Specific Antinuclear Antibodies Research Articles

Antinuclear Antibodies in Non-Rheumatic Diseases

Abstract Antinuclear antibodies (ANAs) are critical immunological markers commonly associated with various connective tissue diseases (CTDs). However, these autoantibodies are also detectable in healthy individuals, patients with non-rheumatic autoimmune diseases, those with viral infections, and subjects using specific medications (such as procainamide, hydralazine, and minocycline) that can lead to drug-induced ANA elevation. The standard method for ANA detection is indirect immunofluorescence, a process that requires precision and thoroughness as it assesses both titer and fluorescence patterns. Additionally, immunoblotting and enzyme-linked immunosorbent assay (ELISA) are recommended to identify specific ANAs precisely, highlighting the importance of precision in ANA detection. This review explores the advantages and limitations of current ANA detection methods. It also describes the clinical implications of ANA presence in non-rheumatic diseases, including autoimmune disorders, infectious conditions, non-autoimmune and non-infectious diseases, and autoimmune cutaneous diseases. The presence of elevated ANA titers in these contexts can complicate clinical decision-making, as the diagnostic value of ANA testing alone is limited in non-rheumatic conditions. However, despite these limitations, ANA remains a key component in diagnosing and prognosis systemic CTDs, as it can indicate disease activity, severity, and response to treatment, which is of utmost importance in rheumatology and internal medicine. This paper provides a comprehensive review of the role of ANA in non-rheumatic diseases. It focuses on ANA diagnostic and prognostic significance and offers valuable insights for clinical practice.

Bicaudal D2 autoantibodies are highly specific for systemic sclerosis

Objective Autoantibodies directed against the intracellular protein bicaudal D2 (BICD2) have been identified as a specific marker of systemic sclerosis (SSc). Since autoantibodies are of value in predicting disease onset and identifying meaningful clinical subsets, as well as having prognostic value, this study aimed to establish the prevalence of BICD2 autoantibodies (anti-BICD2) in a cohort of patients with connective tissue disease and healthy controls. Method In this cross-sectional study, 363 patients with connective tissue disease (121 SSc, 141 systemic lupus erythematosus, 101 myositis, and 100 blood donors) were tested for the presence of anti-BICD2. All SSc patients were tested for specific anti-nuclear antibodies (ANAs), and clinical and laboratory associations were evaluated in the SSc patients, stratified by anti-BICD2 status. Results In the SSc cohort, 35 patients had autoantibodies directed against BICD2. The specificity of anti-BICD2 in SSc patients was 96.5%; however, the sensitivity was only 28.9%. Anti-BICD2 and centromere autoantibodies were present together in 91% of the anti-BICD2-positive SSc patients, and in none of the cases was anti-BICD2 the only antibody present. Anti-BICD2-positive patients had lower forced expiratory volume in 1 s (FEV1) (p = 0.01) and lower carbon monoxide transfer coefficient (KCO) (p = 0.01) than anti-BICD2-negative SSc patients, but they had higher forced vital capacity (p = 0.03). Conclusion Autoantibodies against BICD2 were highly specific for SSc patients. Reduced FEV1 and KCO in anti-BICD2-positive patients may indicate that the presence of anti-BICD2 is associated with altered lung function in an unknown pathophysiological manner, which awaits further elucidation.

Low CD4 + T cell count is related to specific anti-nuclear antibodies, IFNα protein positivity and disease activity in systemic lupus erythematosus pregnancy

