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

Autoantibodies in systemic sclerosis: From disease bystanders to pathogenic players

Autoantibodies (Aab) are recognized as key indicators in the diagnosis, classification, and monitoring of systemic autoimmune diseases (AID). Recent studies have expanded knowledge through the discovery of new antigenic targets, advanced methods for measuring Aab levels, and understanding their possible pathogenic roles in AID. This narrative review uses systemic sclerosis (SSc) as an example to highlight the importance of Aab associated with HEp-2 immunofluorescence assay positivity (traditionally referred as antinuclear antibodies [ANA]), exploring recent developments in the field. Firstly, we outline the various types of ANA found in SSc and their links with specific disease features. Newly discovered antibodies shed light on SSc cases where Aab had previously gone unidentified. Secondly, we emphasize the necessity for novel quantitative techniques to track Aab levels over time by gathering data regarding the timing of Aab occurrence relative to SSc symptoms and the relationships between Aab concentrations and disease severity. Finally, we discuss the experimental findings suggesting a potential direct role of Aab in the development of SSc. The advancements surrounding Aab provide insights into new disease mechanisms and may lead to innovative diagnostic and treatment approaches.

Application of machine learning in assessing disease activity in SLE

OBJECTIVE

SLE is a chronic autoimmune disease with immune complex deposition in various organs, causing inflammation. The Systemic Lupus Erythematosus Disease Activity Index 2000 assesses disease severity but is subjective. This study aimed to construct a machine learning model based on objective laboratory indicators to assess SLE disease activity.

METHODS

A retrospective study was conducted on 319 patients with SLE, collecting their clinical characteristics and laboratory indicators as model-building indicators. Multiple machine learning algorithms were employed to construct models for assessing SLE disease activity.

RESULTS

The patients were divided into two cohorts, cohort 1 used as the training set to build the machine learning models and cohort 2 for external validation. Six laboratory indicators, including anti-dsDNA (IFT), quantitative anti-dsDNA, neutrophils, globulin, proteinuria and NK cells, were selected to construct the SLE disease activity evaluation model. The XGBoost model demonstrated superior performance in distinguishing active SLE, with an area under the receiver operating characteristic curve of 0.934, accuracy of 0.925, sensitivity of 0.969, specificity of 0.750 and F1 score of 0.954.

CONCLUSIONS

This pioneering machine learning model, using objective laboratory indicators, enhances clinical feasibility and provides a novel method for assessing SLE disease activity, that may enable timely evaluation of SLE activity, facilitating preparation for treatment and prognosis.

Protocol for affinity enrichment of polyclonal autoantibodies from human plasma

Autoantibodies (AAbs) contribute to various immune-mediated diseases and are valuable biomarkers for diagnosis, classification, and disease activity. Here, we present a protocol for the affinity enrichment of AAbs from human plasma samples. We describe steps to generate a human cell line lysate, which is immobilized on Sepharose beads for affinity enrichment of AAbs. We then detail the quality-control procedure of verifying autoreactivity of AAb fractions. This protocol has potential application in functional and proteomic analyses of AAbs. For complete details on the use and execution of this protocol, please refer to Hagadorn et al.1.

Systemic Inflammatory Diseases in Children With Sickle Cell Disease: A French Multicenter Observational Study on Diagnostic and Therapeutic Issues

BACKGROUND

Systemic inflammatory diseases (SIDs) have been reported in patients with sickle cell disease (SCD), but clinical data in children are scarce.

OBJECTIVES

To identify clinical and laboratory features at diagnosis of SID in children with SCD and to describe their evolution.

METHODS

Data from children with SCD and SIDs were retrospectively collected in a French multicenter study from 1991 to 2018. Information included clinical characteristics, inflammatory markers, autoantibodies patterns, treatments, and complications. Inflammatory marker levels were compared at SID diagnosis and at the last follow-up. Statistical analyses were performed using Cran R software.

RESULTS

Among a cohort of 3800 children with SCD, 43 SIDs were identified in 35 study participants: autoimmune liver disease (AILD, n = 13), inflammatory bowel disease (IBD, n = 7), juvenile idiopathic arthritis (JIA, n = 6), systemic lupus erythematosus (n = 4), autoimmune hemolytic anemia (n = 3), Sjögren syndrome (n = 1), histiocytic necrotizing lymphadenitis (n = 2), vasculitis (n = 2), myasthenia gravis (n = 1), sarcoidosis (n = 1), idiopathic inflammatory granulomatous uveitis (n = 1), mixed connective tissue disease (n = 2). Prevalence of SID was 0.9% in our cohort of children with SCD. The median time between initial symptoms and SID diagnosis was 10 (3-20) months, notably longer in children with JIA, IBD, and Sjögren syndrome. Sixteen patients (46%) exhibited hypergammaglobulinemia (>20 g/L) at diagnosis. No significant differences were observed for other inflammatory parameters. Twenty-one children (60%) received systemic steroids and 13 (37%) biological therapies. Three patients (9%) underwent hematopoietic stem cell transplantation. Nine patients (26%) had severe infections; one died.

CONCLUSION

Delayed diagnosis was frequent due to overlapping clinical presentations between SCD and SID. Clinicians must be aware of warning signs associated with elevated inflammatory markers, hypergammaglobulinemia, or specific antibodies. Therapeutic strategies remain challenging.

Undifferentiated connective tissue disease: the diagnoses critically revised-experience of a single center

Although anti-nuclear antibodies (ANA) are considered the main entry criteria for a diagnosis of undifferentiated connective tissue disease (UCTD), many patients show different rate of ANA positivity and questionable diagnoses. Aim of the study was to revise the UCTD diagnoses and analyse the main predictors of evolution in a monocentric cohort. We retrospectively revised the diagnoses of 331 ANA positive patients, with at least one year of follow-up, classified as UCTD from 2009 and 2017. The diagnosis of UCTD was confirmed in 180 cases (54.4%). The evolution occurred in 18% of cases, after a follow-up of 6.9 (SD: 4.4) years. Raynaud's phenomenon (RP) (OR: 2.39), puffy hands (OR: 6.3), anti-ENA (OR: 2.34), anti-Topoisomerase I antibodies (OR: 4.93), rheumatoid factor (RF) (OR: 2.86) were associated with evolution. Evolution in Systemic Lupus Erythematosus (SLE) occurred in 5 patients (2.78%) and associated with the addition of new autoantibodies, compared with other evolutions (p: 0.034; OR: 12; 95CI: 1.4-103.4). Evolution in Systemic Sclerosis and pSS was found in 14 (7.8%) and 8 cases (4.4%), respectively. Puffy hands and RF positivity as the predictors of SSc and pSS evolution, respectively. A confirmed diagnosis of UCTD, according with the available criteria, was assessed in about a half patients. The occurrence of puffy hands since the onset defines a patient with a potential evolution into SSc, while the addition of new specific autoantibodies represents a typical "fingerprint" of patients developing SLE. Trial registration: Studio ANACTD np 1318.

Precision Medicine in Rheumatology: The Role of Biomarkers in Diagnosis and Treatment Optimization

Rheumatic diseases encompass a wide range of autoimmune and inflammatory disorders, including rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), psoriatic arthritis (PsA), and systemic sclerosis (SSc). These conditions often result in chronic pain, disability, and reduced quality of life, with unpredictable disease courses that may lead to joint destruction, organ damage, or systemic complications. Biomarkers, defined as measurable indicators of biological processes or conditions, have the potential to transform clinical practice by improving disease diagnosis, monitoring, prognosis, and treatment decisions. While significant strides have been made in identifying and validating biomarkers in rheumatic diseases, challenges remain in their standardization, clinical utility, and integration into routine practice. This review provides an overview of the current state of biomarkers in rheumatic diseases, their roles in clinical settings, and the emerging advancements in the field.

SARS-CoV-2 spike peptide analysis reveals a highly conserved region that elicits potentially pathogenic autoantibodies: implications to pan-coronavirus vaccine development

The SARS-CoV-2 pandemic, while subsiding, continues to plague the world as new variants emerge. Millions have died, and millions more battle with the debilitating symptoms of a clinical entity known as long Covid. The biggest challenge remains combating an ever-changing variant landscape that threatens immune evasion from vaccine and prior infection-generated immunity. In addition, the sequelae of symptoms associated with long Covid almost certainly point to multiple pathologies that range from direct damage to organs during infection to a potential role for infection-induced autoreactive antibodies in promoting autoimmune-like conditions in these patients. In this study, a peptide scan of the SARS-CoV-2 spike protein was done to detect novel, highly conserved linear epitopes that do not elicit autoantibodies. We identified eight predicted linear epitopes capable of eliciting anti-spike IgG antibodies. Immunizations alternating peptide conjugated to KLH with the full trimer yielded the highest antibody levels, but homologous immunization with some of the peptides also yielded high levels when an additional immunization step was added. Of all regions tested, the stem helix adjacent to the heptad repeat 2 (HR2) region also elicited high levels of autoreactive antibodies to known autoantigens in common systemic autoimmune disorders such as lupus and scleroderma and may contribute to the long Covid syndrome seen in some patients. Implications to vaccine design are discussed.

