criteria, the low specificity of ANA for SLE does not affect the specificity of the 2019 SLE classification criteria. An important item that conferred specificity to the 2019 SLE classification was the attribution rule.2 The authors stressed that ANA are a useful screening test, but not specific and that the classification criteria should not be used as diagnostic criteria.2 As ANA are employed in the context of both classification and diagnosis, it is …

Hypomorphic IKBKG mutations in males are typically associated with anhidrotic ectodermal dysplasia with immunodeficiency (EDA-ID). Some mutations cause immunodeficiency without EDA (NEMO-ID). The immunological profile associated with these NEMO-ID variants is not fully documented. We present a 2-year-old patient with suspected immunodeficiency in which a hemizygous p.Glu57Lys IKBKG variant was identified. At the age of 1 year, he had an episode of otitis media that evolved into a bilateral mastoiditis (Pseudomonas spp). Hypogammaglobulinemia, specific (polysaccharide) antibody deficiency, and low switched memory B cell subsets were noticed. The mother was heterozygous for the variant but had no signs of incontinentia pigmenti. Patient peripheral blood mononuclear cells produced low amounts of IL-6 after stimulation with IL-1β, Pam3CSK4, and FSL-1. In patient fibroblasts, IκB-α was degraded normally upon stimulation with IL-1β or TNF-α. Transduction of wild-type and variant NEMO in NEMO-/- deficient SV40 fibroblasts revealed a slight but significant reduction of IL-6 production upon stimulation with IL-1β and TNF-α. In conclusion, we demonstrated that p.Glu57Lys leads to specific immunological defects in vitro. No other pathogenic PID variants were identified through whole exome sequencing. As rare polymorphisms have been described in IKBKG and polygenic inheritance remains an option in the presented case, this study emphasizes the need for thorough functional and genetic evaluation when encountering and interpreting suspected disease-causing NEMO-ID variants.

Patients with Sjögren's syndrome (SS) have a considerable higher risk of lymphoma development.To determine the incidence of lymphoma and the value of biomarkers to predict lymphoma development in patients with SS.Clinical files of all patients with a presumed diagnosis of SS between 1991 and 2016 were retrospectively reviewed for the development of lymphoma. Biochemical data were plotted as a function of the relative time before and after the lymphoma diagnosis (for patients who developed lymphoma) or before the last available blood test (for patients who did not develop lymphoma). Correlations between several biochemical parameters and development of lymphoma were analyzed by logistic regression. In order to evaluate the evolution of cryoglobulins, a random effect model with random intercepts was used.Sixteen patients developed a lymphoma (prevalence 8.9%; median follow-up 6 years). Cryoglobulins were significantly higher in these patients (n = 16), when compared to the rest of patients (n = 164) without lymphoma (121 ± 250 versus 8 ± 24.9 mg/L for IgG; 231 ± 422 versus 13 ± 30 mg/L for IgM; 10 ± 20 versus 1 ± 4 mg/L for IgA in the cryoprecipitate). Cryoglobulin-levels were significantly more increasing (p-values for IgG = 0.0007; for IgM = 0.0123; and for IgA in the cryoprecipitate0.0001) in the time period before the lymphoma diagnosis (patients with lymphoma) compared to the time period before the last available blood test (patients without lymphoma). Also low (i.e. under the detection limit) C3 (OR 13.9) or C4 (OR 7.1) levels, a progressively decreasing total complement activity (OR 6.6), progressively decreasing gammaglobulins (OR 13.4), a persistent detection of monoclonal bands (OR 14.6) on protein electrophoresis, a persistent low or decreasing serum IgG (OR 18), and decreasing IgM-serum levels (OR 17.7) were significantly associated with lymphoma.Periodically follow-up of laboratory markers, such as cryogloblins, over time proved to be an accurate way to predict lymphoma.

Background Bronchiectasis-chronic obstructive pulmonary disease (COPD) overlap presents a possible clinical phenotype of COPD, but it is unclear why it develops in a subset of patients. We hypothesized that sensitization to Aspergillus fumigatus (A fum) is associated with bronchiectasis in COPD and occurs more frequently in vitamin D-deficient patients. Methods This observational study investigated sensitization to A fum in an outpatient clinical cohort of 300 COPD patients and 50 (ex-) smoking controls. Total IgE, A fum-specific IgE against the crude extract and against the recombinant antigens and A fum IgG were measured using ImmunoCAP fluoroenzyme immunoassay. Vitamin D was measured by radioimmunoassay, and computed tomography images of the lungs were scored using the modified Reiff score. Results Sensitization to A fum occurred in 18% of COPD patients compared to 4% of controls (P=0.0110). In all, 31 COPD patients (10%) were sensitized to the crude extract and 24 patients (8%) had only IgE against recombinant antigens. A fum IgG levels were significantly higher in the COPD group (P=0.0473). Within COPD, A fum-sensitized patients were more often male (P=0.0293) and more often had bronchiectasis (P=0.0297). Pseudomonas aeruginosa and Serratia marcescens were more prevalent in historical sputum samples of A fum-sensitized COPD patients compared to A fum-non-sensitized COPD patients (P=0.0436). Vitamin D levels were comparable (P=0.2057). Multivariate analysis demonstrated that sensitization to recombinant f1 or f3 had a 2.8-fold increased risk for bronchiectasis (P=0.0030). Conclusion These results highlight a potential role for sensitization to A fum in COPD-related bronchiectasis.

