Evidence-based guidelines for the use of immunologic tests: antinuclear antibody testing

Measurements of Endpoint Titers Based on the Fluorescence Intensity Trend in Anti-Nuclear Antibody Testing

BACKGROUND

Automated systems for antinuclear antibody (ANA) testing provide endpoint titers that are predicted based on the fluorescence intensity (FI) value at a screening dilution (single-well titration [SWT]) showing frequent titration errors (more than plus or minus 1 dilution).

METHODS

Line slope titration (LST) was based on the trend of FI values on dilutions. Three dilutions per specimen were prepared considering a patient's previous titer or FI at the screening dilution. On the XY plot, with the reciprocal of dilution as the X-axis and FI value as the Y-axis, a fitted line was drawn to obtain the endpoint titers.

RESULTS

The titration error rate (no. of errors/total no.) of LST using a regression line was lower than that of SWT (31/710 [4.4%] and 152/674 [22.6%], respectively; P < .000000001), with serial dilution as a reference. When comparing a regression line using 3 dilution points with a line using 2 dilution points, the error rate of the former was not significantly different from that of the latter (31/710 [4.4%] and 31/746 [4.2%], respectively; P = .842).

CONCLUSIONS

This LST method is useful as an accurate, cost-effective, and rapid approach to measure endpoint titers in routine ANA testing.

Effectiveness of pirfenidone in idiopathic pulmonary fibrosis according to the autoantibody status: a retrospective cohort study

Background

Pirfenidone is an anti-fibrotic agent shown to slow the progression of idiopathic pulmonary fibrosis (IPF). However, its effectiveness in association with serological autoimmune features in IPF remains unclear.

Methods

We retrospectively reviewed the medical records of patients with IPF treated at a tertiary care hospital in South Korea. The autoantibody status was defined as positive if we detected autoantibodies meeting the serological domain criteria for interstitial pneumonia with autoimmune features or anti-neutrophil cytoplasmic antibodies.

Results

We included 142 patients with IPF treated with pirfenidone for over six months (93 were autoantibody-positive and 49 were autoantibody-negative). The mean age was 69.5 ± 7.3 years, and 77.5% of the patients were male. The adjusted mean changes over one year were − 34.4 and − 112.2 mL (p = 0.168) in forced vital capacity (FVC), and − 0.53 and − 0.72 mL/mmHg/min (p = 0.356) in the lungs diffusion capacity for carbon monoxide (DL_CO) in the autoantibody-negative and autoantibody-positive groups, respectively.

Conclusions

Reductions in FVC and DL_CO were similar in autoantibody-positive and autoantibody-negative patients with IPF treated with pirfenidone. Pirfenidone is effective in attenuating the progression of IPF, irrespective of the autoantibody status.

Clinical utility of ANA-ELISA vs ANA-immunofluorescence in connective tissue diseases

We investigated the performance of ANA-ELISA for CTDs screening and diagnosis and comparing it to the conventional ANA-IIF. ANA-ELISA is a solid-phase immune assay includes 17 ANA-targeted recombinant antigens; dsDNA, Sm-D, Rib-P, PCNA, U1-RNP (70, A, C), SS-A/Ro (52 and 60), SS-B/La, Centromere B, Scl-70, Fibrillarin, RNA Polymerase III, Jo-1, Mi-2, and PM-Scl. During the period between March till December 2016 all requests for ANA from primary, secondary, and tertiary care centers were processed with both techniques; ANA-IIF and ANA-ELISA. The electronic medical record of these patients was reviewed looking for CTD diagnosis documented by the Senior rheumatologist. SPSS 22 is used for analysis. Between March and December 2016, a total of 12,439 ANA tests were requested. 1457 patients were assessed by the rheumatologist and included in the analysis. At a cut-off ratio ≥ 1.0 for ANA-ELISA and a dilutional titre ≥ 1:80 for ANA-IIF, the sensitivity of ANA-IIF and ANA-ELISA for all CTDs were 63.3% vs 74.8% respectively. For the SLE it was 64.3% vs 76.9%, Sjogren's Syndrome was 50% vs 76.9% respectively. The overall specificity of ANA-ELISA was 89.05%, which was slightly better than ANA-IIF 86.72%. The clinical performance of ANA-ELISA for CTDs screening showed better sensitivity and specificity as compared to the conventional ANA-IIF in our cohort.

Engineering Advanced In Vitro Models of Systemic Sclerosis for Drug Discovery and Development

Systemic sclerosis (SSc) is a complex multisystem disease with the highest case-specific mortality among all autoimmune rheumatic diseases, yet without any available curative therapy. Therefore, the development of novel therapeutic antifibrotic strategies that effectively decrease skin and organ fibrosis is needed. Existing animal models are cost-intensive, laborious and do not recapitulate the full spectrum of the disease and thus commonly fail to predict human efficacy. Advanced in vitro models, which closely mimic critical aspects of the pathology, have emerged as valuable platforms to investigate novel pharmaceutical therapies for the treatment of SSc. This review focuses on recent advancements in the development of SSc in vitro models, sheds light onto biological (e.g., growth factors, cytokines, coculture systems), biochemical (e.g., hypoxia, reactive oxygen species) and biophysical (e.g., stiffness, topography, dimensionality) cues that have been utilized for the in vitro recapitulation of the SSc microenvironment, and highlights future perspectives for effective drug discovery and validation.

Antinuclear Antibody Testing for the Diagnosis of Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is an autoimmune inflammatory condition that may involve multiple organ systems. Although the antinuclear antibody (ANA) test is positive in nearly every case of SLE, it is not specific for this disease and must be interpreted in the appropriate clinical context. Key features that warrant ANA testing include unexplained multisystem inflammatory disease, symmetric joint pain with inflammatory features, photosensitive rash, and cytopenias. ANA staining patterns and more specific autoantibody testing may be helpful in diagnosis of suspected SLE or ANA-associated disease. For patients with nonspecific symptoms, such as malaise and fatigue, ANA testing is of limited value.

Standardization and Quality Assessment Under the Perspective of Automated Computer-Assisted HEp-2 Immunofluorescence Assay Systems

The recent availability of automated computer-assisted diagnosis (CAD) systems for the reading and interpretation of the anti-nuclear antibody (ANA) test performed with the indirect immunofluorescence (IIF) method on HEp-2 cells, has improved the reproducibility of the results and initiated a process of harmonization of this test. Furthermore, CAD systems provide quantitative expression of fluorescence intensity, allowing the introduction of objective quality control procedures to the monitoring of the entire process. The calibration of the reading systems and the automated image interpretation are essential prerequisites for obtaining reproducible and harmonized IIF test results and form the basis for standardization, regardless of the computer algorithms used in the different systems. The use of automated CAD systems, facilitating control procedures, represents a step forward for the quality certification of the laboratory.

