International recommendations for the assessment of autoantibodies to cellular antigens referred to as anti-nuclear antibodies

Nailfold Videocapillaroscopic Alterations as Markers of Microangiopathy in COVID-19 Patients

Nailfold videocapillaroscopic alterations have been described in COVID-19, but their correlations with biomarkers of inflammation, coagulation and endothelial perturbation are still unclear, and no information is available on nailfold histopathology. Nailfold videocapillaroscopy was performed on fifteen patients with COVID-19 in Milan, Italy and the signs of microangiopathy were correlated with plasma biomarkers of inflammation (C reactive protein [CRP], ferritin), coagulation (D-dimer, fibrinogen), endothelial perturbation (Von Willebrand factor [VWF]) and angiogenesis (vascular endothelial growth factor [VEGF]) along with genetic drivers of COVID-19 susceptibility. Histopathological analysis of autoptic nailfold excisions was performed on fifteen patients who died for COVID-19 in New Orleans, United States. All COVID-19 patients studied with videocapillaroscopy showed alterations rarely seen in healthy individuals consistent with microangiopathy, such as hemosiderin deposits (sign of microthrombosis and microhemorrhages) and enlarged loops (sign of endotheliopathy). The number of hemosiderin deposits correlated both with ferritin and CRP levels (r = 0.67, p = 0.008 for both) and the number of enlarged loops significantly correlated with the levels of VWF (r = 0.67, p = 0.006). Ferritin levels were higher in non-O groups, determined by the rs657152 C > A cluster, (median 619, min-max 551-3266 mg/dL) than in the O group (373, 44-581 mg/dL, p = 0.006). Nailfold histology revealed microvascular damage, i.e., mild perivascular lymphocyte and macrophage infiltration and microvascular ectasia in the dermal vessels of all cases, and microthrombi within vessels in five cases. Alterations in nailfold videocapillaroscopy and elevated biomarkers of endothelial perturbation that match histopathologic findings open new perspectives in the possibility of non-invasively demonstrating microangiopathy in COVID-19.

Screening epitope peptides based on a phage-displayed random peptide and peptide microarrays to contribute to improving the diagnostic efficiency of systemic lupus erythematosus

BACKGROUND

Systemic lupus erythematosus (SLE) is one of the most common autoimmune diseases in China. At present, there are hundreds of autoantibodies in SLE patients; however, only a dozen of the autoantibodies can be routinely detected, and the available diagnostic antibodies are not sufficient for diagnosis or differential diagnosis of SLE patients with atypical clinical manifestations or other autoimmune diseases. Therefore, it is necessary to find new diagnostic markers to improve the diagnostic effect of SLE.

METHODS

The displayed random peptide library and peptide microarray were combined to identify SLE-related epitope peptides. A case-control design was used. The IgG antibodies in the sera from SLE patients, healthy controls, and other autoimmune disease controls underwent a reaction with the phage-display random peptide library, respectively. Selected epitope peptides were used to construct a peptide chip. A total of 644 serum samples (including 296 SLE patients, 168 disease controls, and 180 healthy controls) were used for further screening and verification. Peptides with an area under the curve (AUC) > 0.650 were further verified by ELISA. Finally, 500 serum samples (including 200 SLE patients, 150 disease controls, and 150 healthy controls) were used to verify and evaluate the diagnostic and differential diagnostic efficacy of the selected peptides.

RESULTS

After the previous screening, five epitope peptides (SLE_P19, SLE_P20, SLE_P27, SLE_P28, and SLE_P29) may have potential as SLE diagnostic markers. Additionally, SLE_P27 was superior to the other four peptides in the diagnosis and differential diagnosis of SLE and rheumatoid arthritis (RA). The AUC of SLE_P27 was 0.938, the sensitivity was 76.00%, the specificity was 92.70%, the positive likelihood ratio was 10.411, the negative likelihood ratio was 0.259, and the accuracy was 84.40%. The diagnostic efficacy of SLE can be increased by combining the five selected peptides with the anti-double stranded DNA antibody (anti-dsDNA)and anti-Smith antibodies (anti-Sm).

CONCLUSIONS

In this study, we identified five peptides that may serve as potential biomarkers for SLE diagnosis using the strategy of combining the displayed random peptide library with the peptide microarray. The combination of selected peptides and existing autoantibodies can significantly improve the diagnostic efficiency. These specific peptides are expected to be new diagnostic markers for SLE.

Performance of two multiplex flow cytometric assays for antibody detection in Egyptian patients

Background

Autoantibodies are vital biomarkers for the diagnosis, assessment and prognostic determination of various autoimmune disorders.

Objective

This study aimed to evaluate the performance of the two AtheNA Multi-Lyte^® systems for the detection of various autoantibodies.

Methods

A total of 105 systemic lupus erythematosus patients, 35 patients with other autoimmune diseases (diseased controls), and 30 healthy volunteers (healthy controls) at Zagazig University Hospitals, Zagazig city, Al Sharqia governorate were tested for anti-double-stranded DNA (anti-dsDNA) antibodies using indirect immunofluorescence (IIF) and the AtheNA Multi-Lyte^® anti-nuclear antibodies-II system between May 2020 and April 2022. Seventy-five patients with clinically suspected autoimmune vasculitis (AIV) and 25 healthy volunteers were also tested for anti-myeloperoxidase and anti-proteinase 3 antibodies using IIF, the AtheNA Multi-Lyte^® AIV system, and enzyme-linked immunosorbent assay (ELISA).

Results

The AtheNA anti-dsDNA test (98.5%) was more specific than IIF (96.9%) for diagnosing systemic lupus erythematosus, but both tests had the same sensitivity (38.1%). Combining both methods increased sensitivity to 47.6%, while increasing the cut-off of the AtheNA anti-dsDNA test to 134 international units/mL increased specificity to 100%. The AtheNA Multi-Lyte AIV system exhibited substantial agreement with IIF regarding anti-myeloperoxidase testing (κ = 0.65) and almost perfect agreement with ELISA (κ = 0.85). The AtheNA Multi-Lyte^® AIV system exhibited perfect agreement with IIF (κ = 1) and substantial agreement with ELISA for anti-proteinase 3 testing (κ = 0.63).

Conclusion

AtheNA Multi-Lyte^® systems appear to be reliable for anti-dsDNA, anti-myeloperoxidase, and anti-proteinase 3 screening and may be an optimal choice for monitoring anti-dsDNA levels.

What this study adds

It is necessary to evaluate various autoantibodies detection assays to increase both sensitivity and specificity of autoimmune diseases diagnostic approaches. AtheNA Multi-Lyte^® systems appear to be reliable for anti-dsDNA, anti-myeloperoxidase, and anti-proteinase 3 screening and may be an optimal choice for monitoring anti-dsDNA levels.

Clinical usefulness of anti-nuclear antibody in childhood: real-world experience at a tertiary care center : Usefulness of ANA in pediatric autoimmune diseases

We evaluated the reasons for requesting anti-nuclear antibody (ANA) analysis in clinical practice at a tertiary center and the performance of ANA in pediatric autoimmune diseases. Patients under 18 years of age who underwent ANA testing for various symptoms between 2013 and 2017 were included. We retrieved data from medical records, including demographic and clinical characteristics, diagnoses, ANA results, titers, and staining patterns. The performance assessment tools were calculated according to the ANA titer for autoimmune diseases. Risk factors for autoimmune diseases in ANA-positive patients were evaluated using logistic regression analysis. Changes in ANA titer and seroconversion were evaluated using repeated ANA analyses. A total of 3812 patients underwent ANA. Medical records of 3320 patients were obtained. The rate of ANA positivity was 27.4%. ANA was requested most frequently because of musculoskeletal findings in 1355 patients (40.8%). Juvenile idiopathic arthritis (n = 174, 20.2%) was the most common diagnosis in ANA-positive patients, followed by systemic lupus erythematosus (n = 52, 6%). For autoimmune diseases, a titer of ≥ 1:100, a sensitivity of 40.1%, and a specificity of 77.1% were observed. At a titer ≥ 1:1000, the sensitivity and specificity were 24.1% and 89%, respectively. Homogeneous staining was an additional risk factor for autoimmune diseases in ANA-positive patients by multivariate logistic regression analysis (OR [95% CI]: 4.562 [3.076-6.766], p < 0.001).    Conclusion: Our results revealed that the performance of the ANA test in diagnosing autoimmune diseases in pediatric clinical practice was poor. Therefore, clinical findings should be carefully evaluated before ANA testing is performed. What is Known: • ANA can be detected in systemic autoimmune rheumatic diseases. • The diagnostic role of ANA is controversial, especially in childhood. What is New: • One in four patients who requested the ANA test had an autoimmune disease. • Less than half of patients with an autoimmune disease had ANA positivity.

Autoantibodies testing in autoimmunity: Diagnostic, prognostic and classification value

Diagnosis of autoimmune diseases is in most cases challenging for clinicians as there is not a single specific laboratory or histological marker to diagnose or exclude the presence of the conditions. This review focused on the current knowledge of the role of autoantibodies' testing in various diseases, such as systemic lupus erythematosus, rheumatoid arthritis, antiphospholipid syndrome, undifferentiated connective tissues disease, primary biliary cirrhosis and primary sclerosing cholangitis. Similarly, the prognostic and diagnostic values of autoantibodies testing in patients with interstitial lung disease have been reviewed. In-depth research on the molecular action of these autoantibodies on immune regulation and diseases pathogenesis has been explored beyond their correlation with disease phenotypes, highlighting the impact of autoantibodies targeting on disease outcomes and etiopathogenesis.