BackgroundLymphopenia, autoantibodies and activation of the type I interferon (IFN) system are common features in systemic lupus erythematosus (SLE). We speculate whether lymphocyte subset counts are affected by pregnancy and if they relate to autoantibody profiles and/or IFNα protein in SLE pregnancy.MethodsRepeated blood samples were collected during pregnancy from 80 women with SLE and 51 healthy controls (HC). Late postpartum samples were obtained from 19 of the women with SLE. Counts of CD4 + and CD8 + T cells, B cells and NK cells were measured by flow cytometry. Positivity for anti-nuclear antibodies (ANA) fine specificities (double-stranded DNA [dsDNA], Smith [Sm], ribonucleoprotein [RNP], chromatin, Sjögren’s syndrome antigen A [SSA] and B [SSB]) and anti-phospholipid antibodies (cardiolipin [CL] and β2 glycoprotein I [β2GPI]) was assessed with multiplexed bead assay. IFNα protein concentration was quantified with Single molecule array (Simoa) immune assay. Clinical data were retrieved from medical records.ResultsWomen with SLE had lower counts of all lymphocyte subsets compared to HC throughout pregnancy, but counts did not differ during pregnancy compared to postpartum. Principal component analysis revealed that low lymphocyte subset counts differentially related to autoantibody profiles, cluster one (anti-dsDNA/anti-Sm/anti-RNP/anti-Sm/RNP/anti-chromatin), cluster two (anti-SSA/anti-SSB) and cluster three (anti-CL/anti-β2GPI), IFNα protein levels and disease activity. CD4 + T cell counts were lower in women positive to all ANA fine specificities in cluster one compared to those who were negative, and B cell numbers were lower in women positive for anti-dsDNA and anti-Sm compared to negative women. Moreover, CD4 + T cell and B cell counts were lower in women with moderate/high compared to no/low disease activity, and CD4 + T cell count was lower in IFNα protein positive relative to negative women. Finally, CD4 + T cell count was unrelated to treatment.ConclusionLymphocyte subset counts are lower in SLE compared to healthy pregnancies, which seems to be a feature of the disease per se and not affected by pregnancy. Our results also indicate that low lymphocyte subset counts relate differentially to autoantibody profiles, IFNα protein levels and disease activity, which could be due to divergent disease pathways.

Fully automated chemiluminescence microarray immunoassay for detection of antinuclear antibodies in systemic autoimmune rheumatic diseases

Abstract Objectives Detection of specific antinuclear antibodies is very important in term of diagnosis, prognosis and management of patients with systemic autoimmune rheumatic diseases. Chemiluminescence microarray immunoassay (CLMIA) is a microdot array-based method that allows simultaneous detection of multiple antinuclear antibodies, which received increasing attention. Methods A CLMIA method that can detect 14 kinds of antinuclear antibodies was established and optimized. Basic performance and diagnostic performance of CLMIA was evaluated by comparing it with line immunoassay (LIA) and indirect immunofluorescence (IIF). Results Through conditional exploration, the optimal blocking time and blocking temperature were determined to be 18 h and 25 °C, respectively. The enzyme-labeled secondary antibody reaction concentration was 0.1 μg/mL, the incubation temperature of serum and enzyme-labeled secondary antibody were 30 °C, and the incubation time of serum and enzyme-labeled secondary antibody were 40 min. After parameter optimization, CLMIA demonstrated high accuracy with a relative bias <15 %; high sensitivity with detection limits below 3 IU/mL for dsDNA and below 1 RU/mL for other ANAs; and high reproducibility with both intra-assay and inter-assay coefficients of variation (CV) <15 %.The CLMIA detection method established in this study was also demonstrated to have good clinical diagnostic performance, showing the highest area under curve (AUC=0.87, p=0.042 and p=0.03). The CLMIA and LIA revealed substantial to good agreements on specific antinuclear antibodies except anti-dsDNA, with the Cohen’s kappa from 0.72 to 0.89. Samples that produced discrepant results between the CLMIA and LIA methods were further analyzed. Upon additional testing, most of these samples were ultimately determined to have been correctly detected by the CLMIA assay rather than the LIA assay, suggesting that CLMIA also shows some superiority in diagnosing dsDNA. Conclusions The CLMIA could become a potential routine method for detecting ANAs with the advantages of good detection performance.

Retrospective analysis of the clinical significance of Ro52/TRIM21 antibody and specific antinuclear antibody patterns by indirect immunofluorescence.

To determine the clinical significance of Ro52 protein/tripartite motif-containing 21 antibody and specific antinuclear antibody patterns using indirect immunofluorescence technique. The retrospective study was conducted at the clinical laboratory of the First Affiliated Hospital of Chongqing Medical University, China, and comprised data from January 2017 to December 2021 of patients who underwent antinuclear antibody and anti-extractable nuclear antigen antibody detection. Inpatients with Ro52 antibody-positive status were taken as the cases, while anti-Ro52 negative patients with clear clinical diagnosis were taken as the controls. Data was analysed using SPSS 19. There were 1802 cases and 1211 controls. Positive Ro52 showed significantly greater frequency in patients with primary Sjogren's syndrome, systemic lupus erythematosus, inflammatory myositis, dry eyes and interstitial lung disease (p<0.05). Ro52 antibody showed high positive predictive value for primary Sjogren's syndrome 25(96.15%), systemic lupus erythematosus 259(91.20%), connective tissue disease-associated interstitial lung disease 45(86.67%) and inflammatory myositis 60(86.67%). Antinuclear antibody indirect immunofluorescence patterns most frequently detected were nuclear speckled 128(40.89%) and cytoplasmic speckled 126(40.26%) (p<0.05). Interstitial lung disease was associated with the presence of cytoplasmic speckled antinuclear antibody indirect immunofluorescence pattern 24(19.2%), while tumours 47(36.5%) and hepatitis B 26(20.3%) seemed to be more frequent with nuclear speckled pattern (p<0.05). The simultaneous reactivity extractable nuclear antigen antibodies most frequently detected were antinuclear antibody+Ro52+anti-Sjogren's syndrome A+ 558(33.96%). Ro52 antibody positivity was found to be associated with Sjogren's syndrome, systemic lupus erythematosus, inflammatory myositis, dry eye and interstitial lung disease. The antinuclear antibody immunofluorescence pattern of Ro52 positive was single and primarily granular cytoplasm type. Antinuclear antibody negative and Ro52 positive in the serum of patients also had certain significance in auxiliary disease diagnosis.