Celiac Disease as a Rare Cause of Membranous Nephropathy: A Case Report

Membranous nephropathy is the most common cause of nephrotic syndrome in adults. A non-negligible number of cases are associated with systemic conditions. We report a case of a 50-year-old man who presented with nephrotic syndrome six months after being diagnosed with celiac disease. Although the patient showed disappearance of circulating immunoglobulin A (IgA) anti-tissue transglutaminase antibodies following a gluten-free diet, he had a sudden onset of nephrotic syndrome presenting with severe hypoalbuminemia. Other secondary causes were promptly excluded leading to the assumption of celiac disease-associated membranous nephropathy with remission after treatment with angiotensin system blockade and a gluten-free diet. The goal of this case report is to alert the clinic towards this rare association aiming for an early diagnosis and adequate selection of long-term therapy.

Stratification of Nuclear Homogeneous Patterns on HEp-2 Cells Based on Neutrophil Nuclear Staining

Antinuclear antibody (ANA) testing is used to diagnose systemic autoimmune rheumatic disease (SARD). Nuclear homogeneous patterns on ANA-HEp-2 cells can result from anti-double-stranded DNA (dsDNA), anti-nucleosome, anti-histone, anti-Scl-70, or anti-dense fine speckles 70 (DFS70) antibodies (Abs). This study aimed to find a way to discriminate DFS70 Abs from others by way of assessing neutrophil nuclear staining on anti-neutrophil cytoplasmic antibody (ANCA) testing. Nuclear staining on ANCA-neutrophils was assessed to stratify nuclear homogeneous patterns on ANA-HEp-2 cells. Enrolled subjects included (1) young individuals with a dense fine speckled pattern on ANA testing (young non-SARD group, n=71) and patients with (2) systemic lupus erythematosus (SLE group, n=35); (3) rheumatoid arthritis possibly with histone, nucleosome Abs, and others (RA group, n=51); and (4) diffuse systemic sclerosis with Scl-70 Abs (diffuse SSc group, n=19). Negative rates (95% confidence interval) of neutrophil nuclear staining were 97.2% (90.2%-99.7%) in the young non-SARD group, 2.9% (0.1%-14.9%) in the SLE group, 3.9% (0.5%-13.5%) in the RA group, and 47.4% (24.5%-71.1%) in the diffuse SSc group. The negative rate of the young non-SARD group was significantly higher than those of the other groups (all p<0.05). In conclusion, this study suggests that the assessment of nuclear staining on ANCA-neutrophils can help to stratify nuclear homogeneous patterns on ANA-HEp-2 cells and thus to determine whether the ANA pattern is attributed to DFS70 Abs, which can be found in healthy individuals, especially in young individuals.

Association between endometriosis and risk of systemic lupus erythematosus

To examine the association between endometriosis and the risk of systemic lupus erythematosus (SLE), this nationwide, population-based, retrospective cohort study was conducted based on National Health Insurance Research Database in Taiwan. Endometriosis (N = 16,758) and non-endometriosis (N = 16,758) groups were identified by matching baseline characteristics and comorbidities. Student's t-tests and the Kaplan-Meier estimator were utilized to estimate the hazard ratio (HR) and cumulative probability of SLE in the two groups. The endometriosis group showed a significantly higher incidence density rate (0.3 vs. 0.1 per 1000 person-years) and hazard ratio in SLE group (adjusted HR [aHR], 2.37; 95% confidence interval [CI] 1.35-4.14) compared to the non-endometriosis group. Subgroup analysis revealed that patients with endometriosis between 30 and 45 years of age, or were non-steroidal anti-inflammatory drug users, or were hormonal medications-free participants, had higher risks of SLE. For patients with endometriosis, surgical intervention did not significantly impact on the risk of SLE. Our results demonstrated an increased risk of SLE in patients with endometriosis. Clinicians should be aware of this association when managing patients with endometriosis or SLE.

Unprovoked internal jugular vein thrombosis: a case report and literature review

Background

Managing thrombosis in rare sites is challenging. Existing studies and guidelines provide detailed explanations on how to overcome lower-limb thromboses and pulmonary embolisms, but few studies have examined thrombosis in rare sites. Lack of data makes clinical practice heterogeneous. Recommendations for diagnosing, treating, and following-up internal jugular vein thrombosis are not clearly defined and mostly based on adapted guidelines for lower-limb thrombosis.

Case presentation

A 52-year-old Caucasian woman came to the Emergency Department with chest, neck, and left arm pain. Computed tomography imagery showed a left internal jugular vein thrombosis. An extensive workup revealed a heterozygous factor V Leiden gene. Therapy was initiated with intravenous unfractionated heparin, then switched to oral acenocoumarol, which resolved the symptoms. Based on this case presentation and a literature review, we summarize the causes, treatment options, and prognosis of unprovoked internal jugular vein thrombosis.

Conclusions

Managing internal jugular vein thrombosis lacks scientific data from large randomized clinical trials, partly because such thromboses are rare. Our literature review suggested that clinical treatments for internal jugular vein thrombosis often followed recommendations for treating lower-limb thrombosis. Future specific studies are required to guide clinicians on the modalities of diagnosis, screening for thrombophilia or oncologic disease, treatment duration, and follow-up.

Analysis of antinuclear antibody titers and patterns by using HEp-2 and primate liver tissue substrate indirect immunofluorescence assay in patients with systemic autoimmune rheumatic diseases

BACKGROUND

Indirect immunofluorescence assay (IIFA) is viewed as a preliminary standard to assess antinuclear antibodies (ANAs). Our aim was to explore ANA positivity rate, titers, and patterns in patients with systemic autoimmune rheumatic diseases (SARD), including systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), primary Sjögren's syndrome (pSS), systemic sclerosis (SSc), and mixed connective tissue disease (MCTD), compared with healthy controls (HC).

METHODS

Assess antinuclear antibody titers and patterns were retrospectively identified and compared by IIFA using human epithelial cells (HEp-2) and primate liver tissue substrate according to international consensus in SARD. Serum complement 3 (C3), C4, and immunoglobulin G were compared among subgroups with different ANA titers. The positive predictive values (PPV) for different ANA titers were calculated.

