Prevalence and clinical significance of rare antinuclear antibody patterns

Clinical Significance of Uncommon, Non-Clinical, and Novel Autoantibodies

Autoantibodies are a common mark of autoimmune reaction and their identification in the patients' serum, cerebrospinal fluid, or tissues is generally believed to represent diagnostic or prognostic biomarkers of autoimmune diseases or autoinflammatory conditions. Traditionally, autoantibody testing is an important part of the clinical examination of suspected patients, and in the absence of reliable T cell tests, characterization of autoantibody responses might be suitable in finding causes of specific autoimmune responses, their strength, and sometimes commencement of autoimmune disease. Autoantibodies are also useful for prognostic stratification in clinically diverse groups of patients if checked repeatedly. Antibody discoveries are continuing, with important consequences for verifying autoimmune mechanisms, diagnostic feasibility, and clinical management. Adding newly identified autoantibody-autoantigen pairs to common clinical laboratory panels should help upgrade and harmonize the identification of systemic autoimmune rheumatic disorders and other autoimmune conditions. Herein, we aim to summarize our current knowledge of uncommon and novel autoantibodies in the context of discussing their validation, diagnostic practicability, and clinical relevance. The regular updates within the field are important and well justified.

Recognition of rare antinuclear antibody patterns based on a novel attention-based enhancement framework

Rare antinuclear antibody (ANA) pattern recognition has been a widely applied technology for routine ANA screening in clinical laboratories. In recent years, the application of deep learning methods in recognizing ANA patterns has witnessed remarkable advancements. However, the majority of studies in this field have primarily focused on the classification of the most common ANA patterns, while another subset has concentrated on the detection of mitotic metaphase cells. To date, no prior research has been specifically dedicated to the identification of rare ANA patterns. In the present paper, we introduce a novel attention-based enhancement framework, which was designed for the recognition of rare ANA patterns in ANA-indirect immunofluorescence images. More specifically, we selected the algorithm with the best performance as our target detection network by conducting comparative experiments. We then further developed and enhanced the chosen algorithm through a series of optimizations. Then, attention mechanism was introduced to facilitate neural networks in expediting the learning process, extracting more essential and distinctive features for the target features that belong to the specific patterns. The proposed approach has helped to obtained high precision rate of 86.40%, 82.75% recall, 84.24% F1 score and 84.64% mean average precision for a 9-category rare ANA pattern detection task on our dataset. Finally, we evaluated the potential of the model as medical technologist assistant and observed that the technologist's performance improved after referring to the results of the model prediction. These promising results highlighted its potential as an efficient and reliable tool to assist medical technologists in their clinical practice.

Anti-KIF20B autoantibodies in systemic autoimmune rheumatic diseases: Their high prevalence in systemic lupus erythematosus

The kinesin superfamily protein 20B (KIF20B), also known as M-phase phosphoprotein-1, is a plus-end-directed motor enzyme for cytokinesis. Anti-KIF20B antibodies have been reported in idiopathic ataxia, but no previous studies have examined anti-KIF20B antibodies in systemic autoimmune rheumatic diseases (SARDs). We aimed to establish methods for detecting anti-KIF20B antibodies and to investigate the clinical significance of these antibodies in SARDs. Serum samples from 597 patients with various SARDs and 46 healthy controls (HCs) were included. Fifty-nine samples that had been examined by immunoprecipitation using the recombinant KIF20B protein produced by in vitro transcription/translation were used for establishing the ELISA cutoff with the same recombinant protein for measuring the anti-KIF20B antibodies. The ELISA performed well, showing close agreement with the immunoprecipitation results (Cohen's κ >0.8). The ELISA results for 643 samples showed the prevalence of anti-KIF20B to be higher in the systemic lupus erythematosus (SLE) patients than in the HCs (18/89 vs. 3/46, P = 0.045). Since no SARD other than SLE had higher frequencies of anti-KIF20B antibodies than those of the HCs, we investigated the clinical characteristics of anti-KIF20B antibody-positive cases in SLE. The score on the SLE Disease Activity Index-2000 (SLEDAI-2K) was significantly higher for the anti-KIF20B-positive SLE patients than for the anti-KIF20B-negative SLE patients (P = 0.013). In a multivariate regression analysis of the anti-single-stranded deoxyribonucleic acid, anti-double-stranded deoxyribonucleic acid, and anti-KIF20B antibodies, the presence of anti-KIF20B antibody was significantly associated with high SLEDAI-2K scores (P = 0.003). Anti-KIF20B antibodies were found in ~20% of patients with SLE and were associated with high SLEDAI-2K scores. Much larger cohort and longitudinal studies are needed to confirm the association between anti-KIF20B antibodies and SLE.

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.

The axis of complement C1 and nucleolus in antinuclear autoimmunity

Antinuclear autoantibodies (ANA) are heterogeneous self-reactive antibodies that target the chromatin network, the speckled, the nucleoli, and other nuclear regions. The immunological aberration for ANA production remains partially understood, but ANA are known to be pathogenic, especially, in systemic lupus erythematosus (SLE). Most SLE patients exhibit a highly polygenic disease involving multiple organs, but in rare complement C1q, C1r, or C1s deficiencies, the disease can become largely monogenic. Increasing evidence point to intrinsic autoimmunogenicity of the nuclei. Necrotic cells release fragmented chromatins as nucleosomes and the alarmin HMGB1 is associated with the nucleosomes to activate TLRs and confer anti-chromatin autoimmunogenecity. In speckled regions, the major ANA targets Sm/RNP and SSA/Ro contain snRNAs that confer autoimmunogenecity to Sm/RNP and SSA/Ro antigens. Recently, three GAR/RGG-containing alarmins have been identified in the nucleolus that helps explain its high autoimmunogenicity. Interestingly, C1q binds to the nucleoli exposed by necrotic cells to cause protease C1r and C1s activation. C1s cleaves HMGB1 to inactive its alarmin activity. C1 proteases also degrade many nucleolar autoantigens including nucleolin, a major GAR/RGG-containing autoantigen and alarmin. It appears that the different nuclear regions are intrinsically autoimmunogenic by containing autoantigens and alarmins. However, the extracellular complement C1 complex function to dampen nuclear autoimmunogenecity by degrading these nuclear proteins.

An automatic immunofluorescence pattern classification framework for HEp-2 image based on supervised learning

Immunofluorescence patterns of anti-nuclear antibodies (ANAs) on human epithelial cell (HEp-2) substrates are important biomarkers for the diagnosis of autoimmune diseases. There are growing clinical requirements for an automatic readout and classification of ANA immunofluorescence patterns for HEp-2 images following the taxonomy recommended by the International Consensus on Antinuclear Antibody Patterns (ICAP). In this study, a comprehensive collection of HEp-2 specimen images covering a broad range of ANA patterns was established and manually annotated by experienced laboratory experts. By utilizing a supervised learning methodology, an automatic immunofluorescence pattern classification framework for HEp-2 specimen images was developed. The framework consists of a module for HEp-2 cell detection and cell-level feature extraction, followed by an image-level classifier that is capable of recognizing all 14 classes of ANA immunofluorescence patterns as recommended by ICAP. Performance analysis indicated an accuracy of 92.05% on the validation dataset and 87% on an independent test dataset, which has surpassed the performance of human examiners on the same test dataset. The proposed framework is expected to contribute to the automatic ANA pattern recognition in clinical laboratories to facilitate efficient and precise diagnosis of autoimmune diseases.