The Diagnostic Value of ANA and Anti-SMA in Suspected Patients with Autoimmune Hepatitis

BACKGROUND: Autoimmune hepatitis (AIH) is an unknown chronic disease characterized by hepatocellular inflammation with a tendency to progress to cirrhosis. AIH can present with symptoms of acute hepatitis with symptoms of chronic liver disease. AIH occurs globally; it is more commonly found in females. Autoantibodies such as antinuclear, smooth muscle, liver kidney microsome, and soluble liver antigen are used to aid in the diagnosis of AIH, which presents with a variety of symptoms that also contribute to the classification of AIH. AIM: Evaluation of anti-nuclear antibodies (ANA) and anti-smooth muscle antibodies (SMA) positivity in hepatic diseases, gastrointestinal diseases, viral hepatitis, and extra-hepatic diseases, providing better markers for the early diagnosis of AIH-type 1. MATERIALS AND METHODS: The study included 207 individuals. 62.4% of them were female. Regarding the diagnoses, we grouped them into 4 groups: hepatic diseases (n = 73), viral hepatitis B and C (n = 54), gastrointestinal diseases (n = 34), and extra-hepatic diseases (n = 46). Serum levels of ANA and anti-SMA were measured using an indirect immunofluorescence method following the manufacturer’s instructions (Aesku Diagnostics, Germany). Fluorescence intensity was interpreted semi-quantitatively based on negative control (0) and positive control (+4). RESULTS: The positivity of ANA and anti-SMA resulted as follows: In hepatic diseases 34.2% and 48%, in viral hepatitis B and C, ANA positivity was 14.8% and SMA positivity was 22.2%; in gastrointestinal diseases, ANA and SMA positivity were, respectively, 11.8% and 20.6%; and in extrahepatic diseases, positivity of ANA resulted in 32.6% and SMA in 26%. When compared to the viral hepatitis patient group, the ANA specificity for hemagglutination inhibition (HAI) was 85.2% and that of anti-SMA was 77.8%. The analysis of 46 extrahepatic patient groups provided an ANA specificity of 67.4% and an anti-SMA specificity of 74% for HAI. The comparison to gastrointestinal disease showed that ANA specificity for HAI was 88.2% and anti-SMA specificity was 79.4%. CONCLUSION: Diagnosing AIH is difficult because the clinical spectrum ranges from an asymptomatic presentation to an acute and severe disease. So in all cases, AIH must be suspected. Both males and females can develop AIH, but the disease is more common in females. Based on our diagnostic parameters, we can say that ANA and anti-SMA provide moderate sensitivity for AIH, but they are more specific to AIH type 1.

Diagnostic Validation of Fully Automated ANA Detection by Indirect Immunofluorescence: An Initiative towards Standardization

Objective: This study entailed the diagnostic validation of an automated system utilized for the detection of antinuclear antibodies (ANA) through the indirect immunofluorescence method, juxtaposed with the traditional manual approach for ANA detection. The study was undertaken in the Department of Chemical Pathology at Chughtai Laboratory, Lahore, spanning a period of three months, from December 2018 to February 2019. Methods: A total of 132 patient samples were gathered for the purpose of conducting this validation study. The manual detection of ANA was performed by using slides coated with HEp-2 cells. An LED fluorescence microscope was used for the interpretation of results by a trained technologist as well as by a pathologist. After manual detection of ANA, the same specimens were evaluated by a fully automated ANA-IIF detection system which has inbuilt characteristics of slide processing, microscopy, image capturing and displaying specific ANA patterns. The results were interpreted as positive for those samples having sample titers more than 1:80. The same criteria of positivity were used for both manual and automatic systems. Results: A total of 132 specimens underwent evaluation through both manual and automated ANA indirect immunofluorescence (IIF) detection systems. The concordance between these two methodologies exhibited an overall agreement of 95.7%, with a positive agreement of 97.5% and a negative agreement of 94.9%. Cohen's kappa value stood at 91.7% (ranging from 83.4% to 98.9%), indicating a robust correlation between the two detection systems. The diagnostic sensitivity of the fully automated IIF methodology demonstrated 89.38% (with a 95% confidence interval of 77.24% to 96.13%) and the diagnostic specificity of 95.22% (with a 95% confidence interval of 87.88% to 98.76%). Conclusion: The fully automated showed strong correlation with manual ANA detection methodology based on the principle of indirect immunofluorescence.