Harmonization of anti-nuclear antibody testing (ANA) by indirect immunofluorescence assay: Results from ten years of UK NEQAS external quality assessment

External quality assurance (EQA) programs play a pivotal role in monitoring laboratory practices, allowing each laboratory to evaluate the consistency of results across different methods as well the ability of individual laboratories to compare and improve over time their own performance. The objective of our study was to analyze the UK NEQAS EQA reports for the "Antibodies to Nuclear and Related Antigens" program from 2013 to 2023, to assess the overall level of harmonization of the responses for anti-nuclear antibody (ANA) testing by indirect immunofluorescence (IIF), in terms of both pattern and titer consensus. As a second aim, we analyzed the impact of the introduction in UK NEQAS EQA reports of the International Consensus on ANA Patterns (ICAP) nomenclature and of digital image recognition on the harmonization of the ANA HEp-2 IIF test. The percentage of consensus for positive/negative results was significantly higher (90.9 ± 1.4) in 2023 than in 2013 (64.0 ± 7.8, p < 0.001). Common to all years in the investigated period, consensus on pattern recognition was significantly lower for the homogenous pattern (70.5 ± 16.0) compared to the centromere (84.9 ± 14.9), the speckled (90.3 ± 12.3), and the negative (84.5 ± 18.6, p < 0.001) samples, while it was significantly higher for titers 1:80-1:320 than for titers > 1:320 (p < 0.001). The difference between manual reading and digital reading was not significant (93.8 % vs. 92.4 %; p = 0.078), but it was significant between the pre- and post-use of the ICAP nomenclature (82.6 % vs. 93.8 %; p < 0.001). This study shows that the variability in ANA recognition and reporting is pattern (homogeneous > speckled > centromere) and titer (high titer > low titer) dependent. While we did not find any difference between the use of manual reading compared to digital reading, the adoption of the ICAP nomenclature greatly improved the harmonization of ANA reporting.

Association between antinuclear antibodies and pregnancy prognosis in recurrent pregnancy loss patients

STUDY QUESTION

Can antinuclear antibodies (ANA) affect the subsequent live birth rate (LBR) in patients with unexplained recurrent pregnancy loss (RPL) in the absence of antiphospholipid antibodies (aPL)?

SUMMARY ANSWER

Women with unexplained RPL have a high probability of live birth following a positive pregnancy test (>70%), being similar between those with positive and negative ANA testing, regardless of the cut-off value.

WHAT IS KNOWN ALREADY

The RPL guidelines of the ESHRE state that 'ANA testing can be considered for explanatory purposes'. However, there have been a limited number of studies on this issue and sample sizes have been small, and the impact of ANA on the pregnancy prognosis is unclear.

STUDY DESIGN, SIZE, DURATION

A retrospective cohort study was conducted at Nagoya City University Hospital between 2006 and 2019. The study included 1021 women with RPL without known cause.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Hysterosalpingography or 3D-ultrasound, chromosome analysis for both partners, blood tests for aPL, ANA, hypothyroidism, and diabetes mellitus were performed before a subsequent pregnancy. ANAs were measured by indirect immunofluorescence on Hep-2 cell slides. The cutoff dilution used was 1:40. In addition, patients were classified according to the ANA pattern on immunofluorescence staining: homogeneous, speckled, nucleolar, centromeric, peripheral, cytoplasmic, and others. LBRs were compared between ANA-positive and ANA-negative patients after excluding patients with antiphospholipid antibody syndrome, an abnormal chromosome in either partner and a uterine anomaly.

MAIN RESULTS AND THE ROLE OF CHANCE

Considering the cut-off value = 1:40 dilution, the subsequent LBRs were 72.5% (256/353) for the ANA-positive group and 73.2% (489/668) for the ANA-negative group; odds ratio (OR) = 0.97, 95% CI = 0.72-1.29. After excluding the miscarriages occurring from embryonic aneuploidy, the biochemical pregnancy losses, and the ectopic pregnancies, LBRs were 92.8% (256/276) for the ANA-positive group and 93.0% (489/526) for the ANA-negative group: OR = 0.97 (95% CI = 0.55-1.70). Considering the cut-off value = 1:80 dilution, the subsequent LBRs were 75.0% (87/116) for the ANA-positive group and 72.7% (658/905) for the ANA-negative group; OR = 1.13 (95% CI = 0.72-1.76). After excluding the miscarriages occurring from embryonic aneuploidy, the biochemical pregnancy losses, and the ectopic pregnancies, LBRs were 89.7% (87/97) for the ANA-positive group and 93.3% (658/705) for the ANA-negative group: OR = 0.62 (95% CI = 0.30-1.27). Considering the cut-off value = 1:160 dilution, the subsequent LBRs were 82.4% (28/34) for the ANA-positive group and 72.6% (717/987) for the ANA-negative group; OR = 1.76 (95% CI = 0.72-4.29). After excluding the miscarriages occurring from embryonic aneuploidy, the biochemical pregnancy losses, and the ectopic pregnancies, LBR were 93.3% (28/30) for the ANA-positive group and 92.9% (717/772) for the ANA-negative group: OR = 1.07 (95% CI = 0.25-4.63). There was no difference in LBR between the 2 groups before or after adjustment for age and BMI, but ANA-positive patients were significantly older than ANA-negative patients when using the 1:40 dilution, and ANA-positive patients had significantly lower BMIs than ANA-negative patients when using the 1:80 dilution.

LIMITATIONS, REASONS FOR CAUTION

A healthy control group was not established, making it impossible to compare ANA positivity rates between healthy controls and RPL patients. There were significant differences in age (1:40 dilution) and BMI (1:160 dilution) between the ANA-positive and ANA-negative groups.

WIDER IMPLICATIONS OF THE FINDINGS

Our results suggest that ANA testing is not useful to predict future pregnancy loss in women with RPL without known cause.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by MEXT Promotion of Distinctive Joint Research Center Program, Grant Number JPMXP0621467963 and used for English proofreading costs. There are no competing interests for all authors.

TRIAL REGISTRATION NUMBER

N/A.

The Discovery of New Antibody in Autoimmune Disease Using a Novel Approach of Coombs Test Based on Flow Cytometry Method

BACKGROUND AND OBJECTIVE

The objective of this study was to investigate the antibody to RBC in autoimmune disease patients with ANA using sensitive Coombs test based on flow cytometry method.

MATERIALS AND METHODS

Antinuclear antibodies (ANA) of autoimmune disease patients were added to red blood cells (RBCs) of blood group O. At the same time, healthy individuals' serums were also checked. The sample tubes were incubated for 30 min at 37°C. After incubation, each sample was analyzed on flow cytometry.

RESULTS

The agglutination of antinuclear antibodies in autoimmune patients was observed, while in healthy people, there was no agglutination between RBCs and serum. A significant difference was found between the disease group and healthy group (p < 0.0001) showing that a statistical analysis was conducted to compare the presence of ANA agglutination between the two groups. The reported p-value of less than 0.0001 shows that the observed difference is highly significant. The serum stability test conducted over ten consecutive days demonstrated a CV of 6.90% in the test results, indicating favorable stability.

CONCLUSION

In conclusion, this study emphasizes the effectiveness of flow cytometry as a valuable tool for detecting RBC-bound antibodies and new antibodies in autoimmune disease patients. Its high sensitivity and accuracy have the potential to greatly improve diagnostic capabilities in clinical laboratories.

Automatic classification of HEp-2 specimens by explainable deep learning and Jensen-Shannon reliability index

The Anti-Nuclear Antibodies (ANA) test using Human Epithelial type 2 (HEp-2) cells in the Indirect Immuno-Fluorescence (IIF) assay protocol is considered the gold standard for detecting Connective Tissue Diseases. Computer-assisted systems for HEp-2 image analysis represent a growing field that harnesses the potential offered by novel machine learning techniques to address the classification of HEp-2 images and ANA patterns. In this study, we introduce an innovative platform based on transfer learning with pre-trained deep learning models. This platform combines the power of unsupervised deep description of HEp-2 images, a novel feature selection approach designed for unbalanced datasets, and independent testing using two distinct datasets from different hospitals to tackle cross-hardware compatibility issues. To enhance the trustworthiness of our method, we also present a modified version of gradient-weighted class activation mapping for regional explainability and introduce a new sample quality index based on the Jensen-Shannon divergence to enhance method reliability and quantify sample heterogeneity. The results we provide demonstrate exceptionally high performance in intensity and ANA pattern recognition when compared to state-of-the-art approaches. Our method's ability to eliminate the need for cell segmentation in favor of statistical analysis of the sample makes it applicable, robust, and versatile. Our future work will focus on addressing the challenge of mitotic spindle recognition by expanding our proposed approach to cover mixed patterns.

Prevalence and heterogeneity of antinuclear antibody patterns in adult Italian patients with autoimmune liver diseases: Our experience

BACKGROUND AND AIM

This study aims to explore the clinical significance of antinuclear antibodies (ANA) patterns in liver diseases.

MATERIALS AND METHODS

We included 396 patients with a request for ANA testing for suspected autoimmune liver disease (AILD). For each patient, we collected demographical, clinical, and laboratory data.

RESULTS

Among the patients, 33% had AILD, predominantly aiutoimmune hepatitis (AIH). The AC1 pattern was significantly more prevalent in AIH patients, while the AC21 pattern was strongly associated with primary biliary cholangitis (PBC). AC4-AC5 patterns were less frequent in AIH and PBC patients but more common in non-alcoholic hepatitis. Elevated alkaline phosphatase and gamma-glutamyl transferase levels were observed in AILD patients with AC11, AC12, and AC21 patterns.