Despite the increased identification of specific antibody deficiency (SAD) in chronic rhinosinusitis (CRS), little is known about the relationship between SAD severity and the severity and comorbidities of CRS. The prevalence of an impaired antibody response in the general population is also unknown.The objective of this study was to determine if the SAD severity stratification applies to real-life data of patients with CRS.An electronic health record database was used to identify patients with CRS evaluated for humoral immunodeficiency with quantitative immunoglobulins and Streptococcus pneumoniae antibody titers before and after pneumococcal vaccine. SAD severity was defined, according to the guidelines, based on the numbers of titers ≥1.3 μg/dL after vaccination: severe (≤2 serotypes), moderate (3-6 serotypes), and mild (7-10 serotypes). Comorbidities and therapeutic response were assessed. The prevalence of an impaired antibody response in a normal population was assessed.Twenty-four percent of the patients with CRS evaluated for immunodeficiency had SAD, whereas 11% of a normal population had an impaired immune response to polysaccharide vaccination (P.05). When evaluated by the practice parameter definition, 239 of 595 (40%) met the definition of SAD. Twenty-four (10%) had severe SAD, 120 (50%) had moderate SAD, and 95 (40%) had mild SAD. Patients with moderate-to-severe SAD had worse asthma, a greater likelihood of pneumonia, and more antibiotic courses in the 2 years after vaccination than patients with mild SAD.This study provides real world data supporting stratification of SAD by severity, demonstrating a significant increase in the comorbid severity of asthma and infections in CRS patients with moderate-to-severe SAD compared with those with mild SAD and those without SAD.

Objective. The objective of this multicentre study was to improve the clinical interpretation of PR3- and MPO-ANCAs as an adjunct for the diagnosis of ANCA-associated vasculitis (AAV) by defining thresholds and test result intervals based on predefined specificities and by calculating test result interval-specific likelihood ratios (LRs).Methods. Eight different PR3- and MPO-ANCA immunoassays from seven companies were evaluated using 251 diagnostic samples from AAV patients and 924 diseased controls.Results. Thresholds for antibody levels were determined based on predefined specificities (95, 97.5, 99 and 100%) and used to delimit test result intervals. Test result interval-specific LRs were determined. For all assays, the LR for AAV increased with increasing antibody level. For all but one immunoassay, high antibodies levels (associated with LR>55) were found in a substantial fraction (>65%) of patients. The area under the curve (AUC) of receiver operating characteristics analysis of a diagnostic approach in which positive results were confirmed by IIF or another immunoassay was not substantially higher than the AUC of performing immunoassay only. The highest AUC was found when immunoassay was combined with another immunoassay or with IIF.Conclusion. To diagnose AAV based on PR3- and MPO-ANCA, it is useful to define thresholds for antibody levels and to assign test result interval-specific LRs. Higher antibody levels are associated with a higher likelihood for disease. Such information improves clinical interpretation.

ObjectiveThis multicentre study was performed to evaluate the diagnostic accuracy of a wide spectrum of novel technologies nowadays available for detection of myeloperoxidase (MPO) and proteinase 3 (PR3)-antineutrophil cytoplasmic antibodies (ANCAs).MethodsSera (obtained at the time of diagnosis) from 251 patients with ANCA-associated vasculitis (AAV), including granulomatosis with polyangiitis and microscopic polyangiitis, and from 924 disease controls were tested for the presence of cytoplasmic pattern/perinuclear pattern and atypical ANCA (A-ANCA) by indirect immunofluorescence (IIF) (at two sites) and for the presence of PR3-ANCA and MPO-ANCA by eight different immunoassays.ResultsThe area under the curve (AUC) of the receiver operating characteristic curve to discriminate AAV from controls was 0.923 (95% CI 0.902 to 0.944) and 0.843 (95% CI 0.814 to 0.871) for the two IIF methods. For the antigen-specific immunoassays, the AUC varied between 0.936 (95% CI 0.912 to 0.960) and 0.959 (95% CI 0.941 to 0.976), except for one immunoassay for which the AUC was 0.919 (95% CI 0.892 to 0.945).ConclusionsOur comparison of various ANCA detection methods showed (i) large variability between the two IIF methods tested and (ii) a high diagnostic performance of PR3-ANCA and MPO-ANCA by immunoassay to discriminate AAV from disease controls. Consequently, dual IIF/antigen-specific immunoassay testing of each sample is not necessary for maximal diagnostic accuracy. These results indicate that the current international consensus on ANCA testing for AAV needs revision.

ispartof: Journal of Allergy and Clinical Immunology vol:141 issue:2 pages:768-770 ispartof: location:United States status: published