Autoantibody Determination in the Diagnosis of Systemic Lupus Erythematosus

Increased healthcare utilisation in the 5 years preceding systemic lupus erythematosus diagnosis: a Danish nationwide cohort study

OBJECTIVES

This study aimed to analyse healthcare utilisation patterns in the 5 years preceding a diagnosis of systemic lupus erythematosus (SLE) in Denmark compared to matched healthy individuals. Understanding these patterns could support earlier diagnosis and reduce diagnostic delay.

METHODS

A nationwide, registry-based cohort study was conducted using data from the Danish national healthcare registries between 2006 and 2021. Healthcare utilisation, including general practitioner (GP) visits, specialist consultations, prescriptions, blood tests, diagnostic imaging, and hospital admissions, was examined. Incidence rate ratios were calculated using negative binomial regression models adjusted for demographic and clinical covariates.

RESULTS

We included 2022 individuals diagnosed with SLE and 20,019 matched reference individuals. 83.8% of patients were female, with an average age of 47.1 years. Even at baseline, patients with SLE exhibited significantly higher healthcare utilisation compared to references for all outcomes which continued throughout the 5-year follow-up. Patients with SLE had approximately 12 annual GP contacts until 1.5 year before diagnosis, where the contact rate increased substantially. Reference individuals consistently had about 4 contacts per year. The incidence rate ratio was approximately 3 during the 5 to 1.5 years preceding diagnosis, increasing to 5.20 (95% confidence interval 4.95-5.46) in the last 6 months before diagnosis.

CONCLUSIONS

Increased healthcare utilisation years before SLE diagnosis suggests that early symptoms are present and prompt medical attention long before formal diagnosis. These findings highlight the potential for earlier identification of SLE, underscoring the need for improved diagnostic strategies to reduce delays and enhance patient outcomes.

From neglect to spotlight: the underappreciated role of B cells in cutaneous inflammatory diseases

The skin, covering our entire body as its largest organ, manifests enormous complexities and a profound interplay of systemic and local responses. In this heterogeneous domain, B cells were considered strangers. Yet, recent studies have highlighted their existence in the skin and their distinct role in modulating cutaneous immunity across various immune contexts. Accumulating evidence is progressively shedding light on the significance of B cells in maintaining skin health and in skin disorders. Herein, we integrate current insights on the systemic and local contributions of B cells in three prevalent inflammatory skin conditions: Pemphigus Vulgaris (PV), Systemic Lupus Erythematosus (SLE), and Atopic Dermatitis (AD), underscoring the previously underappreciated importance of B cells within skin immunity. Moreover, we address the potential adverse effects of current treatments used for skin diseases, emphasizing their unintentional consequences on B cells. These comprehensive approaches may pave the way for innovative therapeutic strategies that effectively address the intricate nature of skin disorders.

Increased carotid intima-media thickening and antioxidized low-density lipoprotein in an anti-Ro60 SLE autoantibody subset

Objective

Premature atherosclerosis is associated with systemic lupus erythematosus (SLE). We have previously shown an association of anti-Ro60/La/Ro52 with antioxidized low-density lipoprotein (LDL) in SLE. Here, we hypothesized that carotid intima-media thickening (CIMT) would be associated with antioxidized LDL (anti-oxLDL)/antilipoprotein lipase (ALPL) in a specific SLE autoantibody subset (anti-Ro60 positive, anti-RNP positive, anti-SmRNP positive, or extractable nuclear antigen antibody negative).

Methods

We carried out a case-control study (one time-point testing) of CIMT, ALPL, anti-oxLDL, anti-low density lipoprotein (ALDL), and anti-LDL in 114 SLE patients and 117 age/sex-matched controls. The levels of total cholesterol, LDL, high-density lipoprotein (HDL), triglycerides, and HDL-Trig were also measured. A student's t-test was used for statistical analysis.

Results

Interestingly, the level of CIMT was highest in the SLE subset with anti-Ro60 (23/114). CIMT and anti-oxLDL were statistically significantly elevated in the anti-Ro60 SLE subset (1.3 ± 1.66, p < 0.01; 0.26 ± 0.16, p < 0.002, respectively) compared with controls (0.54 ± 1.26; 0.165 ± 0.13, respectively), but not anti-LPL/anti-LDL. CIMT was significantly elevated (0.9 ± 1.71; p < 0.05) in the SLE subset without antiextractable nuclear antigen (ENA) (63/114) compared with controls. The other antibodies in this subset were not statistically different from other SLE subsets or controls. Only antioxLDL was significantly elevated (0.29 ± 0.27; p < 0.005) in the SLE subset with anti-RNP (14/114) compared with controls, while none were elevated in the anti-SmRNP subset (6/114). We did not find any significant differences in lipids between the various SLE subsets.

Conclusion

CIMT segregates in anti-Ro and ENA negative groups either with or without anti-oxLDL. It will be clinically important if cardiovascular events are augmented in the SLE anti-Ro subset having elevated antioxidized LDL antibodies.

Three Clinical Clusters Identified through Hierarchical Cluster Analysis Using Initial Laboratory Findings in Korean Patients with Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a heterogeneous disorder with diverse clinical manifestations. This study classified patients by combining laboratory values at SLE diagnosis via hierarchical cluster analysis. Linear discriminant analysis was performed to construct a model for predicting clusters. Cluster analysis using data from 389 patients with SLE yielded three clusters with different laboratory characteristics. Cluster 1 had the youngest age at diagnosis and showed significantly lower lymphocyte and platelet counts and hemoglobin and complement levels and the highest erythrocyte sedimentation rate (ESR) and anti-double-stranded DNA (dsDNA) antibody level. Cluster 2 showed higher white blood cell (WBC), lymphocyte, and platelet counts and lower ESR and anti-dsDNA antibody level. Cluster 3 showed the highest anti-nuclear antibody titer and lower WBC and lymphocyte counts. Within approximately 171 months, Cluster 1 showed higher SLE Disease Activity Index scores and number of cumulative manifestations, including malar rash, alopecia, arthritis, and renal disease, than did Clusters 2 and 3. However, the damage index and mortality rate did not differ significantly between them. In conclusion, the cluster analysis using the initial laboratory findings of the patients with SLE identified three clusters. While disease activities, organ involvements, and management patterns differed between the clusters, damages and mortalities did not.

A review of signaling and transcriptional control in T follicular helper cell differentiation

T follicular helper (Tfh) cells are a critical component of adaptive immunity and assist in optimal Ab-mediated defense. Multiple effector functions of Tfh support germinal center B cell survival, Ab class switching, and plasma cell maturation. In the past 2 decades, the phenotype and functional characteristics of GC Tfh have been clarified allowing for robust studies of the Th subset including activation signals and environmental cues controlling Tfh differentiation and migration during an immune response. A unique, 2-step differentiation process of Tfh has been proposed but the mechanisms underlying transition between unstable Tfh precursors and functional mature Tfh remain elusive. Likewise, newly identified transcriptional regulators of Tfh development have not yet been incorporated into our understanding of how these cells might function in disease. Here, we review the signals and downstream transcription factors that shape Tfh differentiation including what is known about the epigenetic processes that maintain Tfh identity. It is proposed that further evaluation of the stepwise differentiation pattern of Tfh will yield greater insights into how these cells become dysregulated in autoimmunity.

Comparative analysis of three methods in anti-dsDNA antibodies detection: implications for Systemic Lupus Erythematosus diagnosis

The evaluation of anti-dsDNA antibodies represents one of the essential diagnostic and prognostic marker features in patients affected by Systemic Lupus Erythematosus (SLE). In this study, we have compared immunoblotting (IB) with Crithidia luciliae indirect immunofluorescence test (CLIFT) and chemiluminescent immunoassay (CLIA) in 91 patients referred to our hospital for anti-dsDNA antibodies detection. The concordance and correlation measured by Cohen's kappa and Spearman's coefficient respectively was significant between CLIFT and CLIA (0.70; 0,7404, P < .0001) and among CLIA and IB (0.79; 0,5377, P < 0,0001) and lower between CLIFT and IB (0.55; 0,4373, P  <0,0001). Among the 46 IB-positive samples, 14 were positive for either CLIA or CLIFT. It is noteworthy that 11 out of these 14 samples had the final diagnosis of SLE. Thirteen out of fourteen samples were also positive for anti-nucleosome antibodies as measured concomitantly in immunoblotting. While our observations are based on a limited number of samples and will have to be confirmed in a bigger cohort, they underline the contribution of immunoblotting as an additional assay in defining the anti-dsDNA antibody profile in association with other well-established methods such as CLIA and CLIFT.