Atrophic Gastritis and Autoimmunity: Results from a Prospective, Multicenter Study

Despite a global decrease, gastric cancer (GC) incidence appears to be increasing recently in young, particularly female, patients. The causal mechanism for this "new" type of GC is unknown, but a role for autoimmunity is suggested. A cascade of gastric precancerous lesions, beginning with chronic atrophic gastritis (CAG), precedes GC. To test the possible existence of autoimmunity in patients with CAG, we aimed to analyze the prevalence of several autoantibodies in patients with CAG as compared to control patients. Sera of 355 patients included in our previous prospective, multicenter study were tested for 19 autoantibodies (anti-nuclear antibodies, ANA, anti-parietal cell antibody, APCA, anti-intrinsic factor antibody, AIFA, and 16 myositis-associated antibodies). The results were compared between CAG patients (n = 154), including autoimmune gastritis patients (AIG, n = 45), non-autoimmune gastritis patients (NAIG, n = 109), and control patients (n = 201). ANA positivity was significantly higher in AIG than in NAIG or control patients (46.7%, 29%, and 27%, respectively, p = 0.04). Female gender was positively associated with ANA positivity (OR 0.51 (0.31-0.81), p = 0.005), while age and H. pylori infection status were not. Myositis-associated antibodies were found in 8.9% of AIG, 5.5% of NAIG, and 4.4% of control patients, without significant differences among the groups (p = 0.8). Higher APCA and AIFA positivity was confirmed in AIG, and was not associated with H. pylori infection, age, or gender in the multivariate analysis. ANA antibodies are significantly more prevalent in AIG than in control patients, but the clinical significance of this finding remains to be established. H. pylori infection does not affect autoantibody seropositivity (ANA, APCA, AIFA). The positivity of myositis-associated antibodies is not increased in patients with CAG as compared to control patients. Overall, our results do not support an overrepresentation of common autoantibodies in patients with CAG.

Interstitial lung disease associated with inflammatory myositis: Autoantibodies, clinical phenotypes, and progressive fibrosis

Progressive pulmonary fibrosis is generally diagnosed when interstitial lung disease progression occurs in the absence of any other cause, and a subset of patients with myositis and associated interstitial lung disease may develop progressive pulmonary fibrosis. Numerous autoantibodies (e.g., against tRNA-synthetase, MDA5, Ro52) increase the risk of this clinical feature in myositis and we speculate that serum biomarkers, sought using the most sensitive laboratory techniques available (i.e., immunoprecipitation) may predict pulmonary involvement and allow the early identification of progressive pulmonary fibrosis. We herein provide a narrative review of the literature and also present original data on pulmonary fibrosis in a cohort of patients with myositis and serum anti-Ro52 with interstitial lung disease. Our results fit into the previous evidence and support the association between anti-Ro52 and signs of pulmonary fibrosis in patients with inflammatory myositis. We believe that the combination of available and real-life data has significant clinical relevance as a paradigm of serum autoantibodies that prove useful in determining precision medicine in rare connective tissue diseases.

Anti-dsDNA Is Associated with Favorable Prognosis in Myasthenia Gravis: A Retrospective Study

Objectives. To investigate the presence of serum antinuclear antibody (ANA) and anti-double-stranded DNA antibody (anti-dsDNA) in patients with myasthenia gravis (MG) and analyze the clinical characteristics and prognostic factors associated with MG. Methods. We retrospectively enrolled 363 patients with MG and analyzed the clinical characteristics and follow-up data between patients positive and negative for ANA and anti-dsDNA. We defined a Myasthenia Gravis Activities of Daily Living (MG-ADL) reduction as a main prognosis predictor and used logistic regression to determine independent factors associated with prognosis. We built a nomogram to predict prognosis and evaluate the internal validity of the model. Results. Ninety-eight (27.0%) patients were positive for ANA, and 51 (14.0%) were positive for anti-dsDNA. Patients positive for ANA and anti-dsDNA antibodies tended to be female and positive for acetylcholine receptor antibody (AChR-Ab). The rate of thymoma was higher in anti-dsDNA-positive patients with MG (p-dsDNA-MG) than in patients negative for anti-dsDNA (49.0% vs. 26.0%, $p=0.001$ ), and p-dsDNA-MG was associated with reduced MG-ADL score. Regression analysis showed that except for age of onset ( $\text{OR}=0.986$ , $95\%\text{CI}=0.973–0.999$ , $p=0.037$ ), anti-dsDNA ( $\text{OR}=2.800$ , $95\%\text{CI}=1.381–5.679$ , $p=0.004$ ), ptosis ( $\text{OR}=2.930$ , $95\%\text{CI}=1.827–4.699$ , $p<0.001$ ), and eye movement disorder ( $\text{OR}=2.815$ , $95\%\text{CI}=1.672–4.741$ , $p<0.001$ ) were independent predictive factors of a favorable prognosis of MG. These predictors were used to generate a nomogram with an excellent predictive value. Conclusions. Being female and the presence of AChR-Ab were features of ANA- or anti-dsDNA-positive MG. The presence of anti-dsDNA was associated with a favorable prognosis of MG.

Utility of repeat extractable nuclear antigen antibody testing: a retrospective audit

OBJECTIVES

Autoantibodies to ENA are frequently ordered during the workup of suspected autoimmune connective tissue diseases. There are no current guidelines for repeat test ordering. The objective of this study was to assess the utility of repeat ENA testing after an initial negative result.

METHODS

A retrospective study was conducted in a single, multicentre tertiary health network in Melbourne, Australia. Results of all ENA tests were extracted from the hospital laboratory information system. For patients who had a change in ENA result from negative to positive, clinical information was obtained from the hospital records regarding new diagnosis of an ANA-associated rheumatic disease (AARD).

RESULTS

A total of 23 438 ENA tests were performed in 19 603 patients from 29 July 2013 to 28 September 2020. In total, 20 918 (89.2%) were negative with 215 (0.9%) being equivocal. Of the 2305 positive tests, the most common ENA auto-antibody specificity detected was anti-Ro52 (1185, 51.4%). A total of 2636 of 19 603 patients (13.4%) had more than one ENA test performed during the study period. Of these, most (2523, 95.7%) had stable ENA results with no change compared with the first test. Only 53 patients (2.2%) had an ENA result that changed from negative to positive. Excluding patients with pre-existing rheumatic conditions and those under 18, there were five new AARDs found in the remaining 34 patients.

CONCLUSION

Repeat ENA test results rarely change or result in a new diagnosis of an AARD, with repeated testing only warranted if there is a change in clinical manifestations.

[Methods of autoantibody diagnostics - when immunofluorescence test, when ELISA?]

The detection of circulating autoantibodies against a variety of structural and functional molecules present in ubiquitous or tissue-specific cells is critical to the diagnosis of many autoimmune diseases (systemic - such as systemic rheumatic diseases - and organ-specific diseases). In particular, the determination of autoantibodies is one of the classification and/or diagnostic criteria for some autoimmune diseases and has a relevant predictive value, since many autoantibodies can be detected years before the clinical manifestation of a disease.The identification of these antigen-antibody systems and the simultaneous development of laboratory methods for detecting and measuring autoantibodies are considered one of the milestones in the history of clinical immunology over the last 60 years. Many different immunoassay methods have been developed and used in laboratory practice, from the early conventional (or monoplex) analytical methods that can detect single autoantibodies to the newer multiplex platforms that can quantify dozens of molecules. Various diagnostic immunoassays commonly used in current laboratory practice for the detection of autoantibodies are presented in this review.

Associations between nailfold capillary aberrations and autoantibodies in children and adults with Raynaud's phenomenon

OBJECTIVE

To characterise associations between individual nailfold capillary aberrations with autoantibodies in a cross-sectional study on children and adults with Raynaud's phenomenon (RP).

METHODS

Consecutive children and adults with RP and without previously known connective tissue disease (CTD) systemically underwent nailfold capillaroscopy and laboratory tests for the presence of antinuclear antibodies (ANA). The prevalence of individual nailfold capillary aberrations and ANA was assessed, and the associations between individual nailfold capillary aberrations and ANA were analysed separately in children and adolescents.

RESULTS

In total, 113 children (median age 15 years) and 2858 adults (median age 48 years) with RP and without previously known CTD were assessed. At least one nailfold capillary aberration was detected in 72 (64%) of included children and in 2154 (75%) of included adults with RP (children vs adults p<0.05). An ANA titre ≥1:80, ≥1:160 or≥1:320 was observed in 29%, 21% or 16% of included children, and in 37%, 27% or 24% of screened adults, respectively. While the occurrence of individual nailfold capillary aberrations was related to the presence of an ANA titre of ≥1:80 in adults (reduced capillary density, avascular fields, haemorrhages, oedema, ramifications, dilations and giant capillaries: each p<0.001), no comparable association between nailfold capillary aberrations and ANA was observed in children with RP without previously known CTD.

CONCLUSION

In contrast to adults, the association between nailfold capillary aberrations and ANA might be less pronounced in children. Further studies are warranted to validate these observations in children with RP.

Choosing which in-hospital laboratory tests to target for intervention: a scoping review

INTRODUCTION

Some laboratory testing practices may be of low value, leading to wasted resources and potential patient harm. Our scoping review investigated factors and processes that developers report using to inform decisions about what tests to target for practice improvement.

