Prevalence of antinuclear antibodies in 3 groups of healthy individuals: blood donors, hospital personnel, and relatives of patients with autoimmune diseases

Prevalence and sociodemographic correlates of antinuclear antibody testing by indirect immunofluorescence or solid-phase assays in a Spanish population: the Camargo Cohort

Autoantibodies are the hallmark of autoimmunity, and specifically, antinuclear antibodies (ANA) are one of the most relevant antibodies present in systemic autoimmune diseases (AID). In the present study, we evaluate the relationship between ANA and sociodemographic and biobehavioral factors in a population with a low pre-test probability for systemic AID. ANA were determined in serum samples at baseline visit from 2997 participants from the Camargo Cohort using indirect immunofluorescence assay, and two solid phase assays (SPA), addressable laser bead immunoassay, and fluorescence enzyme immunoassay. Sociodemographic and biobehavioral features of the subjects were obtained at baseline visit using a structured questionnaire. The prevalence of ANA positive results was significantly higher when indirect immunofluorescence assay was used as screening method in comparison with SPAs, being higher in females, older subjects, and those with higher C-reactive protein levels. Considering biobehavioral features, the prevalence was higher in those individuals with a sedentary lifestyle, and in ex- and non-alcohol users. Moreover, considering the relevance of the antibody load using ANA Screen, the prevalence of the antibody load also increased with age, especially in females. In conclusion, the prevalence of ANA varies depending on sociodemographic and biobehavioral features of the subjects, which could be relevant specifically in a population with a low pre-test probability for systemic AIDs.

Learned cautions regarding antibody testing in mast cell activation syndrome

OBJECTIVES

To describe patterns observed in antibody titer trendlines in patients with mast cell activation syndrome (MCAS, a prevalent but underrecognized chronic multisystem inflammatory disorder of great clinical heterogeneity) and offer clinical lessons learned from such pattern recognition.

METHODS

The available records of 104 MCAS patients drawn from the authors' practices were reviewed, including all antibody tests therein.

RESULTS

All patients had positive/elevated antibodies of various sorts at various points, but for most of the antibodies which were found to be positive at least some points, the diseases classically associated with those antibodies were not present, marking such antibodies as clinically insignificant mimickers (likely consequent to inflammatory effects of MCAS on the immune system itself driving spurious/random antibody production) rather than "on-target" and pathogenic antibodies reflecting true disease warranting treatment. We also observed two distinct patterns in trendlines of the titers of the mimickers vs. the trendline pattern expected in a true case of an antibody-associated disease (AAD).

CONCLUSIONS

Our observations suggest most positive antibody tests in MCAS patients represent detection of clinically insignificant mimicking antibodies. As such, to reduce incorrect diagnoses of AADs and inappropriate treatment in MCAS patients, caution is warranted in interpreting positive antibody tests in these patients. Except in clinically urgent/emergent situations, patience in determining the trendline of a positive antibody in an MCAS patient, and more carefully assessing whether the AAD is truly present, is to be preferred.

Laboratory evaluation for the differential diagnosis of possible multiple sclerosis in the United States: A physician survey

BACKGROUND

There is limited evidence and lack of guidelines for diagnostic laboratory evaluation of patients with possible multiple sclerosis (MS).

OBJECTIVE

To survey neurologists on their practice of laboratory testing in patients with possible MS.

METHODS

An online survey was developed to query the frequency of serum and cerebrospinal fluid (CSF) studies ordered in the routine evaluation of patients with possible MS, and in three hypothetical clinical cases. Non-MS specialist neurologists who evaluate patients for MS in their practice were invited to participate by MedSurvey (a medical market research company).

RESULTS

The survey was completed by 190 neurologists. A mean of 17.2 (SD: 17.0) tests in serum and CSF were reported "always" ordered in the evaluation of patients with possible MS. CSF oligoclonal bands was the most frequently selected ("always" among 73.7% of participants). Antinuclear antibody (43.2%), erythrocyte sedimentation rate (34.2%), and thyroid stimulating hormone (31.6%) were also among the most frequently ordered.

DISCUSSION

Extensive laboratory evaluations are often completed in the evaluation of possible MS. However, many of these tests have poor specificity and false positive results could yield unnecessary increased costs, diagnostic delay, and potentially misdiagnosis. Further research is needed to identify optimal laboratory approaches for possible MS.

Approach to laboratory ordering and interpretation in rheumatology

Evaluation of suspected rheumatic disease is a significant challenge due to overlapping and sometimes non-specific clinical features. Most laboratory tests in rheumatic disease have incomplete sensitivity and specificity, leading to positive results without disease and negative results despite disease presence. Therefore, judicious ordering and correct interpretation of laboratory testing in rheumatology is critical in order to provide high-value care. Herein we review laboratory testing in rheumatology in the context of a framework for approaching rheumatic disease.

Rheumatoid factor is associated with severe COVID ‐19

AIM

Coronavirus disease 2019 (COVID-19) has been proposed as triggering autoimmunity. The aim of this study was to evaluate the presence and clinical significance of autoantibodies in patients with COVID-19.

METHODS

We retrospectively collected data from 245 patients who were hospitalized for COVID-19. All patients were tested for the presence of antinuclear antibody (ANA), rheumatoid factor (RF), anti-citrullinated peptide antibody (ACPA), and anti-cytoplasmic neutrophil antibody (ANCA). Risk factors for death and critical COVID-19, defined as the need for invasive mechanical ventilation or extracorporeal membrane oxygenation, were analyzed.

RESULTS

Ninety (36.7%) patients tested positive for ANA, and 51 (20.8%) patients tested positive for RF. Three patients each (1.2%) tested positive for ACPA and ANCA. RF-positive patients had higher rates of invasive mechanical ventilation and death than RF-negative patients (70.6% vs 28.4%, P < 0.001 and 45.1% vs 18.6%, P < 0.001, respectively). Underlying lung disease, kidney disease, heart disease, quick COVID severity index (qCSI), and lactate dehydrogenase (LDH) were associated with in-hospital death. RF (odds ratio [OR] 7.31, 95% CI 2.50-21.37, P < 0.001), qCSI (OR 1.42, 95% CI 1.19-1.69, P < 0.001), and LDH (OR 1.004, 95% CI 1.002-1.005, P < 0.001) were associated with critical COVID-19. Combination of RF, qCSI, and LDH showed good prognostic value (area under the curve = 0.903, P < 0.001) for critical COVID-19.

CONCLUSIONS

ANA and RF were frequently detected in COVID-19 patients. RF could be a risk factor for critical COVID-19. The results of this study suggest immune dysfunction contributes to the complications of COVID-19.