Uncommon types of autoantibodies - Detection and clinical associations

Immunofluorescence is a basic method for detection of autoantibodies in serum. It is used as screening for people with symptoms suggesting autoimmune process and disease. Antinuclear antibodies (ANA) assay detecting antibodies against nuclear proteins used commonly for diagnosis of systemic autoimmune disease, although antibodies against cytoplasmic components and mitotic structures are usable in clinic. The majority of ANA nuclear patterns have been comprehensively studied with increasing data. However, the cytoplasmic and mitotic patterns are underestimated and still require further assessment. In this review the clinical associations and significance of uncommon types of autoantibodies are presented and discussed.

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

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

Clinical Significance of Antinucleolar Antibodies: Biomarkers for Autoimmune Diseases, Malignancies, and others

Nucleolar staining is one of the standard patterns in immunofluorescence antinuclear antibodies (ANA), seen in 5-9% of ANA in various conditions. Antinucleolar antibodies (ANoA) are classified into 3 patterns in the International Consensus on ANA Patterns (ICAP) classification; AC-8 homogeneous pattern, AC-9 clumpy pattern, and AC-10 punctate pattern. Specificities known to show AC-8 include anti-Th/To, -PM-Scl, -nucleophosmin/B23, -nucleolin/C23, -No55, and others. AC-9 is seen by anti-fibrillarin/U3RNP and AC-10 by anti-RNA polymerase I and hUBF/NOR-90. ANoA has been classically known to be associated with scleroderma (SSc) and the characterization of nucleolar antigens identified several autoantigens recognized by SSc autoantibodies. The clinical association of anti-Th/To, PM-Scl, fibrillarin/U3RNP, and RNA polymerase I with SSc or SSc-overlap syndrome is well established, and commercial assays are developed. Anti-hUBF/NOR90, nucleophosmin/B23, and nucleolin/C23 are known for decades and reported in systemic autoimmune rheumatic diseases (SARDs), malignancies, graft versus host disease (GVHD), and others; however, their clinical significance remains to be established.

Diagnostic and Clinical Value of Specific Autoantibodies against Kelch-like 12 Peptide and Nuclear Envelope Proteins in Patients with Primary Biliary Cholangitis

Primary biliary cholangitis (PBC) is a chronic autoimmune liver disease characterized by the presence of antimitochondrial and antinuclear antibodies in patients’ serum. Here, we analyzed the reactivity of autoantibodies against a novel autoantigen, kelch-like 12 (KLHL12) protein, in a cohort of 138 PBC and 90 non-PBC patients. Additionally, we compared the reactivity of KLHL12 with antinuclear envelope antibodies: anti-gp210, anti-p62, and anti-LBR. Commercially available kits and an ‘in-house’ ELISA were used in the studies. Antinuclear envelope antibodies were detected in 65% of PBC patients and the presence of these antibodies was observed more frequently in patients diagnosed with later stages (III/IV) of PBC, according to Ludwig’s classification (p < 0.05) and were found to correlate with a higher concentration of bilirubin. Overall, anti-KLHL12 antibodies were found more frequently in PBC patients than in non-PBC controls (p < 0.001). Anti-KLHL12 antibodies were detected in 36% of the tested PBC cohort, including PBC patients negative for antimitochondrial antibodies. Presence of anti-KLHL12 was also associated with a higher concentration of bilirubin and correlated with fibrosis (p < 0.05). Anti-KLHL12 antibodies were detected in 30% of PBC individuals positive for antinuclear envelope antibodies, while anti-KLHL12 and antinuclear envelope antibodies were found in 17% of all PBC cases. Concluding, our data confirm that antibodies against the KLHL12 protein are highly specific for PBC and when used in combination with other markers, may significantly increase the diagnosis of PBC.

Association of immune-related adverse events induced by nivolumab with a battery of autoantibodies

BACKGROUND

The aim of this study was to assess the diagnostic performance of an autoantibody battery in patients receiving immune checkpoint inhibitors who experienced immune-related adverse events (irAEs).

METHODS

We retrospectively analyzed several variables potentially related to irAEs, namely, demographic, clinical, and laboratory characteristics, including an autoantibody battery (antinuclear, anti-neutrophil cytoplasmic, anti-thyroid antibodies and rheumatoid factor).

RESULTS

Sixty-nine patients (48 men; 61.8 ± 10.9 years at baseline) diagnosed with stage-4 solid-organ cancer and treated with nivolumab were followed up for 12 ± 10.3 months. Thirty-two irAEs were detected in 26 patients (37.5%). Adverse events occurred more commonly in women (62% vs. 27%, p = .006), and younger patients (irAEs: 58.1 ± 9.8, no irAEs: 64.1 ± 10.9 years, p = .024). Autoantibody battery results were available for 26 patients and were more frequently positive in patients with irAEs (87% vs. 30%, p = .009). The positive predictive value, negative predictive value, and diagnostic accuracy of the battery were 82.3%, 77.8%, and 80.8%, respectively. Among the 64 patients with an evaluable response, 23 (38.5%) experienced tumour progression, this being less frequent in patients with irAEs (19% vs. 48.5%, p = .03). Overall survival was higher in patients developing irAEs (HR = 1.88, p = .05).

CONCLUSION

Positivity in a readily available autoantibody battery may be associated with the occurrence of irAEs.KEY MESSAGESPositivity in an accessible and inexpensive autoantibody battery including antinuclear, anti-neutrophil cytoplasmic, anti-thyroid antibodies and rheumatoid factor may be associated with the occurrence of immune-related adverse events.Patients with cancer on immune checkpoint inhibitors experiencing immune-related adverse events showed a lower risk of progression and better overall survival than patients not experiencing this type of adverse effect.

Anti-Golgi Antibody as a Potential Indicator for Rheumatoid Arthritis

OBJECTIVE

To reveal the relationship between anti-Golgi antibody (AGA) and clinical diseases through retrospective analysis.

METHODS

The clinical data of 584 cases testing positive for AGA in the past 11 years were collected and retrospectively analyzed.

RESULTS

AGA pattern accounted for .2% of positive ANA results. In total, 35.0% of diagnosed patients had autoimmune diseases (AID), mainly rheumatoid arthritis (RA). High-titer AGA (≧1:1000) was common in AID. In nondiagnosed patients with clinical symptoms, joint pain/muscle pain was the most common.

CONCLUSIONS

Positive AGA with high titer was closely related to RA. Joint pain/muscle pain was the most common symptom in patients who tested AGA positive. Therefore, AGA may be a key indicator of RA in the Chinese population.

