A surge in anti-dsDNA titer predicts a severe lupus flare within six months

Duplex Vertical-Flow Rapid Tests for Point-of-Care Detection of Anti-dsDNA and Anti-Nuclear Autoantibodies

The goal of this study is to develop a rapid diagnostic test for rheumatic disease and systemic lupus erythematosus (SLE) screening. A novel rapid vertical flow assay (VFA) was engineered and used to assay anti-nuclear (ANA) and anti-dsDNA (αDNA) autoantibodies from systemic lupus erythematosus (SLE) patients and healthy controls (HCs). Observer scores and absolute signal intensities from the VFA were validated via ELISA. The rapid point-of-care VFA test that was engineered demonstrated a limit of detection of 0.5 IU/mL for ANA and αDNA autoantibodies in human plasma with an inter-operator CV of 19% for ANA and 12% for αDNA. Storage stability was verified over a three-month period. When testing anti-dsDNA and ANA levels in SLE and HC serum samples, the duplex VFA revealed 95% sensitivity, 72% specificity and an 84% ROC AUC value in discriminating disease groups, comparable to the gold standard, ELISA. The rapid αDNA/ANA duplex VFA can potentially be used in primary care clinics for evaluating patients or at-risk subjects for rheumatic diseases and for planning follow-up testing. Given its low cost, ease, and rapid turnaround, it can also be used to assess SLE prevalence estimates.

SMART-SLE: serology monitoring and repeat testing in systemic lupus erythematosus-an analysis of anti-double-stranded DNA monitoring

OBJECTIVE

Disease activity monitoring in SLE includes serial measurement of anti-double stranded-DNA (dsDNA) antibodies, but in patients who are persistently anti-dsDNA positive, the utility of repeated measurement is unclear. We investigated the usefulness of serial anti-dsDNA testing in predicting flare in SLE patients who are persistently anti-dsDNA positive.

METHODS

Data were analysed from patients in a multinational longitudinal cohort with known anti-dsDNA results from 2013 to 2021. Patients were categorized based on their anti-dsDNA results as persistently negative, fluctuating or persistently positive. Cox regression models were used to examine longitudinal associations of anti-dsDNA results with flare.

RESULTS

Data from 37 582 visits of 3484 patients were analysed. Of the patients 1029 (29.5%) had persistently positive anti-dsDNA and 1195 (34.3%) had fluctuating results. Anti-dsDNA expressed as a ratio to the normal cut-off was associated with the risk of subsequent flare, including in the persistently positive cohort (adjusted hazard ratio [HR] 1.56; 95% CI: 1.30, 1.87; P < 0.001) and fluctuating cohort (adjusted HR 1.46; 95% CI: 1.28, 1.66), both for a ratio >3. Both increases and decreases in anti-dsDNA more than 2-fold compared with the previous visit were associated with increased risk of flare in the fluctuating cohort (adjusted HR 1.33; 95% CI: 1.08, 1.65; P = 0.008) and the persistently positive cohort (adjusted HR 1.36; 95% CI: 1.08, 1.71; P = 0.009).

CONCLUSION

Absolute value and change in anti-dsDNA titres predict flares, including in persistently anti-dsDNA positive patients. This indicates that repeat monitoring of dsDNA has value in routine testing.

Association of urine autoantibodies with disease activity in systemic lupus erythematosus

Objective

The presence of urinary autoantibodies in patients with systemic lupus erythematosus (SLE) has been confirmed by several studies; however, the significance of their presence in urine remains unclear. This study aims to further investigate the association between urine autoantibodies and disease activity as well as organ involvement in SLE.

Methods

This cross-sectional study included 89 SLE patients. Data collected included anti-nuclear antibody (ANA), anti-ENA antibodies, and anti-dsDNA antibody levels in both serum and urine, complement (C) 3, C4 levels in serum, SLE disease activity index-2000 (SLEDAI-2000), renal domains of SLEDAI (RSLEDAI) and non-renal SLEDAI (NRSLEDAI).