First-degree relatives of patients with systemic lupus erythematosus: Autoreactivity but not autoimmunity?

BACKGROUND

Systemic lupus erythematosus (SLE) is a disorder with a complex immunopathogenesis. It is well known that the disease begins with immunological alterations and autoantibody appearance in the serum years before clinical onset. As SLE has a strong tendency to familial aggregation, first-degree relatives (FDRs) constitute a group at elevated risk. The current understanding is that external risk factors trigger underlying immune dysregulations, leading to overt disease in those with elevated genetic risk.

OBJECTIVE

This cross-sectional study investigates the degree to which clinical features, external risk factors, and immunological profiles differ in SLE FDRs from healthy individuals and SLE patientts.

METHODS

Three groups were studied: Lupus patient FDRs (n = 56), healthy controls (n = 20), and SLE patients (n = 20). FDRs and healthy participants completed a detailed clinical questionnaire that included questions regarding smoking and estrogen drug history. All participants were tested for the presence of the following antinuclear autoantibodies (ANAs) against: nRNP/Sm, Sm, Ro60, Ro-52, La, Scl-70, PM-Scl, PM- Scl, Jo-1, CENP B, PCNA, dsDNA, nucleosomes, histones, RibP, AMA M2, DFS70, and eight soluble cytokines, including transforming growth factor-β (TGF-β), vitamin D levels, and antibodies against Epstein-Barr virus (EBV).

RESULTS

Compared with the healthy controls, FDRs had higher titers of ANA, more specific staining immunofluorescent patterns, and more autoantibody specificities. Furthermore, FDRs differed significantly in their TGF-β levels from the other two groups. In FDRs, some clinical features (hair loss, skin, and oral ulcer-like lesions) were associated with higher ANA titers and some (oral ulcer-like lesions) with the anti-Ro60-specific antibody. Interestingly, there was an association between ANA titers and levels of antibodies against EBV only in the FDR group.

CONCLUSION

First-degree relatives display unique clinical and immunological profiles, placing them between healthy individuals and SLE patients, with a balance between compensated immune dysregulation and disease-developing potential. A possible association between ANA titer and the number of clinical complaints is observed, which needs to be confirmed in more extensive studies.

Anti-DFS70 antibodies are associated with atopic dermatitis and can cause misdiagnosis of connective tissue disease

BACKGROUND AND OBJECTIVES

Antinuclear antibodies (ANA) detected by HEp2 cell immunofluorescence staining are a characteristic finding in patients with connective tissue disease (CTD). However, even detection of highly elevated ANA is not conclusive for CTD and can result in misdiagnosis. Anti-DFS70 antibodies are ANA, which may also be highly elevated in people without CTD. Thus, we wanted to evaluate whether they could cause misdiagnosis of CTD. Since anti-DSF70 antibodies have been associated with atopic dermatitis (AD) in Japan, we wanted to investigate this association and its potential diagnostic relevance in Germany.

PATIENTS AND METHODS

We retrospectively analyzed data of 40 patients referred for first consultation on CTD and prospectively analyzed the prevalence of anti-DFS70 antibodies in 110 AD patients and 89 controls.

RESULTS

We could not confirm CTD in 75% of our referred patients, 26% of whom had already received systemic treatments. DFS70-typical fluorescence staining was detected in 35% and definitive anti-DFS70 antibodies in 12.5% of these patients. DFS70-typical fluorescence staining was detected in 22% of AD patients and anti-DFS70 antibodies in 10% (versus 5.6% and 0% in control patients, P < 0.001).

CONCLUSIONS

Anti-DFS70 antibodies are significantly associated with AD and could be responsible for misdiagnosis of CTD.

Association between antinuclear antibody positivity and chemical exposure among pregnant Japanese women: A cross-sectional study based on the Japan environment and Children's study

Antinuclear antibodies (ANAs) are detected in healthy individuals, they are more prevalent in women than in men. Pregnant women are immunologically unique, but epidemiological data on ANA positivity in them remain limited. The exposure received from the mother during the fetal period impacts the future health of the fetus and has thus received increased attention in recent years. Thus, we investigated the association between ANA positivity and chemical exposure among pregnant Japanese women, registered in the Japan Environment and Children's Study (JECS). ANA titers were assessed by indirect immunofluorescence with HEp-2 cells at a cutoff dilution of 1:40. Sociodemographic and other data were obtained in the JECS from a self-administered questionnaire. We analyzed 1,235 Japanese women in their first trimester of pregnancy. The ANA prevalence was 17.2%. Among ANA-positive women, a speckled pattern was the most common (95.3%), followed by a homogeneous pattern (72.3%). Exposure to chemicals more than once a week significantly increased the probability of ANA positivity (kerosene, petroleum, benzene, or gasoline: adjusted odds ratio [AOR], 2.11; 95% confidence interval [95% CI], 1.03-4.34; chlorine bleach or germicide: AOR, 1.97; 95% CI, 1.10-3.54; organic solvents: AOR, 5.34; 95% CI, 1.40-20.36; and photocopying machines or laser printers: AOR, 1.73; 95% CI, 1.17-2.54). ANA positivity was associated with exposure to several chemicals in Japanese women. Our exploratory results suggested that ANAs as potential markers of chemical exposure warrant further research.

Prevalence and Significance of Autoantibody Seropositivity in Children with Wilson's Disease

Autoantibodies occur in healthy subjects as well as in children with Wilson's disease (WD), but their prevalence and significance are unknown. Thus, we aimed to assess the prevalence of autoantibodies and autoimmune markers, and their relationship to liver injury in WD children. The study included 74 WD and 75 healthy children as a control group. Patients with WD underwent transient elastography (TE) examinations, as well as determination of liver function tests, copper metabolism markers, and serum immunoglobulins (Ig). In the sera of the WD patients and controls, anti-nuclear (ANA), anti-smooth muscle, anti-mitochondrial, anti-parietal cell, anti-liver/kidney microsomal, anti-neutrophil cytoplasmic autoantibodies, and specific celiac antibodies were determined. Among the autoantibodies, only the prevalence of ANA in children with WD was higher than in the controls. There was no significant relationship between the presence of autoantibodies and liver steatosis or stiffness after TE. However, advanced liver stiffness (E > 8.2 kPa) was related to IgA, IgG, and gamma globulin production. The type of treatment did not influence the prevalence of autoantibodies. Our results suggest that autoimmune disturbances in WD might not be directly related to liver damage as expressed by steatosis and/or liver stiffness after TE.

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.