METHODS

We searched Medline on May 30th, 2019 and June 28th, 2021 and included guidelines, recommendation statements, or empirical studies related to test ordering practices. Studies were included if they were conducted in a tertiary care setting, reported making a choice about a specific test requiring intervention, and reported at least one factor informing that choice. We extracted descriptive details, tests chosen, processes used to make the choice, and factors guiding test choice.

RESULTS

From 114 eligible studies, we identified 30 factors related to test choice including clinical value, cost, prevalence of test, quality of test, and actionability of test results. We identified nine different processes used to inform decisions regarding where to spend intervention resources.

CONCLUSIONS

Intervention developers face difficult choices when deciding where to put scarce resources intended to improve test utilization. Factors and processes identified here can be used to inform a framework to help intervention developers make choices relevant to improving testing practices.

Anti-nuclear autoantibodies in Graves' disease and Graves' orbitopathy

OBJECTIVE

A relationship between thyroid and non-organ-specific autoimmunity could be relevant for Graves' orbitopathy (GO), which affects connective tissue. We investigated the association between GO and anti-nuclear antibodies (ANAs).

METHODS

Retrospective investigation was conducted in 265 patients with Graves' disease (GD), 158 with and 107 without GO. Primary outcome was: prevalence of ANAs in GO vs no-GO. Secondary outcomes were: (1) relationship between ANAs and GO features; (2) prevalence of ANAs in GD compared with non-autoimmune hyperthyroidism [(78 patients with toxic nodular goiter (TNG)]; (3) distribution of ANA patterns.

RESULTS

ANAs were detected in 212 (80%) GD patients, but prevalence did not differ between GO (79.7%) and no-GO (80.3%). Higher ANA titers (1:160) were more common in GO (51.5 vs 38.3%), but only nearly significantly (OR 0.5; 95% CI: 0.3-1; P = 0.059). Proptosis was lower in ANA-positive patients (mean difference: - 1.4 mm; 95% CI from - 2.5 to - 0.3; P = 0.011), in whom nearly significantly lower CAS (Mann-Whitney U: 1.5; P = 0.077) and eyelid aperture (mean difference: - 0.9 mm; 95% CI from - 2 to 0; P = 0.062) were observed. Prevalence of ANAs in GD was lower than in TNG (80 vs 91%; OR 0.3; 95% CI: 0.1-0.9; P = 0.028), but nuclear speckled pattern was more frequent (OR 22.9; 95% CI 1.3-381.3; P = 0.028).

CONCLUSIONS

Although ANAs are not more frequent in GO, they seem to exert a protective role on its severity and on development of GD. A switch of T cell population in ANA-positive patients, resulting in a different phenotype, may be responsible. Further studies are needed to investigate the mechanisms.

Systemic Lupus Erythematosus: New Diagnostic and Therapeutic Approaches

Systemic lupus erythematosus (SLE) is a devastating autoimmune disease that can result in substantial morbidity and mortality. Diagnosis and treatment of SLE are clinical challenges. Patient presentation and response to therapy are heterogeneous because of the complex immune dysregulation that results in SLE disease pathogenesis. An intricate interplay between genetic risk and skewing of adaptive and innate immune system responses leads to overproduction of type I interferons and other cytokines, complement activation, immune-complex deposition, and ultimately inflammation and tissue damage. Here, we review the classification criteria as well as standard and emerging diagnostic tools available to identify patients with SLE. We then focus on medical management, including novel therapeutics, nonpharmacologic interventions, and comorbidity management.

Autoantibodies to dsDNA in the diagnosis, classification and follow-up of patients with systemic lupus erythematosus

Autoantibodies, in particular anti-dsDNA antibodies, are increasingly used for diagnosis, classification and follow-up of patients with SLE. Since standardization of autoantibody assays is a major challenge, more attention should be paid to harmonization initiatives and better definition of required test characteristics in classification criteria. For diagnosis and follow-up separate multi-center studies are required to establish test characteristics of distinct immuno-assays for both purposes. Finally, such studies should consider not to evaluate SLE as a single disease, but as a disease with distinct subtypes.

The Frequency of Immunofluorescence Antinuclear Antibody Patterns and Extractable Nuclear Antigen: Experience From a Large Laboratory in Pakistan

Background Autoimmune disorders have shown an increasing incidence in the last few years. The systemic response to the disorder is characterized by the expression of antinuclear antibody (ANA), which serves as the serological hallmark of autoimmunity. Its presence may indicate either a systemic autoimmune disease such as systemic lupus erythematosus (SLE), scleroderma, and polymyositis/dermatomyositis or an organ-specific condition such as autoimmune thyroiditis and hepatitis. The systemic response may vary from one individual to another in each population. Several specific autoantibodies are also found to be associated with specific rheumatic diseases. Aim We aim to report the frequency of ANA positivity, ANA immunofluorescence patterns, and the presence of extractable nuclear antigen (ENA) among the general Pakistani population from one of the largest laboratories in Pakistan. Material and methods A total of 1,966 blood samples from a random Pakistani population were included, who were referred by their physicians with suspicion of autoimmune disease. These blood samples were subjected to ANA testing by indirect immunofluorescence method, and subsequently, positive samples were further analyzed for ENA detection in the Section of Chemical Pathology, Department of Pathology at Shaukat Khanum Memorial Cancer Hospital and Research Centre, Lahore, Pakistan. An ANA titer of ≥1:80 was taken as positive. ANA was divided into subgroups based on titer: negative, weakly positive (titer of 1:80 or 1:160), moderately positive (titer of 1:320 or 1:640), and strongly positive (titer of ≥1:1280). Further, the frequency of ANA in male and female participants was studied in different age groups (2 to <10, 10 to <20, 20 to <30, 30 to <40, 40 to <50, 50 to <60, 60 to <70, 70 to <80, and 80+ years). Results This study included 1,966 participants, out of which 1,100 (55%) were ANA-positive at a titer of ≥1:80. Out of these ANA positives, the proportion of weakly positive (titer of 1:80 or 1:160), moderately positive (titer of 1:320 or 1:640), and strongly positive (titer of ≥1:1280) were 48.7%, 2.6%, and 4.2%, respectively. The ages ranged from two to 91 years, with a mean age of 43.64 ± 17.4 years. Females (75.5%) showed predominance over males (24.5%) in all age groups, with a ratio of 3:1. The age group in which most ANA positivity was found was 30 to <40 years. Among 1,100 ANA-positive sera, 383 (34.8%) participants tested positive for at least one out of 15 ENA. The most frequent autoantibodies noticed were anti-recombinant Ro52 (Ro52) (19.8%), anti-Sjogren's syndrome type A (SSA) (17.2%), and anti-ribonucleoprotein (RNP) (13.3%). The most prevalent ANA patterns were nuclear homogeneous (27.7%), followed by nuclear speckled (26.5%). Conclusion The frequency of ANA positivity is high in the Pakistani population and differs in different sex and age groups.

Diagnostic value of anti-Kaiso autoantibody in axial spondyloarthritis

Objective

Axial spondyloarthritis (axSpA) is a chronic rheumatic disease predominantly characterized by inflammation and progressive structural damage. Patients are often diagnosed very late, which delays the optimal treatment period. Early diagnosis of axSpA, especially non-radiographic axSpA (nr-axSpA), remains a major challenge. This study aimed to investigate the diagnostic value of anti-Kaiso autoantibodies in axSpA and their correlation with clinical disease indicators.

Methods

Two pooled serum samples (seven patients with nr-axSpA and seven healthy controls) were profiled using HuProt arrays to investigate the diagnostic value of autoantibodies in nr-axSpA. Levels of anti-Kaiso autoantibodies in patients with axSpA and controls were determined using the Meso Scale Discovery assay system. Receiver operating characteristic curve analysis was performed to evaluate the diagnostic performance of anti-Kaiso autoantibodies in axSpA. Pearson's correlation was used to assess the correlation between anti-Kaiso autoantibodies and clinical parameters.

Results

Seven candidate autoantibodies were present in the serum of patients with nr-axSpA. The levels of anti-Kaiso autoantibodies were significantly higher in the nr-axSpA group than in the other groups. It can differentiate nr-axSpA from ankylosing spondylitis (AS), healthy controls, and rheumatoid arthritis. The level of early-stage AS among patients with nr-axSpA decreased when they progressed to the late stage. Of all patients with axSpA, serum anti-Kaiso autoantibody levels were positively correlated with the C-reactive protein level and the Bath Ankylosing Spondylitis Disease Activity Index score and negatively correlated with disease duration.

Conclusion

Anti-Kaiso autoantibody may be a valuable diagnostic biomarker for early-stage AS in the nr-axSpA period and may be a potential therapeutic target.

Autoantibodies associated with systemic sclerosis in three autoimmune diseases imprinted by type I interferon gene dysregulation: a comparison across SLE, primary Sjögren's syndrome and systemic sclerosis

OBJECTIVE

SLE, primary Sjögren's syndrome (pSS) and systemic sclerosis (SSc) are heterogeneous autoimmune diseases with a dysregulated type I interferon (IFN) system. The diseases often show overlapping clinical manifestations, which may result in diagnostic challenges. We asked to which extent SSc-associated autoantibodies are present in SLE and pSS, and whether these link to serum IFN-α, clinical phenotypes and sex. Samples with clinical data from patients with SSc and healthy blood donors (HBDs) served as controls. Finally, the diagnostic performance of SSc-associated autoantibodies was evaluated.