Discovering the signature of a lupus-related microRNA profile in the Gene Expression Omnibus repository

Lupus is one of the most prevalent systemic autoimmune diseases. It is a multifactorial disease in which genetic, epigenetic and environmental factors play significant roles. The pathogenesis of lupus is not yet well understood. However, deregulation of microRNAs (miRNAs) - one of the post-transcriptional regulators of genes - can contribute to the development of autoimmune diseases. Over the last two decades, advances in the profiling of miRNA using microarray have received much attention, and it has been demonstrated that miRNAs play a regulatory role in the pathogenesis of lupus. Therefore, dysregulated miRNAs can be considered as promising diagnostic biomarkers for lupus. This article is an overview of lupus-related miRNA profiling studies and arrays in the Gene Expression Omnibus (GEO) database. The aims of our study were to widen current knowledge of known dysregulated miRNAs as potential biomarkers of SLE and to introduce a bioinformatics approach to using microarray data and finding novel miRNA and gene candidates for further study. We identified hsa-miR-4709-5p, hsa-miR-140, hsa-miR-145, hsa-miR-659, hsa-miR-134, hsa-miR-150, hsa-miR-584, hsa-miR-409 and hsa-miR-152 as potential biomarkers by integrated bioinformatics analysis.

Preclinical and early systemic lupus erythematosus

The challenge of early diagnosis and treatment is a timely issue in the management of systemic lupus erythematosus (SLE), as autoimmunity starts earlier than its clinical manifestations. Hence, growing efforts for stratification of patients according to the individual risk of developing specific clinical manifestations and/or predicting a better response to a given treatment have led to the proposal of several biomarkers, which require validation for use in clinical practice. In this viewpoint, we aim at distinguishing and discussing the features and the approach to asymptomatic immunological abnormalities potentially heralding the development of SLE, defined as preclinical lupus, and clinical manifestations consistent with SLE not yet fulfilling classification criteria, defined as early lupus. In case of preclinical SLE, careful surveillance using available screening tools is paramount, while patients with early lupus deserve an appropriate and timely diagnosis and, consequently, a proper treatment including hydroxychloroquine as the anchor drug.

Non-EBV-Related Aggressive NK-Cell Leukemia: An Oncohematological Great Imitator

Aggressive natural killer (NK)-cell leukemia (ANKL) is a very rare oncohematological disease among youngsters in Latin America. Its clinical picture imitates a variety of syndromes and diseases due to its pathophysiology. Its diagnosis is relatively simple due to the prominence of NK malignant cells in peripheral blood and its clinical aggressiveness. In certain circumstances though, the presence of blast NK cells and the natural course of the disease can be so modified by the treatment of one of the imitated diseases, especially when using steroids, that it becomes very difficult to diagnose early in its course. We present a case of a 16-year-old Mexican male who initiated symptoms imitating dengue to severe dengue for which he received steroids, apparently inducing a partial remission; he was then diagnosed as having community acquired pneumonia, then sepsis, septic shock w/disseminated intravascular coagulation, primary hemophagocytic syndrome, severe hepatitis, lupus and finally hyper IgE. It was not until 1 day before dying of hemorrhagic shock, a month after initiating symptoms, when the (re)emergence of blast NK cells in peripheral blood allowed the correct diagnosis to be made. Knowledge of ANKL pathophysiology may raise awareness of this multifaceted malignancy and may open up possibilities for its therapy. Gained knowledge can also be used for guiding NK cell evident aggressiveness against other malignancies.

Bone Morphogenetic Protein 6 Polymorphisms are Associated With Systemic Lupus Erythematosus Susceptibility in the Korean Population

OBJECTIVES

This study aims to investigate whether bone morphogenetic protein 6 (BMP6) single-nucleotide polymorphism (SNP) is associated with susceptibility to systematic lupus erythematosus (SLE).

PATIENTS AND METHODS

We analyzed the genotype and allele frequencies of BMP6 SNPs using genomic deoxyribonucleic acid isolated from 119 SLE patients (9 males, 110 females; mean age 36.4 years; range 19 to 59 years) and 509 healthy controls (323 males, 186 females; mean age 42.1 years; range 19 to 61 years). Genomic deoxyribonucleic acid was extracted from peripheral blood leukocytes using a standard phenol-chloroform method or by using a genomic deoxyribonucleic acid extraction kit. Erythrocyte sedimentation rate, C-reactive protein, and antinuclear antibody levels of SLE patients were recorded.

RESULTS

Our results showed that the genotype frequencies of rs17557 and rs9505273 for BMP6 in SLE patients significantly differed from those of the control group (p=0.01 and p=0.04, respectively). The genotype frequencies of the rs17557 and rs9505273 for BMP6 in female SLE patients were also significantly different from those in female healthy controls (p=0.04 and p=0.03, respectively). We also revealed that the distribution of the main haplotypes of BMP6 SNPs in SLE patients was significantly different from their distribution in healthy controls.

CONCLUSION

These results suggested that SNPs in BMP6 might be associated with susceptibility to SLE and that haplotypes of BMP6 polymorphisms might represent useful genetic markers for SLE.

Precipitating anti-dsDNA peptide repertoires in lupus

Anti-double-stranded (ds)DNA autoantibodies are prototypical serological markers of systemic lupus erythematosus (SLE), but little is known about their immunoglobulin variable (IgV) region composition at the level of the secreted (serum) proteome. Here, we use a novel proteomic workflow based on de novo mass spectrometric sequencing of anti-dsDNA precipitins to analyse IgV subfamily expression and mutational signatures of high-affinity, precipitating anti-dsDNA responses. Serum anti-dsDNA proteomes were oligoclonal with shared (public) expression of immunoglobulin (Ig)G heavy chain variable region (IGHV) and kappa chain variable region (IGKV) subfamilies. IgV peptide maps from eight subjects showed extensive public and random (private) amino acid replacement mutations with prominent arginine substitutions across heavy (H)- and light (L)-chains. Shared sets of L-chain complementarity determining region 3 (CDR3) peptides specified by arginine substitutions were sequenced from the dominantly expressed IGKV3-20 subfamily, with changes in expression levels of a clonal L-chain CDR3 peptide by quantitative multiple reaction monitoring (MRM) paralleling the rise and fall of anti-dsDNA levels by Farr radioimmunoassays (RIA). The heavily mutated IgV peptide signatures of precipitating anti-dsDNA autoantibody proteomes reflect the strong selective forces that shape humoral anti-dsDNA responses in germinal centres. Direct sequencing of agarose gel precipitins using microlitre volumes of stored sera streamlines the antibody sequencing workflow and is generalizable to other precipitating serum antibodies.

Evidence of a distinct group of Black African patients with systemic lupus erythematosus

Background

The autoimmune disease systemic lupus erythematosus (SLE) occurs more frequently in patients of African descent with high morbidity and mortality. Current SLE diagnostic criteria including antinuclear antibody (ANA) reactivity are derived largely from non-African populations. This study characterises ANA reactivity patterns and relates them to SLE clinical presentation in Black African patients.

Methods

Sera from Black participants (61 patients with SLE and 100 controls) aged 1-81 years were analysed for reactivity against the antigens: uridine 1-ribonuclear protein, Smith uridine-1-5 ribonuclear protein antigen, soluble substance-A, recombinant Ro-52, soluble substance-B, Scl-70, cytoplasmic histidyl-tRNA synthetase antigen, proliferating cell nuclear antigen (PCNA), nucleosomes, ribonuclear P-protein, antimitochondrial antibody M2 (AMA-M2), histones, double-stranded DNA (dsDNA), centromere protein B and polymyositis-sclerosis overlap antigen.