Successful Treatment with Brigatinib after Alectinib-Induced Hemolytic Anemia in Patients with Metastatic Lung Adenocarcinoma-A Case Series

Alectinib is a second-generation anaplastic lymphoma kinase (ALK) inhibitor used in the treatment of advanced ALK-rearrangement positive non-small-cell lung cancer (NSCLC). Many tolerable adverse events were reported with the use of Alectinib; nevertheless, hemolytic anemia was not mentioned in the safety analysis. In this case, series, we report four cases of Alectinib-induced oxidative hemolytic anemia and discuss different etiologic hypotheses on the underlying mechanism of such overlooked adverse event of the drug. Furthermore, we draw attention to the successful treatment with Brigatinib, an alternative second-generation ALK-inhibitor without recurrence of hemolytic anemia in three of our four cases, suggesting a probable class effect.

The Risk of Autoimmunity Development following mRNA COVID-19 Vaccination

The broad spectrum of interactions between autoimmune diseases and the SARS-CoV-2 vaccination is not fully understood. This study aims to evaluate the prevalence of anti-nuclear antibodies (ANA), anti-ENA, anticardiolipin antibodies (ACL), and anti-beta-2 glycoprotein I antibodies (anti-β2GPI) before and after the SARS-CoV-2 mRNA vaccination in a real-life setting in healthcare professionals. The identification of risk factors associated with vaccine immunogenicity was evaluated. The study group consisted of employees of two hospitals (354 individuals). Samples for antibody assays were collected before vaccination and at 7-9 months after complete immunisation. There was no significant increase in the prevalence of ANA, ACL or anti-β2GPI antibodies, or autoimmune diseases in subjects who were vaccinated 7-9 months after complete immunisation. In terms of detected anti-ENA, the anti-DFS70 antibodies were found in 6 times more subjects than before vaccination at the second blood draw (in 18 and 3 subjects, respectively) (p = 0.001). There were no significant relationships between a SARS-CoV-2 infection history, humoral response, cellular response, subject category, smoking, sex, body weight, ANA, anti-ENA, ACL, or anti-β2GPI. This study revealed a possible association between the severity of vaccine adverse events (VAEs) and ANA titre. Individuals with more severe VAEs (>10 points) after the second dose of the vaccine had significantly higher ANA titre after complete immunization. When analysing the significance of time between the ANA, anti-ENA, ACL, and anti- β2GPI assays and complete immunisation antibody values, no qualitative result was statistically significant. There was correlation between the time since complete immunization and ANA after.

Clinical patterns and risk factors in scleritis: a multicentric study in Colombia

PURPOSE

This study aims to describe the clinical characteristics of scleritis in a large cohort of Colombian patients and identify factors associated with the clinical presentation.

METHODS

Retrospective case series of patients with scleritis from 2015 to 2020. Clinical records were obtained from seven uveitis referral centers in Colombia. Patients with a diagnosis of episcleritis were excluded.

RESULTS

We evaluated 389 patients with scleritis (509 eyes). There was a female predominance (75.6%) with a mean age of 51 ± 15 years. Most cases were noninfectious (94.8%) and unilateral (69.2%). The most frequent type of inflammation was diffuse anterior scleritis (41.7%), followed by nodular scleritis (31.9%) and necrotizing scleritis (12.3%). Systemic autoimmune diseases were found in 41.3% of patients, the most common being rheumatoid arthritis (18.5%) and granulomatosis with polyangiitis (5.9%). Polyautoimmunity was found in 10.4% of those with a systemic autoimmune disease. The most frequent treatment was systemic steroids (50.9%), followed by systemic NSAIDs (32.4%). Steroid-sparing immunosuppression was required in 49.1% of patients. Systemic autoimmune diseases were more common in patients with necrotizing scleritis and those older than 40 years of age. Best-corrected visual acuity of 20/80 or worse at presentation was more common in necrotizing scleritis and subjects with associated uveitis, ocular hypertension, or who were over 40 years of age.

CONCLUSIONS

This is the first study in Colombia and the largest in Latin America describing the clinical characteristics and presentation patterns of scleritis. The most common presentation was in females, with unilateral, anterior diffuse noninfectious scleritis. Systemic autoimmune diseases and polyautoimmunity were frequent, as was the need for steroid-sparing immunosuppression. Age over 40 and necrotizing scleritis were associated with higher odds of having a systemic autoimmune disease and worse visual acuity at presentation.

Prevalence of antinuclear antibodies in inflammatory bowel disease and seroconversion after biological therapy

BACKGROUND

Estimates of detectable antinuclear antibodies (ANA) prevalence vary widely, from 6% in healthy populations to 50-80% in patients with autoimmune disease. However, there is a lack of evidence about the overall prevalence in inflammatory bowel disease (IBD) and ANA seroconversion after the beginning of biological therapy.

OBJECTIVES

The aim of the study was to investigate the overall prevalence of ANA in IBD patients, their relationship with different treatments, clinical outcomes and the seroconversion rate of ANA in patients treated with biological therapy.

METHODS

Ambispective observational study including all consecutive IBD patients was carried out. Information about the presence of ANA, disease phenotype, duration, activity, complications, and past and current treatments were transversally collected. Retrospectively, in patients with detectable ANA, data regarding previous ANA detection and the diagnosis of lupus-like syndrome (LLS) was gathered.

RESULTS

A total of 879 IBD patients were included. We observed a detectable ANA prevalence of 13.6%. The presence of ANA was frequently associated with biological therapy (36/118) and decreased when immunomodulators were combined to this therapy (7/32). Of 78 patients with ANA prior to the beginning of biological therapy, a seroconversion rate of 28.8% was observed after a mean of 3.14 years. Only 1 patient suffered LLS.

CONCLUSION

Our study showed a prevalence of detectable ANA higher than the expected in healthy population. The presence of ANA was lower when immunomodulator therapy is associated. The ANA seroconversion rate is relevant after the initiation of biological treatment nevertheless, the risk of LLS appeared to be marginal.

Assessment of ideal serum dilution for screening of antinuclear antibodies by an indirect immunofluorescence method in diagnosis of autoimmune disorders

BACKGROUND

Time and cost constraints lead to majority of clinical laboratories deviating away from an ideal practice of checking for antinuclear antibodies (ANAs) by indirect immunofluorescence (IIF) at multiple dilutions. Usage of screening dilution of 1:40 recommended by most manufacturers of commercial ANA kits results in numerous false positive-tests and misdiagnosis of connective tissue disorders (CTDs). We sought to study the ideal screening dilution for ANA by IIF for a diagnosis of ANA-related CTDs.