The GAR/RGG motif defines a family of nuclear alarmins

The nucleus is the target of autoantibodies in many diseases, which suggests intrinsic nuclear adjuvants that confer its high autoimmunogenicity. Nucleolin (NCL) is one abundant nucleolar autoantigen in systemic lupus erythematosus (SLE) patients and, in lupus-prone mice, it elicits autoantibodies early. With purified NCL, we observed that it was a potent alarmin that activated monocytes, macrophages and dendritic cells and it was a ligand for TLR2 and TLR4. NCL released by necrotic cells also exhibited alarmin activity. The NCL alarmin activity resides in its glycine/arginine-rich (GAR/RGG) motif and can be displayed by synthetic GAR/RGG peptides. Two more GAR/RGG-containing nucleolar proteins, fibrillarin (FBRL) and GAR1, were also confirmed to be novel alarmins. Therefore, the GAR/RGG alarmin motif predicts a family of nucleolar alarmins. The apparent prevalence of nucleolar alarmins suggests their positive contribution to tissue homeostasis by inducing self-limiting tissue inflammation with autoimmunity only occurring when surveillance is broken down.

Application of Supervised Machine Learning to Recognize Competent Level and Mixed Antinuclear Antibody Patterns Based on ICAP International Consensus

Background: Antinuclear antibody pattern recognition is vital for autoimmune disease diagnosis but labor-intensive for manual interpretation. To develop an automated pattern recognition system, we established machine learning models based on the International Consensus on Antinuclear Antibody Patterns (ICAP) at a competent level, mixed patterns recognition, and evaluated their consistency with human reading. Methods: 51,694 human epithelial cells (HEp-2) cell images with patterns assigned by experienced medical technologists collected in a medical center were used to train six machine learning algorithms and were compared by their performance. Next, we choose the best performing model to test the consistency with five experienced readers and two beginners. Results: The mean F1 score in each classification of the best performing model was 0.86 evaluated by Testing Data 1. For the inter-observer agreement test on Testing Data 2, the average agreement was 0.849 (κ) among five experienced readers, 0.844 between the best performing model and experienced readers, 0.528 between experienced readers and beginners. The results indicate that the proposed model outperformed beginners and achieved an excellent agreement with experienced readers. Conclusions: This study demonstrated that the developed model could reach an excellent agreement with experienced human readers using machine learning methods.

Antinuclear Antibodies With a Nucleolar Pattern Are Associated With a Significant Reduction in the Overall Survival of Patients With Leukemia: A Retrospective Cohort Study

OBJECTIVE

Antinuclear antibodies (ANAs) have been reported to be associated with cancers. However, the role of different ANA patterns in cancers is poorly understood, especially in leukemia. This study aimed to investigate the association between ANA patterns and the outcome of leukemia in a retrospective cohort.

METHODS

A total of 429 adult patients initially diagnosed with leukemia at Henan Provincial People's Hospital from January 2014 to December 2018 were included in this study, including information on patients without positive ANAs at the time of initial diagnosis, preexisting autoimmune diseases, infectious diseases, etc. The data were retrieved up to December 2020. The final sample included 196 adult patients. The risk of death outcome according to ANA patterns was estimated using multivariable Cox proportional hazards models and the overall survival for ANA patterns was analyzed using Kaplan-Meier curve.

RESULTS

ANAs with a nucleolar pattern versus negative ANA were associated with a two-fold increased risk of death outcome in leukemia, independent of sex, age, leukemia immunophenotype, cytogenetic abnormality, treatment, and blood transfusion. Further analysis revealed that the association was more significant in elder patients (≥60 years) and patients treated with tyrosine kinase inhibitor or chemotherapy (P for interaction = 0.042 and 0.010). Notably, the patients with a nucleolar pattern had shorter survival than the patients with a non-nucleolar pattern or without ANA (p < 0.001).

CONCLUSION

ANAs with a nucleolar pattern are a significant predictor of poor prognosis, providing clues for prognostic assessment in patients with leukemia.

Uncommon antinuclear antibody patterns as diagnostic indicators

INTRODUCTION

The clinical significance of common antinuclear antibody (ANA) patterns, such as nuclear homogenous and nuclear speckled patterns with their corresponding specific antibodies, has already been established. However, the clinical relevance of these uncommon ANA patterns have not been well elucidated and these patterns are therefore not reported by most clinical laboratories. We herein report some retrospective data analysis linking patients' clinical status to several uncommon ANA patterns.

METHODS

We retrieved and assessed the patient records for ANA reports generated in our hospital over a period of two years. All testing had been performed using the gold standard Indirect Immunofluorescence Assay.

RESULTS

Records of 1235 consecutive patients tested for ANA were reviewed. ANA was positive in 330 of these patients with 6.39% found to have uncommon nuclear, cytoplasmic or mitotic sub-patterns. The mitotic spindle (0.89%), cytoplasmic anti-mitochondrial antibodies (0.80%), followed by discrete nuclear dots-multiple (0.72%) were the dominating patterns, with a higher prevalence in females than in males. Systemic lupus erythematosus and rheumatoid arthritis were the two most common autoimmune disorders associated with mitotic spindle fibers and nuclear centromere and nuclear large/coarse speckled ANA patterns.

CONCLUSION

The prevalence of these relatively uncommon ANA patterns was higher than expected. Further evaluation of these patterns along with their corresponding antibodies and their clinical utility must be encouraged. We trust this endeavour will provide diagnostic information in autoimmune and other disease conditions.

Current laboratory and clinical practices in reporting and interpreting anti-nuclear antibody indirect immunofluorescence (ANA IIF) patterns: results of an international survey

Background

The International Consensus on Antinuclear Antibody (ANA) Patterns (ICAP) has recently proposed nomenclature in order to harmonize ANA indirect immunofluorescence (IIF) pattern reporting. ICAP distinguishes competent-level from expert-level patterns. A survey was organized to evaluate reporting, familiarity, and considered clinical value of ANA IIF patterns.

Methods

Two surveys were distributed by European Autoimmunity Standardization Initiative (EASI) working groups, the International Consensus on ANA Patterns (ICAP) and UK NEQAS to laboratory professionals and clinicians.

Results

438 laboratory professionals and 248 clinicians from 67 countries responded. Except for dense fine speckled (DFS), the nuclear competent patterns were reported by > 85% of the laboratories. Except for rods and rings, the cytoplasmic competent patterns were reported by > 72% of laboratories.

Cytoplasmic IIF staining was considered ANA positive by 55% of clinicians and 62% of laboratory professionals, with geographical and expertise-related differences.

Quantification of fluorescence intensity was considered clinically relevant for nuclear patterns, but less so for cytoplasmic and mitotic patterns. Combining IIF with specific extractable nuclear antigens (ENA)/dsDNA antibody testing was considered most informative.

Of the nuclear competent patterns, the centromere and homogeneous pattern obtained the highest scores for clinical relevance and the DFS pattern the lowest. Of the cytoplasmic patterns, the reticular/mitochondria-like pattern obtained the highest scores for clinical relevance and the polar/Golgi-like and rods and rings patterns the lowest.