METHODS

Samples from well-characterised subjects with SLE (n=510), pSS (n=116), SSc (n=57) and HBDs (n=236) were analysed using a commercially available immunoassay (EuroLine Systemic Sclerosis Profile (IgG)). IFN-α was quantified by ELISA. Self-reported data on Raynaud's phenomenon (RP) were available.

RESULTS

With exceptions for anti-Ro52/SSA and anti-Th/To, SSc-associated autoantibodies were more frequent in SSc than in SLE, pSS and HBDs regardless of sex. IFN-α levels correlated with the number of positive SSc-associated autoantibodies (r=0.29, p<0.0001) and associated with Ro52/SSA positivity (p<0.0001). By using data from SLE, SSc and HBDs, RP was significantly associated with topoisomerase I, centromere protein (CENP)-B, RNA polymerase III 11 kDa, RNA polymerase III 155 kDa and PM-Scl100 whereas Ro52/SSA associated inversely with RP. In SLE, CENP-A was associated with immunological disorder, CENP-B with serositis and Ku with lupus nephritis. By combining analysis of ANA (immunofluorescence) with SSc-associated autoantibodies, the diagnostic sensitivity reached 98% and the specificity 33%.

CONCLUSIONS

The 13 specificities included in the EuroLine immunoassay are commonly detected in SSc, but they are also frequent among individuals with other diseases imprinted by type I IFNs. These findings are valuable when interpreting serological data on patients with suspected SSc, especially as patients may present with disease manifestations overlapping different rheumatological diseases. In SLE, we observed associations between manifestations and SSc-associated autoantibodies which have not previously been reported.

Classification of Systemic Lupus Erythematosus Using Raman Spectroscopy of Blood and Automated Computational Detection Methods: A Novel Tool for Future Diagnostic Testing

The aim of this study was to explore the proof of concept for using Raman spectroscopy as a diagnostic platform in the setting of systemic lupus erythematosus (SLE). We sought to identify unique Raman signatures in serum blood samples to successfully segregate SLE patients from healthy controls (HC). In addition, a retrospective audit was undertaken to assess the clinical utility of current testing platforms used to detect anti-double stranded DNA (dsDNA) antibodies (n = 600). We examined 234 Raman spectra to investigate key variances between SLE patients (n = 8) and HC (n = 4). Multi-variant analysis and classification model construction was achieved using principal component analysis (PCA), PCA-linear discriminant analysis and partial least squares-discriminant analysis (PLS-DA). We achieved the successful segregation of Raman spectra from SLE patients and healthy controls (p-value < 0.0001). Classification models built using PLS-DA demonstrated outstanding performance characteristics with 99% accuracy, 100% sensitivity and 99% specificity. Twelve statistically significant (p-value < 0.001) wavenumbers were identified as potential diagnostic spectral markers. Molecular assignments related to proteins and DNA demonstrated significant Raman intensity changes between SLE and HC groups. These wavenumbers may serve as future biomarkers and offer further insight into the pathogenesis of SLE. Our audit confirmed previously reported inconsistencies between two key methodologies used to detect anti-dsDNA, highlighting the need for improved laboratory testing for SLE. Raman spectroscopy has demonstrated powerful performance characteristics in this proof-of-concept study, setting the foundations for future translation into the clinical setting.

The effect of the BNT162b2 vaccine on antinuclear antibody and antiphospholipid antibody levels

The Food and Drug Administration (FDA) approved the first SARS-CoV-2 mRNA vaccine (Pfizer-BioNTech) in December 2020. New adverse events have emerged since these vaccines have reached market. Although no clear association between messenger ribonucleic acid (mRNA) vaccines and autoimmunity has emerged, the significance of such an association warrants further exploration. After obtaining consent, a standardized survey on baseline characteristics and other relevant variables was conducted on unvaccinated individuals who were scheduled for vaccination and had not previously contracted COVID-19. Blood samples were collected from participants prior to the first dose, prior to the second dose, and 1 month after the second dose. All collected samples were tested for antinuclear antibody (ANA) titers using indirect immunofluorescence microscopy kits, and antiphospholipid (APS) immunoglobulin M (IgM) and immunoglobulin G (IgG) levels using an enzyme-linked immunoassay (ELISA) technique. ANA titers were positive for 9 participants out of 101 (8.9%) in the first pre-vaccination draw. For the second draw, the number of participants testing positive for ANA decreased to 5 (5%). For the last draw, 6 (5.9%) participants tested positive for ANA titers. One participant tested positive for APS IgM at the first pre-vaccination draw, 2 tested positive at the second draw, and 2 at the third draw. As for APS IgG titers, all participants tested negative in the three draws. McNemar's test for two dependent categorical outcomes was conducted on all variables and did not show a statistical significance. The McNemar test of these two composite variables (i.e., ANA/APS, first draw vs. ANA/APS, second and third draws) did not show statistical significance. The 2-sided exact significance of the McNemar test was 1.0. The Friedman test also showed no significance (p = 0.459). No association was found between BNT162b2 vaccine administration and changes in APS and ANA titers. The benefits of the BNT162b2 vaccine significantly outweigh any possible risk of autoimmune dysregulation considering the current evidence.

Diagnostic value of screening methods for the determination of antinuclear antibodies using indirect immunofluorescence on HEp-2 cells and enzyme immunoassay in autoimmune liver diseases

Antinuclear antibodies (ANA) are a heterogeneous group of autoantibodies that react with various components of the cell nucleus and cytoplasm. ANA is the main serological marker for autoimmune liver disease (AILD). The aim of the study was to compare the diagnostic value of two methods of screening for the determination of ANA (indirect immunofluorescence reaction on HEp-2 cells (IIF -HEp-2) and enzyme-linked immunosorbent assay (ELISA) in the sera of AILD patients. The sera of 118 patients with AILD (51 with autoimmune hepatitis - AIH, 19 with primary biliary cholangitis - PBC, 48 with overlapping syndrome - OVERLAP), 30 patients with non-alcoholic fatty liver disease (NAFLD) and 30 healthy donors (HD) were studied. Determination of ANA by the IIF-HEp-2 method was carried out by visual assessment of samples under an AXIOSKOP 40 microscope, by ELISA - on an Alegria automatic analyzer. A weak degree of agreement between the positive and negative results of the ANA screening study using IIF-HEp-2 and ELISA (Cohen's kappa coefficient æ=0.4) was noted. Screening determination of ANA in patients with AILD by the IIF-HEp-2 method was distinguished by greater diagnostic sensitivity (DS) (68.6%) and a lower frequency of false negative results (31.4%) compared with ELISA (35.6% and 64.4 % respectively, p<0.05). The overall diagnostic specificity (DS) of the ANA study in IIF-HEp-2 was lower than with ELISA (66.7% and 86.7%, respectively, p<0.05). Both screening methods for determining ANA (IIF-HEp-2 and ELISA) were useful for diagnosing AILD (positive likelihood ratio - LR+: 2.1 and 2.6, respectively). In terms of the negative likelihood ratio (LR-), screening for ANA by the IIF-HEp-2 method, in contrast to ELISA, served as a "useful" test to exclude the diagnosis of AILD (0.5 and 0.8, respectively). The determination of ANA using IIF-HEp-2 is the most sensitive and "useful" screening test for the diagnosis of AILD, and ELISA is classified as a less "useful" screening method due to low diagnostic sensitivity and a high false-negative rate.

Natural IgG against S-Protein and RBD of SARS-CoV-2 Do Not Bind and Hydrolyze DNA and Are Not Autoimmune

Since the onset of the COVID-19 pandemic, numerous publications have appeared describing autoimmune pathologies developing after a coronavirus infection, with several papers reporting autoantibody production during the acute period of the disease. Several viral diseases are known to trigger autoimmune processes, and the appearance of catalytic antibodies with DNase activity is one of the earliest markers of several autoimmune pathologies. Therefore, we analyzed whether IgG antibodies from blood plasma of SARS-CoV-2 patients after recovery could bind and hydrolyze DNA. We analyzed how vaccination of patients with adenovirus Sputnik V vaccine influences the production of abzymes with DNase activity. Four groups were selected for the analysis, each containing 25 patients according to their relative titers of antibodies to S-protein: with high and median titers, vaccinated with Sputnik V with high titers, and a control group of donors with negative titers. The relative titers of antibodies against DNA and the relative DNase activity of IgGs depended very much on the individual patient and the donor, and no significant correlation was found between the relative values of antibodies titers and their DNase activity. Our results indicate that COVID-19 disease and vaccination with adenoviral Sputnik V vaccine do not result in the development or enhancement of strong autoimmune reactions as in the typical autoimmune diseases associated with the production of anti-DNA and DNA hydrolyzing antibodies.

Interference of Antinuclear Antibody (ANA) in Indirect Immunofluorescence Assay (IIFA)-Based Perinuclear Antineutrophil Cytoplasmic Antibody (pANCA) Interpretation

Background

Indirect immunofluorescence assay (IIFA) based on antineutrophil cytoplasmic antibody (ANCA) testing is a commonly employed test for diagnosing autoimmune vasculitis. Antinuclear antibody (ANA) can give rise to a false interpretation of perinuclear-ANCA (pANCA) in ethanol-fixed granulocyte substrates. Analytical interference could frequently occur in setups where ethanol-fixed substrates are used alone. Here, we intend to investigate this ANA interference in pANCA interpretation.