Findings

A significantly higher proportion (97%) of the 61 patients with SLE had detectable autoantibody reactivity compared with 15% of the 100 controls (p<0.001). The highest frequencies of autoantibody reactivity in patients with SLE were against the dsDNA antigen (41%) and PCNA (54%). Anti-PCNA and anti-dsDNA reactivity were mutually exclusive (p<0.001) giving rise to two distinct groups of Black African patients with SLE. The first group (n=25) had reactivity profiles consistent with international standard SLE definitions, including anti-dsDNA reactivity, and was 13 times more likely to present with joint symptoms. The larger, second group (n=34), characterised by anti-PCNA and anti-AMA-M2 reactivity, was nine times more likely to present with only cutaneous symptoms.

Interpretation

Our study demonstrates a need to extend autoantibody panels to include anti-PCNA in the diagnostic process of Black African patients and further refine the predictive values of the reactivity to different antigens to differentiate SLE syndromes in African populations.

Lupus retinopathy: a marker of active systemic lupus erythematosus

Retinopathy in the context of systemic lupus erythematosus (SLE) is associated with severe disease and poorer prognosis. We studied retinopathy in our cohort of Indian lupus patients. Four hundred and thirty-seven patients fulfilling the Systemic Lupus International Collaborating Clinics-American College of Rheumatology-2012 criteria, attending the department of Clinical Immunology were enrolled under this cross-sectional study. A comprehensive clinical (including ophthalmological) examination and immunological profile were performed. Retinopathy was defined if cotton-wool spots, haemorrhages, vasculitis, retinal detachment or optic disc changes as papilledema, optic atrophy were present. Disease activity was assessed using SLE disease activity index (SLEDAI). Mean age of participants was 28.06 ± 9.7 years (93.1% females); median disease duration 12 months (Interquartile range-IQR 6.36). Forty-five (10.3%) had SLE associated retinopathy. Autoimmune haemolytic anaemia [31.1 vs 14.5%, p value 0.004, odd's ratio-OR (95% confidence interval-CI) 2.65 (1.33-5.29)], serositis [33.3 vs 18.9%, p value 0.023, OR (CI) 2.14 (1.11-4.10)], lupus nephritis [62.2 vs 40.8%, p value 0.006, OR (CI) 2.38 (1.26-4.50)], seizures [28.9 vs 12.8%, p value 0.004, OR (CI) 2.77 (1.36-5.65)] and median SLEDAI score (24 vs 12, p < 0.01) were significantly higher in those with retinopathy. On adjusted binary logistic regression, autoimmune hemolytic anemia, lupus nephritis and presence of antibodies to Smith antigen were predictors for retinopathy. Retinopathy is common in SLE, a marker of active disease with frequent renal involvement and should be screened for in all patients with lupus.

Deoxyribonucleic Acid Methylation in Systemic Lupus Erythematosus: Implications for Future Clinical Practice

Differential deoxyribonucleic acid (DNA) methylation has emerged as a critical feature of systemic lupus erythematosus (SLE). Genome-wide DNA methylation studies have revealed methylation patterns characteristic of SLE—in particular, robust hypomethylation of interferon-regulated genes is a prominent finding in all cells of the immune system studied to date. These patterns reliably distinguish individuals with SLE from healthy controls and from individuals with other autoimmune diseases. For example, hypomethylation within IFI44L is both highly sensitive and highly specific for SLE, superior to currently available biomarkers. Furthermore, methylation status of other genetic loci has been associated with clinically relevant features of SLE including disease severity and organ-specific manifestations. Finally, DNA methylation studies have provided important insights into the pathophysiology of SLE. Most recently, there is a growing body of evidence that the transcription factor enhancer of zeste homolog 2 (EZH2) plays an important role in triggering SLE disease activity via epigenetic mechanisms, and that EZH2 blockade may be a future treatment option in SLE. In this short review, we discuss the DNA methylation patterns associated with SLE, their relationship to clinically significant features of SLE, and their implications in the development of novel diagnostic and therapeutic approaches to this complex disease.

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.

Infection Elicited Autoimmunity and Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: An Explanatory Model

Myalgic encephalomyelitis (ME) often also called chronic fatigue syndrome (ME/CFS) is a common, debilitating, disease of unknown origin. Although a subject of controversy and a considerable scientific literature, we think that a solid understanding of ME/CFS pathogenesis is emerging. In this study, we compiled recent findings and placed them in the context of the clinical picture and natural history of the disease. A pattern emerged, giving rise to an explanatory model. ME/CFS often starts after or during an infection. A logical explanation is that the infection initiates an autoreactive process, which affects several functions, including brain and energy metabolism. According to our model for ME/CFS pathogenesis, patients with a genetic predisposition and dysbiosis experience a gradual development of B cell clones prone to autoreactivity. Under normal circumstances these B cell offsprings would have led to tolerance. Subsequent exogenous microbial exposition (triggering) can lead to comorbidities such as fibromyalgia, thyroid disorder, and orthostatic hypotension. A decisive infectious trigger may then lead to immunization against autoantigens involved in aerobic energy production and/or hormone receptors and ion channel proteins, producing postexertional malaise and ME/CFS, affecting both muscle and brain. In principle, cloning and sequencing of immunoglobulin variable domains could reveal the evolution of pathogenic clones. Although evidence consistent with the model accumulated in recent years, there are several missing links in it. Hopefully, the hypothesis generates testable propositions that can augment the understanding of the pathogenesis of ME/CFS.

DNA damage by lipid peroxidation products: implications in cancer, inflammation and autoimmunity

Oxidative stress and lipid peroxidation (LPO) induced by inflammation, excess metal storage and excess caloric intake cause generalized DNA damage, producing genotoxic and mutagenic effects. The consequent deregulation of cell homeostasis is implicated in the pathogenesis of a number of malignancies and degenerative diseases. Reactive aldehydes produced by LPO, such as malondialdehyde, acrolein, crotonaldehyde and 4-hydroxy-2-nonenal, react with DNA bases, generating promutagenic exocyclic DNA adducts, which likely contribute to the mutagenic and carcinogenic effects associated with oxidative stress-induced LPO. However, reactive aldehydes, when added to tumor cells, can exert an anticancerous effect. They act, analogously to other chemotherapeutic drugs, by forming DNA adducts and, in this way, they drive the tumor cells toward apoptosis. The aldehyde-DNA adducts, which can be observed during inflammation, play an important role by inducing epigenetic changes which, in turn, can modulate the inflammatory process. The pathogenic role of the adducts formed by the products of LPO with biological macromolecules in the breaking of immunological tolerance to self antigens and in the development of autoimmunity has been supported by a wealth of evidence. The instrumental role of the adducts of reactive LPO products with self protein antigens in the sensitization of autoreactive cells to the respective unmodified proteins and in the intermolecular spreading of the autoimmune responses to aldehyde-modified and native DNA is well documented. In contrast, further investigation is required in order to establish whether the formation of adducts of LPO products with DNA might incite substantial immune responsivity and might be instrumental for the spreading of the immunological responses from aldehyde-modified DNA to native DNA and similarly modified, unmodified and/or structurally analogous self protein antigens, thus leading to autoimmunity.

Anti-Ro and Concomitant Anti-La Autoantibodies Strongly Associated With Anti-oxLDL or Anti-Phospholipid Antibody in Systemic Lupus Erythematosus

BACKGROUND

Premature atherosclerosis is observed in systemic lupus erythematosus (SLE). Oxidative modification of LDL is associated with atherosclerotic plaque formation.

OBJECTIVES

We hypothesized that anti-oxidized LDL (oxLDL) and anti-phospholipid (APL) in SLE sera would segregate with specific antibody subsets, and that anti-oxLDL antibodies will linger in circulation over an extended period.