КЛИНИКО-ДИАГНОСТИЧЕСКОЕ ЗНАЧЕНИЕ АНТИНУКЛЕАРНЫХ АНТИТЕЛ В ПРАКТИКЕ ПЕДИАТРА (ЧАСТЬ 3)

Antinuclear antibodies (ANA), first discovered many decades ago in patients with systemic lupus erythematosus (SLE), still remain a diagnostic criterion for this disease. However, subsequent studies have shown that the range of diseases in which ANA are detected is extremely wide and includes not only systemic rheumatic diseases, but also other autoimmune diseases (AD), including autoimmune cytopenias, autoimmune liver diseases, gastrointestinal diseases, autoimmune pathology of the thyroid gland and other endocrine glands, autoimmune skin diseases etc. The low specificity of ANA determines their relatively low diagnostic value, which increases when taking into account the luminescence pattern, indicating the presence of certain autoABs. The presence of ANA in patients with AD has a certain prognostic significance since in a number of diseases it is associated with their clinical features and the nature of the process as well as the expected response to the treatment with various drugs. Due to the fact that various AD are often combined in patients, the detection of ANA may be a reason for expanding the examination aiming to diagnose them in a timely manner. See Part 2 at N.S. Podchernyaeva, M.K. Osminina, E.V. Frolkova, M.A. Kudryashova, M.R. Gripp, N.Yu. Golovanov. Clinical and diagnostic value of antinuclear antibodies in a pediatric physician’s practice (Part 2). Pediatria n.a. G.N. Speransky. 2023; 102 (2): 78-89. DOI: 10.24110/0031-403X-2023-102-2-78-89, and Part 1 at N.S. Podchernyaeva, L.G. Khachatryan, M.K. Osminina, E.V. Frolkova, M.A. Kudryashova. Clinical diagnostic value of antinuclear antibodies in pediatric practice (part I). Pediatria n.a. G.N. Speransky. 2022; 101 (3): 185-198. - DOI: 10.24110/0031-403X-2022-101-3-185-198.

Clinical Performance of the Line Immunoassay, Digital Liquid Chip Method, and Chemiluminescent Immunoassay for Detecting Specific Antinuclear Antibodies.

Antinuclear antibodies (ANAs) against certain antigens are useful for identifying autoimmune disorders. Although new solid phase-based immunoassays have been developed for evaluating ANAs, the conventional line immunoassay (LIA) is commonly used in clinical practice. To compare the clinical performance of 2 newly developed methods for detecting specific ANAs with LIA. Six hundred ninety-six serum samples were collected from 559 patients with autoimmune disease (AID) and 137 controls. The samples were screened by using the LIA, digital liquid chip method (DLCM), and chemiluminescent immunoassay (CLIA) for specific ANAs. The agreement across assays and the clinical performance of each assay in diagnosing ANA-associated rheumatic diseases (AARDs) were evaluated. Almost perfect agreement was observed among all assays for anti-centromere protein B (κ = 0.85-0.97), anti-ribosome P (κ = 0.85-0.88), anti-SSA 52 (κ = 0.86-0.89), and anti-SSA 60 (κ = 0.89-0.91); moderate to substantial agreement was detected for the autoantibodies against Sm, Jo-1, ribonucleoprotein, Scl-70, and SSB (κ = 0.55-0.80). LIA exhibited better sensitivity for diagnosing AARDs, while DLCM and CLIA demonstrated higher specificity. In the subset of AIDs, especially systemic lupus erythematosus, antibody positive percentages varied greatly between assays. The 3 assays showed comparable qualitative agreement; however, the standardization of testing for ANAs remains challenging owing to intermanufacturer variations. Moreover, DLCM and CLIA exhibited better specificity in distinguishing non-AID individuals, whereas LIA was more sensitive in diagnosing AARDs.