RESULTS

There were a total of 3510 samples, including 2034 SLE, 973 RA, 155 SSc, 309 pSS, and 39 MCTD cases. There was no difference in age between HC and SARD, excluding RA. ANA positivity rate in SARD and HC was 78.7% and 12.2%, respectively. A titer of ≥1:320 revealed a PPV of 84.0% in SARD. SLE patients with ANA titers ≥1:320 had significantly lower levels of C3 and C4. AC-4 (31.2%) was the major pattern in patients with SARD, followed by AC-5 (23.9%) and AC-1 (18.8%). SLE mostly presented with AC-4 (30.3%). Several mixed patterns provided a significant hint for SSc and SLE. The major pattern in HC was AC-2 (12.2%).

CONCLUSIONS

Assess antinuclear antibody positivity, titers, and patterns display differences in various SARD, contributing to the classification of SARD.

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.

Different indirect immunofluorescence ANA substrate performance in a diagnostic setting of patients with SLE and related disorders: retrospective review and analysis

OBJECTIVE

Given the increasing relevance of the ANA assay to classification of SLE and the uncertainty and variation surrounding different ANA assay performance, we compared the human epithelial type 2 (HEp-2) to mouse liver (ML) substrate in our local cohort and provided a review of the evidence for their use in autoimmune rheumatic diseases (ARDs).

METHODS

Electronic health record data (2003-2008) were used to identify patients who had concurrent HEp-2 and ML ANA, and a diagnosis of SLE or other ARDs. We determined the agreement between HEp-2 and ML ANA regarding positivity, titre and pattern, and their predictors. Sensitivity of HEp-2 ANA, ML ANA, repeating HEp-2 ANA, and combining HEp-2 and ML ANA assays was assessed.

RESULTS

There were 961 patients with concurrent HEp-2 and ML ANA samples, including 418 SLEs. There was generally fair to moderate agreement in HEp-2 and ML ANA (kappa (κ)=0.35-0.79), titres (κ=0.34-0.79) and patterns (κ=0.35-0.93). In SLE, the presence of anti-dsDNA antibodies was predictive of ANA agreement between HEp-2 and ML ANA (adjusted OR 6.27, 95% CI 1.45 to 27.20, p=0.01). The ANA sensitivity for most ARDs was highest when the HEp-2 test was repeated, followed by when the HEp-2 and ML ANA were combined and when only the HEp-2 or ML ANAs were used.

CONCLUSION

In keeping with prior studies, we demonstrated that there was fair to moderate agreement between HEp-2 and ML assays in the largest comparison of HEp-2 and ML as substrates for ANA testing in various ARDs. Furthermore, ANA sensitivity was higher when the HEp-2 assay was repeated rather than combining HEp-2 and ML.

The antinuclear antibody dense fine speckled pattern and possible clinical associations: An indication of a proinflammatory microenvironment

BACKGROUND

Indirect immunofluorescence (IIF) is the most prevalent screening antinuclear antibody test for systemic autoimmune rheumatic disease (SARD). Certain IIF patterns have known antibody and disease associations, but the dense fine speckled (ANA-DFS) pattern has no confirmed clinical associations. Our objective was to determine the prevalence of SARD among a group of ANA-DFS positive individuals and to identify final diagnoses among non-SARD individuals in order to determine possible clinical associations with the ANA-DFS pattern.

METHODS

A retrospective study of 425 patients from a university health care system with a positive ANA-DFS pattern consecutively between August 2017 and September 2018. Sera samples underwent ANA testing by IIF on HEp-2 cell substrates (Euroimmun, Germany). Clinical information was retrieved from electronic health records and stored in a de-identified database.

RESULTS

The prevalence of SARD was 24%. Undetermined diagnosis (17%), skin disorders (12.1%), and fibromyalgia/chronic pain syndrome/chronic fatigue syndrome (11.8%) were the most common non-SARD diagnoses. Taking into account past medical history, the most common non-SARD were atopic disorders (21.2%), fibromyalgia/chronic pain syndrome/chronic fatigue syndrome (17.6%), and skin disorders (16.7%).

CONCLUSIONS

The ANA-DFS pattern may be indicative of an underlying antigen-antibody interaction that plays a role in either the initiation or propagation of immunologic reactions. DFS70/LEDGF is a transcription factor involved in cell survival and stress protection, and autoantibodies may inhibit its function. It is likely that there are other antibodies producing the ANA-DFS pattern besides anti-DFS70/LEDGF, and more research is necessary to identify additional antibody specificities. The ANA-DFS pattern may be an indicator of a proinflammatory microenvironment given the high frequency of symptomatic patients and disease processes with an immunologic basis (including SARD).

Evaluation of a novel latex enhanced turbidimetric immunoassay for detecting autoantibody against extractable nuclear antigens

Detection of autoantibody against extractable nuclear antigens (ENAs) plays a critical role in the diagnosis and management of autoimmune diseases.In this study, we assessed the performance of LETIA in detecting anti-ENAs. Total 606 serum samples from the Second Hospital of Shanxi Medical University were collected. Anti-SSA, anti-SSB, anti-Sm, anti-U1-snRNP, and anti-Sm/RNP were parallelly detected by LETIA and line immunoblot (LIA). Besides, this study assessed LETIA for its repeatability in detecting anti-ENAs autoantibodies, and consistency with LIA. A receiver operating characteristic (ROC) curves was drawn to assess the accuracy of LETIA. The LETIA and LIA showed high coincidence rate in detecting anti-SSA, anti-SSB, anti-Sm, anti-U1-snRNP, and anti-Sm/RNP autoantibodies, with the results being 87.22%, 96.61%, 97.03%, 88.28%, and 92.06%, respectively. Almost perfect consistency (kappa > 0.8) were found in the detection of anti-SSB and anti-Sm by LETIA and LIA. While in the detection of anti-SSA, anti-U1-snRNP, and anti-Sm/RNP, moderate consistency (0.6 ⩽ kappa ⩽ 0.8) were shown. The AUCs of anti-SSA, anti-SSB, anti-Sm, anti-U1-snRNP, and anti-Sm/RNP detected by LETIA were 0.972 (95% confidence interval (CI): 0.941–1.000, p < 0.001), 0.986 (95% CI: 0.967–1.000, p < 0.001), 0.912 (95% CI: 0.763–1.000, p < 0.001), 0.829 (95% CI: 0.731–0.928, p < 0.001), and 0.828 (95% CI: 0.715–0.941, p < 0.001), respectively. LETIA and LIA showed considerable consistency in detecting anti-ENAs. Moreover, with the pronounced advantages of automatic and rapid detection, and high universality, LETIA can meet the requirements for quantitative detection of anti-ENAs.

E-consults: an effective way to decrease clinic wait times in rheumatology

Background

To evaluate the effect of E-consults on wait times and resource utilization for positive antinuclear antibody (ANA) referrals in outpatient rheumatology.