PATIENTS AND METHODS

Sixty-seven SLE and control subjects and two SLE subjects with sera collected longitudinally for 13 years were tested for anti-oxLDL and IgG/IgM/IgA APL antibodies.

RESULTS

Anti-oxLDL ELISA values above 57.48 Activity Units (AcU) (means of normals + 3 standard deviations) and anti-IgG/IgM/IgA APL above 10 phospholipid units (PU) were considered positive. Average anti-oxLDL was 67.7 ± 50.5 AcU in SLE compared to 23.9 ± 11.19 AcU in normals (P = 0.018). Ten out of ten subjects with anti-Ro60/anti-La/anti-Ro52 antibodies had highly significant (P < 0.0001) anti-oxLDL (127.29 ± 45.67 AcU) and IgG APL (18.66 ± 7.4 PU) (P < 0.02). Subjects with anti-RNP were positive for anti-oxLDL (P < 0.002), but subjects with anti-Ro60/anti-Ro52 and subjects negative for extractable nuclear antigen (ENA) antibody were not positive for anti-oxLDL. Anti-oxLDL/anti-IgG APL remained significantly elevated in two patients studied longitudinally. Interestingly, one developed anti-oxLDL/anti-APL antibodies several years before anti-Ro60 development.

CONCLUSIONS

Presence of antibodies against Ro RNP and La, and RNP is highly associated with developing anti-oxLDL and APL antibodies in SLE. It will be clinically important to see if cardiovascular events occur in these SLE subsets having elevated anti-oxLDL and APL antibodies. Emergence of anti-oxLDL/IgG APL before anti-Ro60 over time in a patient indicates that these antibodies could not be cross-reactive in nature, at least in this particular patient.

IFI44L promoter methylation as a blood biomarker for systemic lupus erythematosus

OBJECTIVE

Systemic lupus erythematosus (SLE) is a clinically heterogeneous disease with limited reliable diagnostic biomarkers. We investigated whether gene methylation could meet sensitivity and specificity criteria for a robust biomarker.

METHODS

IFI44L promoter methylation was examined using DNA samples from a discovery set including 377 patients with SLE, 358 healthy controls (HCs) and 353 patients with rheumatoid arthritis (RA). Two independent sets including 1144 patients with SLE, 1350 HCs, 429 patients with RA and 199 patients with primary Sjögren's syndrome (pSS) were used for validation.

RESULTS

Significant hypomethylation of two CpG sites within IFI44L promoter, Site1 (Chr1: 79 085 222) and Site2 (Chr1: 79 085 250; cg06872964), was identified in patients with SLE compared with HCs, patients with RA and patients with pSS. In a comparison between patients with SLE and HCs included in the first validation cohort, Site1 methylation had a sensitivity of 93.6% and a specificity of 96.8% at a cut-off methylation level of 75.5% and Site2 methylation had a sensitivity of 94.1% and a specificity of 98.2% at a cut-off methylation level of 25.5%. The IFI44L promoter methylation marker was also validated in an European-derived cohort. In addition, the methylation levels of Site1 and Site2 within IFI44L promoter were significantly lower in patients with SLE with renal damage than those without renal damage. Patients with SLE showed significantly increased methylation levels of Site1 and Site2 during remission compared with active stage.

CONCLUSIONS

The methylation level of IFI44L promoter can distinguish patients with SLE from healthy persons and other autoimmune diseases, and is a highly sensitive and specific diagnostic marker for SLE.

Advances in the diagnosis and classification of systemic lupus erythematosus

INTRODUCTION

Systemic lupus erythematosus (SLE) is the prototype of systemic autoimmune diseases. Patients with SLE display a wide spectrum of clinical and serological findings that can mislead and delay the diagnosis. Diagnostic criteria have not been developed yet, whereas several sets of classification criteria are available; however, none of them has 100% sensitivity and 100% specificity, i.e. the hallmark of diagnostic criteria. Nevertheless, classification criteria are often misused as diagnostic criteria, which may affect earliness of diagnosis and lead to more misdiagnosed cases. Areas covered: In this review, we compare old and new classification criteria, discussing their application and pinpointing their limitations in the management of patients. Moreover, we will focus on current and novel biomarkers for SLE diagnosis, highlighting their predictive value and applicability in clinical practice. Expert commentary: SLE diagnosis still represents a challenge, remaining largely based on a clinical judgment. Besides SLE diagnosis, even its classification is still challenging to date. Indeed, although classification of SLE seems to be achieved more frequently with the 2012 SLICC criteria than with the previous 1997 ACR criteria, this last-updated 2012 set might be improved. Notably, diagnostic and classification criteria should be applied to any subject in the world, and consequently they should include immunological variables validated in different populations, which is still an unmet need.

The critical role of epigenetics in systemic lupus erythematosus and autoimmunity

One of the major disappointments in human autoimmunity has been the relative failure on genome-wide association studies to provide "smoking genetic guns" that would explain the critical role of genetic susceptibility to loss of tolerance. It is well known that autoimmunity refers to the abnormal state that the dysregulated immune system attacks the healthy cells and tissues due to the loss of immunological tolerance to self-antigens. Its clinical outcomes are generally characterized by the presence of autoreactive immune cells and (or) the development of autoantibodies, leading to various types of autoimmune disorders. The etiology and pathogenesis of autoimmune diseases are highly complex. Both genetic predisposition and environmental factors such as nutrition, infection, and chemicals are implicated in the pathogenic process of autoimmunity, however, how much and by what mechanisms each of these factors contribute to the development of autoimmunity remain unclear. Epigenetics, which refers to potentially heritable changes in gene expression and function that do not involve alterations of the DNA sequence, has provided us with a brand new key to answer these questions. In the recent decades, increasing evidence have demonstrated the roles of epigenetic dysregulation, including DNA methylation, histone modification, and noncoding RNA, in the pathogenesis of autoimmune diseases, especially systemic lupus erythematosus (SLE), which have shed light on a new era for autoimmunity research. Notably, DNA hypomethylation and reactivation of the inactive X chromosome are two epigenetic hallmarks of SLE. We will herein discuss briefly how genetic studies fail to completely elucidate the pathogenesis of autoimmune diseases and present a comprehensive review on landmark epigenetic findings in autoimmune diseases, taking SLE as an extensively studied example. The epigenetics of other autoimmune diseases such as rheumatic arthritis, systemic sclerosis and primary biliary cirrhosis will also be summarized. Importantly we emphasize that the stochastic processes that lead to DNA modification may be the lynch pins that drive the initial break in tolerance.

Childhood Lupus--Diagnosis and Management

Though rare, childhood lupus is a disease with the potential to have serious short and long term effects in children. These effects are to do with the disease itself, organ damage consequent to ongoing inflammation and/or because of side effects of medications. As children have an early disease onset, accrual organ damage over the years and growth and puberty issues are important aspects of care. Thus it is essential to recognize the disease early, objectively assess the patient at regular intervals, treat to a target of remission and limit the use of steroids as far as possible. This review focuses on the elements that help identify these patients in the clinic, discusses the role of objective disease assessment and outlines management and co-morbidities in these patients.

Concomitant immune-related events in Wilson disease: implications for monitoring chelator therapy

BACKGROUND AND AIMS

Current guidelines favor the use of chelating agents (d-penicillamine, trientine) in first line therapy of symptomatic Wilson disease patients. Development of chelator induced immunological adverse events are a concern especially under d-penicillamine therapy. This study assessed the prevalence of co-existing or therapy-related immune-mediated diseases in Wilson disease patients, and evaluated the role of antinuclear antibodies in therapy monitoring.

METHODS

We retrospectively analyzed 235 Wilson disease patients. Medical regimens were classified and analyzed in relation to adverse events and antinuclear antibody courses.