Conclusion

This survey confirms that the major nuclear and cytoplasmic ANA IIF patterns are considered clinically important. There is no unanimity on classifying DFS, rods and rings and polar/Golgi-like as a competent pattern and on reporting cytoplasmic patterns as ANA IIF positive.

A Hospital-Based Insight into the Antinuclear Antibody Patterns in Autoimmune Disorders

Background  The incidence of autoimmune disorders has seen a rise in India in recent times. The symptoms and signs of these conditions are caused by a systemic autoimmune response, essentially characterized by the expression of the antinuclear antibodies (ANA). Presence of ANA in serum of patient could be the prime evidence of an autoimmune disorder.

Aim  This study aimed to determine the antibody patterns and assess the clinical significance of ANA in patients of a teaching tertiary care hospital of central India.

Material and Methods  This retrospective cross-sectional data analysis study retrieved 538 reports of individuals, who were prescribed the ANA test by indirect immunofluorescence assay over a period of 11 months, from the archives of the Department of Biochemistry. For continuous data, student t -test was used while Chi-square and Fisher exact was conducted for categorical data. A p value less than 0.05 were taken as significant.

Results  Out of the 538 patients investigated for ANA testing by indirect immunofluorescence assay, 33% were positive, among which 74% were female, and majority belonged to the young adult age group. The most common pattern identified was nuclear, subpattern nuclear speckled.

Conclusion  A high-ANA pattern positivity could be related to a high-autoimmunity prevalence in this region, and also promotes its use as a tool of evidence of suspected autoimmune disorders.

Antinuclear antibodies (ANA) patterns in paraneoplastic cerebellar degeneration during the course of disease and treatment protocols - A case report

Paraneoplastic cerebellar degeneration (PCD) is a rare disease that is triggered by an abnormal immune response to a malignant tumor by cross-reaction of antibodies. The low prevalence of this condition has not allowed for large-scale randomized controlled trials. Suspecting a paraneoplastic syndrome followed by rapid diagnosis is crucial before the symptoms irreversibely progress. Indirect immunofluorescence (IIF) with HEp-2 ​cells is currently the most widely used screening technique for the detection of a wide range of nuclear and cytoplasmatic autoantibodies. Here, we present a case of a female Caucasian patient, 61 years of age, who started having sudden symptoms of PCD starting April 2016 that progressed through the course of 10 months before the final diagnosis. Assuming that antinuclear antibodies (ANA) testing could give rise to suspicion of an underlying malignancy but also to an underlying autoimmune etiology of PCD, we followed the ANA patterns of the patient during the course of disease and treatment protocols. A total of four ANA follow ups were done on serum dilution 1:100 and all showed weak positive results on hepatic cells and a mix of similar patterns that, through the course of time, differed slightly on HEp-2 ​cells. Finding positive antinuclear or anticytoplasmic auto-antibodies might guide toward an extensive and useless search for a systemic autoimmune disease ignoring the possibility of searching for paraneoplastic-specific antibodies. An unspecified mix of patterns should not be ignored and might, through further research, show to be more valuable in the ANA screening than is the case now. Weak positive results should not mislead into thinking that there is no overall effect on health, since quite the opposite was the case here. In our example, neither the tumor response to treatment, neurological presentation nor the immunological treatment had a strong effect on the ANA patterns which remained almost identical throughout the course of disease and treatment. Ultrastructural and molecular events in the pathogenesis of the disease could have caused certain minor changes in the pattern but are not of clinical value at the moment and further research is needed.

Antinuclear Antibody Tests

The presence of antinuclear antibodies (ANAs), which include autoantibodies to extractable nuclear antigens (ENAs), in the sera of patients with connective tissue diseases provides useful immunologic and pathophysiologic insight into the nature of their disease. This article discusses the most commonly used diagnostic modalities for detecting and quantitating the presence of ANA: indirect immunofluorescence assay, enzyme-linked immunosorbent assay, and multiplex bead technology, which serve as useful screening tests. We also review testing for autoantibodies to ENAs, which are often helpful to confirm the diagnosis of a specific connective tissue disease.

Autoantibodies to mRNA processing pathways (glycine and tryptophan-rich bodies antibodies): prevalence and clinical utility in a South Australian cohort

Autoantibodies to glycine and tryptophan-rich bodies (GWB) can be detected on routine antinuclear antibodies (ANA) testing and might have important disease associations. The aim of this study was to investigate the prevalence of anti-GWB antibodies identified on routine ANA testing, define their antigenic specificities and describe their clinical association. Anti-GWB antibodies were identified by distinct cytoplasmic staining pattern on all samples referred for ANA testing over a 6-month period. All positive anti-GWB samples were further tested on a multiplex addressable bead immunoassay (ALBIA) with known GWB antigens. Extractable nuclear antigens (ENA) were characterised by line immunoblot assay. Clinical details were collected retrospectively by contacting patients and the requesting clinicians. Eleven patients (7 females, 4 males) out of a total of 2136 positive ANAs requested on 11,265 samples had the classical GWB pattern (0.5%). The median age of patients was 66 years (range 39-92). There was no consistent disease association. Ten were confirmed to have distinct antigenic specificity for known GWB antigens. Ge-1/Hedls and RAP55 were the most common antigenic specificity targets [seen in 7 patients (64%) and in 5 patients (45%), respectively]. Ro52 was positive in 5/9 (56%) patients, SSB in 2/9 (22%) patients and Ro60 in 1/9 (11%) patient. The clinical association of anti-GWB antibodies is uncertain but might point towards autoimmune origin of certain non-specific musculoskeletal symptoms. The antigenic specificity of anti-GWB reactivity could point towards specific clinical associations: anti-RAP55 and Ge-1 in non-specific musculoskeletal conditions versus anti-GW182 in neurological diseases.

Clinical relevance of HEp-2 indirect immunofluorescent patterns: the International Consensus on ANA patterns (ICAP) perspective

The indirect immunofluorescence assay (IIFA) on HEp-2 cells is widely used for detection of antinuclear antibodies (ANA). The dichotomous outcome, negative or positive, is integrated in diagnostic and classification criteria for several systemic autoimmune diseases. However, the HEp-2 IIFA test has much more to offer: besides the titre or fluorescence intensity, it also provides fluorescence pattern(s). The latter include the nucleus and the cytoplasm of interphase cells as well as patterns associated with mitotic cells. The International Consensus on ANA Patterns (ICAP) initiative has previously reached consensus on the nomenclature and definitions of HEp-2 IIFA patterns. In the current paper, the ICAP consensus is presented on the clinical relevance of the 29 distinct HEp-2 IIFA patterns. This clinical relevance is primarily defined within the context of the suspected disease and includes recommendations for follow-up testing. The discussion includes how this information may benefit the clinicians in daily practice and how the knowledge can be used to further improve diagnostic and classification criteria.