METHODS

Serum samples of patients with ANA-related conditions (n = 233) and healthy controls (n = 154) were evaluated by IIF using Immuno Concepts Hep-2000 ® ANA kits at dilutions from 1:40 to 1:640. Accuracy for diagnosis of CTDs for each serum dilution was assessed by receiver operating curve (ROC) analysis.

RESULTS

Antinuclear antibodies (ANA) positivity was observed in 19.5%, 10.4%, 4.55%, 0.65%, and 0% of healthy controls at dilutions of 1:40, 1:80, 1:160, 1:320, and 1:640, respectively. ANA positivity at 1:40 dilution was observed among 26.4% cases with mimics of CTDs. Prevalence of ANA positivity in ANA-related CTDs was 97.3%, 96.4%, 89.3%, 83.9%, and 71.4% at dilutions of 1:40, 1:80, 1:160, 1:320, and 1:640, respectively. ROC analysis revealed best test performance for distinction between healthy and ANA-related CTD populations at a serum dilution of 1 in 80.

CONCLUSIONS

Antinuclear antibodies (ANA) positivity at low titers (1:40) is highly prevalent in healthy population (19.5%) as well as amongst mimics of CTD (26.4%). Our study suggests a higher screening dilution of 1:80 for ANA by IIF for diagnosis of CTD maybe better. Combination of 1:80 and 1:160 dilutions provides optimum sensitivity and specificity for diagnosis of ANA-related disorders.

Autoantibodies to dense-fine-speckled 70 (DFS70) do not necessarily rule out connective tissue diseases

OBJECTIVES

In some patients with antinuclear antibodies (ANA), a pattern called anti-dense-fine-speckled-70 antibody (anti-DFS70) can be detected. Presence of anti-DFS70 is less frequently observed in patients with connective tissue diseases (CTD) and is therefore used as an exclusion criterion by some rheumatologists. To date, however, it is unclear as to what extent the presence of an anti-DFS70 can reliably rule out CTDs.

METHODS

Data of 460 patients who were tested for the presence of anti-DFS70 at University Hospital Bonn, Germany, were analyzed. Patients were examined with regard to clinical symptoms and signs, type of disease, type of CTD, fulfillment of the classification criteria, presence of anti-DFS70, other systemic autoantibodies and ANA titers by indirect immunofluorescence (IIF) assays and line immunoassays. Differences in DFS70 antibody status between patients with CTD were examined. In addition, specificity, sensitivity, and positive predictive values for different ANA titers were calculated.

RESULTS

In 182 of the 460 patients (of whom 79.8% were female), CTD was diagnosed. 354 patients (77.0%) tested negative, 81 (17.6%) positive and 25 (5.4%) borderline for anti-DFS70. Twenty-one patients (25.9%) with a positive result had CTD. No significant differences were observed between anti-DFS70 positive and anti-DFS70 negative patients with CTD concerning age, gender, symptoms, clinical signs, and other disease-specific antibodies. However, of these 21 patients, only one patient showed the monospecific appearance of anti-DFS70. Anti-DFS70 had a sensitivity and a specificity of 26.9% and 86.8%, respectively, with a positive predictive value of 68.2% at an ANA titer of ≥1:160 with respect to the absence of CTD.

CONCLUSIONS

Autoantibodies to DFS70 seem to be prevalent in CTD patients and are thus not a good exclusion criterion. The monospecific occurrence of anti-DFS70 can, however, be helpful in ambiguous situations.

Prevalence of antinuclear antibody in patients with multiple sclerosis: a case-control study

Background

Antinuclear antibody (ANA) is a common test for excluding alternative diagnoses. However, the significance of ANA testing in patients with multiple sclerosis (MS) remains unclear.

Objectives

To compare the prevalence of positive ANA antibody and its titer between patients with MS (cases) and non-MS patients who attended neurology clinics (control) in Saudi Arabia.

Methods

A case-control review of ANA results for all patients who attended a neurology MS clinic. We compared a convenience sample of patients with MS with individuals with general neurology problems and no known autoimmune diseases.

Results

There were 115 and 103 participants in the MS and control group, respectively. The mean age in the MS and control group was 33.76 ± 8.96 years and 34.95 ± 8.56 years, respectively. In the MS group, 25.22%, 60%, 11.30%, and 3.48% were negative, mildly positive, moderately positive, and strongly positive for ANA, respectively. In the control group, there were 34.95%, 54.37%, and 10.68% were negative, mild positive, and moderate positive, respectively. There were numerically, but not significantly, more positive cases in the MS group (74.78%) than in the control group (65.05%) (p = .117).

Conclusion

ANA testing in routine MS screening for excluding alternative diagnoses should be discouraged unless there is a remarkable history or clinical examination finding. Mild positive ANA is common among patients with MS and does not significantly differ from the general population.

Profiling Serum Antibodies Against Muscle Antigens in Facioscapulohumeral Muscular Dystrophy Finds No Disease-Specific Autoantibodies

BACKGROUND

FSHD is caused by specific genetic mutations resulting in activation of the Double Homeobox 4 gene (DUX4). DUX4 targets hundreds of downstream genes eventually leading to muscle atrophy, oxidative stress, abnormal myogenesis, and muscle inflammation. We hypothesized that DUX4-induced aberrant expression of genes triggers a sustained autoimmune response against skeletal muscle cells.

OBJECTIVE

This study aimed at the identification of autoantibodies directed against muscle antigens in FSHD. Moreover, a possible relationship between serum antibody reactivity and DUX4 expression was also investigated.

METHODS

FSHD sera (N = 138, 48±16 years, 48% male) and healthy control sera (N = 20, 47±14 years, 50% male) were analyzed by immunoblotting for antibodies against several skeletal muscle protein extracts: healthy muscle, FSHD muscle, healthy and FSHD myotubes, and inducible DUX4 expressing myoblasts. In addition, DUX4 expressing myoblasts were analyzed by immunofluorescence with FSHD and healthy control sera.

RESULTS

The results showed that the reactivity of FSHD sera did not significantly differ from that of healthy controls, with all the tested muscle antigen extracts. Besides, the immunofluorescent staining of DUX4-expressing myoblasts was not different when incubated with either FSHD or healthy control sera.

CONCLUSION

Since the methodology used did not lead to the identification of disease-specific autoantibodies in the FSHD cohort, we suggest that autoantibody-mediated pathology may not be an important disease mechanism in FSHD. Nevertheless, it is crucial to further unravel if and which role the immune system plays in FSHD pathogenesis. Other innate as well as adaptive immune players could be involved in the complex DUX4 cascade of events and could become appealing druggable targets.