Results

The rate of positive urine ANA (uANA) was 33.3% (29/87) among the enrolled patients. Compared to the uANA negative group, the positive group exhibited significantly higher SLEDAI-2000 scores (7.85 ± 5.88 vs. 18.69 ± 6.93, p < 0.001), RSLEDAI scores [0 (0, 4.0) vs. 12.0 (8.0, 16.0), p < 0.001], and NRSLEDAI [4 (2.0, 8.0) vs. 6.0 (4.0, 9.5), p = 0.038]. Patients with positive urine anti-Sm antibody demonstrated significantly elevated SLEDAI-2000 scores compared to those who were negative (25.0 ± 8.80 vs. 10.09 ± 6.63, p < 0.001). Similarly, they also had higher RSLEDAI [16.0 (12.0, 16.0) vs. 4.0 (0, 8.0), p < 0.001] and NRSLEDAI [9.5 (6.0, 13.5) vs. 4.0 (3.0, 8.0), p = 0.012], as well as a greater prevalence of renal involvement compared to their negative counterparts (100% vs. 58.2, p = 0.022). There was a positive correlation between uANA titer and both SLEDAI-2000 (rs = 0.663, p < 0.001) and RSLEDAI (rs = 0.662, p < 0.001). The serum anti-dsDNA antibody level did not exhibit a significant correlation with RSLEDAI (rs = 0.143, p = 0.182). Conversely, the urine anti-dsDNA antibody level demonstrated a significant positive correlation with RSLEDAI (rs = 0.529, p < 0.001).

Conclusion

Urine ANA is associated with both global SLEDAI and RSLEDAI scores. Urine anti-Sm antibody is associated with an increased incidence of renal involvement in SLE. The urine anti-dsDNA antibody level, rather than the serum anti-dsDNA antibody level, exhibits a significant association with RSLEDAI in SLE.

Development and validation of a prognostic nomogram for the renal relapse of lupus nephritis

OBJECTIVES

This study aims to assess the risk of relapse after complete remission (CR) and partial remission (PR), and to develop a prognostic nomogram predicting the probability in lupus nephritis (LN) patients.

METHODS

Data from patients with LN who had been in remission were collected as a training cohort. The prognostic factors were analyzed using the univariable and multivariable Cox model for the training group. A nomogram was then developed using significant predictors in multivariable analysis. Both discrimination and calibration were assessed by bootstrapping with 100 resamples.

RESULTS

A total of 247 participants were enrolled, including 108 in the relapse group and 139 in the no relapse group. In multivariate Cox analysis, Systemic Lupus Erythematosus Disease Activity Index (SLEDAI), erythrocyte sedimentation rate (ESR), complement 1q (C1q), and antiphospholipid (aPL), anti-Sm antibody were found to be significant for predicting relapse rates. The prognostic nomogram including the aforementioned factors effectively predicted 1- and 3-year probability of flare-free. Moreover, a favorable consistency between the predicted and actual survival probabilities was demonstrated using calibration curves.

CONCLUSIONS

High SLEDAI, ESR, and positive aPL, anti-Sm antibody are potential risk factors for LN flare, while high C1q can reduce its recurrence. The visualized model we established can help predict the relapse risk of LN and aid clinical decision-making for individual patients.

B cell polygenic risk scores associate with anti-dsDNA antibodies and nephritis in systemic lupus erythematosus

OBJECTIVE

B cell function and autoantibodies are important in SLE pathogenesis. In this work, we aimed to investigate the impact of cumulative SLE B cell genetics on SLE subphenotype and autoantibody profile.

METHODS

Female patients with SLE (n=1248) and healthy controls (n=400) were genotyped using Illumina's Global Screening Array. Two polygenic risk scores (PRSs), one representing B cell genes and the other B cell activation genes, were calculated for each individual using risk loci for SLE in genes assigned to B cell-related pathways according to the Kyoto Encyclopedia of Genes and Genomes, Gene Ontology and Reactome Databases.