CONCLUSIONS

These findings highlight the different distribution of ANA patterns in liver diseases, with specific patterns showing strong associations with distinct liver conditions.

Genetic burden of lupus increases the risk of transition from normal to preclinical autoimmune conditions via antinuclear antibody development

OBJECTIVES

This study aimed to investigate the association between the genetic burden of systemic lupus erythematosus (SLE) and the loss of tolerance to self-nuclear antigens in the preclinical stage.

METHODS

We analysed genetic data from 349 Korean individuals who tested positive for autoantibodies in the preclinical stage, along with 33,596 healthy controls and 2057 patients with SLE. Genome-wide and pathway-specific polygenic risk scores (PRSs) of SLE were calculated based on 180 known non-human leukocyte antigen (non-HLA) SLE loci, HLA-DRB1 classical alleles, and predefined immune-related pathways to subsequently correlate with clinical phenotypes, particularly the presence of antinuclear antibodies (ANAs) at various titre thresholds.

RESULTS

Individuals with preclinical autoimmune conditions exhibited significantly higher SLE PRSs than healthy controls (P = 2.99 × 10-5), with a significantly upward trend between ANA titres and PRS (P = 1.12 × 10-3). Stratification analysis revealed that preclinical-stage individuals with PRSs exceeding the means of age- and sex-matched PRSs among patients with SLE were at a significantly higher risk of ANA development (odds ratio = 2.25; P = 8.12 × 10-3 at a dilution factor of 1:80). Pathway-specific PRS analysis identified the significant enrichment of SLE-risk effects in nine pathways, such as signalling related to reactive oxygen species production, T cell receptor, B cell receptor, and cytokines, in ANA-positive preclinical individuals (Padjusted < 0.05).

CONCLUSIONS

Our findings illustrate that the genetic burden of SLE may lead to a crucial transition from normal to preclinical autoimmune conditions prior to the pathogenic stage by increasing the susceptibility to and levels of ANAs.

Identification of nuclear valosin-containing-protein-like as a target of anti-nuclear autoantibodies in systemic sclerosis

Objective

To identify the target antigen of an anti-nuclear autoantibody (ANA) from a patient with a suspected systemic autoimmune disease and to study the autoantibody's clinical association.

Methods

The index patient serum was screened for autoantibodies using indirect immunofluorescence assay (IFA) and line blots (membrane strips coated with parallel lines of different purified antigens). Immunoprecipitation with fixed HEp-2 cells followed by SDS-PAGE and MALDI-TOF mass spectrometry was used to identify the autoantigen, which was verified by competitive inhibition experiments, recombinant HEK293 cell-based IFA, and Western and line blots based on the recombinant antigen. The prevalence of autoantibodies against this antigen was studied in 693 patients with systemic autoimmune rheumatic diseases (SARD) and 150 healthy controls.

Results

The index patient serum displayed a homogeneous nucleolar staining pattern on HEp-2 cells and monkey liver by IFA but did not react with 27 known nuclear antigens. Nuclear valosin-containing-protein-like (NVL) was identified as the ANA target antigen. Preincubation with recombinant NVL abolished the reactivity of the patient serum with HEp-2 cells in IFA. Additionally, the patient serum reacted with recombinant NVL in cell-based IFA and Western blot analysis, whereas sera from 15 healthy controls were nonreactive. Using line blots coated with recombinant NVL, anti-NVL autoantibodies were exclusively found in four out of 378 patients with systemic sclerosis, but neither in 315 patients with other SARD nor in 150 healthy controls.

Conclusion

These findings indicate that autoantibodies against NVL may be a suitable marker to help narrowing the serological gap in systemic sclerosis.

A Multi-task learning U-Net model for end-to-end HEp-2 cell image analysis

Antinuclear Antibody (ANA) testing is pivotal to help diagnose patients with a suspected autoimmune disease. The Indirect Immunofluorescence (IIF) microscopy performed with human epithelial type 2 (HEp-2) cells as the substrate is the reference method for ANA screening. It allows for the detection of antibodies binding to specific intracellular targets, resulting in various staining patterns that should be identified for diagnosis purposes. In recent years, there has been an increasing interest in devising deep learning methods for automated cell segmentation and classification of staining patterns, as well as for other tasks related to this diagnostic technique (such as intensity classification). However, little attention has been devoted to architectures aimed at simultaneously managing multiple interrelated tasks, via a shared representation. In this paper, we propose a deep neural network model that extends U-Net in a Multi-Task Learning (MTL) fashion, thus offering an end-to-end approach to tackle three fundamental tasks of the diagnostic procedure, i.e., HEp-2 cell specimen intensity classification, specimen segmentation, and pattern classification. The experiments were conducted on one of the largest publicly available datasets of HEp-2 images. The results showed that the proposed approach significantly outperformed the competing state-of-the-art methods for all the considered tasks.

Diversity and Epitope Spreading of Anti-RNA Polymerase III Antibodies in Systemic Sclerosis: A Potential Biomarker for Skin and Lung Involvement

OBJECTIVE

Epitope spreading (ES), involving autoantibodies, plays a crucial role in the development and persistence of autoimmune reactions in various autoimmune diseases. This study aimed to investigate the relationship between ES of anti-RNA polymerase III (RNAP III) antibodies (ARAs) and the clinical manifestations of systemic sclerosis (SSc).

METHODS

We investigated whether intermolecular ES occurs in the subunits of the RNAP III complex and whether intramolecular ES targets the major antigen, RNA polymerase III subunit A (RPC1), in patients with SSc. To achieve this, we synthesized 17 full-length subunit proteins of the RNAP III complex and 5 truncated forms of RPC1 in vitro using a wheat germ cell-free translation system. Subsequently, we prepared antigen-binding plates and measured autoantibodies in the serum of patients with SSc.

RESULTS

Autoantibodies against different RNAP III complex subunits were found in patients who were ARA-positive with SSc. The intermolecular ES indicators significantly correlated with the modified Rodnan skin thickness score (mRSS) and surfactant protein-D, a biomarker of interstitial lung disease. However, the extent of disease on high-resolution computed tomography or pulmonary function tests did not show any significant correlation. Intramolecular ES indicator against RPC1 were significantly correlated with mRSS and renal crisis. Furthermore, longitudinal assessment of ES in RNAP III complex subunits correlated with mRSS and exhibited potential as a disease activity biomarker.

CONCLUSION

Our findings indicate a correlation between ES levels and the severity of skin sclerosis or the risk of other complications in SSc. This study suggests that measuring ES in SSc serves as a novel biomarker for disease activity.

Examination of antinuclear antibody staining patterns and titers in patients with childhood-onset systemic lupus erythematosus

OBJECTIVE

Antinuclear antibodies (ANA) staining patterns can provide useful information in systemic lupus erythematosus (SLE). In our study, we examined the frequency of ANA staining patterns in disease-related features in childhood-onset SLE patients.

METHODS

ANA and its staining patterns were assessed in childhood-onset SLE patients.

RESULTS

Two hundred twenty-three patients were included (F/M = 3/1). Their median age at diagnosis was 14.3 (11.9-16.1) years. The anti-cell (AC)-4/5 (fine or large speckled) pattern was the most common nuclear ANA pattern (75.8%), while the AC-19 (dense fine speckled) pattern was the most frequently detected cytoplasmic ANA pattern (13.1%). The AC-4/5 (fine or large speckled) patterns were notably seen in fever, acute and chronic cutaneous lupus, arthritis, serositis, hematologic involvement, renal involvement, neuropsychiatric involvement, gastrointestinal involvement, and cardiopulmonary involvement (all p < .001). Conversely, the AC-1 (homogeneous) pattern was significantly detected in oral/nasal ulcers and non-scarring alopecia (both p < .001). Regarding the laboratory features, the AC-4/5 (fine or large speckled) patterns exhibited a predominant seen in autoimmune hemolytic anemia, leukopenia, thrombocytopenia, elevated ESR and CRP, hypocomplementemia, direct Coombs, anti-Smith (Sm), anti-SSA and SS-B, anti-ribonucleoprotein (RNP), anti-histone, anti-ribosomal P, lupus anticoagulant, anti-cardiolipin immunoglobulin (Ig)M/IgG, and anti-β2-glycoprotein IgM/IgG positivities (all p < .001). In contrast, the AC-1 (homogeneous) pattern was detected in anti-double-stranded (ds) DNA and anti-histone positivity (both p < .001).

CONCLUSION

Our study showed that AC-4/5 and AC-1 patterns of ANA are frequently detected in many clinical and serological features of childhood-onset SLE patients. However, further studies are needed in larger populations to verify these results.

Brain-immune interactions: implication for cognitive impairments in Alzheimer's disease and autoimmune disorders

Progressive memory loss and cognitive dysfunction, encompassing deficits in learning, memory, problem solving, spatial reasoning, and verbal expression, are characteristics of Alzheimer's disease and related dementia. A wealth of studies has described multiple roles of the immune system in the development or exacerbation of dementia. Individuals with autoimmune disorders can also develop cognitive dysfunction, a phenomenon termed "autoimmune dementia." Together, these findings underscore the pivotal role of the neuroimmune axis in both Alzheimer's disease and related dementia and autoimmune dementia. The dynamic interplay between adaptive and innate immunity, both in and outside the brain, significantly affects the etiology and progression of these conditions. Multidisciplinary research shows that cognitive dysfunction arises from a bidirectional relationship between the nervous and immune systems, though the specific mechanisms that drive cognitive impairments are not fully understood. Intriguingly, this reciprocal regulation occurs at multiple levels, where neuronal signals can modulate immune responses, and immune system-related processes can influence neuronal viability and function. In this review, we consider the implications of autoimmune responses in various autoimmune disorders and Alzheimer's disease and explore their effects on brain function. We also discuss the diverse cellular and molecular crosstalk between the brain and the immune system, as they may shed light on potential triggers of peripheral inflammation, their effect on the integrity of the blood-brain barrier, and brain function. Additionally, we assess challenges and possibilities associated with developing immune-based therapies for the treatment of cognitive decline.