Interstitial lung disease and inflammatory myopathy in antisynthetase syndrome with PL-12 antibody

We report the case of an 80-year-old Caucasian man with PL-12 antibody positive antisynthetase syndrome. He presented with progressive dyspnoea and weight loss, later developing dysphagia, mild proximal muscle weakness and mild sicca symptoms. Investigations revealed interstitial lung disease, inflammatory myopathy and an immunology profile consistent with PL-12 antisynthetase syndrome. Prednisolone and cyclophosphamide resulted in a significant improvement of all his symptoms.

Uncommon patterns of antinuclear antibodies recognizing mitotic spindle apparatus antigens and clinical associations

Antinuclear antibodies (ANA) are key biomarkers in the evaluation of rheumatic diseases. The prevalence and clinical significance of uncommon or rare patterns, particularly those directed at the mitotic spindle apparatus (MSA), are not well understood. We aimed to investigate the prevalence and clinical significance of anti-MSA patterns in a Colombian population.During 2013 and 2014, 113,491 consecutive determinations of ANA were studied for the presence of uncommon patterns. Clinical and laboratory data of anti-MSA positive patients were retrospectively collected and analyzed.Of the 113,491 patients tested, 60,501 (53%) were positive for ANA, of which 834 (1.3%) were positive for uncommon/rare patterns of ANA (anti-MSA in 592 cases). Of these 592 cases, complete data were available in 329 patients, of whom 116 had an established diagnosis. Anti-MSA antibodies were the only ANA positive test in 81% patients. At least one fine reactivity was identified in 19/116 (16.3%) of ANA-positive patients, of which anti-Ro was the most prevalent (18/116, 15.5%).The most frequent patterns were nuclear mitotic apparatus (NuMA) (56%) and MSA-2 (25%). The NuMA pattern had the highest ANA titers: mean 320 (range 80-2560) and behaved as monospecific antibodies. The most frequent systemic autoimmune diseases were Sjögren syndrome (SS) (18.1%), rheumatoid arthritis (RA) (13.8%), and systemic lupus erythematosus (SLE) (11%). Undifferentiated connective tissue disease (UCTD) was associated with the centrosome (P < .001), NuMA (P < .02) and MSA-2 (P < .45) patterns. Chronic idiopathic urticaria (CIU) was associated with the NuMA pattern (P < .02) and sensorineural hearing loss (SNHL) was associated with the MSA-2 (P < .001), centrosome (P < .68) and CENP-F (P < .38) patterns, previously unreported findings. Malignancies were found in 8 patients (50% were papillary thyroid cancer).In a large cohort of ANA determinations, uncommon patterns were found in around 1% of cases. The most frequent anti-MSA patterns found were NuMA and MSA-2. More than 50% of patients with anti-MSA had an associated CTD, mainly SS, RA and SLE, and anti-MSA behaved as monospecific antibodies. Other entities of presumed autoimmune origin, like CIU and SNHL, might be associated with these patterns.

Broad Susceptibility of Nucleolar Proteins and Autoantigens to Complement C1 Protease Degradation

Anti-nuclear autoantibodies, which frequently target the nucleoli, are pathogenic hallmarks of systemic lupus erythematosus (SLE). Although the causes of these Abs remain broad and ill-defined, a genetic deficiency in C1 complex (C1qC1r₂C1s₂) or C4 is able to induce these Abs. Considering a recent finding that, in dead cells, nucleoli were targeted by C1q and two nucleolar autoantigens were degraded by C1r/C1s proteases, we considered that C1 could help protect against antinuclear autoimmunity by broadly degrading nucleolar proteins or autoantigens. Nucleoli were isolated to homogeneity and structurally defined. After C1 treatment, cleaved nucleolar proteins were identified by proteomic two-dimensional fluorescence difference gel electrophoresis and mass spectrometry, and further verified by Western blotting using specific Abs. The extent of nucleolar autoantigen degradation upon C1 treatment was estimated using SLE patient autoantibodies. The isolated nucleoli were broadly reactive with SLE patient autoantibodies. These nucleoli lacked significant autoproteolysis, but many nucleolar proteins and autoantigens were degraded by C1 proteases; >20 nucleolar proteins were identified as C1 cleavable. These were further validated by Western blotting using specific Abs. The broad autoantigenicity of the nucleoli may attribute to their poor autoproteolysis, causing autologous immune stimulation upon necrotic exposure. However, C1q targets at these nucleoli to cause C1 protease activation and the cleavage of many nucleolar proteins or autoantigens. This may represent one important surveillance mechanism against antinuclear autoimmunity because C1 genetic deficiency causes anti-nuclear autoantibodies and SLE disease.

Signs and symptoms of rheumatic diseases as first manifestation of pediatric cancer: diagnosis and prognosis implications

OBJECTIVE

To assess the prevalence and describe the clinical, laboratory and radiological findings, treatment and outcome of children with cancer initially referred to a tertiary outpatient pediatric rheumatology clinic.

METHODS

Retrospective analysis of medical records from patients identified in a list of 250 new patients attending the tertiary Pediatric Rheumatology Clinic, Ribeirão Preto Medical School hospital, University of São Paulo, from July 2013 to July 2015, whose final diagnosis was cancer.

RESULTS

Of 250 patients seen during the study period, 5 (2%) had a cancer diagnosis. Among them, 80% had constitutional symptoms, especially weight loss and asthenia, and 60% had arthritis. Initially, all patients had at least one alteration in their blood count, lactate dehydrogenase was increased in 80% and a bone marrow smear was conclusive in 60% of patients. Bone and intestine biopsies were necessary for the diagnosis in 2 patients. JIA was the most common initial diagnosis. The definitive diagnosis was acute lymphoblastic leukemia (2 patients), M3 acute myeloid leukemia, lymphoma, and neuroblastoma (one case each). Of 5 patients studied, 3 (60%) are in remission and 2 (40%) died, one of them with prior use of steroids.

CONCLUSION

The constitutional and musculoskeletal symptoms common to rheumatic and neoplastic diseases can delay the diagnosis and consequently worsen the prognosis of neoplasms. Initial blood count and bone marrow smear may be normal in the initial framework of neoplasms. Thus, the clinical follow-up of these cases becomes imperative and the treatment, mainly with corticosteroids, should be delayed until diagnostic definition.

Next-Generation Autoantibody Testing by Combination of Screening and Confirmation-the CytoBead® Technology

Occurrence of autoantibodies (autoAbs) is a hallmark of autoimmune diseases, and the analysis thereof is an essential part in the diagnosis of organ-specific autoimmune and systemic autoimmune rheumatic diseases (SARD), especially connective tissue diseases (CTDs). Due to the appearance of autoAb profiles in SARD patients and the complexity of the corresponding serological diagnosis, different diagnostic strategies have been suggested for appropriate autoAb testing. Thus, evolving assay techniques and the continuous discovery of novel autoantigens have greatly influenced the development of these strategies. Antinuclear antibody (ANA) analysis by indirect immunofluorescence (IIF) on tissue and later cellular substrates was one of the first tests introduced into clinical routine and is still an indispensable tool for CTD serology. Thus, screening for ANA by IIF is recommended to be followed by confirmatory testing of positive findings employing different assay techniques. Given the continuous growth in the demand for autoAb testing, IIF has been challenged as the standard method for ANA and other autoAb analyses due to lacking automation, standardization, modern data management, and human bias in IIF pattern interpretation. To address these limitations of autoAb testing, the CytoBead® technique has been introduced recently which enables automated interpretation of cell-based IIF and quantitative autoAb multiplexing by addressable microbead immunoassays in one reaction environment. Thus, autoAb screening and confirmatory testing can be combined for the first time. The present review discusses the history of autoAb assay techniques in this context and gives an overview and outlook of the recent progress in emerging technologies.