Methods

In this retrospective study, we studied anti-MPO-negative but ANA-positive and pANCA (IIFA based) samples. We also correlated immunoblot results (where data were available) and checked the association between grades of blot positivity (an indicator of the concentration of ANA) and frequency of pANCA interpretation. Data were analyzed by appropriate statistical techniques (Chi-square and kappa statistics).

Results

About 19.2% of ANA blot (ENA-blot) positive samples displayed a pANCA positive pattern in the ethanol-fixed substrate, while this positivity in ENA-blot negatives was 6.5%. In positive ANA-IIFA samples, about 14.7% yielded pANCA patterns (on ethanol fixed substrates). Out of this, nuclear homogenous pattern yielding samples gave the highest frequency pANCA, that is, in 31.5% followed by speckled (11.1%), DFS (10.3%), and centromere (6.7%).The association of the nuclear homogenous pattern was statistically significant.

Conclusions

ANA-positive results may interfere with the interpretation of pANCA as observed in ANA-IIFA and ENA-blot positive samples. ANA-IIFA patterns like nuclear homogenous may strongly associate this pANCA interpretation. This can help laboratories perform ANCA testing more effectively, ruling out ANA interference in ANCA screening.

A retrospective study of prevalence and pattern of international consensus on ANA patterns among patients with hepatitis C virus infection

Background

A previous study reported a 30% prevalence of various autoantibodies among patients with hepatitis C virus (HCV) infection. The International Consensus on Anti-Nuclear Antibody (ANA) Patterns was recently introduced to classify ANA patterns based on immunoassay on HEp-2 cells. There is no previous report with this newly developed classification to evaluate patients with HCV infection. The study aims to study the prevalence and pattern of ANA patterns among HCV-infected patients.

Methods

We retrospectively analyzed the medical records of patients with HCV infection from September 2020 to June 2021 at our institution. A positive ANA is defined as a titer of more than 1:320. We compared patient features among the positive and negative groups.

Results

Overall, 258 patients were enrolled-184 patients with negative ANA and 74 patients (28.7%) with positive ANA. The mean age was 67.3 in ANA positive group and 61.2 ANA negative group. Female was prominent with ANA positive and accounted for 63.5%. The most detected ANA pattern was AC-1(homogeneous) (25.9%), followed by AC-4(fine speckled) (25.2%) and AC-21(anti-mitochondrial antibody) (9.6%). In ANA positive group, we found a trend of lower HCV viral load (5.72 log₁₀ IU/ML vs. 6.02 log₁₀ IU/ML), lower alanine aminotransferase level (39.5 U/L vs. 44 U/L), and higher advanced fibrosis (F3 and F4) (38.5% vs. 26.1%). In addition, higher positive ANA (more than 1:640) is significantly associated with lower estimated glomerular filtration rate (eGFR) (77.76 vs. 87.94 mL/min/1.73 m², P = 0.044).

Conclusions

A high prevalence (28.7%) of ANA was found in patients with chronic hepatitis C. The presence of positive ANA is not related to the severity of their hepatic manifestation. However, higher positive ANA was significantly associated with lower eGFR.

Systematic evaluation of imaging techniques and baseline characteristics in patients with suspected vasculitis

PURPOSE

To assess the diagnostic value of different imaging modalities in distinguishing systemic vasculitis from other internal and immunological diseases.

METHODS

This retrospective study included 134 patients with suspected vasculitis who underwent ultrasound, magnetic resonance imaging (MRI), or 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) between 01/2010 and 01/2019, finally consisting of 70 individuals with vasculitis. The main study parameter was the confirmation of the diagnosis using one of the three different imaging modalities, with the adjudicated clinical and histopathological diagnosis as the gold standard. A secondary parameter was the morphological appearance of the vessel affected by vasculitis.

RESULTS

Patients with systemic vasculitis had myriad clinical manifestations with joint pain as the most common symptom. We found significant correlations between different imaging findings suggestive of vasculitis and the final adjudicated clinical diagnosis. In this context, on MRI, vessel wall thickening, edema, and diameter differed significantly between vasculitis and non-vasculitis groups (p < 0.05). Ultrasound revealed different findings that may serve as red flags in identifying patients with vasculitis, such as vascular occlusion or halo sign (p = 0.02 vs. non-vasculitis group). Interestingly, comparing maximal standardized uptake values from PET/CT examinations with vessel wall thickening or vessel diameter did not result in significant differences (p > 0.05).

CONCLUSIONS

We observed significant correlations between different imaging findings suggestive of vasculitis on ultrasound or MRI and the final adjudicated diagnosis. While ultrasound and MRI were considered suitable imaging methods for detecting and discriminating typical vascular changes, 18F-FDG PET/CT requires careful timing and patient selection given its moderate diagnostic accuracy.

Absolute quantification and characterization of oxylipins in lupus nephritis and systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease with multi-organ inflammation and defect, which is linked to many molecule mediators. Oxylipins as a class of lipid mediator have not been broadly investigated in SLE. Here, we applied targeted mass spectrometry analysis to screen the alteration of oxylipins in serum of 98 SLE patients and 106 healthy controls. The correlation of oxylipins to lupus nephritis (LN) and SLE disease activity, and the biomarkers for SLE classification, were analyzed. Among 128 oxylipins analyzed, 92 were absolutely quantified and 26 were significantly changed. They were mainly generated from the metabolism of several polyunsaturated fatty acids, including arachidonic acid (AA), linoleic acid (LA), docosahexanoic acid (DHA), eicosapentanoic acid (EPA) and dihomo-γ-linolenic acid (DGLA). Several oxylipins, especially those produced from AA, showed different abundance between patients with and without lupus nephritis (LN). The DGLA metabolic activity and DGLA generated PGE1, were significantly associated with SLE disease activity. Random forest-based machine learning identified a 5-oxylipin combination as potential biomarker for SLE classification with high accuracy. Seven individual oxylipin biomarkers were also identified with good performance in distinguishing SLE patients from healthy controls (individual AUC > 0.7). Interestingly, the biomarkers for differentiating SLE patients from healthy controls are distinct from the oxylipins differentially expressed in LN patients vs. non-LN patients. This study provides possibilities for the understanding of SLE characteristics and the development of new tools for SLE classification.

Guidelines of the Polish Respiratory Society on the Diagnosis and Treatment of Progressive Fibrosing Interstitial Lung Diseases Other than Idiopathic Pulmonary Fibrosis

The recommendations were developed as answers to previously formulated questions concerning everyday diagnostic and therapeutic challenges. They were developed based on a review of the current literature using the GRADE methodology. The experts suggest that PF-ILD be diagnosed based on a combination of different criteria, such as the aggravation of symptoms, progression of radiological lesions, and worsening of lung function test parameters. The experts recommend a precise diagnosis of an underlying disease, with serological testing for an autoimmune disease always being included. The final diagnosis should be worked out by a multidisciplinary team (MDT). Patients with an interstitial lung disease other than IPF who do not meet the criteria for the progressive fibrosis phenotype should be monitored for progression, and those with systemic autoimmune diseases should be regularly monitored for signs of interstitial lung disease. In managing patients with interstitial lung disease associated with autoimmune diseases, an opinion of an MDT should be considered. Nintedanib rather than pirfenidon should be introduced in the event of the ineffectiveness of the therapy recommended for the treatment of the underlying disease, but in some instances, it is possible to start antifibrotic treatment without earlier immunomodulatory therapy. It is also admissible to use immunomodulatory and antifibrotic drugs simultaneously. No recommendations were made for or against termination of anti-fibrotic therapy in the case of noted progression during treatment of a PF-ILD other than IPF. The experts recommend that the same principles of non-pharmacological and palliative treatment and eligibility for lung transplantation should be applied to patients with an interstitial lung disease other than IPF with progressive fibrosis as in patients with IPF.

Primary Healthcare Practitioners' Knowledge, Attitude, and Practice Toward Systemic Lupus Erythematosus in the Qassim Region, Saudi Arabia

Objective The study aims to evaluate the primary healthcare practitioner's (PHCP) knowledge, attitude, and practice toward systemic lupus erythematosus (SLE) and to explore the difficulties of early referral to specialized clinics. Method This is a cross-sectional study conducted between February and March 2022 targeting the PHCP among the primary healthcare centers in Qassim, Saudi Arabia. The study was conducted among 203 participants who enrolled via a cluster random sampling technique depending on the survey. Qualitative categorical variables are expressed as frequencies and percentages, while continuous variables are reported as means and standard deviations (SD). The one-way analysis of variance (ANOVA) test and the independent T-test have been used to explore the relationship between participants' knowledge scores and their socio-demographic characteristics. A P-value ≤0.05 was considered statistically significant. Result The study found that only 4.4% of participating PHCPs had good knowledge related to SLE, while 45.8% of them had fair knowledge, and nearly half of them (49.8%) had poor knowledge. It was noted that GPs who specialized in family medicine or saw more than 40 patients each week had comparably better knowledge than others, which was statistically significant (p<0.05). The difficulty in diagnosing SLE patients was mentioned by 48.3% of the PHCPs. Family medicine consultants (p<0.001), those who worked in a tertiary care facility for more than six months (p<0.001) and those who worked in a rheumatology department (p<0.05), reported considerably better levels of comfort when treating SLE patients. Conclusion This study found that included participants' understanding of SLE, its diagnosis, and management was inadequate. Coordination between rheumatologists and experts from many disciplines at the primary, secondary, and tertiary levels of care is critical for overcoming ambiguities and obstacles in the diagnosis and therapy of SLE patients.