RESULTS

Coexisting immune-mediated diseases were evident in 19/235 (8.1%) patients, of which 13/235 (5.5%) had pre-existing autoimmune diseases. Six patients (2.6%) developed an autoimmune disease under therapy, all of them under long-term d-penicillamine treatment. Data relating to antinuclear antibody courses during treatment and adverse events were available for patients treated with d-penicillamine (n = 91), trientine (n = 58), and zinc salts (n = 58). No significant increase in antinuclear antibody titers in patients treated with d-penicillamine (16/91; 17.6%), trientine (12/58; 20.7%), and zinc (7/58; 12.1%) were found.

CONCLUSION

Under long-term d-penicillamine therapy a minority of patients developed immune-mediated disease. Elevations in antinuclear antibodies were found frequently, but no correlations were evident between increases in antinuclear antibodies and the development of immune-mediated diseases or medical regimes. Thus, the value of antinuclear antibodies for monitoring adverse events under chelator therapy seems to be limited.

Recurrent Miscarriage: Diagnostic and Therapeutic Procedures. Guideline of the DGGG (S1-Level, AWMF Registry No. 015/050, December 2013)

Purpose: Official guideline coordinated and published by the German Society of Gynecology and Obstetrics (DGGG). Aim of the guideline was to standardize the diagnosis and treatment of patients with recurrent miscarriage (RM). Recommendations were proposed, based on the current national and international literature and the experience of the involved physicians. Consistent definitions, objective assessments and standardized therapy were applied. Methods: Members of the different involved societies developed a consensus in an informal process based on the current literature. The consensus was subsequently approved by the heads of the scientific societies. Recommendations: Recommendations for the diagnosis and treatment of patients with RM were compiled which took the importance of established risk factors such as chromosomal, anatomical, endocrine, hemostatic, psychological, infectious and immunological disorders into consideration.

Autoantigen Microarray for High-throughput Autoantibody Profiling in Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a complex autoimmune disease characterized by the production of autoantibodies to a broad range of self-antigens. Profiling the autoantibody repertoire using array-based technology has emerged as a powerful tool for the identification of biomarkers in SLE and other autoimmune diseases. Proteomic microarray has the capacity to hold large number of self-antigens on a solid surface and serve as a high-throughput screening method for the determination of autoantibody specificities. The autoantigen arrays carrying a wide variety of self-antigens, such as cell nuclear components (nucleic acids and associated proteins), cytoplasmic proteins, phospholipid proteins, cell matrix proteins, mucosal/secreted proteins, glomeruli, and other tissue-specific proteins, have been used for screening of autoantibody specificities associated with different manifestations of SLE. Arrays containing synthetic peptides and molecular modified proteins are also being utilized for identification of autoantibodies targeting to special antigenic epitopes. Different isotypes of autoantibodies, including IgG, IgM, IgA, and IgE, as well as other Ig subtypes, can be detected simultaneously with multi-color labeled secondary antibodies. Serum and plasma are the most common biologic materials for autoantibody detection, but other body fluids such as cerebrospinal fluid, synovial fluid, and saliva can also be a source of autoantibody detection. Proteomic microarray as a multiplexed high-throughput screening platform is playing an increasingly-important role in autoantibody diagnostics. In this article, we highlight the use of autoantigen microarrays for autoantibody exploration in SLE.

Role of 4-hydroxynonenal-protein adducts in human diseases

SIGNIFICANCE

Oxidative stress provokes the peroxidation of polyunsaturated fatty acids in cellular membranes, leading to the formation of aldheydes that, due to their high chemical reactivity, are considered to act as second messengers of oxidative stress. Among the aldehydes formed during lipid peroxidation (LPO), 4-hydroxy-2-nonenal (HNE) is produced at a high level and easily reacts with both low-molecular-weight compounds and macromolecules, such as proteins and DNA. In particular, HNE-protein adducts have been extensively investigated in diseases characterized by the pathogenic contribution of oxidative stress, such as cancer, neurodegenerative, chronic inflammatory, and autoimmune diseases.

RECENT ADVANCES

In this review, we describe and discuss recent insights regarding the role played by covalent adducts of HNE with proteins in the development and evolution of those among the earlier mentioned disease conditions in which the functional consequences of their formation have been characterized.

CRITICAL ISSUES

Results obtained in recent years have shown that the generation of HNE-protein adducts can play important pathogenic roles in several diseases. However, in some cases, the generation of HNE-protein adducts can represent a contrast to the progression of disease or can promote adaptive cell responses, demonstrating that HNE is not only a toxic product of LPO but also a regulatory molecule that is involved in several biochemical pathways.

FUTURE DIRECTIONS

In the next few years, the refinement of proteomical techniques, allowing the individuation of novel cellular targets of HNE, will lead to a better understanding the role of HNE in human diseases.

Membrane strip affinity purification of autoantibodies

A method for affinity purification of autoantibodies from a membrane strip using small volumes of human sera is described. The membrane strip is excised from a western blot containing a target antigen electrophoretically transferred from a sodium dodecyl sulfate (SDS) polyacrylamide gel. This method is a very useful alternative for affinity column chromatography, particularly when the antigen of interest is of low abundance in a HeLa cell extract. The protein mixture is resolved on a preparative SDS polyacrylamide gel and transferred to nitrocellulose membrane. A couple of strips are excised from either side of the blotted membrane and immunoblotted with specific antisera to identify the target band. Then the target band is excised horizontally and used for affinity purification. We have used this procedure to affinity purify antibodies to a 70,000 molecular weight protein derived from HeLa cell extract. A sham band, excised away from the target antigen, was used as a control for sham purification of autoantibodies. The autoantibodies purified in this manner reproduced the multiple nuclear dot anti-nuclear antibody pattern obtained using crude sera from 21 patients without primary biliary cirrhosis or anti-mitochondrial antibody.

Low doses of mercuric chloride cause the main features of anti-nucleolar autoimmunity in female outbred CFW mice

The growth of the influence of anthropogenic factors aimed on the improvement of human life has its side effect, for example, living organisms receive increasing exposure to toxic mercuric compounds. Experimental data show that mercury (Hg) salts are able to induce systemic autoimmunity in rodents. This Hg-induced autoimmune process (HgIA) is characterized by T cell-dependent polyclonal activation of B lymphocytes, increased level of serum immunoglobulin G1 (IgG1) and immunoglobulin E (IgE), production of antinucleolar autoantibodies (ANoA), and immune complex deposition in multiple organs. HgIA in mice is used as a model of human systemic autoimmune disorders. However, the dose of mercuric chloride (HgCl2) usually used in laboratory mice to induce HgIA is above the allowable limit for everyday levels of Hg exposure in humans. So, we decided to determine the lowest dose of HgCl2 that is able to trigger autoimmunity in outbred Carworth Farms Swiss Webster (CFW) mice not genetically prone to HgIA development. The lowest dose (50 µg/kg body weight (b.w.)/week) was chosen to match the World Health Organization provisional weekly tolerable intake of total Hg for humans. We also tested HgCl2 at 500 and 1500 µg/kg b.w./week (6.5- and 2-fold less than usually used for induction of HgIA in mice). We found that even the lowest dose of Hg resulted in a statistically significant increase in serum level of IgG1 after 8 weeks of treatment. HgCl2 in doses 500 and 1500 µg/kg b.w./week resulted in a significant increase in serum level of IgG1 after 4 weeks of treatment, followed by ANoA production. Sera of HgCl2-treated mice stained the regions in which the major autoantigen in HgIA, fibrillarin, was revealed. These results suggest that low doses of Hg are able to induce the main features of HgIA in genetically heterozygous mice, and that humans chronically exposed to low doses of Hg may be at risk of autoimmunity induction regardless of their genetic background.

Immune profiling in patients with recurrent miscarriage

The central role of the maternal immune system for successful and disturbed pregnancies such as recurrent miscarriage (RM) is apparent. Recent studies have increased understanding of the complex interaction of the different immunological players and the adaptation of the maternal immune system to the semi-allogeneic embryo. There is growing evidence for immunological abnormalities in RM patients, including autoimmune and allogeneic factors. However, the question remains unsolved whether these changes represent the cause or the consequence of RM. As in half of the RM patients the underlying mechanism remains unknown, further diagnostic methods are urgently needed. Within this review we summarize (recent) literature on the immunological diagnosis in RM patients to find out current trends and to identify potential targets of therapy. As the exact mechanisms of feto-maternal tolerance have not yet been determined we suggest that the immunological diagnosis should be implemented only in well-designed clinical trials in specialized centers to establish a standardized immunological work-up in RM patients.