Methods

We conducted a pre-post study of E-consult implementation for positive ANA referrals. We retrospectively reviewed “positive ANA” referrals from 1/2015–3/2017. A statistical process control chart was created to display monthly average wait times for in-person clinic visits and to identify special cause variation. Final diagnoses, wait times and resource utilization were recorded and compared between E-consults and in-person referrals.

Results

There were 139 referrals for positive ANA with 126 occurring after E-consult implementation in August 2015. Forty-four percent (55/126) of referrals were E-consults; 76% did not have an in-person visit after initial electronic rheumatology recommendation. A control chart demonstrated special cause variation in the form of a shift from June 2016 – January 2017, suggesting a temporal association between decreased wait times and the implementation of E-consults. Eleven patients were diagnosed with ANA-associated rheumatic disease; the majority of patients (73%, 86/139) did not have a rheumatologic diagnosis. Overall E-consults utilized more labs than in-person visits, but this was not statistically significant. In-person visits utilized more imaging studies, which was statistically significant.

Conclusion

E-consults are an effective way to address positive ANA consults without significant increase in resource utilization and were temporally associated with decreased wait times for in-person visits.

A Broader Perspective on Anti-Ro Antibodies and Their Fetal Consequences-A Case Report and Literature Review

The presence of maternal Anti-Ro/Anti-La antibodies causes a passively acquired autoimmunity that may be associated with serious fetal complications. The classic example is the autoimmune-mediated congenital heart block (CHB) which is due in most cases to the transplacental passage of Anti-Ro/Anti-La antibodies. The exact mechanisms through which these pathologic events arise are linked to disturbances in calcium channels function, impairment of calcium homeostasis and ultimately apoptosis, inflammation and fibrosis. CHB still represents a challenging diagnosis and a source of debate regarding the best management. As the third-degree block is usually irreversible, the best strategy is risk awareness and prevention. Although CHB is a rare occurrence, it affects one in 20,000 live births, with a high overall mortality rate (up to 20%, with 70% of in utero deaths). There is also concern over the lifelong consequences, as most babies need a pacemaker. This review aims to offer, apart from the data needed for a better understanding of the issue at hand, a broader perspective of the specialists directly involved in managing this pathology: the rheumatologist, the maternal-fetal specialist and the cardiologist. To better illustrate the theoretical facts presented, we also include a representative clinical case.

New findings associated with presumptive systemic lupus erythematosus in a kitten

CASE SUMMARY

An 8-month-old neutered male domestic shorthair kitten was examined for anorexia, lethargy and palatine ulcers. Systemic lupus erythematosus (SLE) was suspected based on a positive antinuclear antibody (ANA) titer and six manifestations of autoimmunity: fever, paronychia, oral ulcers, proteinuria, thrombocytopenia and leukopenia. Mastocytemia was observed on the blood smear. Although the clinical presentation of this case meets the classification criteria for SLE in humans, tick-borne disease and histopathology evaluation of the oral and cutaneous lesions would have been necessary to support a definite diagnosis of SLE. Baseline ANA titration was performed in two laboratories with conflicting results, which may reflect substrate differences used for the titration, but a false-positive result cannot be excluded. The cat received prednisolone and all clinical and laboratory abnormalities resolved after two months of treatment. Subsequent ANA titers remained positive and were not correlated to the patient's clinical progression.

RELEVANCE AND NOVEL INFORMATION

This report describes new findings associated with a presumptive diagnosis of SLE in a kitten, highlighting that SLE may not be ruled out even in young cats and may be associated with mastocytemia. ANA titration is part of the initial diagnostic work-up of SLE but is a non-specific test and discrepancies can be observed between laboratories. The titration of more specific antibodies such as those used in humans would be helpful to diagnose SLE. ANA titration may not correlate with clinical activity of SLE; hence, the interest of an ANA titer follow-up to establish disease control warrants further investigation.

IgG4 Autoantibodies Attenuate Systemic Lupus Erythematosus Progression by Suppressing Complement Consumption and Inflammatory Cytokine Production

Pathogenic autoantibodies can cause inflammation and tissue injury in systemic lupus erythematosus (SLE). Although IgG4 is considered non-inflammatory owing to the unique structure of its hinge region, the role of IgG4 autoantibodies in SLE remains largely unknown. The titers of serum anti-nuclear-IgG antibodies (ANA-IgG) and anti-nuclear-IgG4 antibodies (ANA-IgG4) in newly diagnosed SLE patients were detected. The effects of IgG4 purified from SLE patients (SLE IgG4) and healthy controls on complement consumption and inflammatory cytokine production were evaluated in vitro. The therapeutic effects of mouse IgG1 (functionally resembles human IgG4) purified from lupus-prone MRL-lpr/lpr mice (lupus IgG1) and control mice on disease progression were examined in MRL-lpr/lpr mice. The results showed that SLE patients with equal titers of total serum ANA-IgG (1:3,200) were divided into group I with lower ANA-IgG4 titers (≤ 1:10) and group II with higher ANA-IgG4 titers (≥ 1:100), and disease activity, inflammatory cytokine production, complement consumption, and renal-function parameters in group I SLE patients were more severe than those in group II. Further, compared with control IgG4, SLE IgG4 inhibited complement consumption by autoantibody-autoantigen immune complexes, and also inhibited inflammatory cytokines production by SLE PBMCs in vitro. Moreover, compared with control IgG1, lupus IgG1 exhibited a therapeutic effect on lupus by attenuating disease progression in MRL-lpr/lpr mice. These findings, for the first time, suggest that IgG4 autoantibodies can attenuate SLE progression by suppressing complement consumption and inflammatory cytokine production. Hence, this study may provide novel therapeutic strategies against SLE and other autoimmune diseases.

A new diagnostic algorithm for pattern-oriented autoantibody testing according to the ICAP nomenclature: A pilot study

The commercial tests currently available as second-level tests to detect ANA sub-specificities are generally used independently from the ANA immunofluorescence (IIF) pattern. The aim of this study was to evaluate the efficacy of the use of a customizable pattern-oriented antigenic panel by immunoblot (IB) using the International Consensus on ANA Patterns (ICAP) classification scheme, in order to introduce a novel and updated autoimmune diagnostic flowchart. 710 sera referred for routine ANA testing were selected on the basis of the ANA pattern according to the ICAP nomenclature (nuclear speckled AC-2,4,5; nucleolar AC-8,9,10,29; cytoplasmic speckled AC-18,19,20) and on an IIF titer ≥1:320. They were then assayed by three experimental IB assays using a panel of selected antigens. ICAP-oriented IB detected 515 antibody reactivities vs. 457 of traditional anti-ENA in the nuclear speckled pattern group, 108 vs. 28 in the nucleolar pattern group, and 43 vs. 34 in the cytoplasmic speckled pattern. This pilot study may lead the way for a new approach introducing an ICAP pattern-oriented follow up testing as a valid alternative to the existing standard panels, thus enabling more patients with autoimmune rheumatic disease to be accurately diagnosed.