Antinuclear antibodies in children: indirect immunofluorescence patterns, antigen targets and associated diagnoses

Antinuclear antibodies tests are of a paramount importance in the diagnosis, classification, prognostic evaluation and management of autoimmune diseases in children. The present study aimed to describe the immuno-clinical profile of antinuclear antibodies tests in a pediatric population in order to guide the clinical practice of biologists and clinicians. Our study enrolled 268 children. Antinuclear antibodies screening was performed using the indirect immunofluorescence assay on HEp-2 cells. Identification of target antigens was conducted using separately or at one timepoint the following techniques: enzyme-linked immunosorbent assay, Immunodot and Chemiluminescence. The average age of patients was 9.6 ± 4.3 years, with a female predominance (sex-ratio = 1.9). Antinuclear antibodies screening was positive in 40.67% of cases. The most frequently observed antinuclear antibodies patterns were speckled (52.3%), homogeneous (13.8%) and mixed homogeneous-speckled (13.8%). Autoantibodies were detected in 4 patients (2.51%) for whom ANA testing using the indirect immunofluorescence assay was negative. Positive antinuclear antibodies specificities were detected in connective tissue diseases (44.03%; n = 48), organ-specific autoimmune diseases (10.09%; n = 11), and in non-autoimmune conditions (inflammatory diseases, infections, hematological diseases, vasculitis and Wilson’s disease) (32.08%; n = 35). Our study revealed a high rate of positive antinuclear antibodies tests in the pediatric population, mainly related to autoimmune diseases (54.12%) besides non-autoimmune conditions (32.08%). Therefore, screening and interpretation of antinuclear antibodies testing in children require the consideration of clinical data and a close collaboration between clinicians and biologists.

Determination of specific autoantibodies in patients with systemic lupus erythematosus by Line immunoassay, ELISA and CLIF assay.

Detection of specific antinuclear-antibodies is very importance in term of diagnosis, prognosis and management of patients with systemic lupus erythematosus (SLE). To date, Line immunoassay (LIA), enzyme-linked immunosorbent assay (ELISA) and Crithidia luciliae indirect immunofluorescence (CLIF) assay are commonly used for detection of specific antinuclear-antibodies. To determine the performance of LIA, ELISA and CLIF for the detection of anti-double-stranded DNA (dsDNA), anti-nucleosome, and anti-extractable nuclear antigens (ENA) antibodies in patients with SLE. A total 100 sera from 50 patients with SLE, 25 patients with disease control and 25 healthy control subjects were tested for anti-dsDNA, anti-nucleosome, and anti-ENA antibodies by LIA, ELISA, and CLIF assay. Agreement and diagnostic performance of each assay were analyzed using Cohen's kappa coefficient and receiver operating characteristic curve analysis. For the detection of anti-dsDNA antibody, ELISA had a substantial agreement with CLIF assay (? = 0.74) but LIA had a fair agreement with ELISA and CLIF assay (? = 0.37, and 0.35 respectively). For the detection of anti-nucleosome, anti-nRNP/Sm, anti-Sm, anti-SSA, and anti-SSB antibodies, LIA had a substantial to perfect agreement with ELISA (? = 0.64, 0.78, 0.68, 0.91, and 0.74, respectively). Anti-dsDNA-NcX ELISA and anti-dsDNA CLIF assay had equally diagnostic performance (sensitivity, 66% vs. 68%, and specificity, 96% vs. 94%, respectively) whereas, anti-dsDNA LIA has low sensitivity (22%) but high specificity (100%). LIA, ELISA, and CLIF demonstrated comparable performance for the detection of specific antinuclear-antibodies. However, there were some discrepancy between assays particularly in the detection of anti-dsDNA antibody.

Holistic Patient Care in Primary Biliary Cholangitis: Managing Both the Disease and the Symptoms

In the progressive, immune-mediated liver disease primary biliary cholangitis (PBC), the intrahepatic bile ducts are gradually destroyed over several years. The primary biochemical means to diagnose PBC, and assess progression and treatment response, is serum alkaline phosphatase (ALP). Further diagnostic criteria depend on antimitochondrial antibody (AMA) and specific antinuclear antibody status, and histological confirmation in some patients. First-line therapy for PBC is ursodeoxycholic acid (UDCA), which has been shown to improve biochemical indices of PBC and slow disease progression. However, major quality of life (QoL)-impacting symptoms of PBC, including pruritus and fatigue, are demonstrated to be independent of disease severity. There is evidence confirming that these symptoms negatively impact a number of aspects, including emotional status, ability to work, and social life, for some patients. In a symposium as part of the European Association for the Study of the Liver (EASL) International Liver Congress™ (ILC) 2022, Gideon Hirschfield, Toronto Centre for Liver Disease, University of Toronto, Ontario, Canada; Ana Lleo, Humanitas University and Humanitas Clinical and Research Centre, Milan, Italy; and David Jones, Newcastle University and Newcastle-upon-Tyne Hospitals NHS Foundation Trust, UK, discussed the holistic treatment of patients with PBC and whether goals of such should be more or equally dependent on biochemical status or impact on QoL. This discussion was expanded on in a session moderated by Jessica K. Dyson, Newcastle University and Newcastle-upon-Tyne Hospitals NHS Foundation Trust, UK.