Excess female siblings and male fetal loss in families with systemic lupus erythematosus

OBJECTIVE

Systemic lupus erythematosus (SLE) occurs more frequently among women than men. We aimed to determine whether the male-female ratio in SLE families is different from what would be expected by chance, and whether excess male fetal loss is found.

METHODS

All patients with SLE met the revised American College of Rheumatology classification criteria, while unaffected subjects were shown not to satisfy these same criteria. Putative family relationships were confirmed by genetic testing. Pregnancy history was obtained from all subjects, including unrelated control women. Adjusted Wald binomial confidence intervals were calculated for ratio of boys to girls in families and compared to the expected ratio of 1.06.

RESULTS

There were 2579 subjects with SLE, with 6056 siblings. Considering all subjects, we found 3201 boys and 5434 girls (ratio 0.59, of 95% CI 0.576-0.602). Considering only the SLE-unaffected siblings, there were 2919 boys and 3137 girls (ratio 0.93, 95% CI 0.92-0.94). In both cases, the ratio of males to females was statistically different from the known birth rate. Among patients with SLE as well as among their sisters and mothers, there was an excess of male fetal loss compared to the controls.

CONCLUSION

Siblings of patients with SLE are more likely than expected to be girls. This finding may be in part explained by excess male fetal loss, which is found among patients with SLE and their first-degree relatives.

Belimumab: a technological advance for systemic lupus erythematosus patients? Report of a systematic review and meta-analysis

OBJECTIVES

To undertake a systematic review and meta-analysis to investigate clinical effectiveness of belimumab for patients with systemic lupus erythematosus (SLE) and antinuclear and/or anti-double-stranded DNA (dsDNA) autoantibodies.

METHODS

We searched eight electronic databases and reference lists for randomised controlled trials (RCTs) of belimumab against placebo or best supportive care. Quality assessment and random effects meta-analysis were undertaken.

DESIGN

A meta-analysis of RCTs.

PARTICIPANTS

2133 SLE patients.

PRIMARY AND SECONDARY OUTCOME MEASURES

SLE Responder Index (SRI) at week 52.

RESULTS

Three double-blind placebo-controlled RCTs (L02, BLISS-52 BLISS-76) investigated 2133 SLE patients. BLISS-52 and BLISS-76 trials recruited patients with antinuclear and/or anti-dsDNA autoantibodies and demonstrated belimumab effectiveness for the SRI at week 52. Ethnicity and geographical location of participants varied considerably between BLISS trials. Although tests for statistical heterogeneity were negative, BLISS-52 results were systematically more favourable for all measured outcomes. Meta-analysis of pooled 52-week SRI BLISS results showed benefit for belimumab (OR 1.63, 95% CI 1.27 to 2.09). By week 76, the primary SRI outcome in BLISS-76 was not statistically significant (OR 1.31, 95% CI 0.919 to 1.855).

Evaluation of anti-nuclear antibodies and kidney pathology in Lewis rats following exposure to Libby amphibole asbestos

The prevalence of anti-nuclear antibodies (ANA) and self-reported systemic autoimmune diseases were increased in residents of Libby, MT, as was the incidence of ANA in Lewis rats exposed to Libby amphibole (LA) asbestos. However, rats induced to develop rheumatoid arthritis (RA) did not develop autoantibodies associated with RA, nor was RA exacerbated by LA exposure, suggesting that increased ANA expression might be related to some other autoimmune process. Libby residents self-reported increased numbers of physician-diagnosed cases of systemic lupus erythematosus (SLE). Thus, the goal of this study was to determine if the increased incidence of ANA in Lewis rats exposed to LA is related to the development of SLE-like disease. Female Lewis rats were intratracheally instilled bi-weekly for 13 weeks with total doses of 0.15, 0.5, 1.5, or 5.0 mg of LA or 0.5 or 1.5 mg of a positive control fiber, amosite. ANA incidence was significantly increased in all asbestos dose groups, although no dose response was observed. The occurrence of proteinuria was increased in LA 0.5, LA 5.0, and amosite 0.5 dose groups; however, the microscopic appearance of the kidneys was normal, no binding of autoimmune complexes to glomerular surfaces was observed, and antibodies to double-stranded DNA were not elevated. Therefore, an increased prevalence of ANA in rats exposed to asbestos does not appear to correlate with disease markers typically observed in SLE. Analysis of ANA specificity for extractable nuclear antigens (ENA) determined that 98% of ENA(+) samples were specific for the Jo-1 antigen. Autoantibodies to Jo-1 have been reported in patients with interstitial lung disease, suggesting that autoantibodies to Jo-1 may be a biomarker for asbestos-related pulmonary disease.

Application of linear discriminant analysis in performance evaluation of extractable nuclear antigen immunoassay systems in the screening and diagnosis of systemic autoimmune rheumatic diseases

This study applied a linear discriminant analysis model to evaluate the performance of 2 types of commercially available extractable nuclear antigen (ENA) immunoassays for the screening and diagnosis of systemic autoimmune rheumatic diseases (SARDs) in a large tertiary hospital reference laboratory: (1) an enzyme-linked immunosorbent assay (ELISA) and (2) a multiplex bead-based immunoassay (MPBI). The results of the study showed both ENA immunoassays had comparable sensitivity for the detection of SARDs compared with the antinuclear antigen immunofluorescence (ANA-IF) method (ANA-IF: 85.6%, ENA-ELISA: 91.5%, ENA-MPBI: 83.1%, pairwise comparisons with ANA-IF: P > .05). However, both ENA immunoassays offered improved specificity compared with the ANA-IF (ANA-IF: 24.2%; ENA-ELISA: 39.8%; ENA-MPBI: 53.1%; pairwise comparison with ANA-IF: P < .001). The use of a more specific screening immunoassay with comparable sensitivity to ANA-IF is important in a tertiary hospital with high prevalence of non-SARD immune diseases. Diagnostic performance of the ENA/dsDNA components by the MPBI and ELISA methods did not differ significantly (area under the curve [AUC], 81.0% vs 83.0%, respectively, P > .05), but the key ENA/dsDNA variables contributing to the discriminating power of the assays for the diagnosis of specific SARDs were reagent/method dependent.

A contemporary case series of lupus myocarditis

Objectives: The purpose of this study was to describe clinical phenotype and treatment outcomes in lupus myocarditis (LM), an uncommon but serious manifestation of systemic lupus erythematosus (SLE). Methods: The study involved a 10-year retrospective case series of hospitalized patients with LM, with a search of a diagnosis database using systemic lupus erythematosus and either myocarditis, cardiomyopathy, or congestive heart failure, and of a pathology database for biopsy-proved LM. Results: Twenty-four patients met the study criteria, with 79% female and 82% white (age: mean (SD), 47.6 (20.4) years; follow-up: mean (SD), 9.2 (6.1) months). The frequency of antibodies SS-A (69%) and anti-RNP (62%) was greater than in published lupus populations (25%–40%). On echocardiography, the mean initial left ventricular ejection fraction was 33.8%, improving to 49.5% after a mean of 7.2 months. All patients received immunosuppression, most with high-dose corticosteroid treatment and subsequent corticosteroid taper. One patient died of cardiogenic shock during hospitalization; two patients died within one year posthospitalization. Conclusions: A high index of suspicion is necessary in suspected LM. Higher frequency of elevated SS-A and anti-RNP antibody levels in our series than in the literature is suggestive of an LM association. Echocardiography is a useful initial investigation for LM, but patients should be referred early for cardiac magnetic resonance imaging or endomyocardial biopsy to confirm diagnosis if it is clinically indicated in difficult cases.