Recognition and Management of Cutaneous Connective Tissue Diseases

Connective tissue diseases (CTDs) encompass a broad spectrum of clinical presentations that involve multidisciplinary management. Cutaneous findings are common in CTD and careful examination of these features aids in appropriate diagnosis and subsequent evaluation. Thorough work-up of CTD is crucial to properly identify disease subtypes and systemic involvement. Management plans can be developed based on diagnosis and systemic manifestations of disease. Disease management often requires treatment with pharmacotherapies with potential for toxicities, further underscoring the importance of diagnostic accuracy in this patient population. Evolving research strives to better elucidate the pathogenic mechanisms of CTDs allowing for more targeted treatment modalities.

Antinuclear Autoantibodies in Health: Autoimmunity Is Not a Synonym of Autoimmune Disease

The incidence of autoimmune diseases is increasing. Antinuclear antibody (ANA) testing is a critical tool for their diagnosis. However, ANA prevalence in healthy persons has increased over the last decades, especially among young people. ANA in health occurs in low concentrations, with a prevalence up to 50% in some populations, which demands a cutoff revision. This review deals with the origin and probable physiological or compensatory function of ANA in health, according to the concept of immunological clearance, theory of autoimmune regulation of cell functions, and the concept of functional autoantibodies. Considering ANA titers ≤1:320 as a serological marker of autoimmune diseases seems inappropriate. The role of anti-DFS70/LEDGFp75 autoantibodies is highlighted as a possible anti-risk biomarker for autoimmune rheumatic disorders. ANA prevalence in health is different in various regions due to several underlying causes discussed in the review, all influencing additive combinations according to the concept of the mosaic of autoimmunity. Not only are titers, but also HEp-2 IFA) staining patterns, such as AC-2, important. Accepting autoantibodies as a kind of bioregulator, not only the upper, but also the lower borders of their normal range should be determined; not only their excess, but also a lack of them or "autoimmunodeficiency" could be the reason for disorders.

Urinary Metals Concentrations and Biomarkers of Autoimmunity among Navajo and Nicaraguan Men

Metals are suspected contributors of autoimmune disease among indigenous Americans. However, the association between metals exposure and biomarkers of autoimmunity is under-studied. In Nicaragua, environmental exposure to metals is also largely unexamined with regard to autoimmunity. We analyzed pooled and stratified exposure and outcome data from Navajo (n = 68) and Nicaraguan (n = 47) men of similar age and health status in order to characterize urinary concentrations of metals, compare concentrations with the US National Health and Nutrition Examination Survey (NHANES) male population, and examine the associations with biomarkers of autoimmunity. Urine samples were analyzed for metals via inductively coupled plasma mass spectrometry (ICP-MS) at the US Centers for Disease Control and Prevention. Serum samples were examined for antinuclear antibodies (ANA) at 1:160 and 1:40 dilutions, using an indirect immunofluorescence assay and for specific autoantibodies using enzyme-linked immunosorbent assay (ELISA). Logistic regression analyses evaluated associations of urinary metals with autoimmune biomarkers, adjusted for group (Navajo or Nicaraguan), age, and seafood consumption. The Nicaraguan men had higher urinary metal concentrations compared with both NHANES and the Navajo for most metals; however, tin was highest among the Navajo, and uranium was much higher in both populations compared with NHANES. Upper tertile associations with ANA positivity at the 1:160 dilution were observed for barium, cesium, lead, strontium and tungsten.

Current insights in the pathogenesis of scleritis

Scleritis is a sight-threatening inflammation characterized by severe pain and redness of the eye. It can cause blindness by severe complications like scleral and corneal necrosis, keratitis, and uveitis. The pathogenesis of scleritis is largely unknown due to a combination of the rarity of the disease, the little available human tissue-based research material, and the lack of animal models. The immune system is assumed to play a crucial role in the pathogenesis of scleritis. Multiple clues indicate probable antigenic stimuli in scleritis, and the involvement of matrix metalloproteinases in the destruction of scleral tissue. In this article we review the current insights into the pathogenesis of scleritis, and we suggest new hypotheses by implementing knowledge of systemic autoimmune disease pathogenesis. Understanding the pathogenesis of scleritis is crucial to improve the clinical management, as well as to find novel treatment modalities.

[Antinuclear antibodies in the diagnostics of rheumatic diseases]

Testing for antinuclear antibodies (ANA) on human epithelial cell lines (HEp-2) using indirect immunofluorescence (IIF) is central for ruling out or for diagnosing connective tissue diseases and other diseases, such as primary biliary cholangitis and autoimmune hepatitis as well as drug-induced ANA. The comprehensive description of 29 different ANA-IIF patterns by the international consensus of ANA patterns (ICAP) facilitates the harmonization of ANA-IIF diagnostics. Positive ANA tests are frequently observed in healthy individuals and a reason for referral to rheumatologists. In these cases, the detection of anti-DFS70 antibodies can be helpful to exclude systemic autoimmune rheumatic diseases.

Longitudinal anti-nuclear antibody (ANA) seroconversion in systemic lupus erythematosus: a prospective study of Swedish cases with recent-onset disease

Serum immunoglobulin (Ig)G anti-nuclear antibodies (ANA) detected by indirect immunofluorescence (IF) microscopy remains a hallmark of systemic lupus erythematosus (SLE). Whether or not IF-ANA status varies over time is controversial. We therefore designed a prospective study with longitudinal follow-up of patients with recent-onset SLE. The study population consisted of 54 recently diagnosed SLE cases, all meeting the 1982 American College of Rheumatology (ACR) and/or the 2012 Systemic Lupus International Collaborating Clinics (SLICC) criteria. Clinical follow-up data, including disease activity, organ damage and sera, were collected from clinical onset of SLE and onwards, in most cases yearly (0-96 months). IF-ANA was analysed on human epithelial cells-2 (HEp-2) cells and categorized regarding staining patterns. Using an addressable laser bead assay (FIDIS™ Connective profile), we measured IgG-ANA fine specificities against Ro52/SSA, Ro60/SSA, Sjögren's syndrome type B antigen (La/SSB), Smith antigen (Sm), Smith antigen/ribonucleoprotein (Sm/RNP), U1 RNP (U1RNP), dsDNA, ribosomal-P protein and histone. At baseline, all patients were judged ANA-positive at an abnormal titre corresponding to the 95th percentile of healthy blood donors, but seven of 54 patients (13%) lost ANA-positivity over time. Homogeneous (AC-1; 46%) and speckled (AC-4 or 5; 31%) were the most frequently observed patterns at inclusion, whereas 7% switched pattern at least once during follow-up. Established associations between ANA fine specificities and clinical data were confirmed. Levels of anti-Sm/RNP, but not of anti-dsDNA, correlated with clinical disease activity [modified SLE disease activity 2000 (mSLEDAI-2K)]. Our data indicate that a considerable proportion of Swedish patients with SLE lose ANA-positivity over time, whereas consistent staining patterns were frequent. The clinical and mechanistic relevance of ANA seroconversion remains uncertain. Further prospective evaluations in larger SLE populations with more diverse ethnicities are warranted.