RESULTS

Double-stranded DNA (dsDNA) antibodies were more prevalent among patients with a high compared with a low SLE B cell PRS (OR 1.47 (1.07 to 2.01), p=0.018), and effect sizes were augmented in patients with human leucocyte antigen (HLA) risk haplotypes HLA-DRB1*03:01 and HLA-DRB1*15:01 (DRB1*03/15 -/- (OR 0.99 (0.56 to 1.77), p=0.98; DRB1*03/15 +/- or -/+ (OR 1.64 (1.06 to 2.54), p=0.028; and DRB1*03/15 +/+ (OR 4.47 (1.21 to 16.47), p=0.024). Further, a high compared with a low B cell PRS was associated with low complement levels in DRB1*03/15 +/+ patients (OR 3.92 (1.22 to 12.64), p=0.022). The prevalence of lupus nephritis (LN) was higher in patients with a B cell activation PRS above the third quartile compared with patients below (OR 1.32 (1.00 to 1.74), p=0.048).

CONCLUSIONS

High genetic burden related to B cell function is associated with dsDNA antibody development and LN. Assessing B cell PRSs may be important in order to determine immunological pathways influencing SLE and to predict clinical phenotype.

Anti-dsDNA Is Associated with Favorable Prognosis in Myasthenia Gravis: A Retrospective Study

Objectives. To investigate the presence of serum antinuclear antibody (ANA) and anti-double-stranded DNA antibody (anti-dsDNA) in patients with myasthenia gravis (MG) and analyze the clinical characteristics and prognostic factors associated with MG. Methods. We retrospectively enrolled 363 patients with MG and analyzed the clinical characteristics and follow-up data between patients positive and negative for ANA and anti-dsDNA. We defined a Myasthenia Gravis Activities of Daily Living (MG-ADL) reduction as a main prognosis predictor and used logistic regression to determine independent factors associated with prognosis. We built a nomogram to predict prognosis and evaluate the internal validity of the model. Results. Ninety-eight (27.0%) patients were positive for ANA, and 51 (14.0%) were positive for anti-dsDNA. Patients positive for ANA and anti-dsDNA antibodies tended to be female and positive for acetylcholine receptor antibody (AChR-Ab). The rate of thymoma was higher in anti-dsDNA-positive patients with MG (p-dsDNA-MG) than in patients negative for anti-dsDNA (49.0% vs. 26.0%, $p=0.001$ ), and p-dsDNA-MG was associated with reduced MG-ADL score. Regression analysis showed that except for age of onset ( $\text{OR}=0.986$ , $95\%\text{CI}=0.973–0.999$ , $p=0.037$ ), anti-dsDNA ( $\text{OR}=2.800$ , $95\%\text{CI}=1.381–5.679$ , $p=0.004$ ), ptosis ( $\text{OR}=2.930$ , $95\%\text{CI}=1.827–4.699$ , $p<0.001$ ), and eye movement disorder ( $\text{OR}=2.815$ , $95\%\text{CI}=1.672–4.741$ , $p<0.001$ ) were independent predictive factors of a favorable prognosis of MG. These predictors were used to generate a nomogram with an excellent predictive value. Conclusions. Being female and the presence of AChR-Ab were features of ANA- or anti-dsDNA-positive MG. The presence of anti-dsDNA was associated with a favorable prognosis of MG.

Risk of systemic lupus erythematosus flares according to autoantibody positivity at the time of diagnosis