Immune biomarkers in the spectrum of childhood noncommunicable diseases

A biomarker is an accurately and reproducibly quantifiable biological characteristic that provides an objective measure of health status or disease. Benefits of biomarkers include identification of therapeutic targets, monitoring of clinical interventions, and development of personalized (or precision) medicine. Challenges to the use of biomarkers include optimizing sample collection, processing and storage, validation, and often the need for sophisticated laboratory and bioinformatics approaches. Biomarkers offer better understanding of disease processes and should benefit the early detection, treatment, and management of multiple noncommunicable diseases (NCDs). This review will consider the utility of biomarkers in patients with allergic and other immune-mediated diseases in childhood. Typically, biomarkers are used currently to provide mechanistic insight or an objective measure of disease severity, with their future role in risk stratification/disease prediction speculative at best. There are many lessons to be learned from the biomarker strategies used for cancer in which biomarkers are in routine clinical use and industry-wide standardized approaches have been developed. Biomarker discovery and validation in children with disease lag behind those in adults; given the early onset and therefore potential lifelong effect of many NCDs, there should be more studies incorporating cohorts of children. Many pediatric biomarkers are at the discovery stage, with a long path to evaluation and clinical implementation. The ultimate challenge will be optimization of prevention strategies that can be implemented in children identified as being at risk of an NCD through the use of biomarkers.

Use of panel testing for detection of antinuclear antibody in a resource-limited setting: an appraisal

OBJECTIVES

Despite an increase in the incidence of systemic connective tissue diseases (CTD), panel testing for detection of antinuclear antibodies (ANA) is not a routine practice in many health centers of the Indian subcontinent. Consequently, the data on its significance is scanty.

METHODS

To evaluate utility of panel testing, line immunoassay (LIA) and indirect immunofluorescence antinuclear antibody test (IIF-ANA) were performed in 321 cases of CTD.

RESULTS

Out of 321 serum samples screened by the above tests, 227 were positive and 18 were negative by both LIA and IIF-ANA. Additional 11/321 (3.4%) cases were picked up by LIA. SSA was most common specificity in these cases followed by SSA/SSB, SSB, Ro-52, Jo-1, dsDNA and nRNP/Sm.

CONCLUSION

Use of LIA along with IF-ANA and ELISA improves sensitivity of CTD screening.

The ANA-reflex test as a model for improving clinical appropriateness in autoimmune diagnostics

Reflex tests are widely used in clinical laboratories, for example, to diagnose thyroid disorders or in the follow-up of prostate cancer. Reflex tests for antinuclear antibodies (ANA) have recently gained attention as a way to improve appropriateness in the immunological diagnosis of autoimmune rheumatic diseases and avoid waste of resources. However, the ANA-reflex test is not as simple as other consolidated reflex tests (the TSH-reflex tests or the PSA-reflex tests) because of the intrinsic complexity of the ANA test performed by the indirect immunofluorescence method on cellular substrates. The wide heterogeneity of the ANA patterns, which need correct interpretation, and the subsequent choice of the most appropriate confirmatory test (ANA subserology), which depend on the pattern feature and on clinical information, hinder any informatics automation, and require the pathologist's intervention. In this review, the Study Group on Autoimmune Diseases of the Italian Society of Clinical Pathology and Laboratory Medicine provides some indications on the configuration of the ANA-reflex test, using two different approaches depending on whether clinical information is available or not. We further give some suggestions on how to report results of the ANA-reflex test.

Atopic diseases and inflammation of the brain in the pathogenesis of autism spectrum disorders

Autism spectrum disorders (ASDs) affect as many as 1 in 45 children and are characterized by deficits in sociability and communication, as well as stereotypic movements. Many children also show severe anxiety. The lack of distinct pathogenesis and reliable biomarkers hampers the development of effective treatments. As a result, most children with ASD are prescribed psychopharmacologic agents that do not address the core symptoms of ASD. Autoantibodies against brain epitopes in mothers of children with ASD and many such children strongly correlate with allergic symptoms and indicate an aberrant immune response, as well as disruption of the blood-brain barrier (BBB). Recent epidemiological studies have shown a strong statistical correlation between risk for ASD and either maternal or infantile atopic diseases, such as asthma, eczema, food allergies and food intolerance, all of which involve activation of mast cells (MCs). These unique tissue immune cells are located perivascularly in all tissues, including the thalamus and hypothalamus, which regulate emotions. MC-derived inflammatory and vasoactive mediators increase BBB permeability. Expression of the inflammatory molecules interleukin (IL-1β), IL-6, 1 L-17 and tumor necrosis factor (TNF) is increased in the brain, cerebrospinal fluid and serum of some patients with ASD, while NF-kB is activated in brain samples and stimulated peripheral blood immune cells of other patients; however, these molecules are not specific. Instead the peptide neurotensin is uniquely elevated in the serum of children with ASD, as is corticotropin-releasing hormone, secreted from the hypothalamus under stress. Both peptides trigger MC to release IL-6 and TNF, which in turn, stimulate microglia proliferation and activation, leading to disruption of neuronal connectivity. MC-derived IL-6 and TGFβ induce maturation of Th17 cells and MCs also secrete IL-17, which is increased in ASD. Serum IL-6 and TNF may define an ASD subgroup that benefits most from treatment with the natural flavonoid luteolin. Atopic diseases may create a phenotype susceptible to ASD and formulations targeting focal inflammation of the brain could have great promise in the treatment of ASD.

Comparison of Screening Dilution and Automated Reading for Antinuclear Antibody Detection on HEP2 Cells in the Monitoring of Connective Tissue Diseases

BACKGROUND

Indirect immunofluorescence plays a major role in the detection of antinuclear antibodies (ANAs) and follow-up of their titers in the context of connective tissue diseases. Given the numerous unfavorable features of the conventional manual reading of HEP2 slides (need of time and expert morphologists for the reading, lack of standardization, subjectivity of the interpretation), the biomedical industry has developed automated techniques of slide preparation and microscope reading.