Antinuclear antibodies do not affect euploidy rate in preimplantation genetic testing for aneuploidy

RESEARCH QUESTION

Do antinuclear antibodies affect the blastocyst aneuploidy rate during preimplantation genetic testing for aneuploidy (PGT-A) cycles?

DESIGN

A retrospective cohort study was undertaken of 259 patients who underwent PGT-A and immunological screening at the study centre between May 2018 and May 2023. Patients were divided into an antinuclear-antibody-negative group (213 cycles) and an antinuclear-antibody-positive group (46 cycles) based on the presence/absence of antinuclear antibodies, and embryo outcomes were compared.

RESULTS

Significant differences were found between antinuclear-antibody-negative and antinuclear-antibody-positive patients in terms of paternal age (34 versus 37 years; P = 0.032), maternal age (33 versus 35 years; P = 0.046) and duration of infertility (2 versus 3 years; P = 0.009). No significant differences were found in the number of retrieved oocytes, metaphase II (MII) oocytes, available embryos, high-quality embryos, blastocysts biopsied, euploid blastocysts, MII oocyte rate, fertilization rate, high-quality embryo rate and euploidy rate. Multiple linear regression revealed that, in infertile couples who underwent PGT-A, maternal age was an independent factor influencing the euploidy rate (regression coefficient -0.009), whereas the presence of antinuclear antibodies was not an independent factor influencing the euploidy rate.

CONCLUSION

In couples who underwent PGT-A, the presence of antinuclear antibodies did not affect the euploidy rate. This study did not observe any negative effects of antinuclear antibodies on oocyte or embryo outcomes.

Comparison of quantitative and qualitative anti-dsDNA assays

OBJECTIVE

In evaluation of systemic lupus erythematosus (SLE), anti-double-stranded DNA antibodies (anti-dsDNA) play a significant role in diagnosis, monitoring SLE activity, and assessing prognosis. However, evaluations of the performance and limitations for recently developed methods for anti-dsDNA assessment are sparse.

METHODS

Specimens used for antinuclear antibody testing (n = 129) were evaluated for anti-dsDNA assay comparability across 4 medical centers in the United States. The methods compared were Werfen Quanta Lite dsDNA, Zeus Scientific dsDNA Enzyme Immunoassay, Bio-Rad multiplex immunoassay (MIA) dsDNA, ImmunoConcepts Crithidia, and Bio-Rad Laboratories Crithidia.

RESULTS

For quantitative anti-dsDNA measurements, Spearman's correlation coefficient was highest between Zeus and Werfen (ρ = 0.86; CI, 0.81-0.90; P < .0001). Comparison of MIA to Werfen or Zeus yielded similar results to each other (ρ = 0.58; CI, 0.44-0.68; P < .0001; and ρ = 0.59; CI, 0.46-0.69; P < .0001, respectively), but lower than the correlation between Zeus and Werfen. Positive concordance between assays ranged from 31.4% to 97.1%, and negative concordance between assays ranged from 58.5% to 100%. The detection of anti-dsDNA in those with SLE diagnosis ranged from 50.9% to 77.4% for quantitative assays and 15.1% to 24.5% for Crithidia assays.

CONCLUSION

Current quantitative anti-dsDNA assays are not interchangeable for patient follow-up. Crithidia-based assays demonstrate high negative concordance and lack positive concordance among the methods.

Elevated antibody binding to striatal cholinergic interneurons in patients with pediatric acute-onset neuropsychiatric syndrome

Pediatric Acute-onset Neuropsychiatric Syndrome (PANS) is characterized by the abrupt onset of significant obsessive-compulsive symptoms (OCS) and/or severe food restriction, together with other neuropsychiatric manifestations. An autoimmune pathogenesis triggered by infection has been proposed for at least a subset of PANS. The older diagnosis of Pediatric Autoimmune Neuropsychiatric Disorder Associated with Streptococcus (PANDAS) describes rapid onset of OCD and/or tics associated with infection with Group A Streptococcus. The pathophysiology of PANS and PANDAS remains incompletely understood. We recently found serum antibodies from children with rigorously defined PANDAS to selectively bind to cholinergic interneurons (CINs) in the striatum. Here we examine this binding in children with relapsing and remitting PANS, a more heterogeneous condition, collected in a distinct clinical context from those examined in our previous work, from children with a clinical history of Streptococcus infection. IgG from PANS cases showed elevated binding to striatal CINs in both mouse and human brain. Patient plasma collected during symptom flare decreased a molecular marker of CIN activity, phospho-riboprotein S6, in ex vivo brain slices; control plasma did not. Neither elevated antibody binding to CINs nor diminished CIN activity was seen with plasma collected from the same children during remission. These findings replicate what we have seen previously in PANDAS and support the hypothesis that at least a subset of PANS cases have a neuroimmune pathogenesis. Given the critical role of CINs in modulating basal ganglia function, these findings confirm striatal CINs as a locus of interest in the pathophysiology of both PANS and PANDAS.

Cutting edge confusion about cut-off settings in autoimmune diagnostics

In autoimmune diagnostics results are interpreted in relation to a single or multiple cut-off value(s) in order to decide if the test is negative, weak positive, positive, or even strong positive. The way a cut-off is established appears to be very heterogeneous and this hampers harmonization of test results obtained in assays, either established in-house or obtained from different companies. In this context it is surprising that in diagnostic and classification criteria for distinct autoimmune diseases referral is made to cut-off values with the intention of harmonization. In this review article distinct ways to establish cut-off values will be described and discussed in relation to some disease criteria in order to increase the awareness of the confusion matrix of cut-off values and, as a consequence, the implications for test result interpretation.

Prevalence and clinical significance of anti-SSA antibody in the Chinese health screening population

Anti-Sjögren's syndrome type A (anti-SSA) antibodies are non-organ-specific autoantibodies highly prevalent in various autoimmune diseases. This study primarily investigated the prevalence of anti-SSA antibodies in the health screening population. Additionally, we explored the clinical features of the anti-SSA antibody-positive population and evaluated the development of connective tissue diseases (CTD) over the years in individuals with anti-SSA antibodies for whom follow-up was available. A total of, 64 045 individuals without a history of CTD from 2013 to 2022 who visited Peking Union Medical College Hospital for health screening were screened for autoimmune antibodies: 1.7% (1091/64 045) of the Chinese health screening population were positive for anti-SSA antibodies, with a prevalence of 0.9% (290/33 829) in men and 2.7% (801/30 216) in women. Compared with matched autoantibody-negative controls, anti-SSA antibody-positive individuals had higher levels of serological abnormalities, including erythrocyte sedimentation rate (ESR) [10 (6-15) mm/h vs. 7 (4-12) mm/h, P < 0.0001], rheumatoid factor (RF) [7.15 (4.30-16.90) IU/ml vs. 5.00 (3.20-7.90) IU/ml, P < 0.0001], and immunoglobulin G [13.09 (11.20-15.45) g/L vs. 11.34 (9.85-13.18) g/L, P < 0.0001], and lower levels of white blood cells (WBC; 5.49 ± 1.50 × 109/L vs. 5.82 ± 1.49 × 109/L, P < 0.0001). Additionally, they had a higher proportion of coexisting thyroid autoantibodies, including anti-thyroid peroxidase antibodies (TPO-Ab) (17.1% vs. 11.3%, P < 0.0001) and anti-thyroglobulin antibodies (Tg-Ab) (17.8% vs. 11.0%, P < 0.0001). Among the 381 subjects who were anti-SSA positive and followed up for a median of 4.6 years, 146 (38.3%) individuals developed CTD, including 68 (17.8%) cases of primary Sjögren's syndrome (pSS), 10 (2.6%) cases of rheumatoid arthritis (RA), 5 (1.3%) cases of systemic lupus erythematosus (SLE), 4 (1.0%) cases of secondary Sjögren's syndrome (sSS), and 59 (15.5%) cases of undifferentiated connective tissue disease (UCTD). In all, 235 (61.7%) individuals did not develop CTD over a median time of 5.9 (2.9-8.1) years after the earliest autoantibody detection. Elevated ESR (>20 mm/h), RF positivity (>20 IU/ml), and female gender were identified as independent risk factors for CTD among the anti-SSA antibody-positive individuals. Anti-SSA antibodies were found in 17 among approximately 1000 individuals without a history of autoimmune diseases. Anti-SSA antibody-positive individuals are advised to periodically monitor thyroid function. Elevated ESR (>20 mm/h), female gender, and RF positivity may delineate a high-risk cohort for CTDs.