Comparison of the effect of reporting cytoplasmic patterns as anti-nuclear antibody positive and anti-nuclear antibody negative on reflex test ordering

Objective Anti-nuclear antibody (ANA) patterns are classified as nuclear, cytoplasmic or mitotic. The International Consensus on ANA patterns (ICAP) suggests three parameters for ANA reporting – assay type, results and advice for reflex testing – but has not yet reached a consensus on the reporting of cytoplasmic/mitotic patterns as ANA-negative or positive. We investigated the effect of ICAP’s two proposals for reporting cytoplasmic patterns as ANA-positive and negative with a view to the recommendation for reflex testing in a country that has no national reimbursement policies for automatic reflex testing.

Methods This non-interventional descriptive study included 1241 patients with positive cytoplasmic ANA patterns. 442 patients were reported as ANA-negative and 799 as ANA-positive. Patients were followed up for a two-year period to determine testing recommendations based upon nuclear and cytoplasmic patterns. For statistical analysis, the t-test was used, with a significance threshold of p-value<0.05.

Results Appropriate reflex orders were seen more commonly with cytoplasmic patterns reported as ANA-positive (27.30%) than with those reported as ANA-negative (5.51%, p-value<0.05). However, ANA-positive reports led to higher ordering of nuclear pattern reflex tests (12.97%) compared with ANA-negative reports (1.10%, p-value<0.05). A large group of patients (59.73% ANA-positive, 93.39% ANA-negative) did not receive reflex testing.

Conclusion Reporting cytoplasmic patterns as ANA-positive was considered more significant, but reading the result report without considering the pattern and recommendation notes could lead to inappropriate reflex testing. Besides reaching a consensus for reporting cytoplasmic patterns as ANA-negative or positive, it is important to consider solutions to reimbursement policies for automatic reflex testing to decrease the impediments in reporting cytoplasmic ANA patterns.

Frequency of ANA/DFS70 autoantibodies in Colombian patients with undifferentiated connective tissue disease

The objective was to describe the clinical characteristics and the frequency of the ANA/DFS70 autoantibodies in patients affected by undifferentiated connective tissue disease (UCTD) in a tertiary hospital in Colombia. This descriptive cross-sectional study enrolled patients who fulfilled the classification criteria for UCTD. ANAHEp- 2 test and the modified assay for ANA/DFS70 autoantibodies were performed through the indirect immunofluorescence technique. Erythrocyte sedimentation rate, C-reactive protein, rheumatoid factor, and the antibodies to anti-extractable nuclear antigens, DNA, phospholipids (IgG, IgM, IgA), and cyclic citrullinated peptide were also evaluated. Fifty-three patients were studied; 42/53 (79%) tested positive for ANA and 5/42 (11.9%) for ANA/DFS70 antibodies with a dense fine speckled fluorescent pattern (AC-2) in ANA HEp-2 test that was confirmed by a modified HEp-2-DFS70 assay. Patients had arthralgia (87%, n=47), non-erosive arthritis (66%, n=34), xerostomia (64%, n=34), xerophthalmia (42%, n=22), and Raynaud’s phenomenon (17%, n=9). Arthralgia, xerophthalmia, xeroderma, and absence of disease evolution to a specific disease over five years were more frequent in patients with a positive result for the anti-DFS70 antibodies. The ANA/DFS70 autoantibodies were more frequent in patients with UCTD compared to other rheumatic diseases for which they were initially evaluated. More studies are required to support the predictive role of this antibody to the absence of progression to a well-defined connective tissue disease.

Association between dietary inflammatory index scores and the increased disease activity of rheumatoid arthritis: a cross-sectional study

Background

Diet plays an important role in regulating inflammation, which is a hallmark of rheumatoid arthritis (RA). Our aim was to investigate the association between the Dietary Inflammatory Index (DII) scores and RA activity.

Methods

This cross-sectional study was conducted on 184 patients with RA in rheumatology clinic in Kermanshah city, Iran, in 2020. RA was diagnosed according to the criteria of the 2010 American College of Rheumatology/ European League against Rheumatism. The overall inflammatory potential of the diet was extracted from a validated 168-item food frequency questioner (FFQ) using the DII. RA disease activity was assessed using Disease Activity Score 28 (DAS-28) scores. Logistic regression and one-way ANOVA/ ANCOVA were conducted.

Results

Individuals in the highest DII quartile had the significantly higher odds of positive C-reactive protein than those in the lowest quartile of the DII scores (OR 4.5, 95% CI 1.16 – 17.41, P = 0.029). A statistically significant downward linear trend in fat-free mass and weight were observed with increasing the DII quartiles (P = 0.003, P = 0.019, respectively). Patients in the highest DII quartile had higher DAS-28 scores than those in the first quartile (Mean difference: 1.16, 95% CI 0.51 – 1.81, P < 0.001) and second quartile of the DII scores (Mean difference: 1.0, 95% CI 0.34 – 1.65, P < 0.001).

Conclusion

Our results indicated that reducing inflammation through diet might be one of the therapeutic strategies to control and reduce the disease activity in RA patients.

The influence of demography and referral medical specialty on the detection of autoantibodies to HEP-2 cells in a large sample of patients

Background

The prevalence of anti-cell autoantibodies detected by indirect immunofluorescence assay on HEp-2 cells (HEp-2-IIFA) increases with age and is higher in female sex. The number of medical specialties that use HEp-2-IIFA in the investigation of autoimmune diseases has increased lately. This study aimed to determine the prevalence and patterns of autoantibodies on HEp-2-IIFA according to demographics variables and referring medical specialties.

Methods

A retrospective analysis of the HEp-2-IIFA carried out between January and June of 2017 was performed. The International Consensus on Antinuclear Antibodies Patterns (ICAP) and the Brazilian Consensus on Autoantibodies were used for patterns definition on visual reading of the slides. Anti-cell (AC) codes from ICAP and Brazilian AC codes (BAC) were used for patterns classification.

Results

From 54,990 samples referred for HEp-2-IIF testing, 20.9% were positive at titer ≥ 1/80. HEp-2-IIFA positivity in females and males was 24% and 12%, respectively (p < 0.0001). The proportion of positive results in the 4 age groups analyzed: 0–19, 20–39, 40–59, and ≥ 60 years was 23.3, 20.2, 20.1, and 22.8%, respectively (p < 0.0001). Considering all positive sera (n = 11,478), AC-4 nuclear fine speckled (37.7%), AC-2 nuclear dense fine speckled (21.3%), BAC-3 nuclear quasi-homogeneous (10%) and mixed/composite patterns (8.8%) were the most prevalent patterns. The specialties that most requested HEp-2-IIFA were general practitioner (20.1%), dermatology (15%), gynecology (9.9%), rheumatology (8.5%), and cardiology (5.8%). HEp-2-IIFA positivity was higher in patients referred by rheumatologists (35.7% vs. 19.6%) (p < 0.0001). Moderate (46.4%) and high (10.8%) titers were more observed in patients referred by rheumatologists (p < 0.0001). We observed a high proportion of mixed and cytoplasmic patterns in samples referred by oncologists and a high proportion of BAC-3 (nuclear quasi-homogeneous) pattern in samples referred by pneumologists.

Conclusions

One-fifth of the patients studied were HEp-2-IIFA-positive. The age groups with more positive results were 0–19 and ≥ 60 years. AC-4, AC-2, BAC-3 and mixed/composite patterns were the most frequent patterns observed. Rheumatologists requested only 8.5% of HEp-2-IIFA. Positive results and moderate to high titers of autoantibodies were more frequent in patients referred by rheumatologists.

Frequency and Clinical Utility of Antibodies to Extractable Nuclear Antigen in the Setting of a Negative Antinuclear Antibody Test

OBJECTIVE

Simultaneous antibody testing during screening for autoimmune conditions is discouraged. The incidence of positive extractable nuclear antigen (ENA) in the setting of a negative antinuclear antibody (ANA) has been reported as low. Our objective was to characterize the frequency of diagnosis of new ANA-associated rheumatic disease (AARD) in the setting of a negative ANA with a positive ENA.

METHODS

This was a 7-year retrospective study from a multicenter tertiary health network in Australia. Clinical information was sought on patients over 18 years old who had a negative ANA but positive ENA test result. Results were extracted from hospital computer systems.

RESULTS

From March 19, 2011, to July 23, 2018, ENA testing was ordered simultaneously with an ANA test on 4,248 occasions in 3,484 patients. ANA was positive in 2,520 patients (59.3%) and ENA was positive in 1,980 patients (46.6%). Among positive ANA patients, ENA was positive in 1,563 patients (62.0%). Among 1,728 negative ANA tests, ENA was positive in 417 (24.1%) (P < 0.001). A total of 328 patients with discordant ANA/ENA results had data available for further analysis, of whom 279 had no pre-established rheumatologic condition. A new AARD was diagnosed in 17 of 279 patients, yielding a positive predictive value of 6.09% (95% confidence interval 3.59-9.58).

CONCLUSION

Despite the higher-than-expected incidence of positive ENA in the setting of a negative ANA, the yield of newly diagnosed rheumatic diseases was low. Our findings support the stepwise addition of ENA requests when an ANA test result is positive and clinical suspicion of an AARD is high.