Autoantibody profiling to follow evolution of lupus syndromes

INTRODUCTION

Identification of patients who are in early stages of lupus is currently done through clinical evaluation and is not greatly facilitated by available diagnostic tests. Profiling for patient characteristics and antibody specificities that predict disease would enhance the ability of physicians to identify and treat early cases prior to onset of organ damaging illness.

METHODS

A group of 22 patients with 4 or fewer diagnostic criteria for lupus were studied for changes in clinical and autoantibody profiles after a mean follow up period of 2.4 years. An array with more than 80 autoantigens was used to profile immunoglobulin G (IgG) and immunoglobulin M (IgM) autoantibodies. Correlations with clinical disease progression were examined.

RESULTS

3 of the 22 patients (14%) added sufficient criteria during follow up to satisfy a diagnosis of systemic lupus erythematosus (SLE) or to acquire a diagnosis of SLE renal disease. Patients who progressed were all females and were younger than those who did not progress (P=0.00054). IgG but not IgM autoreactivity showed greater increases in the progressor group than in the non-progressor group (P=0.047). IgG specificities that were higher at baseline in progressors included proliferating cell nuclear antigen (PCNA), beta 2 microglobulin, C1q and hemocyanin (P<0.019). Progressors had significant increases in La/SSB and liver cytosol type 1 (LC1) IgG autoantibodies over the period of evaluation (P≤0.0072). A quantitative risk profile generated from baseline demographic and autoantibody variables yielded highly different scores for the progressor and non-progressor groups (P=1.38 × 10⁻⁷)

CONCLUSIONS

In addition to demographic features, autoantibody profiles using an expanded array of specificities were correlated with the risk of progressive disease in patients with lupus. These findings suggest the feasibility of developing a simple diagnostic that could be applied by nonspecialists to screen for lupus and permit effective triage for specialty care.

Putative sequences on Ro60 three-dimensional structure accessible for 4-hydroxy-2-nonenal (HNE) modification compared to in vitro HNE modification of Ro60 sequences

We have previously reported accelerated acquisition of new autoreactivity upon immunization with 4-hydroxy-2-nonenal (HNE)-modified Ro60, as well as differential induction of lupus or Sjögren's syndrome by immunization with Ro60 containing varying amounts of HNE. Since the number of HNE molecules on Ro60 appears to be important, we hypothesized that specific sequences on Ro60 are targets for HNE-modification. Using surface plasmon resonance (SPR) we have also shown intramolecular protein-protein interaction between Ro60 and Ro multiple antigenic peptides (MAPs). We also hypothesized that intramolecular protein-protein interaction would be abolished by HNE-modification. To test this hypotheses we investigated (a) the epitopes of Ro60, using 19 Ro MAPs in an in vitro assay (involving HNE-modification of MAPs following immobilization on ELISA plates) to identify targets of HNE modification on Ro60 and (b) the protein-protein interaction between unmodified Ro60 MAPs, immobilized on the sensor surface of BIAcore, and unmodified Ro60 or HNE-modified Ro60 using SPR. New data obtained with SPR strengthens our earlier observation that immunization with HNE-Ro60 induces a stronger response. Unmodified Ro60 bound to several Ro60 MAPs through protein-protein interaction analyzed using SPR. This interaction was totally abrogated using HNE-modified Ro60 suggesting that sequences on Ro had become modified with HNE. When 19 Ro60 MAPs were modified in vitro with HNE, it was found that 10/19 MAPs significantly bound HNE covalently (p<0.001 compared to MAPs binding HNE poorly). The amino acid sequences 126-137, 166-272 and 401-495 on Ro60 were strongly HNE modified. Using computational model system based on the recently published crystal structure for Ro60 enabled us to identify regions on the Ro60 molecule represented by the HNE-modified Ro MAPs, which are part of the exposed tertiary structure of the Ro60 protein.

Effects of Libby amphibole asbestos exposure on two models of arthritis in the Lewis rat

Epidemiological data suggest that occupational exposure to the amphibole-containing vermiculite in Libby, MT, was associated with increased risk for developing autoimmune diseases and had an odds ratio of 3.23 for developing rheumatoid arthritis (RA). The collagen-induced arthritis (CIA) and the peptidoglycan-polysaccharide (PG-PS) models of RA were employed to determine whether exposure to Libby amphibole (LA) induced a more rapid onset, increased expression, or prolonged course of RA. Female Lewis rats were intratracheally instilled with total doses of 0.15, 0.5, 1.5, or 5 mg LA or 0.5 or 1.5 mg amosite asbestos, and arthritis was induced with either the PG-PS or CIA model. Neither LA nor amosite exposure affected the disease course in the CIA model, or the production of rheumatoid factor (RF) or anti-cyclic citrullinated peptide (CCP) antibodies. LA exposure reduced swelling in the PG-PS model and decreased anti-PG-PS and total immunoglobulin M (IgM) antibody titers. Both amosite and LA exposure increased the number of rats with circulating anti-nuclear antibodies (ANA), the majority of which presented a speckled staining pattern. However, this ANA enhancement was not dose responsive. These results failed to show a positive correlation between LA exposure and RA disease in two animal models, although upregulated ANA suggest an altered immunological profile consistent with other systemic autoimmune diseases.

Sex chromosome aneuploidies among men with systemic lupus erythematosus

About 90% of patients with systemic lupus erythematosus (SLE) are female. We hypothesize that the number of X chromosomes, not sex, is a determinate of risk of SLE. Number of X chromosomes was determined by single nucleotide typing and then confirmed by karyotype or fluorescent in situ hybridization in a large group of men with SLE. Presence of an sry gene was assessed by RT-PCR. We calculated 96% confidence intervals using the Adjusted Wald method, and used Bayes' theorem to estimate the prevalence of SLE among 47,XXY and 46,XX men. Among 316 men with SLE, 7 had 47,XXY and 1 had 46,XX. The rate of Klinefelter's syndrome (47,XXY) was statistically different from that found in control men and from the known prevalence in the population. The 46,XX man had an sry gene, which encodes the testes determining factor, on an X chromosome as a result of an abnormal crossover during meiosis. In the case of 46,XX, 1 of 316 was statistically different from the known population prevalence of 1 in 20,000 live male births. A previously reported 46,XX man with SLE had a different molecular mechanism in which there were no common gene copy number abnormalities with our patient. Thus, men with SLE are enriched for conditions with additional X chromosomes. Especially since 46,XX men are generally normal males, except for infertility, these data suggest the number of X chromosomes, not phenotypic sex, is responsible for the sex-bias of SLE.

Antinuclear autoantibodies in women with recurrent pregnancy loss

PROBLEM

To investigate the possibility that antinuclear antibodies (ANA) are involved in recurrent pregnancy loss (RPL).

METHODS

Case-control study carried out on 294 women (194 cases and 100 controls) in two University hospitals. The presence, the serum titers and the indirect immunofluorescence (IIF) patterns of ANA were determined in women with RPL and in control women.

RESULTS

Antinuclear antibodies at titers ≥ 1:80 were detected in 97 (50%) women with RPL and in 16 (16%) control women. Elevated ANA titers (≥1:180) were detected only in RPL women, whereas all control women had ANA titers no greater than 1:80. No differences could be detected in the IIF patterns between RPL and control women. No differences in ANA positivity could be detected according to the type (primary or secondary) or number (>2 versus ≥3) of losses.

CONCLUSIONS

ANA could be of some value in identifying women with RPL with potential, although still not fully defined, immune abnormalities.