Issues in autoantibody tests used in the classification criteria for autoimmune rheumatic diseases: the laboratory autoimmunologist's perspective

Classification criteria of autoimmune rheumatic diseases are an important means to define homogenous groups of patients that can be compared across studies for clinical trials and research purposes. The measurement of autoantibodies is a relevant aspect in the definition of classification criteria, with a significant weight in the scores necessary to classify patients with autoimmune rheumatic diseases. The impact of autoantibodies has gradually increased over the years, contributing to the evolution and improvement of the classification criteria. However, these criteria often do not take into consideration how autoantibodies are measured, i.e. differences in diagnostic accuracy of the methods. This is a critical point especially when obsolete analytical methods that are no longer used in many clinical laboratories are taken into consideration. In this review we have critically examined assays and methods for the determination of autoantibodies that are (or could be) included among the classification criteria of autoimmune rheumatic diseases in light of more recent evidence and technology evolution.

Reflecting on a decade of the international consensus on ANA patterns (ICAP): Accomplishments and challenges from the perspective of the 7th ICAP workshop

The International Consensus on ANA Patterns (ICAP) is an ongoing international initiative dedicated to harmonizing technical and interpretation aspects of the HEp-2 IFA test. Comprised of internationally recognized experts in autoimmunity and HEp-2 IFA testing, ICAP has operated for the last 10 years by promoting accurate reading, interpretation, and reporting of HEp-2 IFA images by professionals involved in various areas related to autoimmune diseases, such as clinical diagnostic laboratories, academic research, IVD industry, and patient care. ICAP operates through continuous information exchange with the international community and encourages the participation of younger experts from all over the world. The 7th ICAP workshop has addressed several aspects that originated from this interaction with the international community and has effectively established objective goals and tasks to be delivered over the next two years. Some of these are outlined in this article, including the planning of three audio-visual educational modules to be posted at the www.anapattern.org website, the classification of two novel HEp-2 IFA patterns, the implementation of a project dedicated to continuously updating the information on the clinical and immunologic relevance of the HEp-2 IFA patterns, and the launch of two additional branches of the HEp-2 Clinical and Immunological (HEp-2 CIC) project.

Autoimmune diseases, autoantibody status and silicosis in a cohort of 1238 workers from the artificial stone benchtop industry

OBJECTIVES

Autoimmune disorders are multifactorial but occupational exposures have long been implicated, including respirable crystalline silica (RCS). A modern epidemic of silicosis is emerging internationally, associated with dry processing of engineered stone with high (>90%) RCS content. We aimed to investigate the prevalence of clinical autoimmune disease and common autoantibodies in exposed workers.

METHODS

Stone benchtop industry workers in Victoria, Australia were offered free screening for silicosis and related disorders. Symptoms or diagnoses of autoimmune disease were evaluated by questionnaire and blood tests taken for rheumatoid factor (RF), antinuclear antibodies (ANAs) and extractable nuclear antigens (ENAs).

RESULTS

Among 1238 workers (93.3% male) screened from 2019 to 2021, 0.9% were confirmed with autoimmune disease. Among those without clinical disease, 24.6% had detectable ANAs (93.5% male), 4.6% detectable ENAs and 2.6% were positive for RF. Silicosis was diagnosed in 253 workers (24.3% of those with diagnostic information available). Of those with ANA readings, 54 (6.6%) had ANA titre >1:320. The likelihood of positive autoantibodies increased with age; smoking; higher exposure to RCS and silicosis diagnosis.

CONCLUSION

The proportion of workers with detectable ANAs or ENAs was considerably higher than the 5%-9% expected in the general population. Some of the antibodies detected (eg, Scl-70, CENPB) have high sensitivity and specificity for systemic sclerosis. Long-term follow-up will be needed to estimate incidence. Rheumatologists should explore occupational history in new cases of autoimmune disease. Screening for autoimmune disease is indicated in workers exposed to RCS as these individuals need specialised management and may be entitled to compensation.

Longitudinal antinuclear antibody titers in systemic lupus erythematosus and other rheumatic diseases

Introduction

Antinuclear antibodies (ANAs) are a key feature of systemic lupus erythematosus (SLE) and marker of subclinical autoimmunity. Little is known about longitudinal ANA titers in individuals from the general population or in predicting clinical disease course in persons with rheumatic diseases.

Methods

We performed an exploratory analysis from an academic health system between 1999 and 2020 to assess intra-individual variation in ANAs longitudinally in persons with SLE, other ANA-associated rheumatic diseases, and ANA+ controls without rheumatic disease.

Results

Persons with SLE had a higher odds of positive ANA compared to those with other ANA-associated rheumatic diseases [OR 2.10, 95% CI (1.82, 2.43)] controlling for time and demographics (age, sex, race, ethnicity). Compared to ANA+ controls, the ANA titer strength was significantly higher for both the ANA-associated rheumatic disease (0.33 log units higher) and SLE groups (0.42 log units higher) controlling for demographics and time (p < 0.001 for both). Over time from the first positive ANA, titer strength significantly decreased for all three groups, with average monthly decreases ranging between 0.001 to 0.004 log titer units (p ≤ 0.001 for all).

Conclusion

Based on this analysis of electronic health data spanning two decades, ANA titers may be more dynamic than previously accepted in patients with SLE and ANA-associated rheumatic diseases, with average titers tending to be higher in early disease and decreasing over time.

Screening for autoimmune diseases in apparently healthy antinuclear antibody positive individuals

Background

Anti-nuclear antibodies (ANA) assessed by immunofluorescence (IF) microscopy are associated with systemic autoimmune rheumatic diseases (SARD) and can be detected years before onset of clinical symptoms. Recent data indicate dysregulation of the immune system with increased levels of proinflammatory cytokines, including type I interferons (IFN), in ANA-positive versus ANA-negative individuals. Herein, the aims were to investigate IF-ANA, ANA fine specificities, and IFN-α protein levels in relation to self-reported symptoms, as well as clinical signs, of SARD in a large group of healthy blood donors (HBD).

Methods

Sera from 825 HBD (48.8% females) were included. IF-ANA was assessed, using HEp-2 cells, according to the routine at the accredited laboratory of Clinical Immunology, Linköping University Hospital. All samples were analyzed for IgG-ANA fine specificities using addressable laser bead assay (ALBIA) at the same laboratory. IFN-α was determined using ELISA. Antibody-positive individuals, and their sex- and age-matched antibody-negative controls, were asked to fill a questionnaire regarding symptoms associated with SARD.

Results

In total, 130 HBD (15.8%) were positive with IF-ANA and/or ALBIA. Anti-U1RNP was significantly more common among women. Generally, self-reported symptoms correlated poorly with IF-ANA and/or ALBIA results. Two females with high levels of Ro60/SSA, Ro52/SSA and IFN-α reported mild sicca symptoms and were diagnosed with Sjögren's disease after clinical evaluation.

Conclusion

A considerable proportion of apparently HBD are autoantibody positive, but without clear association to self-reported symptoms. Nevertheless, the combination of autoantibodies, relevant symptoms and high IFN-α levels identified the small proportion of individuals with SARD in the study population.

Autoantibodies inhibit Plasmodium falciparum growth and are associated with protection from clinical malaria

Many infections, including malaria, are associated with an increase in autoantibodies (AAbs). Prior studies have reported an association between genetic markers of susceptibility to autoimmune disease and resistance to malaria, but the underlying mechanisms are unclear. Here, we performed a longitudinal study of children and adults (n = 602) in Mali and found that high levels of plasma AAbs before the malaria season independently predicted a reduced risk of clinical malaria in children during the ensuing malaria season. Baseline AAb seroprevalence increased with age and asymptomatic Plasmodium falciparum infection. We found that AAbs purified from the plasma of protected individuals inhibit the growth of blood-stage parasites and bind P. falciparum proteins that mediate parasite invasion. Protected individuals had higher plasma immunoglobulin G (IgG) reactivity against 33 of the 123 antigens assessed in an autoantigen microarray. This study provides evidence in support of the hypothesis that a propensity toward autoimmunity offers a survival advantage against malaria.

Association between Epstein-Barr virus infection and serum positivity rate of anti-nuclear antibodies in Chongqing, China: A cross-sectional observational study

Epstein-Barr virus (EBV) infects over 95% of the global population and is strongly associated with various autoimmune diseases. Anti-nuclear antibodies (ANA) serve as valuable laboratory biomarkers for screening and supporting the diagnosis of various autoimmune diseases. The aim of this study was to assess the prevalence of EBV infection and its association with ANA. This retrospective study employed standard indirect immunofluorescence assay to determine ANA levels, EBV-specific immunofluorescence assay, or plasma EBV-DNA testing. Demographic data including gender and age were collected to observe variations in EBV infection status and ANA positivity rates among different populations. Incorporating 6492 hospitalized patients who underwent ANA antibody spectrum testing, it was observed that serum positivity rates gradually increased with age. The overall serum positivity rate of ANA in females (25.14%) was significantly higher than that in males (13.76%). Among hospitalized patients undergoing EBV-DNA testing, adults aged 21 to 40 years were least affected by EBV, with a positivity rate of 11.96%; however, as age increased, the positivity rate gradually increased. Among the 5225 patients undergoing EBV antibody spectrum testing, ANA-positive patients exhibited significantly higher serum positivity rates for Epstein-Barr nuclear antigen 1 immunoglobulin G, Epstein-Barr virus early antigen immunoglobulin G, Epstein-Barr virus early antigen immunoglobulin A, and Epstein-Barr virus viral capsid antigen immunoglobulin A antibodies compared to ANA-negative patients (P < .001; P < .001; P = .013; P < .001). The EBV-DNA positivity rate in ANA-positive patients was also significantly higher than in ANA-negative patients, yielding the same conclusion (P = .012). The positivity rates of ANA antibodies in patients with past EBV infection and reactivation were significantly higher than those in uninfected patients (P < .001; P = .006). The positivity rate of ANA antibodies in reactivated patients was significantly higher than that in primary infected patients and those with past infections (P < .001; P < .001). Among ANA-positive patients, the positivity rates of EBV antibody spectrum and EBV-DNA were higher compared to ANA-negative patients. The positivity rates of ANA in patients with past EBV infection and reactivation were higher than those in uninfected patients.