Pediatric Antinuclear Antibody Negative Full-House Nephropathy: A Clinical Conundrum

Introduction: Lupus nephritis is common in pediatric systemic lupus erythematosus (SLE). The presence of full-house immunoglobulin deposits is a unique feature for histopathological diagnosis in lupus nephritis. Our case report highlights two cases with antinuclear antibody (ANA) negative full-house nephropathy (FHN), their clinical phenotypes and intermediate long-term renal outcome. A review of the pediatric literature on this clinical entity ensued. Case Presentation: Two girls, aged three and nine years old presented with acute onset of kidney impairment. One needed temporary dialysis support. Both showed hypocomplementemia and biopsies concurred with FHN. Notably, ANA was absent in both patients. They achieved complete remission soon after introducing immunosuppressive therapy and the disease remained quiescent for many years thereafter. ANA remained negative during surveillance. Conclusions: There have been reports on a possible incomplete form when the characteristic of FHN is seen in isolation. Although natural history of this entity remains uncertain, most literature reports apparent long-term remission following the initial episode. ANA positivity, as an obligatory criterion of diagnosing lupus nephritis (LN), recommended in the new EULAR/ACR 2019 guideline, may raise many uncertainties for this group of patients. There is a need to elucidate whether this should continue to be perceived as part of a lupus continuum or it may be considered a unique clinical entity? Such uncertainties possibly subject the child and his/her caregivers to perpetual mental stress.

Anti-Phospholipid Antibodies and Coronavirus Disease 2019: Vaccination Does Not Trigger Early Autoantibody Production in Healthcare Workers

A molecular mimicry between severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and human proteins supports the possibility that autoimmunity takes place during coronavirus disease 2019 (COVID-19) contributing to tissue damage. For example, anti-phospholipid antibodies (aPL) have been reported in COVID-19 as a result of such mimicry and thought to contribute to the immunothrombosis characteristic of the disease. Consistently, active immunization with the virus spike protein may elicit the production of cross-reactive autoantibodies, including aPL. We prospectively looked at the aPL production in healthcare workers vaccinated with RNA- (BNT162b2, n. 100) or adenovirus-based vaccines (ChAdOx1, n. 50). Anti-cardiolipin, anti-beta2 glycoprotein I, anti-phosphatidylserine/prothrombin immunoglobulin G (IgG), IgA, and IgM before and after vaccination were investigated. Anti-platelet factor 4 immunoglobulins were also investigated as autoantibodies associated with COVID-19 vaccination. Additional organ (anti-thyroid) and non-organ (anti-nuclear) autoantibodies and IgG against human proteome were tested as further post-vaccination autoimmunity markers. The antibodies were tested one or three months after the first injection of ChAdOx1 and BNT162b2, respectively; a 12-month clinical follow-up was also performed. Vaccination occasionally induced low titers of aPL and other autoantibodies but did not affect the titer of pre-existing autoantibodies. No significant reactivities against a microarray of approximately 20,000 human proteins were found in a subgroup of ChAdOx1-vaccinees. Consistently, we did not record any clinical manifestation theoretically associated with an underlying autoimmune disorder. The data obtained after the vaccination (two doses for the RNA-based and one dose for the adenovirus-based vaccines), and the clinical follow-up are not supporting the occurrence of an early autoimmune response in this cohort of healthcare workers.

Autoantibodies Associated with Autoimmune Liver Diseases in a Healthy Population: Evaluation of a Commercial Immunoblot Test

Autoantibodies constitute important tools for diagnosing the autoimmune liver diseases (AILD) autoimmune hepatitis and primary biliary cholangitis. The EUROLINE immunoblot assay, detecting multiple specificities, is widely used, but the clinical importance of weakly positive findings is unclear. The manufacturer’s recommended cut-off was evaluated by investigating AILD-associated autoantibodies in 825 blood donors and 60 confirmed AILD cases. Positive findings were followed up with immunofluorescence microscopy on rat tissue, anti-M2-ELISA, alternative immunoblot assay, and liver function tests. Thirty-six (4.4%) blood donors were positive with EUROLINE. The most common specificities were LC-1 (1.6%), gp210 (1.3%), and AMA-M2 (1.1%). In general, the positive results were higher in patients than in blood donors, whereas anti-LC-1 was higher in blood donors. The liver function tests were slightly elevated in 2 of the 36 immunoblot positive blood donors. The majority of the positive EUROLINE findings could not be confirmed with the follow-up tests. The EUROLINE-Autoimmune Liver Diseases-(IgG) immunoblot detected autoantibodies in 4.4% of blood donors without signs of AILD. Our findings indicate that the recommended cut-off can be raised for most specificities without loss of diagnostic sensitivity. The prevalence of anti-LC-1 among blood donors indicates a problem with the antigen source.

Prediction of Immune-Related Adverse Events Induced by Immune Checkpoint Inhibitors With a Panel of Autoantibodies: Protocol of a Multicenter, Prospective, Observational Cohort Study

Introduction: Immune checkpoint inhibitor (ICI) therapy is markedly improving the prognosis of patients with several types of cancer. On the other hand, the growth in the use of these drugs in oncology is associated with an increase in multiple immune-related adverse events (irAEs), whose optimal prevention and management remain unclear. In this context, there is a need for reliable and validated biomarkers to predict the occurrence of irAEs in patients treated with ICIs. Thus, the main objective of this study is to evaluate the diagnostic performance of a sensitive routinely available panel of autoantibodies consisting of antinuclear antibodies, rheumatoid factor, and antineutrophil cytoplasmic antibodies to identify patients at risk of developing irAEs.

Methods and Analysis: A multicenter, prospective, observational, cohort study has been designed to be conducted in patients diagnosed with cancer amenable to ICI therapy. Considering the percentage of ICI-induced irAEs to be 25% and a loss to follow-up of 5%, it has been estimated that a sample size of 294 patients is required to detect an expected sensitivity of the autoantibody panel under study of 0.90 with a confidence interval (95%) of no less than 0.75. For 48 weeks, patients will be monitored through the oncology outpatient clinics of five hospitals in Spain. Immune-related adverse events will be defined and categorized according to CTCAE v. 5.0. All the patients will undergo ordinary blood tests at specific moments predefined per protocol and extraordinary blood tests at the time of any irAE being detected. Ordinary and extraordinary samples will be frozen and stored in the biobank until analysis in the same autoimmunity laboratory when the whole cohort reaches week 48. A predictive model of irAEs will be constructed with potential risk factors of immune-related toxicity including the autoantibody panel under study.

Ethics and Dissemination: This protocol was reviewed and approved by the Ethical Committee of the Basque Country and the Spanish Agency of Medicines and Medical Devices. Informed consent will be obtained from all participants before their enrollment. The authors declare that the results will be submitted to an international peer-reviewed journal for their prompt dissemination.

An indirect comparison of automated indirect immunofluorescence vs automated solid-phase immunoassays for antinuclear antibody detection: A meta-analysis and adjusted indirect comparison of diagnostic test accuracy

OBJECTIVE

The primary aim of this study was to conduct a meta-analysis to compare the diagnostic accuracy of automated indirect immunofluorescence (automated-IIF) and fully automated solid-phase immunoassays (solid-phase assays), compared with gold standard conventional manual indirect immunofluorescence (manual-IIF) for antinuclear antibody (ANA) detection.

METHODS

Indirect meta-comparison was performed using prospective studies reporting comparative data between automated-IIF and fully automated solid-phase assays individually to conventional manual-IIF. Diagnostic tests regarding different automated solid-phase assays and automated-IIF for ANA detection were retrieved from the Cochrane Library, PubMed, Embase, Web of Science, Chinese Biological Medicine Database (CBM), China National Knowledge Infrastructure (CNKI), and WANFANG electronic databases from their inception to January 2022. Assessment of the quality of the studies was undertaken using a second version of the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool. The investigated diagnostic indices including pooled sensitivity, pooled specificity, pooled positive likelihood ratio (PLR), pooled negative likelihood ratio (NLR), pooled diagnostic odds ratio (DOR), area under the summary receiver operating characteristic (AUC) of automated-IIF and solid-phase assays, respectively. Relative diagnostic odds ratio (RDOR) was calculated to indirectly compare the diagnostic accuracy of automated-IIF and solid-phase assays. To visualize results, we provide forest plots showing the RDOR with 95% confidence intervals (CI) of the 2 methods against the "gold standard" manual-IIF by R software. Deeks' funnel was used to investigate the publication bias.

RESULTS

A total of 16 studies involving 6111 subjects were included in the analysis. The pooled sensitivity, pooled specificity, pooled PLR, pooled NLR, pooled DOR and the AUC were 0.85 (95% CI: 0.84-0.86), 0.82 (95% CI 0.81-0.84), 14.22 (95% CI 8.55-23.65), 0.06 (95% CI 0.03-0.12), 287.0 (95% CI 124.30-662.68) and 0.983 for automated-IIF respectively, and as for solid-phase assays those were 0.73 (95% CI 0.70-0.75), 0.87 (95% CI 0.85-0.89), 5.66 (95% CI 3.33-9.62), 0.30 (95% CI 0.20-0.47), 19.14 (95% CI 8.00-45.79) and 0.894. The results of indirect comparison indicated that automated-IIF had statistically significant higher accuracy for the detection of ANA.