METHODS

We collected 49 sera beforehand analyzed by the conventional reading of slides. They were prepared again by QUANTA-Lyser(®) and reanalyzed in four different conditions: two dilutions of screening (1/40 and 1/80), two different systems of analysis, NOVA View(®) automated reading (INOVA Diagnostics), then confirmation by the operator, and conventional manual reading by two different qualified operators. The analysis was realized in blind of the first interpretation and clinical diagnosis. The sera were classified in four groups, on the basis of the results of the first analysis: negative sera (titer < 1/160; 11 patients), low positives (titer at 1/160; 18 patients), moderated positives (titers between 1/320 and 1/640; 10 patients), and strong positives (titers between 1/1,280 and 1/2,560; 10 patients).

RESULTS

Among the 49 patients, 13 presented a connective tissue disease including 4 systemic scleroderma (SS), 3 rheumatoid arthritis (RA), 2 Goujerot-Sjogren (GS), 2 systemic lupus erythematosus (SLE), 1 polymyositis (PM), 1 Raynaud's syndrome (RS), and 1 CREST syndrome. One patient presented both an SLE and an SS. Regarding the screening dilution, the 1/40 dilution is less specific than the 1/80 dilution for both the systems of analysis (5.6% vs. 16.7% for the manual reading, and 27.8% vs. 50% for the automated reading). It also generates statistically more false positives (P = 0.037 for the conventional analysis and P = 0.003 for the automated system). The automated NOVA View(®) reading of slides allows a gain in specificity for both dilutions, and also statistically less false positives (P = 0.002 at the 1/40 and P = 0.0006 at the 1/80), and detriment of the sensitivity at the highest dilution (84.6% vs. 92.3% with manual reading). Thus, according to our analysis of 49 sera, the automated NOVA View(®) system of reading of slides at the dilution 1/80 seems to be a successful condition for the detection of ANAs on HEP2 cells, close to the significance (P = 0.067).

CONCLUSION

The automated NOVA View(®) reading of slides allows saving time, and an improvement in the standardization. Nevertheless, it requires a confirmation by a qualified operator, to interpret mixed patterns in particular.

Anti-pseudo-PCNA type 1 (anti-SG2NA) pattern: Track down Cancer, not SLE

OBJECTIVE

Describe the clinical significance of anti-SG2NA antibodies also called anti-pseudo-PCNA type 1 (proliferating cell nuclear antigen auto-antibodies) which are rare antinuclear antibodies (ANAs) staining distinctly S/G2 proliferative HEp-2 cells by indirect immunofluorescence. By analogy with anti-PCNA antibodies, they have been suspected to be associated with systemic lupus erythematosus (SLE), cancers or viral diseases.

METHODS

From May 2006 to February 2013, 16,827 patients were tested positive for ANAs in the Laboratory of Immunology, Strasbourg, France. We retrospectively analyzed clinical and biological data from 126 patients with anti-pseudo-PCNA type 1 antibodies.

RESULTS

There was a 0.75% prevalence of anti-pseudo-PCNA type 1 Abs among ANAs(+) patients. Median age was 56.9 years (standard deviation [SD] 13.4 years) with a sex ratio female/male of 1.9. Compared to ANAs(+) patients, many more patients have been hospitalized in the Oncology and Hematology Department (23% vs. 6.3%, P < 0.05). Indeed, anti-pseudo-PCNA type 1 Abs were detected in 33 patients suffering from solid and hematological cancers (26%). Another group of patients presented various auto-immune diseases but surprisingly none of our patients was affected with SLE when 5 out of 8 patients in anti-PCNAs(+) Abs group (P < 5.10(-6)) were. Finally, the presence of anti-pseudo-PCNA type 1 Abs was associated in 30 cases with other auto-Abs reflecting a more general breakdown of B cell tolerance against other self-antigens.

CONCLUSION

Considering our results, explorations for tumors should be at least recommended for patients with anti-pseudo-PCNA type 1 Abs. Lupus disease is not associated with these autoAbs.

Unique topics and issues in rheumatology and clinical immunology

Clinicians are facing unexpected issues in everyday practice, and these may become counterintuitive or challenging. Illustrative examples are provided by the hypersensitivity to universally used immunosuppressants such as corticosteroids or antibiotics such as beta-lactam. Secondly, additional issues are represented by the discovery of new pathogenetic mechanisms involved in rheumatoid and psoriatic arthritis or other chronic inflammatory diseases, genomic susceptibility to enigmatic diseases such as giant cell arteritis, or the shared role of specific mediators such as semaphorins. Third, the therapeutic armamentarium has dramatically changed over the past decade following the introduction of biotechnological drugs, and new mechanisms are being proposed to reduce adverse events or increase the drug effectiveness, particularly on cardiovascular comorbidities. Finally, rare diseases continue to represent difficult cases, as for Cogan's syndrome, with limited literature available for clinical recommendations. For these reason, the present issue of Clinical Reviews in Allergy and Immunology is timely and dedicated to these and other unique topics in clinical immunology and allergy. The aim of this issue is thus to help clinicians involved in internal medicine as well as allergists and clinical immunologists while discussing new pathways that will prove important in the near future.

Autoimmunity in 2013

The peer-reviewed publications in the field of autoimmunity published in 2013 represented a significant proportion of immunology articles and grew since the previous year to indicate that more immune-mediated phenomena may recognize an autoimmune mechanism and illustrated by osteoarthritis and atherosclerosis. As a result, our understanding of the mechanisms of autoimmunity is becoming the paradigm for translational research in which the progress in disease pathogenesis for both tolerance breakdown and inflammation perpetuation is rapidly followed by new treatment approaches and clinical management changes. The similarities across the autoimmune disease spectrum outnumber differences, particularly when treatments are compared. Indeed, the therapeutics of autoimmune diseases are based on a growing armamentarium that currently includes monoclonal antibodies and small molecules which act by targeting molecular markers or intracellular mediators with high specificity. Among the over 100 conditions considered as autoimmune, the common grounds are well illustrated by the data reported for systemic lupus erythematosus and rheumatoid arthritis or by the plethora of studies on Th17 cells and biomarkers, particularly serum autoantibodies. Further, we are particularly intrigued by studies on the genomics, epigenetics, and microRNA at different stages of disease development or on the safe and effective use of abatacept acting on the costimulation of T and B cells in rheumatoid arthritis. We are convinced that the data published in 2013 represent a promising background for future developments that will exponentially impact the work of laboratory and clinical scientists over the next years.

Report of the First International Consensus on Standardized Nomenclature of Antinuclear Antibody HEp-2 Cell Patterns 2014-2015

During the 12th International Workshop on Autoantibodies and Autoimmunity held in Sao Paulo, Brazil, on August 28, 2014, a full day session was devoted to establishing a consensus on the nomenclature of staining patterns observed in the antinuclear antibody (ANA) indirect immunofluorescence test on HEp-2 cells. The current report summarizes the collective agreements with input from the host Brazilian and international communities that represented research, clinical, and diagnostic service laboratories. Patterns are categorized in three major groups (nuclear, cytoplasmic, and mitotic patterns) and each pattern has been defined and described in detail. The consensus nomenclature and representative patterns are made available online at the international consensus on antinuclear antibody pattern (ICAP) website (www.ANApatterns.org). To facilitate continuous improvement and input, specific comments on ICAP are encouraged and these will be discussed in subsequent ICAP meetings. The ultimate goal with the establishment of the ICAP is to promote harmonization and understanding of autoantibody test nomenclature, as well as interpretation guidelines for ANA testing, thereby optimizing usage in patient care.