Evolving story of autoantibodies in systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a prototypic autoimmune disease characterized by antinuclear antibody (ANA) production. ANAs bind to DNA, RNA and complexes of proteins and nucleic acids and are important markers for diagnosis and activity. According to current models, ANAs originate from antigen-driven processes; nevertheless, antibody responses to both DNA and RNA binding proteins display features unexpected in terms of current paradigms for antigenicity. These differences may reflect disturbances in both B and T cells critical for autoreactivity. Clinically, ANA testing has new uses for determining classification as well as assessing eligibility for clinical trials. Studies of patients with established disease show frequent seronegativity. In this setting, seronegativity may indicate a stage of disease called post-autoimmunity in which the natural history of disease or effects of immunosuppressive therapies modifies responses. The new uses of ANA testing highlight the importance of understanding autoantigenicity and developing sensitive and informative assays for clinical assessments.

Seroconversion to antinuclear antibody negativity and its association with disease flare in patients with systemic lupus erythematosus

OBJECTIVE

To evaluate the rate of seroconversion to antinuclear-antibody negativity in patients with systemic lupus erythematosus and its association with subsequent systemic lupus erythematosus flare risk.

METHODS

Medical records of patients with systemic lupus erythematosus with positive antinuclear antibodies (titer ≥1 : 40) at diagnosis and at least one repeat antinuclear antibody test were reviewed. We determined the frequency of seroconversion to antinuclear antibody negativity among these patients and investigated whether seroconversion to antinuclear antibody negativity was associated with subsequent systemic lupus erythematosus flare risk. The seroconversion to antinuclear antibody negativity was defined as a conversion of positive antinuclear antibodies to a titer below the cut-off of 1 : 40. Systemic lupus erythematosus flare was defined as one new British Isles Lupus Assessment Group A or two new British Isles Lupus Assessment Group B domain scores. To estimate hazard ratios and 95% confidence intervals for systemic lupus erythematosus flare according to seroconversion to antinuclear antibody negativity, Cox regression analysis with adjustment for known systemic lupus erythematosus flare risk factors was performed. Kaplan-Meier analysis was used to compare flare-free survival rates between negative converters and non-converters.

RESULTS

Among the total 175 patients, seroconversion to antinuclear antibody negativity was found in 17 (9.7%) patients in a median 53.5 (range: 25.7-84.0) months. After the last antinuclear antibody tests, 53 systemic lupus erythematosus flare cases were identified during 14.3 (range: 8.2-21.7) months of follow-up. Systemic lupus erythematosus flare risk was significantly lower in patients with negatively seroconverted antinuclear antibodies (adjusted hazard ratio 0.13, 95% confidence interval 0.03-0.58, p = 0.007). Kaplan-Meier analysis showed significantly higher flare-free survival in negative converters than in non-converters (p = 0.004).

CONCLUSION

Seroconversion to antinuclear antibody negativity occurred in 9.7% of patients over 53.5 months and was associated with a lower future systemic lupus erythematosus flare risk.

Frequency of repeat antinuclear antibody testing in Ontario: a population-based descriptive study

BACKGROUND

Repeat antinuclear antibody (ANA) testing may be unnecessary, potentially harmful and costly. Our aim was to assess the frequency and correlates of repeat ANA testing in Ontario.

METHODS

We performed a retrospective descriptive study identifying ANA tests performed over 2008-2015 among adults within the Ontario Laboratories Information System. Our primary outcome was any ANA test performed within 1 year of a previous ANA test. Our secondary outcome was any repeat test after a previous positive result. Repeat testing overall (regardless of who performed the previous test) and repeat testing by the same provider who performed the previous test were determined separately. We assessed correlates of repeat testing (e.g., patient and physician characteristics) and of repeat testing after a positive result using separate logistic regression models by means of generalized estimating equations to account for clustering of repeat testing within patients and within physician practices.

RESULTS

In total, 587 357 ANA tests were performed in 437 966 patients over the study period, of which 126 322 (21.5%) gave a positive result and 164 913 (28.1%) were repeat tests. Family physicians ordered 358 422 tests (61.0%), and rheumatologists ordered 65 071 tests (11.1%). Of the repeat tests, 82 332 (49.9%) were ordered within 12 months of the previous test. Among the 73 961 repeat tests ordered by the same practitioner within 12 months, the previous test result was positive for 22 657 (30.6%). A higher proportion of rheumatologists than other physicians ordered repeat tests within 12 months (36.1% v. 11.3%). The most significant correlate of potentially redundant testing was testing among patients with suspected or confirmed connective tissue disease.

INTERPRETATION

Over a quarter of ANA tests in Ontario were repeat tests; rheumatologists were most likely to order repeat testing. Our findings may be useful to inform quality-improvement initiatives related to the appropriateness of ANA testing.

Interferon-induced protein 44-like gene promoter is differentially methylated in peripheral blood mononuclear cells of systemic lupus erythematosus patients

Background:

The objectives of this study were to compare the interferon-induced protein 44-like (IFI44L) promoter methylation level between systemic lupus erythematosus (SLE) patients and healthy controls and to evaluate its diagnostic value in SLE.

Materials and Methods:

The IFI44L promoter methylation level was measured in 49 patients with SLE and 50 healthy controls. Quantitative analysis of promoter methylation IFI44L gene in genomic DNA samples extracted from peripheral blood mononuclear cells was examined in SLE patients and healthy controls. The level of DNA methylation was compared between SLE patients and healthy controls as well as within SLE patient groups based on the presence of renal involvement. Moreover, diagnostic values of IFI44L were calculated.

Results:

The IFI44L promoter methylation level in SLE patients was significantly lower than healthy controls (median, 43.8 vs. 57, respectively; P = 0.008). The level of IFI44L promoter methylation was not significantly different between SLE patients with renal involvement and SLE patients without renal involvement (84.6% vs. 92.7%, respectively; P = 0.774). The IFI44L promoter methylation level ≤94.3% was the best cutoff point with a sensitivity of 91.8% and a specificity of 38% to distinguish patients with SLE from healthy individuals.