Clinical Significance of Antibodies to DFS70 in Immunoinflammatory Rheumatic Diseases

The relevance of the problem of immunoinflammatory rheumatic diseases (IIRD) for modern medicine is determined by their high prevalence in the population, the difficulty of early diagnosis, the rapid development of disability and poor life prognosis. Recent data on the significance of anti-DFS70 have opened up new possibilities for optimizing the step-by-step diagnosis of IIRD. The detection of these antibodies can help in the interpretation of a positive result for antinuclear antibodies (ANA) by indirect immunofluorescence assay on HEp-2 cells (IIFA-HEp-2) in the absence of autoantibodies specific for IIRD. Detection of anti-DFS70 in antinuclear factor (ANF) seropositive patients without clinical and/or serological markers characteristic of a certain disease from the IIRD group can be considered as a potential marker that excludes this group of diseases.

Evaluation of the Accuracy of Estimated Endpoint Titer of NOVA View in Indirect Immunofluorescent Antinuclear Antibody Testing

For antinuclear antibody (ANA) screening, the gold standard method is an indirect immunofluorescence assay (IIFA) using HEp-2 cells, and a serial dilution test is needed to determine the endpoint titer. We aimed to evaluate the accuracy of the estimated endpoint titer (eEPT) by the NOVA View system, by comparing it with the EPT by the serial dilution method (dEPT). The endpoint titers of a total of 1518 ANA positive cases with five major patterns including speckled, homogeneous, centromere, nucleolar, and nuclear dots patterns were determined using both the estimation function and the serial dilution method by the NOVA View system. A significant correlation between the light intensity unit (LIU) values and dEPTs was identified in all five patterns with high ρ values, ranging from 0.666 to 0.832. However, the overall exact match rate between dEPT and eEPT was 22.1% (336/1518), with the ±one-titer match rate being highest in the centromere pattern (62.8%, 81/129), and lowest in the homogeneous pattern (37.6%, 200/532). This suggests that while LIU values correlate well with dEPT, there are discrepancies in numerical agreement. Most cases that did not show an exact match, showed one-to-three-titer overestimations by eEPT. Therefore, adjusting eEPT downward significantly improved the concordance rates with dEPTs. Further investigation for an appropriate cutoff of LIU values for determining eEPT should be performed for clinical application and contribution to the standardization of the ANA titer.

Assessing serum anti-nuclear antibodies HEp-2 patterns in synucleinopathies

This study investigates the presence of antinuclear antibodies (ANA) in three primary synucleinopathies - Parkinson's disease (PD), multiple system atrophy (MSA), and dementia with Lewy bodies (DLB), compared to healthy controls. Autoinflammatory disorders typically involve the immune system mistakenly attacking the body's own cells and start producing ANA. There is an increasing body of evidence that immune-mediated inflammation is a pathological feature linked to synucleinopathies. To investigate whether this could be autoimmune mediated we analyzed for ANA in the plasma of 25 MSA, 25 PD, and 17 DLB patients, along with 25 healthy controls, using the ANA HEp-2 indirect immunofluorescence antibody assay (ANA HEp-2 IFA). Contrary to initial expectations, results showed ANA HEp-2 positivity in 12% of PD, 8% of MSA patients, 18% of DLB patients, and 17% of healthy controls, indicating no increased prevalence of ANA in synucleinopathies compared to age-matched healthy individuals. Various ANA HEp-2 patterns were identified, but no specific pattern was associated with individual synucleinopathies. We conclude hereby that synucleinopathies are not associated with detectable presence of ANA in plasma.

Harmonization of ANA testing challenge: quantification strategy to accurately predict end-point titers avoiding serial dilution

Despite the advantages of automated systems for antinuclear antibody (ANA) analysis, the prediction of end-point titers avoiding serial dilutions is still in progress. The aims of this study were to set a conversion table providing discriminant ranges of fluorescence signal intensity values (FI) corresponding to the end-point titers and validate this tool in a real-life laboratory setting. Eight hundred ninety-four serum samples were analyzed for ANA using Image Navigator System. In order to classify FI into non-overlapping groups corresponding to conventional end-point titers, statistical discriminant analysis was used. Validation study was performed calculating agreement and error rates between visual readings and conversion table of 1119 routine ANA positive samples. Setting of FI ranges corresponding to the end-point titers for different staining patterns was computed. For samples showing single pattern, the overall agreement between visual readings and conversion table was 98.4% for all titers ranging from 1:160 to 1:2560, of which 68.0% had the same titer and 30.4% were within ± one titer difference. Concordance rates according to ANA patterns were as follows: (1) nuclear 98.4%, of which 67.0% had the same titer and 31.4% ± one titer; (2) cytoplasmic 100%, of which 72.7% had the same titer and 27.3% than ± one titer; (3) mitotic 66.6%, of which 33.3% had more ± one titer. Our study developed a quantification method for autoantibodies titers assessment based on just one single sample dilution instead of traditional serial dilution approach, providing significant advantages in routine laboratory in terms of reduction in hand-on time and harmonization of results.

Novel multiclass classification machine learning approach for the early-stage classification of systemic autoimmune rheumatic diseases

OBJECTIVE

Systemic autoimmune rheumatic diseases (SARDs) encompass a diverse group of complex conditions with overlapping clinical features, making accurate diagnosis challenging. This study aims to develop a multiclass machine learning (ML) model for early-stage SARDs classification using accessible laboratory indicators.

METHODS

A total of 925 SARDs patients were included, categorised into SLE, Sjögren's syndrome (SS) and inflammatory myositis (IM). Clinical characteristics and laboratory markers were collected and nine key indicators, including anti-dsDNA, anti-SS-A60, anti-Sm/nRNP, antichromatin, anti-dsDNA (indirect immunofluorescence assay), haemoglobin (Hb), platelet, neutrophil percentage and cytoplasmic patterns (AC-19, AC-20), were selected for model building. Various ML algorithms were used to construct a tripartite classification ML model.

RESULTS

Patients were divided into two cohorts, cohort 1 was used to construct a tripartite classification model. Among models assessed, the random forest (RF) model demonstrated superior performance in distinguishing SLE, IM and SS (with area under curve=0.953, 0.903 and 0.836; accuracy= 0.892, 0.869 and 0.857; sensitivity= 0.890, 0.868 and 0.795; specificity= 0.910, 0.836 and 0.748; positive predictive value=0.922, 0.727 and 0.663; and negative predictive value= 0.854, 0.915 and 0.879). The RF model excelled in classifying SLE (precision=0.930, recall=0.985, F1 score=0.957). For IM and SS, RF model outcomes were (precision=0.793, 0.950; recall=0.920, 0.679; F1 score=0.852, 0.792). Cohort 2 served as an external validation set, achieving an overall accuracy of 87.3%. Individual classification performances for SLE, SS and IM were excellent, with precision, recall and F1 scores specified. SHAP analysis highlighted significant contributions from antibody profiles.

CONCLUSION

This pioneering multiclass ML model, using basic laboratory indicators, enhances clinical feasibility and demonstrates promising potential for SARDs classification. The collaboration of clinical expertise and ML offers a nuanced approach to SARDs classification, with potential for enhanced patient care.

Association of urine autoantibodies with disease activity in systemic lupus erythematosus

Objective

The presence of urinary autoantibodies in patients with systemic lupus erythematosus (SLE) has been confirmed by several studies; however, the significance of their presence in urine remains unclear. This study aims to further investigate the association between urine autoantibodies and disease activity as well as organ involvement in SLE.

Methods

This cross-sectional study included 89 SLE patients. Data collected included anti-nuclear antibody (ANA), anti-ENA antibodies, and anti-dsDNA antibody levels in both serum and urine, complement (C) 3, C4 levels in serum, SLE disease activity index-2000 (SLEDAI-2000), renal domains of SLEDAI (RSLEDAI) and non-renal SLEDAI (NRSLEDAI).