Report of the First International Consensus on Standardized Nomenclature of Antinuclear Antibody HEp-2 Cell Patterns 2014-2015

During the 12th International Workshop on Autoantibodies and Autoimmunity held in Sao Paulo, Brazil, on August 28, 2014, a full day session was devoted to establishing a consensus on the nomenclature of staining patterns observed in the antinuclear antibody (ANA) indirect immunofluorescence test on HEp-2 cells. The current report summarizes the collective agreements with input from the host Brazilian and international communities that represented research, clinical, and diagnostic service laboratories. Patterns are categorized in three major groups (nuclear, cytoplasmic, and mitotic patterns) and each pattern has been defined and described in detail. The consensus nomenclature and representative patterns are made available online at the international consensus on antinuclear antibody pattern (ICAP) website (www.ANApatterns.org). To facilitate continuous improvement and input, specific comments on ICAP are encouraged and these will be discussed in subsequent ICAP meetings. The ultimate goal with the establishment of the ICAP is to promote harmonization and understanding of autoantibody test nomenclature, as well as interpretation guidelines for ANA testing, thereby optimizing usage in patient care.

Genetics and novel aspects of therapies in systemic lupus erythematosus

Autoimmune diseases, such as rheumatoid arthritis, multiple sclerosis, autoimmune hepatitis and inflammatory bowel disease, have complex pathogeneses and the factors which cause these disorders are not well understood. But all have in common that they arise from a dysfunction of the immune system, interpreting self components as foreign antigens. Systemic lupus erythematosus (SLE) is one of these complex inflammatory disorders that mainly affects women and can lead to inflammation and severe damage of virtually any tissue and organ. Recently, the application of advanced techniques of genome-wide scanning revealed more genetic information about SLE than previously possible. These case-control or family-based studies have provided evidence that SLE susceptibility is based (with a few exceptions) on an individual accumulation of various risk alleles triggered by environmental factors and also help to explain the discrepancies in SLE susceptibility between different populations or ethnicities. Moreover, during the past years new therapies (autologous stem cell transplantation, B cell depletion) and improved conventional treatment options (corticosteroids, traditional and new immune-suppressants like mycophenolate mofetile) changed the perspective in SLE therapeutic approaches. Thus, this article reviews genetic aspects of this autoimmune disease, summarizes clinical aspects of SLE and provides a general overview of conventional and new therapeutic approaches in SLE.

Clinical aspects of indirect immunofluorescence for autoimmune diseases

Because the most common term used in conversations considering autoimmunity is autoantibodies, it is well-expected that the indirect immunofluorescence assay, which detects antibodies directed against various antigens, is one of our most impressive techniques for investigating autoimmune diseases (AIDs). Roughly speaking, the current literature corroborates that this immunopathologic investigation means that autoantibodies detection makes a considerable contribution to both diagnostic and prognostic aspects of AIDs in the clinical setting. However, it varies between different AIDs, autoantibodies, ethnicities or detection methodologies. Directly focusing on the indirect immunofluorescence assay, we present evidence to support this multidimensional variation regarding the subject via reviewing briefly the best-investigated autoantibodies in the well-documented AIDs, including vasculitis, inflammatory bowel disease, scleroderma, autoimmune hepatitis, primary biliary cirrhosis, systemic lupus erythematosus and Sjögren's syndrome.

Autoantibodies 2015: From diagnostic biomarkers toward prediction, prognosis and prevention

At the 12th International Workshop on Autoantibodies and Autoimmunity (IWAA), organized in August 2014 in Sao Paulo, Brazil, more than 300 autoimmunologists gathered to discuss the status of many novel autoantibodies in clinical practice, and to envisage additional value of autoantibodies in terms of prediction, prognosis and prevention of autoimmune diseases. Two separate workshops were dedicated to standardization and harmonization of autoantibody testing and nomenclature: International Autoantibody Standardization (IAS) and International Consensus on ANA Patterns (ICAP). It was apparent to all in attendance that the discovery and elucidation of novel autoantibodies did not slow down, but that multiple challenges lay ahead of us in order to apply these discoveries to effective and efficient clinical practice. Importantly, this requires optimal bidirectional communication between clinicians and laboratory specialists, as well as close collaboration with the diagnostic industry. This paper is a report on the 12th IWAA in combination with a review of the recent developments in the field of autoantibodies.

Diagnostic profile on the IFA 40: HEp-20-10 - an immunofluorescence test for reliable antinuclear antibody screening

Indirect immunofluorescence assay is the recommended gold standard to test for antinuclear antibodies (ANA), which are important biomarkers for systemic rheumatic autoimmune diseases. It is internationally accepted that indirect immunofluorescence assay ANA screening is most sensitive on human epithelial (HEp-2) cells. The cells present a multitude of antigens that display distinguishable localization patterns in interphase and mitotic cells in indirect immunofluorescence analysis. Here, we present the IFA 40: HEp-20-10 test kit (Euroimmun AG, Lübeck, Germany), which is cleared for sale on the US market by the FDA. The test has been designed for qualitative and semiquantitative screening of ANA in human sera. It uses the commonly applied 1:40 cutoff dilution and the enhanced HEp-20-10 cell line for more efficient pattern recognition and has been validated in various studies and by method comparison. The IFA 40: HEp-20-10 test fulfills the essential criteria for reliable application in autoimmune diagnostics.

A comparison of anti-nuclear antibody quantification using automated enzyme immunoassays and immunofluorescence assays

Anti-nuclear antibodies (ANA) have traditionally been evaluated using indirect fluorescence assays (IFA) with HEp-2 cells. Quantitative immunoassays (EIA) have replaced the use of HEp-2 cells in some laboratories. Here, we evaluated ANA in 400 consecutive and unselected routinely referred patients using IFA and automated EIA techniques. The IFA results generated by two independent laboratories were compared with the EIA results from antibodies against double-stranded DNA (dsDNA), from ANA screening, and from tests of the seven included subantigens. The final IFA and EIA results for 386 unique patients were compared. The majority of the results were the same between the two methods (n = 325, 84%); however, 8% (n = 30) yielded equivocal results (equivocal-negative and equivocal-positive) and 8% (n = 31) yielded divergent results (positive-negative). The results showed fairly good agreement, with Cohen's kappa value of 0.30 (95% confidence interval (CI) = 0.14–0.46), which decreased to 0.23 (95% CI = 0.06–0.40) when the results for dsDNA were omitted. The EIA method was less reliable for assessing nuclear and speckled reactivity patterns, whereas the IFA method presented difficulties detecting dsDNA and Ro activity. The automated EIA method was performed in a similar way to the conventional IFA method using HEp-2 cells; thus, automated EIA may be used as a screening test.