Novel biomarkers for primary biliary cholangitis to improve diagnosis and understand underlying regulatory mechanisms

BACKGROUND AND AIMS

Primary biliary cholangitis is an autoimmune biliary disease characterized by injury of bile ducts, eventually leading to cirrhosis and death. In most cases, anti-mitochondrial antibodies and persistently elevated serum alkaline phosphatase are the basis for the serological diagnosis. Anti-nuclear antibodies are also useful and may indicate a more aggressive diseases course. In patients in which anti-mitochondrial antibodies are not detected, an accurate diagnosis requires liver histology. This study aims at identifying specific biomarkers for the serological diagnosis of primary biliary cholangitis.

METHODS

Sera from patients affected by primary biliary cholangitis, primary sclerosing cholangitis, hepatitis C virus (with and without cryoglobulinemia), hepatocarcinoma and healthy donors were tested on a protein array representing 1658 human proteins. The most reactive autoantigens were confirmed by DELFIA analysis on expanded cohorts of the same mentioned serum classes, and on autoimmune hepatitis sera, using anti-PDC-E2 as reference biomarker.

RESULTS

Two autoantigens, SPATA31A3 and GARP, showed high reactivity with primary biliary cholangitis sera, containing or not anti-mitochondrial antibodies. Their combination with PDC-E2 allowed to discriminate primary biliary cholangitis from all tested control classes with high sensitivity and specificity. We found that GARP expression is upregulated upon exposure to biliary salts in human cholangiocytes, an event involving EGFR and insulin pathways. GARP expression was also detected in biliary duct cells of PBC patients.

CONCLUSIONS

This study highlighted SPATA31A3 and GARP as new biomarkers for primary biliary cholangitis and unravelled molecular stimuli underlying GARP expression in human cholangiocytes.

Antinuclear antibodies in healthy people and non-rheumatic diseases - diagnostic and clinical implications

The presence of antinuclear antibodies (ANA) is mainly associated with connective tissue diseases (CTD). In addition, their presence is found in healthy people. These antibodies are more common in women and the elderly. Some drugs and xenobiotics are also important for the development of autoimmunity and ANA synthesis. Moreover, the deficiency of vitamin D in the body of patients correlates with occurrence of these antibodies. Unlike the healthy group, a positive ANA count was observed in patients with atopic dermatitis (AD) and in people with immune disorders. Antinuclear antibodies in low counts are also found in the course of chronic bacterial or viral infection and in patients with hematological malignancies. Also the possibility of false positive results, which may be caused by the choice of method used to determine antibodies, should be borne in mind. Taking into account all these factors, it is concluded that the ANA result itself has no diagnostic value.

Autoimmunity in uveitis

PURPOSE

Recent insights into the pathogenesis of immune-mediated diseases proposed a new classification, which includes autoimmune and auto-inflammatory diseases. The prevalence of specific autoimmune and auto-inflammatory diseases in uveitis and/or scleritis is not yet known. In this study, we examine the presence of systemic immune-mediated diseases in patients with uveitis and/or scleritis and put a special emphasis on autoimmune disorders by reporting on their clinical manifestations and visual prognosis.

METHODS

In this retrospective study, we reviewed data of 1327 patients presenting with uveitis and/or scleritis between January 2010 and July 2016 at the Erasmus Medical Center, Rotterdam, the Netherlands. All patients with noninfectious uveitis and/or scleritis were classified according to novel criteria for immune-mediated diseases. Various clinical data, including visual acuity (VA), of patients with uveitis of autoimmune origin were registered during 5-year follow-up.

RESULTS

The origin of uveitis was in 5% (62/1327) autoimmune, in 15% (197/1327) auto-inflammatory and in 14% (180/1327) mixed autoimmune/auto-inflammatory. Patients with classical autoimmune connective tissue disease (N = 17) suffered mostly from rheumatoid arthritis and granulomatosis with polyangiitis and exhibited predominantly scleritis (53%). After 5 years of follow-up, none of the eyes of these patients developed legal blindness (VA of <0.1). The VA in patients with uveitis associated with autoimmune neuro-ophthalmological diseases (multiple sclerosis and neuromyelitis optica; N = 27) remained stable over time.

CONCLUSION

Uveitis and scleritis of autoimmune origin were observed in 5% of the total series. The term autoimmune uveitis should not be used as a synonym for intraocular inflammation of noninfectious origin.

Anti-phospholipid Antibodies and Smoking: An Overview

Antiphospholipid syndrome is characterized by the presence of antiphospholipid antibodies, specifically lupus anticoagulant, anticardiolipin antibodies, and anti-β2 glycoprotein-I antibodies. Antiphospholipid syndrome can occur on its own or in association with other autoimmune diseases, most commonly systemic lupus erythematosus (SLE). A connection between cigarette smoking and anti-phospholipid antibodies (aPL) was first reported in the late1980s. Systemic lupus erythematosus patients with aPL are more likely to be smokers than those without aPL. These patients have a particularly high frequency of vascular events. Recently, a potential link between periodontitis, tobacco, and aPL has been proposed. Research has also suggested that periodontitis and Porphyromonas gingivalis infection are associated with citrullination through the action of peptidylarginine deiminase. A strong correlation between smoking and the presence of citrillunated autoantibodies, which are characteristic of rheumatoid arthritis, has also been observed. While many studies have investigated possible links between infection and aPL in patients with autoimmune diseases, the association of smoking with aPL has not been systematically examined. The fact that both aPL and tobacco are risk factors for thrombosis has complicated efforts to evaluate these factors separately. Also, there has been great variability in measurement techniques, and laboratories lack routine methods for differentiating transient and persistent aPL; both of these factors can make interpretation of autoantibody results quite challenging. This review summarizes the clinical evidence supporting a posited link between aPL and smoking, both in patients with a systemic autoimmune disease and in patients with other medical conditions.

Autoantibodies Associated With Connective Tissue Diseases: What Meaning for Clinicians?