Degree of modification of Ro60 by the lipid peroxidation by-product 4-hydroxy-2-nonenal may differentially induce Sjögren syndrome or systemic lupus erythematosus in BALB/c mice

Our previous work showed that immunization of rabbits with 4-hydroxy-2-nonenal-modified Ro60 (HNE-Ro60) accelerates autoimmunity. We extended this model into mice, hypothesizing that the severity of autoimmunity would be dependent on the degree of HNE modification of Ro60. Five groups of BALB/c mice (10/group) were used. Group I was immunized with Ro60. Groups II to IV were immunized with Ro60 modified with 0.4 mM (low), 2 mM (medium), and 10 mM (high) HNE, respectively. Group V controls received Freund's adjuvant. A rapid abrogation of tolerance to Ro60/La antigens occurred in mice immunized with HNE-modified Ro60, especially in the low and medium HNE-Ro60 groups. Lymphocytic infiltration and significantly high decrement in salivary flow (37%) compared to controls was observed only in the high HNE-Ro60 group, suggesting induction of a Sjögren syndrome-like condition in this group. Anti-dsDNA occurred only in mice immunized with medium HNE-Ro60. This group did not have a significant decrement in salivary flow, suggesting induction of a systemic lupus erythematosus-like manifestation in this group. Significantly high antibodies to Ro60 were found in saliva of mice in the low and medium HNE-Ro60 and the Ro60 groups, as well as anti-HNE Ro60 in the low and medium HNE-Ro60 groups. Understanding the mechanism of this differential induction may help discriminate between these two autoimmune diseases.

Identification of three new autoantibodies associated with systemic lupus erythematosus using two proteomic approaches

Our objective was to identify new serum autoantibodies associated with systemic lupus erythematosus (SLE), focusing on those found in patients with central nervous system (CNS) syndromes. Autoantigens in human brain proteins were screened by multiple proteomic analyses: two-dimensional polyacrylamide gel electrophoresis/Western blots followed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry analysis and immunoprecipitation followed by liquid chromatography-tandem mass spectrometry shotgun analysis. The presence of serum IgG autoantibodies against 11 selected recombinant antigens was assessed by Western blot and enzyme-linked immunosorbent assay (ELISA) in the sera of 106 SLE patients and 100 normal healthy controls. The O.D. values in sera from SLE patients were significantly higher than those of controls for the antigens crystallin αB (p = 0.0002), esterase D (p = 0.0002), APEX nuclease 1 (p < 0.0001), ribosomal protein P0 (p < 0.0001), and PA28γ (p = 0.0005); the first three are newly reported. The anti-esterase D antibody levels were significantly higher in the CNS group than in the non-CNS group (p = 0.016). Moreover, when the SLE patients were categorized using CNS manifestations indicating neurologic or psychiatric disorders, the anti-APEX nuclease 1 antibody levels were significantly elevated in SLE patients with psychiatric disorders (p = 0.037). In conclusion, the association of SLE with several new and previously reported autoantibodies has been demonstrated. Statistically significant associations between anti-esterase D antibodies and CNS syndromes as well as between anti-APEX nuclease 1 antibodies and psychiatric disorders in SLE were also demonstrated. The combined immunoproteomic approaches used in this study are reliable and effective methods for identifying SLE autoantigens.

Anti-histone H1 IgGs from blood serum of systemic lupus erythematosus patients are capable of hydrolyzing histone H1 and myelin basic protein

Novel hydrolytic activity of the anti-histone H1 antibodies (Ab) toward histone H1 and myelin basic protein (MBP) was shown. Blood serum of ten patients with clinically diagnosed systemic lupus erythematosus (SLE), and nine healthy donors (control) were screened for the anti-histone H1 antibody- and anti-MBP antibody-mediated specific proteolytic activity. IgGs were isolated by chromatography on Protein G-Sepharose, and four of ten SLE patients appeared to possess IgGs that were capable of cleaving both histone H1 and MBP. Such activity was confirmed to be an intrinsic property of the IgG molecule, since it was preserved at gel filtration at alkaline and acidic pH. At the same time, proteolytic activity was absent in the sera-derived Ab of all healthy donors under control. Anti-histone IgGs were purified by the affinity chromatography on histone H1-Sepharose. Their cross-reactivity toward cationic proteins (histones, lysozyme, and MBP) and their capability of hydrolyzing histone H1 and MBP were detected. However, these IgGs were not cleaving core histones, lysozyme, or albumin. Capability of cleaving histone H1 and MBP was preserved after additional purification of anti-histone H1 IgGs by the HPLC gel filtration. The protease activity of anti-histone H1 IgG Ab was inhibited by serine protease inhibitors.

Heat-solubilized curry spice curcumin inhibits antibody-antigen interaction in in vitro studies: a possible therapy to alleviate autoimmune disorders

Chronic and complex autoimmune diseases, currently treated palliatively with immunosuppressives, require multi-targeted therapy for greater effectiveness. The naturally occurring polyphenol curcumin has emerged as a powerful "nutraceutical" that interacts with multiple targets to regress diseases safely and inexpensively. Up to 8 g/day of curcumin for 18 months was non-toxic to humans. However, curcumin's utility is limited by its aqueous insolubility. We have demonstrated a heat-mediated 12-fold increase in curcumin's aqueous solubility. Here, we show by SDS-PAGE and surface plasmon resonance that heat-solubilized curcumin binds to proteins. Based on this binding we hypothesized that heat-solubilized curcumin or turmeric would prevent autoantibody targeting of cognate autoantigens. Heat-solubilized curcumin/turmeric significantly decreased binding of autoantibodies from Sjögren's syndrome (up to 43/70%, respectively) and systemic lupus erythematosus (up to 52/70%, respectively) patients as well as an animal model of Sjögren's syndrome (up to 50/60%, respectively) to their cognate antigens. However, inhibition was not specific to autoimmunity. Heat-solubilized curcumin/turmeric also inhibited binding of commercial polyclonal anti-spectrin to spectrin (50/56%, respectively). Thus, we suggest that the multifaceted heat-solubilized curcumin can ameliorate autoimmune disorders. In addition, the non-toxic curcumin could serve as a new protein stain in SDS-PAGE even though it is less sensitive than the Coomassie system which involves toxic chemicals.

Prevalence and clinical significance of 15 autoantibodies in patients with new-onset systemic lupus erythematosus

INTRODUCTION

It is necessary to assay multiple autoantibodies simultaneously in the same group of new-onset systemic lupus erythematosus (SLE) patient.

AIM

To determine the prevalence and clinical significance of 15 autoantibodies in patients with new-onset SLE.

METHODS

Twenty new-onset patients with SLE and 32 healthy individuals were enrolled in the present study. Serum levels of 15 autoantibodies were detected by enzyme linked immunosorbent assay. The clinical parameters of the patients were also recorded.

RESULTS

The positive rate of anti-ssDNA was the highest (85%). The positive rates of anti-dsDNA, anti-ssDNA, AHA, anti-SSA, anti-SSB, anti-Sm, anti-U1RNP, AnuA, and rRNP were significantly higher in SLE patients than in nomal controls. In terms of clinical manifestation, there were significant associations of rRNP with photaesthesia and of AHA with nephritis.

CONCLUSION

Clusters of autoantibodies were identified and associations of antibodies with symptoms were found in new-onset patients with SLE.

The impact of the EUSCLE core set questionnaire for the assessment of cutaneous lupus erythematosus

Epidemiological data and standard European guidelines for the diagnosis and treatment of cutaneous lupus erythematosus (CLE) are lacking in the current literature. In order to provide a standardized tool for an extensive consistent data collection, a study group of the European Society of Cutaneous Lupus Erythematosus (EUSCLE) recently developed a Core Set Questionnaire for the assessment of patients with different subtypes of CLE. The EUSCLE Core Set Questionnaire includes six sections on patient data, diagnosis, skin involvement, activity and damage of disease, laboratory analysis, and treatment. An instrument like the EUSCLE Core Set Questionnaire is essential to gain a broad and comparable data collection of patients with CLE from different European centres and to achieve consensus concerning clinical standards for the disease. The data will also be important for further characterization of the different CLE subtypes and the evaluation of therapeutic strategies; moreover, the EUSCLE Core Set Questionnaire might also be useful for the comparison of data in clinical trials. In this review, the impact of the EUSCLE Core Set Questionnaire is discussed in detail with regard to clinical and serological features as well as therapeutic modalities in CLE. Lupus (2010) 19, 1144—1152.