КЛИНИКО-ДИАГНОСТИЧЕСКОЕ ЗНАЧЕНИЕ АНТИНУКЛЕАРНЫХ АНТИТЕЛ В ПРАКТИКЕ ПЕДИАТРА (ЧАСТЬ I)

In recent decades, there has been an increase in the incidence of various autoimmune, including rheumatic diseases, while their debut has been shifted to an earlier age. The clinical picture of rheumatic diseases is distinguished by severe polymorphism; therefore, laboratory diagnostic methods are important for diagnostic search. One of the most widely used tests in the rheumatological practice is the detection and identification of antinuclear antibodies (ANA). ANA are a large group of autoantibodies (auto-Abs) directed against various cell structures, including not only the nucleus but also the nuclear membrane, mitotic apparatus, cytoplasm components and cell organelles, as well as cell membranes. Different methods are used for testing, but the method of ANA detection through indirect immunofluorescence antinuclear antibody test (IF-ANA) is recommended as a “gold standard” with human laryngeal carcinoma HEp-2 cells being recognized as a standard substrate. IF-ANA with HEp-2 has the highest diagnostic sensitivity compared with other methods, it includes the phase of serial dilutions of positive serums and a visual analysis of the type of glow, the list of which currently has 30 patterns. ANA glow types are caused by various auto-Abs that respond with antigens located in the nucleus and cytoplasm of the HEp-2 cells line. Assessment of the type of glow in conjunction with clinical and laboratory data allows planning of further examination with confirming tests to determine the specificity of ANA, some of which, in particular, are auto-Abs to DFS70 antigen, which in the absence of other types of autoantibodies, are more likely to doubt the presence of a systemic rheumatic disease. The diagnostic specificity of various screening techniques for ANA detection is relatively low, they are detected with a fairly high frequency in patients with other diseases and in healthy individuals of different gender and age, including children.

Antinuclear antibodies positivity is not rare during multiple sclerosis and is associated with relapsing status and IgG oligoclonal bands positivity

IntroductionAs an immune-mediated disease of the central nervous system, multifaceted aspects of a humoral immune response are widely described during multiple sclerosis (MS). However, the prevalence of different auto-antibodies, such as antinuclear antibodies (ANA), during MS is very variable and their clinical relevance remains controversial. Our aim was to evaluate the prevalence and clinical correlations of ANA positivity in South Tunisian MS patients. Material and methodsWe performed ANA screening using indirect immunofluorescence (IIF) on HEp-2 cells (Biosystems®) in 82 MS patients. For ANA positive samples (titer ≥1/160), anti-ds-DNA detection (IIF on Crithidia luciliae (Biosystems®)) and extractable nuclear antigen typing (immunodot (Euroimmun®)) were performed. ResultsANA were positive in 35/82 MS patients (42.7%). The titer was ≥1/320 in 16/35 patients. The antigenic specificity of ANA was identified in 7/35 patients. None of the patients had extra-neurological manifestations. No correlation was found between ANA and age, gender, MS course, disease duration, disability, annual relapse rate nor IgG index. ANA positivity was more frequent in patients with IgG oligoclonal bands (OCB) (47.1%) than in patients without IgG OCB (16,6%) (p=0.049). Regarding disease activity, ANA positivity was significantly more frequent in patients with relapse (52.6%) than in patients in remission (25.9%) (p=0.031). ConclusionOur results showed that ANA positivity in MS disease is not rare. This positivity was not associated with clinical expression of any connective tissue disease. ANA occurrence in MS was associated with IgG OCB+ profile and relapsing status, probably reflecting an ongoing immune dysregulation.

Precursors to Systemic Sclerosis and Systemic Lupus Erythematosus: From Undifferentiated Connective Tissue Disease to the Development of Identifiable Connective Tissue Diseases.