Connective tissue diseases (CTDs) such as systemic lupus erythematosus, systemic sclerosis, myositis, Sjögren's syndrome, and rheumatoid arthritis are systemic diseases which are often associated with a challenge in diagnosis. Autoantibodies (AAbs) can be detected in these diseases and help clinicians in their diagnosis. Actually, pathophysiology of these diseases is associated with the presence of antinuclear antibodies. In the last decades, many new antibodies were discovered, but their implication in pathogenesis of CTDs remains unclear. Furthermore, the classification of these AAbs is nowadays misused, as their targets can be localized outside of the nuclear compartment. Interestingly, in most cases, each antibody is associated with a specific phenotype in CTDs and therefore help in better defining either the disease subtypes or diseases activity and outcome. Because of recent progresses in their detection and in the comprehension of their pathogenesis implication in CTD-associated antibodies, clinicians should pay attention to the presence of these different AAbs to improve patient's management. In this review, we propose to focus on the different phenotypes and features associated with each autoantibody used in clinical practice in those CTDs.

Anti-nuclear autoantibodies in the general German population: prevalence and lack of association with selected cardiovascular and metabolic disorders-findings of a multicenter population-based study

BACKGROUND

We determined the prevalence of anti-nuclear autoantibodies (ANAs) in the German adult population and examined the association between ANAs and cardiovascular and metabolic disorders.

METHODS

We used data and blood samples from the pretest phases of the German National Cohort, obtained from six of the 18 study centers (n = 1199). All centers applied standardized instruments including face-to-face interviews, anthropometric measurements and collection of blood samples. Self-reported histories of diabetes mellitus, heart attack and elevated blood cholesterol and/or lipids were recorded. Height, weight and blood pressure were measured. ANAs were detected using a semi-automated system (AKLIDES®; Medipan GmbH, Dahlewitz, Germany). A positive ANA was defined as a titer ≥ 1:80. ANA were classified as weakly (1:80 or 1:160), moderately (1:320 or 1:640) or strongly (≥1:1280) positive. Specific autoantibodies against nuclear antigens were detected with second-step assays according to the ANA staining pattern. Associations between the assessed disorders and ANA positivity and pattern were examined using sex and age-adjusted mixed-effects logistic regression models.

RESULTS

Thirty-three percent (95% confidence interval; 31-36%) of the 1196 participants (measurements could not be obtained from three samples) were ANA positive (titer ≥ 1:80). The proportions of weakly, moderately and strongly positive ANA were 29%, 3.3% and 1.3%, respectively. ANA positivity was more common among women than men across all titers (χ², p = 0.03). ANA positivity, even when stratified according to height of titer or immunofluorescent pattern, was not associated with diabetes, elevated blood cholesterol and/or lipids, obesity or hypertension. Second-step autoantibody assays were positive in 41 of the 83 samples (49%) tested, with anti-DFS70 (n = 13) and anti-dsDNA (n = 7) being most frequent. These subgroups were too small to test for associations with the disorders assessed.

CONCLUSIONS

The prevalence of ANA positivity in the German general population was similar to values reported from other countries. Contrary to other studies, there was no association with selected self-reported and objectively measured cardiovascular and metabolic variables.

Prevalence of systemic autoimmune rheumatic diseases and clinical significance of ANA profile: data from a tertiary hospital in Shanghai, China

It is necessary and useful to explore prevalence of various systemic autoimmune rheumatic diseases (SARDs) in patients with suspicion of having SARDs and to characterize antinuclear antibodies (ANA) profile for identifying different populations (SARDs and non-SARDs). A total of 5024 consecutive patients with available medical records were investigated, whose sera had been tested for ANA profile, including ANA, anti-dsDNA and anti-extractable nuclear antigen (ENA) antibodies, between 31 January 2012 and 26 March 2014. Only 594 (11.8%) patients were diagnosed with SARDs of those suspected with SARDs. The prevalence of systemic lupus erythematosus (SLE) was highest (3.2%), followed by rheumatoid arthritis (RA) (2.5%), primary Sjögren's syndrome (pSS) (1.7%), ankylosing spondylitis (AS) (1.5%), etc. Of females, SLE also showed the highest prevalence (6%), while of males, AS showed the highest prevalence (1.9%). The prevalence of most SARDs was closely associated with age, except mixed connective tissue disease (MCTD), and the variation characteristics among different age groups were different among various SARDs. The prevalence of ANA was significantly increased in most SARD patients [especially in SLE, systemic sclerosis (SSc) and MCTD]. For anti-ENA antibodies, in contrast to some autoantibodies associated with multiple SARDs (e.g. anti-SSA, SSB, nRNP), others were relatively specific for certain diseases, such as anti-dsDNA, Sm, histone, nucleosome and Rib-P for SLE, anti-SCL-70 for SSc and anti-Jo-1 for polymyositis/dermatomyositis (PM/DM). Of note, ANA profile appeared to be of little significance for AS, ANCA-associated vasculitis (AAV), polymyalgia rheumatic (PMR), adult-onset Still's disease (ASD) and Behcet's disease (BD). The younger were more likely to have the presence of anti-dsDNA, Sm, histone or Rib-P for SLE, and anti-SSA for RA or MCTD. No significant differences for frequencies of ANA and anti-ENA autoantibodies were found between sexes in most SARDs, with the exception of RA and AS. The present study suggests that, of patients with SARDs-like clinical manifestations, the proportion of those with true SARDS is small, for most of whom tests for autoantibodies are necessary and useful to help make a prompt and precise diagnosis.

Association between antinuclear antibody titers and connective tissue diseases in a Rheumatology Department

OBJECTIVE

To determine the dilution titles at antinuclear antibodies (ANA) by indirect immunofluorescence observed in cell substrate HEp-2 and its association with the diagnosis of systemic connective tissue disease in ANA test requested by a Rheumatology Unit.

METHOD

Samples of patients attended for the first time in the rheumatology unit, without prior ANA test, between January 2010 and December 2012 were selected. The dilution titers, immunofluorescence patterns and antigen specificity were recorded. In January 2015 the diagnosis of the patients were evaluated and classified in systemic disease connective tissue (systemic lupus erythematosus, Sjögren's syndrome, systemic sclerosis, undifferentiated connective, antiphospholipid syndrome, mixed connective tissue and inflammatory myophaty) or not systemic disease connective tissue.

RESULT

A total of 1282 ANA tests requested by the Rheumatology Unit in subjects without previous study, 293 were positive, predominance of women (81.9%). Patients with systemic connective tissue disease were recorded 105, and 188 without systemic connective tissue disease. For 1/640 dilutions the positive predictive value in the connective was 73.3% compared to 26.6% of non-connective, and for values ≥1/1,280 85% versus 15% respectively. When performing the multivariate analysis we observed a positive association between 1/320 dilution OR 3.069 (95% CI: 1.237-7.614; P=.016), 1/640 OR 12.570 (95% CI: 3.659-43.187; P=.000) and ≥1/1,280 OR 42.136 (95% CI: 8.604-206.345; P=.000).