Results

The rate of positive urine ANA (uANA) was 33.3% (29/87) among the enrolled patients. Compared to the uANA negative group, the positive group exhibited significantly higher SLEDAI-2000 scores (7.85 ± 5.88 vs. 18.69 ± 6.93, p < 0.001), RSLEDAI scores [0 (0, 4.0) vs. 12.0 (8.0, 16.0), p < 0.001], and NRSLEDAI [4 (2.0, 8.0) vs. 6.0 (4.0, 9.5), p = 0.038]. Patients with positive urine anti-Sm antibody demonstrated significantly elevated SLEDAI-2000 scores compared to those who were negative (25.0 ± 8.80 vs. 10.09 ± 6.63, p < 0.001). Similarly, they also had higher RSLEDAI [16.0 (12.0, 16.0) vs. 4.0 (0, 8.0), p < 0.001] and NRSLEDAI [9.5 (6.0, 13.5) vs. 4.0 (3.0, 8.0), p = 0.012], as well as a greater prevalence of renal involvement compared to their negative counterparts (100% vs. 58.2, p = 0.022). There was a positive correlation between uANA titer and both SLEDAI-2000 (rs = 0.663, p < 0.001) and RSLEDAI (rs = 0.662, p < 0.001). The serum anti-dsDNA antibody level did not exhibit a significant correlation with RSLEDAI (rs = 0.143, p = 0.182). Conversely, the urine anti-dsDNA antibody level demonstrated a significant positive correlation with RSLEDAI (rs = 0.529, p < 0.001).

Conclusion

Urine ANA is associated with both global SLEDAI and RSLEDAI scores. Urine anti-Sm antibody is associated with an increased incidence of renal involvement in SLE. The urine anti-dsDNA antibody level, rather than the serum anti-dsDNA antibody level, exhibits a significant association with RSLEDAI in SLE.

Exploring cardiovascular implications in systemic lupus erythematosus: A holistic analysis of complications, diagnostic criteria, and therapeutic modalities, encompassing pharmacological and adjuvant approaches

Systemic lupus erythematosus (SLE) poses a diagnostic challenge due to its heterogeneity. This study examines the cardiac complications of SLE comprehensively, covering pericarditis, myocarditis, pleural effusion, valvular disease, atherosclerosis, and cardiac arrhythmias. Nearly one-third of SLE-related deaths are attributed to cardiovascular diseases, necessitating a deeper understanding of cardiac pathophysiology. The impact of SLE on the cardiovascular system manifests in various ways, including recurrent and resistant pericarditis, severe myocarditis, and pleural effusion. Valvular diseases, atherosclerosis, and cardiac arrhythmias are prevalent, with immune complex deposition playing a role in atherosclerosis. Diagnostic criteria involve clinical features, laboratory findings, and autoantibodies, emphasizing the need for early diagnosis and a multidisciplinary diagnostic approach. The review explores pharmacological and non-pharmacological modalities for managing cardiac manifestations in SLE. Recommendations include NSAIDs, colchicine, and proton pump inhibitors for acute pericarditis, while selective immunosuppressive therapy is emerging for myocarditis. Valvular diseases require individualized treatment approaches, and careful corticosteroid management is crucial to avoid increased cardiovascular events. Anti-malarial therapy, particularly hydroxychloroquine, shows promise in mitigating cardiovascular risk factors. Non-pharmacological modifications, such as diet, exercise, and smoke cessation, significantly contribute to cardiovascular health in SLE patients. Adjuvant therapies involving glutathione and glutathione peroxidase focus on redox balance, offering potential interventions. This integrated approach combines diagnostic insights with diverse treatment modalities, providing a holistic strategy for managing cardiac complications in SLE. Ongoing research is essential to refine these strategies and optimize individualized treatment plans for improved patient outcomes.

Recommendations for the use of anti-dsDNA autoantibodies in the diagnosis and follow-up of systemic lupus erythematosus - A proposal from an expert panel

Anti-dsDNA autoantibodies are listed as one of the classification criteria for systemic lupus erythematosus (SLE) and are relatively effective indicators for monitoring disease activity and treatment response. Therefore, clinicians rely on them to diagnose and adjust medication and treatment strategies for SLE patients. However, the use of anti-dsDNA antibodies is not free from controversy. Part of this controversy stems from the fact that anti-dsDNA antibodies are found in several disorders, besides SLE. In addition to this, anti-dsDNA antibodies are a heterogeneous group of antibodies, and their determination still lacks proper standardization. Moreover, anti-dsDNA testing specificity and diagnostic performance change depending on the population under study. These and other issues result in inconsistency and encumber the clinical use of anti-dsDNA antibodies. A panel of medical laboratory and clinical experts on SLE discussed such issues based on their clinical experience in a first meeting, establishing a series of recommendations. The proceedings of this first meeting, plus an exhaustive review of the literature, were used to compose a paper draft. The panel subsequently discussed and refined this draft in a second meeting, the result of which is this paper. This document is relevant to clinical laboratories as it guides to improving diagnosis and monitoring of SLE. Simultaneously, it will help laboratories compile more informative reports, not limited to a mere number. It is also relevant to clinical doctors who wish to better understand laboratory methods so that they can do a more efficient, better-aimed laboratory test ordering.

Screening for latent infectious disease in patients with alopecia areata before initiating JAK inhibitors therapy: a single-center real-world retrospective study

Introduction

Although there is growing evidence supporting the effectiveness of Janus kinase (JAK) inhibitors in treating alopecia areata, the high rate of recurrence following drug discontinuation has led to prolonged treatment courses and raised concerns about long-term safety. In clinical practice, caution should be exercised while using JAK inhibitors for various indications, and a comprehensive pre-treatment screening.

Methods

This study presents an analysis of screening data collected from real-world settings before the initiation of Janus kinase inhibitors in patients with alopecia areata. Investigators collected retrospective medical data characterizing patients' screening data. Data on demographic and clinical data, including age, sex, disease duration, severity of alopecia tool scale, history of prior treatment, and treatment regimen were recorded.

Results

In this cohort (N = 218), JAK inhibitors were initiated for 163 of 218 (74.8%) alopecia areata patients. The numbers of patients positive for antinuclear antibodies, hepatitis B surface antigen, hepatitis C virus antibodies, human immunodeficiency virus antibody, treponema pallidum hemagglutination assay, and thyroid-stimulating hormone were 32 (32/176), 10(10/218), 0 (0/218), 0 (0/218), 3 (3/218) and 9 (9/176), respectively. The number of patients with T-cell spot positive or imaging of the chest indicating tuberculosis was 37 (37/218).

Disccusion

Our data provide additional information on the safety profile of JAK inhibitors in patients with alopecia areata. As such, it is necessary and crucial to screen for JAK inhibitors before it is used, particularly for individuals with a high risk of tuberculosis, hepatitis B, and other infections.

Clinical significance of antinuclear antibodies in primary immune thrombocytopenia

There are discrepancies across guidelines about whether the dosage of antinuclear antibodies (ANAs) is of use at the diagnosis of primary immune thrombocytopenia (ITP). This review describes the current knowledge about ANA prevalence in patients with primary ITP, and their potential usefulness as biomarkers for ITP evolution, response to treatments and increased risk of subsequent development of systemic lupus and thrombosis.

Laboratory and clinical practices in antinuclear antibody detection and related antigens: recommendations from a Spanish multicentre survey

Antinuclear antibodies (ANA) are the most widely used immunological test for the diagnosis of autoimmune diseases. Despite the recommendations of experts, there is some variability in performing and interpreting this test in routine practice. In this context, the Spanish Group on Autoimmune Diseases (GEAI) of the Spanish Society of Immunology (SEI) conducted a national survey of 50 autoimmunity laboratories. Here we report the survey results on ANA testing, detection of related antigens, and our recommendations. The survey showed that most of the participating laboratories use a similar approach for most key practices: 84% perform ANA by indirect immunofluorescence (IIF) on HEp-2 cells as the screening methodology while the other laboratories use IIF to confirm positive screens; 90% report ANA test results as either negative or positive with titer and pattern; 86% indicated that the ANA pattern conditioned follow-up testing for specific antigen-related antibodies; and 70% confirm positive anti-dsDNA. However, testing practices were highly heterogeneous for certain items, such as sera dilutions and the minimum time period for repeating ANA and related antigen determinations. Overall, this survey shows that most autoimmune laboratories in Spain use a similar approach but that further standardization of testing and reporting protocols is needed.

Autoantibodies in COVID-19, a possible role in the pathogenesis of the disease

OBJECTIVES

In this study, we investigated whether SARS-CoV-2 stimulates autoantibody production.

METHODS

The study included 91 patients hospitalized due to COVID 19, with no previous history of immunological diseases. Immunofluorescence assays were performed to detect antinuclear antibodies (ANAs) and antineutrophil cytoplasmic antibodies (ANCAs), along with tests for specific autoantibodies.

RESULTS

The median age (57% male) was 74 years (range 38-95 years). Autoantibodies were positive in 67 (74%), ANA in 65 (71%), and ANCA in 11 (12%) patients. Female gender (p = 0.01), age (p = 0.005), and Charlson comorbidity index (p = 0.004) were significant predictors for the development of ANA/ANCA antibodies (p = 0.004). Nuclear mitotic apparatus (NuMA)-like, positivity was the strongest predictor of acute kidney injury (AKI), together with noninvasive ventilation and eGFR (χ2  = 49.01, P < 0.001).

CONCLUSION

Positive autoantibodies in a large proportion of patients suggest a role of autoimmunity in the pathophysiology of acute COVID-19 disease. NuMA was the strongest predictor of AKI.

Differences in the Clinical Significance of Antinuclear Antibodies According to Titers and Patterns in Children

This study aimed to evaluate the differences in the clinical significance of antinuclear antibody (ANA) according to their titers and patterns in the diagnosis of systemic autoimmune diseases (AiD) in pediatric patients. Of the 2442 children who had undergone an ANA test, 473 (19.4%) were positive for ANA, of whom 33 (7.0%) were diagnosed with significant AiD. The positive predictive value (PPV) for significant AiD was considerably high on application of an ANA titer of ≥1:640, and the PPV of a dense fine speckled (DFS) pattern was significantly lower compared with those of speckled and homogenous patterns. The diagnostic value of ANA positivity for AiD is limited, and the clinical significance of the DFS pattern is relatively lower compared with that of other patterns, such as homogenous and speckled patterns, in children. It is necessary to approach the significance of ANA in children individually depending on titers and patterns.