Conclusion:

The level of IFI44L promoter methylation from whole peripheral blood in Iranian SLE patients was significantly lower than healthy controls. Furthermore, the DNA methylation level of IFI44L promoter was not associated with renal damage in patients with SLE.

A multi-centre study for standardization of antinuclear antibody indirect immunofluorescence screening with automated system

INTRODUCTION

ndirect immunofluorescence assay (IFA) using HEp-2 as substrate plays a consolidate role for the detection and measurement of ANA, which is currently considered as the reference method for detection. Manual operation is still very common in China, therefore, the need of standardization and automation for ANA-IFA detecting has been highlighted.

OBJECTIVE

The current multi-center study is aimed to evaluate if HELIOS (AESKU Diagnostics, Wendelsheim, Germany) contributes to comparability of ANA screening results among different labs，and establish application specification of HELIOS for standardization of ANA detection.

METHODS

ANA detection by manual IFA method and HELIOS on 230 clinical serum samples in eight laboratories. The performance to discriminate positive/negative screening results, endpoint titer estimation and pattern recognition were evaluated in HELIOS and manual visual.

RESULTS

The positive coincident rate for ANA detection by manual IFA ranges from 87.7% to 97.8%, the negative coincidence rate ranges from 68.8% to 100%, the correctly estimated titer evaluation were 80 to 171 cases, the correct pattern in 146 to 161 cases, respectively. The positive coincident rate of HELIOS for ANA detection ranges from 91.2% to 97.7%, the negative coincidence rate ranges from 96.5% to 100%, the correctly estimated titer evaluation were 145 to 157 cases, the correct pattern in 123 to 140 cases, respectively.

CONCLUSION

HELIOS could provide accurate diagnostic results, this include not only positive/negative results, but also endpoint titer, common patterns. The application of this system can help to promote standardization of ANA detection.

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.

Evaluation of patients with dry eye for the presence of primary or secondary Sjӧgren's syndrome

PURPOSE

To assess the frequency of Sjӧgren's syndrome (SS), either primary or secondary to rheumatic disease, in a cohort of patients with aqueous-deficient dry eye and to determine the most accurate objective test for diagnosis of SS.

METHODS

A total of 111 patients with dry eye were recruited from Minia University's ​Ophthalmology Outpatient Clinic (69 patients) and Rheumatology Outpatient Clinic (42 patients). The patients were screened for aqueous tear-deficient dry eye by abnormal test results of Schirmer test I (<10 mm) and tear-film break-up time (<10 seconds) in at least one eye. The diagnosis of SS was made according to the 2012 American College of Rheumatology​ criteria. A complete work up for SS was performed, including clinical examination, serological tests, ocular tests, and labial salivary-gland biopsy (LSGB).

RESULTS

Of the 111 patients, 58 had aqueous-deficient dry eye: 23 in the ophthalmology clinic cohort (group I) and 35 in the rheumatology clinic cohort (group II). Three patients had pSS, and its frequency was 13% in group I and 5.2% among all studied patients. The ocular staining score is the most diagnostic ocular test (sensitivity 100% and specificity 90.9%). Anti-SSA/Ro antibody is the most accurate serological method (sensitivity 33.3% and specificity 100%). LSGB histopathology is the most diagnostic method for SS, with sensitivity, specificity, and positive and negative predictive values of 100%.

CONCLUSION

SS was detected with reasonable frequency among dry-eye patients, particularly pSS. Screening of dry eye for SS can select SS patients early in the disease course.

Autoimmune Diseases in Patients With Cutaneous Lupus Erythematosus

Importance

Increased rates of autoimmune conditions have been reported in association with systemic lupus erythematosus (SLE). Little is known about coexisting autoimmune conditions in patients with cutaneous lupus erythematosus (CLE) without SLE.

Objective

To determine the prevalence and risk factors of having coexisting autoimmune conditions in patients with CLE.

Design, Setting, and Participants

This cross-sectional study was performed from November 2008 to February 2017 at the University of Texas Southwestern Medical Center (UTSW) and Parkland Health and Hospital System, Dallas, Texas. Participants were identified through the UTSW Cutaneous Lupus Registry. All participants had a dermatologist-confirmed diagnosis of CLE using clinicopathological correlation. Exclusion criteria included age younger than 18 years, and meeting at least 4 American College of Rheumatology diagnostic criteria for SLE. Participants with CLE and without concomitant autoimmune diseases were compared by demographic and disease characteristics.

Main Outcomes and Measures

The primary and secondary outcomes were presence of coexisting autoimmune condition(s) and individual autoimmune diseases, respectively. Predictor variables significantly associated with coexisting autoimmune diseases were identified by univariate and multivariable logistic regression analyses.

Results

Among the 285 participants initially screened, 129 participants with CLE were included (102 [79.1%] female; median age, 49 years [interquartile range, 38.3-57.1 years]). Coexisting autoimmune conditions were found in 23 (17.8%). Autoimmune thyroid disease had the highest frequency at 4.7% (n = 6). Multivariable logistic regression analyses showed that patients with CLE who were white (odds ratio [OR], 2.88; 95% CI, 1.00-8.29; P = .0498), never smokers (OR, 3.28; 95% CI, 1.14-9.39; P = .03), had family history of autoimmune disease (OR, 3.54; 95% CI, 1.21-10.39; P = .02), and history of positive antinuclear antibody test result (OR, 4.87; 95% CI, 1.69-14.03; P = .003) had a significant association with having coexisting autoimmune conditions.

Conclusions and Relevance

This study suggests that patients with CLE without concurrent SLE can have increased rates of coexisting autoimmune conditions. Collecting a thorough review of systems can prompt clinicians to pursue further testing and evaluation by other specialists. Future studies investigating development of coexisting autoimmune conditions over time in the CLE population are necessary to confirm these findings.

Comprehensive Analysis of the Safety Profile of a Single-Stranded RNA Nano-Structure Adjuvant

Adjuvants enhance the efficacy of vaccines by stimulating immune response-related gene expression and pathways. Although some adjuvants have been approved for commercial use in human vaccines (e.g., Alum, MF59, and AS03), they might elicit adverse side effects, such as autoimmune diseases. Recently, we developed a novel single-stranded RNA (ssRNA) nano-structure adjuvant, which can stimulate both Th1 and Th2 responses. In this study, we evaluated the safety and toxicological profiles of this ssRNA nano-structure adjuvant in vitro and in vivo. Mice were intramuscularly immunized with the ssRNA nano-structure adjuvant three times, once every 2 weeks. The results indicate no significant differences in hematological and serum biochemistry parameters between the ssRNA-treated groups and the control group. From a histopathological perspective, no evidence of tissue damage was found in any group. The levels of IgE and anti-nuclear antibodies, which are markers of autoimmune disease, were not different between the ssRNA-treated groups and the control group. The findings of this study suggest that the ssRNA nano-structure can be used as a safe adjuvant to increase vaccine efficacies.