The pathogenesis of connective tissue diseases (CTDs), such as systemic lupus erythematosus (SLE) and systemic sclerosis (SSc), is characterized by derangements of the innate and adaptive immune system, and inflammatory pathways leading to autoimmunity, chronic cytokine production, and chronic inflammation. The diagnosis of these diseases is based on meeting established criteria with symptoms, signs and autoantibodies. However, there are pre-clinical states where criteria are not fulfilled but biochemical and autoimmune derangements are present. Understanding the underlying processes responsible for disease pathogenesis in pre-clinical states, which place patients at increased risk for the development of established connective tissue diseases, represents an opportunity for early identification and potentially enables timely treatment with the goal of limiting disease progression and improved prognosis. This scoping review describes the role of the innate and adaptive immune responses in the pre-clinical states of undifferentiated CTD at risk for SSc and prescleroderma, the evolution of antibodies from nonspecific to specific antinuclear antibodies prior to SLE development, and the signaling pathways and inflammatory markers of fibroblast, endothelial, and T cell activation underlying immune dysregulation in these pre-clinical states.

Assessing the Prevalence of Disease-Specific Antinuclear Antibodies and their Detection in Diagnosis of Rheumatic Disorders in Syria

Background: Antinuclear antibodies (ANA) detection is a crucial laboratory test for diagnosing systemic autoimmune disorders and is commonly the initial step in autoantibodies screening. ANA are immunoglobulins that differentiate a wide range of nuclear and cytoplasmic components. ANAs are consistently present in the sera of patients with a variety of rheumatic disorders. The purpose of the study was to investigate the kinds and the expansion of disease-specific antinuclear antibodies (ANAs) and their link to rheumatic disorders in the general Syrian people. &#x0D; Method: Immunofluorescence (IIF) was used for testing ANA in serum samples gained from 529 patients. Individualities positive for IF­ ANA were further tested for disease­ specific ANAs using line Immunoblot assay. &#x0D; Results: Based on the result of the IF­ ANA assay, the rates of positive samples were 7.9%. Anti-SSA/Ro and anti-dsDNA antibodies were detected in 7and 6 individuals, respectively, anti Scl70, anti-Nucleosome, anti-U1-RNP, anti-CENP B were detected in 4 different individuals, but anti-Sm, anti-PCNA, and anti-Jo-1 antibodies were undetectable. Among 42 IF­ ANA­ positive individualities, 24 were found to have disease ­specific ANAs: nine SLE, three Sclerosis, and two rheumatoid arthritis.&#x0D; Conclusions ANA should generally not be examined without a clinical indication. Positive ANA finding in the absence of clinical symptoms and signs has limited diagnostic usefulness and should be interpreted by a rheumatologist constantly, in the context of clinical symptoms and the results of laboratory tests for specific autoantibodies.

Autoimmune markers in screening for orbital inflammatory disease

PurposeImmunogenic causes of inflammation may be difficult to differentiate in the work-up of orbital inflammatory disease. The study aims to investigate the utility of autoimmune markers in the screening for orbital inflammation. Markers studied included angiotensin-converting enzyme (ACE), antinuclear antibody (ANA), anti-neutrophilic cytoplasmic autoantibodies (ANCA), extractable nuclear antigen (ENA), anti-cyclic citrullinated peptide (Anti-CCP) and anti-double stranded DNA antibody (Anti-dsDNA antibody).MethodsA retrospective single-centre study of consecutive patients with non-infective orbital inflammation screened for autoimmune markers at presentation. Serology was interpreted alongside clinical course and other investigations (e.g. radiographic features and histopathology). Tabulated data and Pearson’s Chi-square allowed analysis of trends between serology, diagnosis and the decision to biopsy.Results79 patients, between 1999 and 2021, were included (50 females, mean age was 50.4 ± 17.4 years). 28 (34.6%) patients had specific orbital inflammation and 53 (65.4%) patients had non-specific orbital inflammation (NSOI). Of the 12 patients with positive serology and a specific diagnosis, only 5 (41.7%) patients had concordant serological results. There was no association between serology results and the patient undergoing biopsy (P = 0.651). Serology was unable to exclude nor differentiate NSOI from other specific conditions and ANA had limited discriminatory value between specific conditions and NSOI.ConclusionSerological testing alone may not provide a clear direction for further investigation of orbital inflammation and a biopsy may occur independently of the serological results. The value of autoimmune markers may lie in subsequent follow-up as patients may develop suggestive symptoms after an indeterminate positive result or initially seronegative disease.

Anti-RNP antibodies are associated with the interferon gene signature but not decreased complement levels in SLE

ObjectivesThe goals of these studies were to elucidate the inter-relationships of specific anti-nuclear antibody (ANA), complement, and the interferon gene signature (IGS) in the pathogenesis of systemic lupus erythematosus (SLE).MethodsData...