Diagnostic Work-Up in Patients with Nonbacterial Thrombotic Endocarditis

Nonbacterial thrombotic endocarditis (NBTE) is a form of endocarditis that occurs in patients with predisposing conditions, including malignancies, autoimmune diseases (particularly antiphospholipid antibody syndrome, which accounts for the majority of lupus-associated cases), and coagulation disturbances for which the correlation with classical determinants is unclear. The condition is commonly referred to as "marantic", "verrucous", or Libman-Sacks endocarditis, although these are not synonymous, representing clinical-pathological nuances. The clinical presentation of NBTE involves embolic events, while local valvular complications, generally regurgitation, are typically less frequent and milder compared to infective forms of endocarditis. In the past, the diagnosis of NBTE relied on post mortem examinations, while at present, the diagnosis is primarily based on echocardiography, with the priority of excluding infective endocarditis through comprehensive microbiological and serological tests. As in other forms of endocarditis, besides pathology, transesophageal echocardiography remains the diagnostic standard, while other imaging techniques hold promise as adjunctive tools for early diagnosis and differentiation from infective vegetations. These include cardiac MRI and 18FDG-PET/CT, which already represents a major diagnostic criterion of infective endocarditis in specific settings. We will herein provide a comprehensive review of the current knowledge on the clinics and therapeutics of NBTE, with a specific focus on the diagnostic tools.

Charting the Next Road Map for CSF Biomarkers in Alzheimer's Disease and Related Dementias

Clinical prediction of underlying pathologic substrates in people with Alzheimer's disease (AD) dementia or related dementia syndromes (ADRD) has limited accuracy. Etiologic biomarkers - including cerebrospinal fluid (CSF) levels of AD proteins and cerebral amyloid PET imaging - have greatly modernized disease-modifying clinical trials in AD, but their integration into medical practice has been slow. Beyond core CSF AD biomarkers (including beta-amyloid 1-42, total tau, and tau phosphorylated at threonine 181), novel biomarkers have been interrogated in single- and multi-centered studies with uneven rigor. Here, we review early expectations for ideal AD/ADRD biomarkers, assess these goals' future applicability, and propose study designs and performance thresholds for meeting these ideals with a focus on CSF biomarkers. We further propose three new characteristics: equity (oversampling of diverse populations in the design and testing of biomarkers), access (reasonable availability to 80% of people at risk for disease, along with pre- and post-biomarker processes), and reliability (thorough evaluation of pre-analytical and analytical factors influencing measurements and performance). Finally, we urge biomarker scientists to balance the desire and evidence for a biomarker to reflect its namesake function, indulge data- as well as theory-driven associations, re-visit the subset of rigorously measured CSF biomarkers in large datasets (such as Alzheimer's disease neuroimaging initiative), and resist the temptation to favor ease over fail-safe in the development phase. This shift from discovery to application, and from suspended disbelief to cogent ingenuity, should allow the AD/ADRD biomarker field to live up to its billing during the next phase of neurodegenerative disease research.

Detection of antinuclear antibodies: recommendations from EFLM, EASI and ICAP

OBJECTIVES

Antinuclear antibodies (ANA) are important for the diagnosis of various autoimmune diseases. ANA are usually detected by indirect immunofluorescence assay (IFA) using HEp-2 cells (HEp-2 IFA). There are many variables influencing HEp-2 IFA results, such as subjective visual reading, serum screening dilution, substrate manufacturing, microscope components and conjugate. Newer developments on ANA testing that offer novel features adopted by some clinical laboratories include automated computer-assisted diagnosis (CAD) systems and solid phase assays (SPA).

METHODS

A group of experts reviewed current literature and established recommendations on methodological aspects of ANA testing. This process was supported by a two round Delphi exercise. International expert groups that participated in this initiative included (i) the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) Working Group "Autoimmunity Testing"; (ii) the European Autoimmune Standardization Initiative (EASI); and (iii) the International Consensus on ANA Patterns (ICAP).

RESULTS

In total, 35 recommendations/statements related to (i) ANA testing and reporting by HEp-2 IFA; (ii) HEp-2 IFA methodological aspects including substrate/conjugate selection and the application of CAD systems; (iii) quality assurance; (iv) HEp-2 IFA validation/verification approaches and (v) SPA were formulated. Globally, 95% of all submitted scores in the final Delphi round were above 6 (moderately agree, agree or strongly agree) and 85% above 7 (agree and strongly agree), indicating strong international support for the proposed recommendations.

CONCLUSIONS

These recommendations are an important step to achieve high quality ANA testing.

Laboratory risk factors for coexistent primary biliary cholangitis in patients with Sjögren's syndrome: a retrospective study

BACKGROUND

Limited research exists on the laboratory characteristics of coexistent primary biliary cholangitis (PBC) and Sjögren's syndrome (SS). This study aimed to investigate the laboratory risk factors for the coexistence of PBC in patients with SS.

METHODS

Eighty-two patients with coexistent SS and PBC (median age 52.50 years) and 82 age- and sex-matched SS controls were retrospectively enrolled between July 2015 and July 2021. The clinical and laboratory characteristics of the two groups were compared. Laboratory risk factors for the coexistence of PBC in patients with SS were analyzed using logistic regression analysis.

RESULTS

Both groups had a similar prevalence of hypertension, diabetes, thyroid disease, and interstitial lung disease. Compared with the SS group, patients in the SS + PBC group had higher levels of liver enzymes, immunoglobulins M (IgM), G2, and G3 (P < 0.05). The percentage of patients with an antinuclear antibody (ANA) titre > 1:10000 in the SS + PBC group was 56.1%, higher than that in the SS group (19.5%, P < 0.05). Additionally, cytoplasmic, centromeric, and nuclear membranous patterns of ANA and positive anti-centromere antibody (ACA) were observed more frequently in the SS + PBC group (P < 0.05). Logistic regression analysis showed that elevated IgM levels, high ANA titre, cytoplasmic pattern, and ACA were independent risk factors for PBC coexistence in SS.

CONCLUSIONS

In addition to established risk factors, elevated IgM levels, positive ACA, and high ANA titre with cytoplasmic pattern provide clues to clinicians for the early screening and diagnosis of PBC in patients with SS.

Prevalence of antinuclear antibodies among healthy blood donors: An experience of a regional blood transfusion center

Objectives:

Antinuclear antibodies (ANAs) are antibodies directed against one or more molecules within the nucleus. Although ANA is present in patients suffering from connective tissue diseases, few reports reveal the presence of ANA in a healthy population. The present study aimed to identify the prevalence of ANA in healthy blood donors.

Materials and Method:

Blood samples from 370 healthy blood donors were included in the present study. To detect serum ANA, an indirect immunofluorescence technique was used using HEp-2000 slides. A titer of 1:80 was used and the type of pattern (if positive) cases were also noticed.

Results:

Out of 370 healthy donors, there were 187 males and 183 females (M: F = 1.02:1). ANA was detected in four out of 370 samples (1.081%). All the positive donors were female (100%). Among all the positive cases, three cases showed a speckled pattern and one showed a homogenous pattern at 1:80 dilution.

Conclusion:

In conclusion, there is a low prevalence of ANA positivity among healthy individuals. Although, along with clinical signs and symptoms, ANA is diagnostic of autoimmune disease, the mere presence of ANA is not synonymous with the presence of clinically significant autoimmune disease.

Serum levels of soluble urokinase plasminogen activator receptor in juvenile idiopathic arthritis: a single-center Swedish case-control study

OBJECTIVES

Reliable biomarkers in the early stages of idiopathic arthritis (JIA) are scarce and the disease heterogeneity makes it clinically challenging to predict the risk of joint damage. Biomarkers with prognostic potential are warranted in order to individualize treatment and follow-up in JIA. The soluble urokinase plasminogen activator receptor (suPAR) has been reported as an easily measurable biomarker for prognosis and severity in several rheumatic diseases but it has never been studied in JIA.

METHODS

Sera from 51 well-characterized patients with JIA and 50 age- and sex-matched control subjects were collected and stored for later analysis of suPAR. Patients were carefully followed clinically over 3 years and analysis of erythrocyte sedimentation rate, C-reactive protein, rheumatoid factor (RF) and antibodies against cyclic citrullinated peptides (anti-CCP) were analyzed as part of clinical routine. Signs of joint erosions were evaluated by radiography.

RESULTS

Overall, the levels of suPAR did not differ significantly between JIA patients and controls but those with polyarticular involvement showed higher suPAR (p = 0.013). In addition, elevated suPAR were associated with joint erosions (p = 0.026). Two RF/anti-CCP negative individuals with erosions showed high levels of suPAR.

CONCLUSIONS

We present new data on the biomarker suPAR in JIA. Our results indicate that, apart from RF and anti-CCP, analysis of suPAR could be of additional value in assessing the risk of erosions. Analysis of suPAR early could potentially guide treatment decision-making in JIA, but our observations should be confirmed in prospective studies.