CONCLUSION

These results show association titles dilution ≥1/320 in ANA's first test requested by a Rheumatology Unit with patients with systemic connective tissue disease. The VPP in these patients was higher than previous studies requested by other medical specialties. This may indicate the importance of application of the test in a targeted way.

Analysis of Characteristics Similar to Autoimmune Disease in Keloid Patients

BACKGROUND

Keloid is a fibrotic skin disease for which immune cell infiltration is a primary pathological hallmark. Meanwhile, in autoimmune diseases, triggering of the inflammation response can lead to tissue injury and subsequent organ fibrosis. When the skin is involved in autoimmune disease, skin fibrosis such as that seen in scleroderma can occur. In this study, we propose that keloid possesses features of autoimmune disease.

METHODS

To verify whether keloid possesses features of autoimmune disease, immune cell infiltration and immune complex deposits were detected with immunohistochemical staining and immunofluorescence, respectively, in keloid and normal skin tissues. A routine antinuclear antibody profile was tested in sera from 28 keloid patients and 28 healthy controls. Lastly, the anti-hnRNPA2B1 autoantibody in sera was evaluated by enzyme-linked immunosorbent assay.

RESULTS

The numbers of CD1α(+) Langerhans cells, CD3(+) T lymphocytes, CD68(+) macrophages, and CD20(+) B lymphocytes increased in keloid tissues compared to normal skin. IgA, IgM, C3, and C1q deposits were found in keloid tissues but not in normal skin, while anti-hnRNPA2B1 levels in sera from keloid patients were elevated.

CONCLUSION

The above findings suggest that keloids have some characteristics that are similar to autoimmune disease and might be mediated by autoimmune responses.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

The significance of autoantibodies to DFS70/LEDGFp75 in health and disease: integrating basic science with clinical understanding

Antinuclear autoantibodies (ANAs) displaying the nuclear dense fine speckled immunofluorescence (DFS-IIF) pattern in HEp-2 substrates are commonly observed in clinical laboratory referrals. They target the dense fine speckled autoantigen of 70 kD (DFS70), most commonly known as lens epithelium-derived growth factor p75 (LEDGFp75). Interesting features of these ANAs include their low frequency in patients with systemic autoimmune rheumatic diseases (SARD), elevated prevalence in apparently healthy individuals, IgG isotype, strong trend to occur as the only ANA specificity in serum, and occurrence in moderate to high titers. These autoantibodies have also been detected at varied frequencies in patients with diverse non-SARD inflammatory and malignant conditions such as atopic diseases, asthma, eye diseases, and prostate cancer. These observations have recently stimulated vigorous research on their clinical and biological significance. Some studies have suggested that they are natural, protective antibodies that could serve as biomarkers to exclude a SARD diagnosis. Other studies suggest that they might be pathogenic in certain contexts. The emerging role of DFS70/LEDGFp75 as a stress protein relevant to human acquired immunodeficiency syndrome, cancer, and inflammation also points to the possibility that these autoantibodies could be sensors of cellular stress and inflammation associated with environmental factors. In this comprehensive review, we integrate our current knowledge of the biology of DFS70/LEDGFp75 with the clinical understanding of its autoantibodies in the contexts of health and disease.

Anti-nuclear antibodies in daily clinical practice: prevalence in primary, secondary, and tertiary care

For the diagnosis of systemic autoimmune rheumatic diseases (SARD), patients are screened for anti-nuclear antibodies (ANA). ANA, as assessed by indirect immunofluorescence (IIF), have a poor specificity. This hampers interpretation of positive results in clinical settings with low pretest probability of SARD. We hypothesized that the utility of positive ANA IIF results increases from primary to tertiary care. We retrospectively determined ANA, anti-ENA, and anti-dsDNA antibody prevalence in patient cohorts from primary (n = 1453), secondary (n = 1621), and tertiary (n = 1168) care settings. Results reveal that from primary care to tertiary care, ANA prevalence increases (6.2, 10.8, and 16.0%, resp.). Moreover, in primary care low titres (70% versus 51% and 52% in secondary and tertiary care, resp.) are more frequent and anti-ENA/dsDNA reactivities are less prevalent (21% versus 39% in secondary care). Typically, in tertiary care the prevalence of anti-ENA/dsDNA reactivities (21%) is lower than expected. From this descriptive study we conclude that positive ANA IIF results are more prone to false interpretation in clinical settings with low pretest probabilities for SARD, as in primary care. Whether alternative approaches, that is, immunoadsorption of anti-DFS70 antibodies or implementation of anti-ENA screen assays, perform better, needs to be determined.

Predictive value of antinuclear antibodies in autoimmune diseases classified by clinical criteria: Analytical study in a specialized health institute, one year follow-up

Introduction: Determination of antinuclear antibodies (ANA) by indirect immunofluorescence (IIF) is usually the initial test for the diagnosis of systemic rheumatic diseases (SRD). Assigning predictive values to positive and negative results of the test is vital because lack of knowledge about ANAs and their usefulness in classification criteria of SRD leads to inappropriate use. Methods: Retrospective study, ANA tests requested by different specialties, correlation to patients' final diagnosis. Results: The prevalence of autoimmune disease was relatively low in our population yielding a low PPV and a high NPV for the ANA test. 40% of the patients had no clinical criteria applied prior to test. Coexistence of two or more autoimmune disorders affects prevalence and predictive values. Conclusion: Application of the test after careful evaluation for clinical criteria remarkably improves the positive likelihood ratio for the diagnosis.

Cutaneous lupus erythematosus: diagnosis and treatment

Cutaneous lupus erythematosus (CLE) encompasses a wide range of dermatologic manifestations, which may or may not be associated with the development of systemic disease. Cutaneous lupus is divided into several sub-types, including acute CLE (ACLE), sub-acute CLE (SCLE) and chronic CLE (CCLE). CCLE includes discoid lupus erythematosus (DLE), LE profundus (LEP), chilblain cutaneous lupus and lupus tumidus. The diagnosis of these diseases requires proper classification of the sub-type, through a combination of physical examination, laboratory studies, histology, antibody serology and occasionally direct immunofluorescence, while ensuring to exclude systemic disease. The treatment of cutaneous lupus consists of patient education on proper sun protection along with appropriate topical and systemic agents. Systemic agents are indicated in cases of widespread, scarring or treatment-refractory disease. In this chapter, we discuss issues in classification and diagnosis of the various sub-types of CLE, as well as provide an update on therapeutic management.