Identification of Serum Biomarkers for Systemic Lupus Erythematosus Using a Library of Phage Displayed Random Peptides and Deep Sequencing

Systemic lupus erythematosus (SLE) is one of the most serious autoimmune diseases, characterized by highly diverse clinical manifestations. A biomarker is still needed for accurate diagnostics. SLE serum autoantibodies were discovered and validated using serum samples from independent sample cohorts encompassing 306 participants divided into three groups, i.e. healthy, SLE patients, and other autoimmune-related diseases. To discover biomarkers for SLE, a phage displayed random peptide library (Ph.D. 12) and deep sequencing were applied to screen specific autoantibodies in a total of 100 serum samples from 50 SLE patients and 50 healthy controls. A statistical analysis protocol was set up for the identification of peptides as potential biomarkers. For validation, 10 peptides were analyzed using enzyme-linked immunosorbent assays (ELISA). As a result, four peptides (SLE2018Val001, SLE2018Val002, SLE2018Val006, and SLE2018Val008) were discovered with high diagnostic power to differentiate SLE patients from healthy controls. Among them, two peptides, i.e. SLE2018Val001 and SLE2018Val002, were confirmed between SLE with other autoimmune patients. The procedure we established could be easily adopted for the identification of autoantibodies as biomarkers for many other diseases.

Anti-centrosome antibodies: Prevalence and disease association in Chinese population

Anti-centrosome antibodies are rare findings with undefined clinical significance in clinical research. We aimed at investigating the prevalence and clinical significance of anti-centrosome antibodies in Chinese population. Testing results of total of 281,230 ANA-positive sera were retrospectively obtained from West China Hospital Sichuan University in China between 2008 and 2017. We retrospectively collected and analysed the clinical and laboratory data of the patients with positive anti-centrosome antibody. Of the 356 453 patients tested, 281 230 patients had positive antinuclear antibodies (ANAs, 78.9%), but only 78 patients with positive anti-centrosome antibodies (0.022%), of which 74.4% are females. Diagnoses were established in 69 of 78 patients: 37 cases were autoimmune diseases, mainly including undifferentiated connective tissue diseases (UCTD, 9/37), rheumatoid arthritis (RA, 6/37), Sjögren's syndrome (SS, 5/37) and primary biliary cirrhosis (PBC, 5/37), and the remaining were other autoimmune conditions. The most frequent clinical symptoms of the anti-centrosome-positive patients were arthralgia and eyes and mouth drying. Additionally, 86.7% of anti-centrosome antibodies were not associated with other ANA profiles; however, when associated, the most frequent ANA was anti-U1RNP. Anti-centrosome antibodies are featured by a low prevalence and female gender predominance. They are correlated with some specific diseases, both autoimmune diseases, especially UCTD, RA, SS and PBC, and non-autoimmune diseases, such as infection and cancer, which suggests that they might be potential supporting serological markers of these diseases.

Systematic review and meta-analysis of clinical significance of autoantibodies for idiopathic pulmonary fibrosis

OBJECTIVE

To clarify clinical significance of the sole presence of autoantibodies for idiopathic pulmonary fibrosis (IPF) without any other symptoms or signs suggestive of autoimmune disease.

DESIGN

Systematic review and meta-analysis DATA SOURCES: Medline, EMBASE, Science Citation Index Expanded and Google Scholar were searched from 1 January 2002 through 12 February 2019.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Primary studies addressing all-cause mortality and the development of a defined autoimmune disease for IPF with autoantibodies were included for the review.

DATA EXTRACTION AND SYNTHESIS

Two reviewers extracted relevant data and assessed risk of bias independently. Meta-analysis was conducted using a random-effects model if three or more studies reported the same outcome for a certain autoantibody. The quality of evidence was assessed by the Grades of Recommendation, Assessment, Development and Evaluation system.

RESULTS

Out of 4603 records retrieved nine studies were included in this review. All studies contained some risk of bias. Based on pooled data myeloperoxidase antineutrophil cytoplasmic antibody (MPO-ANCA) was significantly associated with microscopic polyangiitis incidence with risk ratio (RR) of 20.2 (95% CI: 7.22 to 56.4) and antinuclear antibody (ANA) was also significantly associated with the development of connective tissue diseases with RR of 7.11 (p=0.001) (10 cases in 157 patients with ANA) in one study. However, there was no significant association of autoantibodies with all-cause mortality aside from MPO-ANCA and proteinase 3-ANCA in one study each. MPO-ANCA was not demonstrated to be associated with all-cause mortality by meta-analysis. The quality of evidence was deemed as either low or very low.

CONCLUSIONS

The presence of autoantibodies such as MPO-ANCA and ANA was demonstrated to be associated with the development of some autoimmune diseases for patients with IPF although there was no difference of all-cause mortality. However, the results should be interpreted with caution due to low evidence level.

PROSPERO REGISTRATION NUMBER

CRD42017077336.

A Multicenter Analysis of Subjectivity of Indirect Immunofluorescence Test in Antinuclear Antibody Screening

Objectives

This study aims to evaluate the interpretation of the antinuclear antibody (ANA)-indirect immunofluorescence (IIF) test results based on the interpreter-related subjectivity and to examine the inter-center agreement rates with the performance of each laboratory.

Patients and methods

The ANA-IIF testing was carried out in a total of 600 sera and evaluated by four laboratories. The inter-center agreement rates were detected. The same results given by the four centers were accepted as gold standard and the predictive values of each center were calculated.

Results

The inter-center agreement was reported for ANA-IIF test results from 392 of 600 (65.3%) sera, while 154 of 392 results were positive. Four study centers reported 213 (35.5%), 222 (37.0%), 266 (44.3%), and 361 (60.2%) positive test results, respectively. In terms of the patterns, the highest and lowest positive predictive values were 72.3% and 42.7%, respectively, while the highest and lowest negative predictive values were 99.6% and 61.5%, respectively. The agreement for semi-quantitative evaluation at three levels of fluorescence intensity stated by four centers was detected in 100 sera at 87% 3(+), while the other two levels were 6% and 7%. The highest predictive value for the highest fluorescence intensity of 3(+) was found to be 71.9%.