CONCLUSION

This meta-analysis and indirect comparison suggest that automated-IIF should be recommended as an alternative assay for ANA screening under the condition of increased demand for ANA testing in clinical immunology laboratories.

Systemic Sclerosis-Specific Antibodies: Novel and Classical Biomarkers

Disease-specific autoantibodies are considered the most important biomarkers for systemic sclerosis (SSc), due to their ability to stratify patients with different severity and prognosis. Anti-nuclear antibodies (ANA), occurring in subjects with isolated Raynuad's phenomenon, are considered the strongest independent predictors of definite SSc and digital microvascular damage, as observed by nailfold videocapillaroscopy. ANA are present in more than 90% of SSc, but ANA negativity does not exclude SSc diagnosis: a little rate of SSc ANA negative exists and shows a distinct subtype of disease, with less vasculopathy, but more frequent lower gastrointestinal involvement and severe disease course. Anti-centromere, anti-Th/To, and anti-Topoisomerase I antibodies could be considered as classical biomarkers, covering about 60% of SSc and defining patients with well-described cardio-pulmonary complications. In particular, anti-Topoisomerase I represent a risk factor for development of diffuse cutaneous involvement and digital ulcers in the first 3 years of disease, as well as severe interstitial lung disease (ILD). Anti-RNA polymerase III is a biomarker with new clinical implications: very rapid skin thickness progression, gastric antral vascular ectasia, the occurrence of synchronous cancers, and possible association with silicone breast implants rupture. Moreover, novel SSc specific autoantibodies have been globally described in about 10% of "seronegative" SSc patients: anti-elF2B, anti-RuvBL1/2 complex, anti-U11/U12 RNP, and anti-BICD2 depict specific SSc subtypes with severe organ complications. Many autoantibodies could be considered markers of overlap syndromes, including SSc. Anti-Ku are found in 2-7% of SSc, strictly defining the PM/SSc overlap. They are associated with synovitis, joint contractures, myositis, and negatively associated with vascular manifestation of disease. Anti-U3RNP are associated with a well-defined clinical phenotype: Afro-Caribbean male patients, younger at diagnosis, and higher risk of pulmonary hypertension and gastrointestinal involvement. Anti-PM/Scl define SSc patients with high frequency of ILD, calcinosis, dermatomyositis skin changes, and severe myositis. The accurate detection of autoantibodies SSc specific and associated with overlap syndromes is crucial for patients' stratification. ANA should be correctly identified using indirect immunofluorescent assay and a standardized way of patterns' interpretation. The gold-standard technique for autoantibodies' identification in SSc is still considered immunoprecipitation, for its high sensitivity and specificity, but other assays have been widely used in routine practice. The identification of SSc autoantibodies with high diagnostic specificity and high predictive value is mandatory for early diagnosis, a specific follow-up and the possible definition of the best therapy for every SSc subsets. In addition, the validation of novel autoantibodies is mandatory in wider cohorts in order to restrict the gap of so-called seronegative SSc patients.

Advances in SLE classification criteria

This year, the American College of Rheumatology (ACR) 1982 classification criteria for systemic lupus erythematosus (SLE) celebrate their 40th anniversary. From this start, the quest for optimal SLE criteria has led to the 1997 ACR update, the 2012 publication of the Systemic Lupus International Collaborating Clinics (SLICC) criteria, and, in 2019, the European League Against Rheumatism (EULAR)/ACR classification criteria. The latter have since been externally validated in more than two dozen studies and have become the gold standard inclusion criterion of SLE clinical trials. This comprehensive review attempts to follow the evolving success story of SLE classification, highlighting relevant decisions and their rationale, and discussing consequences for the way SLE is defined and managed.

Analytical and clinical performance of different platforms simultaneously detecting 15 antinuclear antibodies

Background

Antinuclear antibodies (ANAs) are invaluable biomarkers for the diagnosis of autoimmune diseases (AIDs). This study aims to compare the performances of line immunoassay (LIA), multiplex bead‐based flow fluorescent immunoassay (MBFFI), and magnetic bar code immunofluorescence assay (MBC‐IF) to detect ANA‐Profile‐15S.

Methods

In total, 184 samples from AID patients and 50 healthy controls (HCs) were collected. Fifteen ANAs (anti‐dsDNA, nucleosome, histone, Sm, PCNA, ribosomal‐P, SS‐A/Ro52, SS‐A/Ro60, SS‐B/La, centromere B [CENP‐B], Scl‐70, U1‐snRNP, AMA‐M2, Jo‐1, and Pm/Scl) were subjected to parallel detection by the LIA, MBFFI, and MBC‐IF. The consistency between assays was analyzed. The discrepant results were further examined by chemiluminescent immunoassay (CLIA).

Results

Anti‐SS‐A/Ro52 and SS‐A/Ro60 autoantibodies were the most common autoantibodies in ANA positive‐profiles, and were detected with equal efficiency by the LIA, MBFFI, and MBC‐IF (p = 0.101 and p = 0.732, respectively). The three assays showed excellent agreement (consistency range: 66.5%–97.5%), and total consistency was 85.8%. The MBFFI and MBC‐IF assays were in good agreement in terms of ANA‐Profile‐15S determination; the kappa coefficient ranged from 0.59 to 0.95, except for the PCNA and PM‐Scl. Of the 262 re‐assessed divergent results, 124 (47.33%) were positive on CLIA; the various autoantibodies exhibited variable patterns. More importantly, the ANA‐Profile‐15S results of the MBFFI and MBC‐IF accurately identified patients with AID; the area under the curves ranged from 0.642 to 0.919.

Conclusions

The novel MBFFI and MBC‐IF assay performed well in detecting ANA‐Profile‐15S. The application of MBFFI and MBC‐IF play important roles in laboratory diagnosis of AIDs.

Current technologies for anti-ENA antibody detection: State-of-the-art of diagnostic immunoassays

BACKGROUND

Autoantibodies against extractable nuclear antigens (ENA) play a pivotal role in the diagnosis and classification of systemic autoimmune rheumatic diseases (SARD). In recent years, newly developed methods have enabled the simultaneous and quantitative detection of multiple anti-ENA reactivities. However, data regarding the comparability of results obtained using different technologies across different platforms are scarce. In this study we compared eight different immunoassays, commonly used in current laboratory practice for detection of anti-ENA antibodies.

METHODS

Sixty patients suffering from different SARD, 10 inflammatory arthritis patients (disease controls) and 10 healthy blood donors were included in this comparative study. Sera were collected in 15 centers belonging to the Study Group on Autoimmune Diseases of the Italian Society of Clinical Pathology and Laboratory Medicine. We evaluated the analytical sensitivity, specificity and diagnostic accuracy of each method for antibodies to Sm, RNP, Ro60, Ro52, Scl70, CENP-B and Jo1. Cohen's kappa was used to analyze the agreement among methods.

RESULTS

Average agreement among methods was 0.82, ranging from substantial (k = 0.72) to almost perfect (k = 0.92). However, while the specificity was very good for all methods, some differences emerged regarding the analytical sensitivity.

CONCLUSIONS

Diagnostic performance of current technologies for anti-ENA antibody detection showed good comparability. However, as some differences exist among methods, laboratory scientists and clinicians must be aware of the diagnostic accuracy of the testing method in use.

Anti-double stranded DNA antibodies: A rational diagnostic approach in limited resource settings

Context

Anti-double-stranded deoxyribonucleic acid antibodies (dsDNA Abs) are highly specific markers of systemic lupus erythematosus (SLE). Multiple methods are employed for their detection in routine diagnostics.

Objectives

The aim of this study was to evaluate a diagnostic approach for anti-dsDNA Abs using DNA-ELISA and Crithidia luciliae fluorescence test (CLIFT), in combination with antinuclear antibody (ANA) screening.

Methods

We enrolled 113 patients—53 with SLE, 50 with other systemic autoimmune rheumatic diseases (OSARD), and 10 with non-autoimmune clinical conditions (NAICC).

Patients’ samples were tested for anti-dsDNA Abs using an enzyme-linked immunosorbent assay (ELISA) and CLIFT, combined to ANA screening by indirect immunofluorescence assay (ANA-IIFA).

Results

The mean age of patients was 39.94 ± 15 years (ranges: 11–85 years). Overall, specimens from 77.3%, 11.7%, and 20% of patients with SLE, OSARD and NAICC respectively were ELISA-positive; and those from 54.7% to 4% of patients with SLE and OSARD, respectively, were CLIFT-positive. CLIFT positivity was significantly associated with high ELISA titers (p = 0.002) and homogeneous ANA-IIF pattern (p = 0.0002).

Conclusion

For better clinical relevance of anti-dsDNA antibodies, we suggest a combined detection strategy based on ELISA, CLIFT and ANA-IIFA, considering the clinical criteria of SLE.

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Anti-dsDNA Abs represent an excellent indicator of systemic lupus erythematosus (SLE) activity and valuable diagnostic biomarker.

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We tested 103 autoimmune disease cases and 10 non-autoimmune condition cases for anti-dsDNA Abs using DNA and CLIFT, in combination with ANA-IIF screening.

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CLIFT positivity was significantly associated with high DNA-ELISA titers (p = 0.002) and homogeneous ANA-IIF pattern (p = 0.0002).

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High DNA-ELISA titers with a positive CLIFT are clinically relevant for the diagnosis of SLE, especially in the presence of a homogeneous ANA-IIF pattern.