Comparison study of bead-based and line-blot multiplex ANA immunoassays in the diagnosis of systemic autoimmune rheumatic diseases

Detection of antinuclear antibodies (ANA) by immunofluorescence assay (IFA) is increasingly substituted by multiplex bead-based immunoassay (MBA) and line-blot immunoassay (LIA). This study is to compare the diagnostic performance of MBA and LIA ANA assays on clinically characterized patient samples. A total of 728 serum samples from 385 patients with systemic autoimmune rheumatic diseases (SARD), 204 patients with non-SARD diseases, and 139 apparently healthy subjects were tested with the BioPlex 2200 ANA Screen and EuroLine ANA Profile 3 as the representative MBA and LIA technologies and HEp-2 ANA IFA. Clinical data were collected independent of laboratory analysis and later related to the ANA test results. The clinical diagnostic performances were analyzed using Analyse-it software. The MBA demonstrated higher area under curve (AUC) compared to LIA (0.814 vs 0.761, p = 0.002) and HEp-2 IFA (0.814 vs 0.771, p = 0.008). The MBA and LIA ANA methods showed higher specificity (83.8% and 77.0% vs 67.6%, p < 0.001 and p = 0.005) but lower sensitivity (79.0% and 75.3% vs 86.5%, p < 0.001) compared to HEp-2 IFA. The MBA and LIA ANA revealed substantial to excellent agreements on specific antinuclear antibodies except anti-dsDNA, with the total agreement from 92.3 to 99.9% and Cohen's kappa from 0.71 to 0.98. The MBA demonstrated significantly higher sensitivity (58.1% vs 19.8%, p < 0.001) and comparable specificity (95.9% vs 97.5%, p = 0.221) on anti-dsDNA assay for the diagnosis of SLE compared to LIA. The MBA and LIA ANA assays have higher specificity but lower sensitivity compared to HEp-2 IFA. There are good agreements between MBA and LIA ANA for the specific antinuclear antibodies except for anti-dsDNA. The MBA ANA demonstrated better assay performance compared to LIA as the MBA possesses higher sensitivity and specificity in the diagnosis of SARD. Key Points • The multiplex bead-based immunoassay (MBA) ANA outperformed line-blot immunoassay (LIA) and traditional HEp-2 IFA. • There are good agreements between the MBA BioPlex 2200 ANA Screen and LIA EuroLine ANA Profile 3 for the most of specific antinuclear antibodies except anti-dsDNA. • Additional anti-dsDNA testing is suggested when EuroLine ANA Profile 3 is used for the aid of SLE diagnosis and management. • The positive predictive value of both multiplex ANA assays can be substantially increased without significantlyaffecting negative predictive value by using at least two specific antinuclear antibodies for reporting a positive ANAresult.

Clinical impact of antibodies to Sp100 on a bacterial infection in patients with primary biliary cholangitis.

BackgroundA specific antinuclear antibody for primary biliary cholangitis (PBC) is anti‐Sp100, which was recognized as a serological marker of concurrent urinary tract infection. We sought to determine the clinical characteristics of PBC patients who had anti‐Sp100.Patients and MethodsFifty‐one patients with PBC and 10 healthy controls (HCs) were enrolled. Anti‐Sp100 were determined with an ELISA method. Lipopolysaccharide‐binding protein (LBP) was measured as a serological hallmark for bacterial infection. The correlations of anti‐Sp100 with demographic, laboratory, and pathological parameters were investigated.ResultsSix of the 51 (11.8%) PBC patients had anti‐Sp100, whereas none of the HCs did. There was no significant difference in the frequency of antimitochondrial antibodies (AMAs) between PBC patients with and without anti‐Sp100 (67% vs. 82%, p = 0.5839). Biochemical and immunological parameters were not associated with the emergence of anti‐Sp100 in these patients. The clinical stage by Scheuer classification was not correlated with the existence of anti‐Sp100. No significant difference in the serum LBP levels was found between PBC patients with and without anti‐Sp‐100, although serum LBP levels were significantly higher in PBC patients with anti‐Sp100 than in HCs (8.30 ± 2.24 ng/ml, vs. 5.12 ± 2.48 ng/ml, p = 0.0022). The frequency of granuloma formation was higher in the liver specimens of PBC patients with anti‐Sp100 than in those without anti‐Sp100 (67% vs 29%, p = 0.0710).Conclusionanti‐Sp100 does not become a complementary serological marker for PBC in AMA‐negative patients. A bacterial infection may trigger the production of anti‐Sp100. Another factor is required to initiate the autoantibody production.