Conclusion

Significant differences may be observed among laboratories in terms of qualitative results, patterns, and semi-quantitative determination of the fluorescence intensity in the ANA-IIF testing, particularly at low fluorescence intensity levels and in those with speckled patterns. In case of any discrepancy between ANA-IIF test and clinical prediagnosis, the test should be repeated in another laboratory, if necessary.

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.

Antinuclear antibodies in patients with cervical lesions and invasive cervical cancer

BACKGROUND

Antinuclear antibodies (ANA) have been found in several types of cancer although the meaning of its presence is not completely known.

AIM

To study the prevalence of ANA in patients with cervical intraepithelial lesion and invasive cervical cancer.

METHODS

A total of 205 women who underwent screening for cervical cancer or treatment at the Erasto Gaertner Cancer Hospital in Curitiba - Brazil, were enrolled in the study. Based on their latest cervical colposcopy-guided biopsy results, they were divided into four groups: CIN-I: 19.4%; CIN-II: 24.0%; CIN-III: 24.0%; and invasive cancer: 32.4%. As control were studied 68 healthy controls. ANA was searched by immunofluorescence in Hep-2 cells evaluating the pattern and titer.

RESULTS

Controls had 4/68 (5.8%) of ANA positivity and patients with CIN and invasive cancer had 15.1% (p = 0.001). Patients with CIN-I and CIN-II had the same prevalence of ANA as controls (p = 1.0 and p = 0.11 respectively), but not those with CIN-III (p = 0.03) and invasive cancer (p = 0.05). The most common ANA immunofluorescence pattern was fine speckled pattern (38.7%) and fine dense speckled pattern (38.7%); the mean titer was 1:160.

CONCLUSION

ANA is more common in invasive cervical lesions than in controls or non invasive lesions. To understand the meaning of this finding more studies are needed.

Harmonizing by reducing inter-run variability: performance evaluation of a quality assurance program for antinuclear antibody detection by indirect immunofluorescence

Background

The introduction of automated anti-nuclear antibody (ANA) indirect immunofluorescence (IIF) analysis may allow for more harmonized ANA IIF reporting, provided that a thorough quality assurance program controls this process. The aim of this study was to evaluate various quality indicators used for ANA IIF analysis with the final goal of optimizing the iQC program.

Methods

In an experimental setup, we introduced artificial errors, mimicking plausible problems during routine practice on a QUANTA-Lyser-NOVA View® system (Inova Diagnostics, San Diego, CA, USA). Predetermined quality indicators were evaluated against predefined acceptance criteria. In addition, we retrospectively investigated the applicability of the selected quality indicators in the daily routine practice during three pre-defined periods.

Results

Both the experimental as the retrospective study revealed that pre-analytical, analytical and post-analytical errors were not highlighted by company internal quality control (iQC) materials. The use of patient derived iQC samples, median fluorescence intensity results per run and the percentage of positive ANA IIF results as additional quality indicators ensured a more adequate ANA IIF quality assurance. Furthermore, negative and moderate positive sample iQC materials merit clinical validation, as titer changes of >1 correspond to clinically important shifts. Traditional Westgard rules, including a clinically defined stop limit, revealed to be useful in monitoring of the supplemental quality indicators.

Conclusions

A thorough ANA IIF quality assurance for daily routine practice necessitates the addition of supplemental quality indicators in combination with well-defined acceptance criteria.

High Seroprevalence of Autoantibodies Typical of Autoimmune Liver Disease in Eastern Ethiopia: Is Chewing of Khat (Catha edulis) a Triggering Factor?

BACKGROUND

Recent studies have identified chewing of khat (Catha edulis) as an independent risk factor for liver injury; however, the pathogenetic mechanism remains poorly understood. Case series have found markers of autoimmune hepatitis in patients with khat-related liver disease, suggesting that khat chewing might trigger an autoimmune response. The aims of the present study were (i) to assess the prevalence of autoantibodies typical for autoimmune liver diseases in a healthy population in Ethiopia and (ii) to explore the hypothesis that khat usage triggers autoimmunity.

METHODS

Consenting adults (≥18 years) without known autoimmune disease or manifest liver disease were included. One-hundred-and-sixty-nine individuals with current khat use were compared to 104 individuals who never used khat. Seroprevalence of antinuclear (ANA), antismooth muscle (SMA), and antimitochondrial antibodies (AMA) were determined and compared between the groups using logistic regression models to adjust for age and sex.

RESULTS

Overall, 2.6% of the study subjects were positive for ANA, 15.4% for SMA, and 25.6% for AMA. When comparing khat users to nonusers, ANA was detected in 4.1% vs. 0% (p=0.047), SMA in 16.0% vs. 14.4% (p=0.730), and AMA in 24.9% vs. 26.9% (p=0.704). ANA was excluded from multivariable analysis since there was no seropositive in the reference group. After adjusting for sex and age, no significant association between khat use and SMA or AMA was found.

CONCLUSIONS

No association between khat usage and the seropresence of SMA or AMA was found, weakening the hypothesis that khat-related liver injury is mediated through autoimmune mechanisms. However, the seroprevalences of AMA and SMA were strikingly high in this Ethiopian population compared to global estimates, suggesting that diagnostic algorithms for autoimmune liver diseases developed in Europe and North America might lead to misdiagnosis of patients on the African continent.

A computer-aided diagnosis system for HEp-2 fluorescence intensity classification

BACKGROUND AND OBJECTIVE

The indirect immunofluorescence (IIF) on HEp-2 cells is the recommended technique for the detection of antinuclear antibodies. However, it is burdened by some limitations, as it is time consuming and subjective, and it requires trained personnel. In other fields the adoption of deep neural networks has provided an effective high-level abstraction of the raw data, resulting in the ability to automatically generate optimized high-level features.

METHODS

To alleviate IIF limitations, this paper presents a computer-aided diagnosis (CAD) system classifying HEp-2 fluorescence intensity: it represents each image using an Invariant Scattering Convolutional Network (Scatnet), which is locally translation invariant and stable to deformations, a characteristic useful in case of HEp-2 samples. To cope with the inter-observer discrepancies found in the dataset, we also introduce a method for gold standard computation that assigns a label and a reliability score to each HEp-2 sample on the basis of annotations provided by expert physicians. Features by Scatnet and gold standard information are then used to train a Support Vector Machine.

RESULTS

The proposed CAD is tested on a new dataset of 1771 images annotated by three independent medical centers. The performances achieved by our CAD in recognizing positive, weak positive and negative samples are also compared against those obtained by other two approaches presented so far in the literature. The same system trained on this new dataset is then tested on two public datasets, namely MIVIA and I3Asel.

CONCLUSIONS

The results confirm the effectiveness of our proposal, also revealing that it achieves the same performance as medical experts.