To estimate the risk of systemic lupus erythematosus (SLE) flares based on the autoantibody positivity at the time of SLE diagnosis. This retrospective cohort study included 228 patients with newly diagnosed SLE. Clinical characteristics including autoantibody positivity at the time of diagnosis of SLE were reviewed. Flares were defined as a new British Isles Lupus Assessment Group (BILAG) A score or BILAG B score for at least one organ system. Multivariable Cox regression analyses were performed to estimate the risk of flares according to autoantibody positivity. Anti-dsDNA, anti-Sm, anti-U1RNP, anti-Ro, and anti-La antibodies (Abs) were positive in 50.0%, 30.7%, 42.5%, 54.8%, and 22.4% of the patients, respectively. The incidence rate of flares was 28.2/100 person-years. Multivariable Cox regression analysis, adjusted for potential confounders, revealed that anti-dsDNA Ab positivity (adjusted hazard ratio [HR]: 1.46, p = 0.037) and anti-Sm Ab positivity (adjusted HR: 1.81, p = 0.004) at the time of diagnosis of SLE were associated with higher risk of flares. To better delineate the flare risk, patients were categorized as double-negative, single-positive, double-positive for anti-dsDNA and anti-Sm Abs. Compared with double-negativity, double-positivity (adjusted HR: 3.34, p < 0.001) was associated with higher risk of flares, while anti-dsDNA Ab single-positivity (adjusted HR: 1.11, p = 0.620) or anti-Sm Ab single-positivity (adjusted HR: 1.32, p = 0.270) was not associated with higher risk of flares. Patients who are double-positive for anti-dsDNA and anti-Sm Abs at the time of the diagnosis of SLE are at higher risk of flares and may benefit from stringent monitoring and early preventive treatment.

Anti-dsDNA B-Cell ELISpot as a Monitoring and Flare Prediction Tool in SLE Patients

Anti-dsDNA autoantibodies quantification and complement levels are widely used to monitor disease activity in systemic lupus erythematosus (SLE). However, better biomarkers are still needed. We hypothesised whether the dsDNA antibody-secreting B-cells could be a complementary biomarker in disease activity and prognosis of SLE patients. Fifty-two SLE patients were enrolled and followed for up to 12 months. Additionally, 39 controls were included. An activity cut-off (comparing active and non-active patients according to clinical SLEDAI-2K) was established for SLE-ELISpot, chemiluminescence and Crithidia luciliae indirect immunofluorescence tests (≥11.24, ≥374.1 and ≥1, respectively). Assays performances together with complement status were compared regarding major organ involvement at the inclusion and flare-up risk prediction after follow-up. SLE-ELISpot showed the best performance in identifying active patients. High SLE-ELISpot results were associated with haematological involvement and, after follow-up, with an increased hazard ratio for disease flare-up (3.4) and especially renal flare (6.5). Additionally, the combination of hypocomplementemia and high SLE-ELISpot results increased those risks up to 5.2 and 32.9, respectively. SLE-ELISpot offers complementary information to anti-dsDNA autoantibodies to evaluate the risk of a flare-up in the following year. In some cases, adding SLE-ELISpot to the current follow-up protocol for SLE patients can improve clinicians' personalised care decisions.

Down-regulated ALKBH5 Expression Could Affect the Function of T Cells in Systemic Lupus Erythematosus Patients

BACKGROUND

N6-methyladenosine (m6A) modification is widespread in eukaryotic mRNA, regulated by m6A demethylase, AlkB homolog 5 (ALKBH5). However, the role of m6A in systemic lupus erythematosus (SLE) is still obscure. We explored ALKBH5 expression in SLE patients and its effects on T cells.

METHODS

100 SLE patients and 110 healthy controls were recruited to investigate the expression of ALKBH5 in peripheral blood mononuclear cells (PBMCs). An additional 32 SLE patients and 32 health controls were enrolled to explore the expression of ALKBH5 in T cells. Then we explored the function of ALKBH5 in T cells by lentivirus.

RESULTS

The expressions of ALKBH5 were downregulated in both PBMCs and T cells in SLE patients (all P<0.05). In PBMCs: ALKBH5 mRNA levels were associated with complement C4 level in plasma (P<0.05). In T cells: ALKBH5 mRNA levels were downregulated in SLE patients with low complement levels, high anti-dsDNA, anti-Sm, anti-RNP, and proteinuria compared with those without, respectively (all P<0.05); ALKBH5 mRNA levels were negatively related with SLE disease activity index score, erythrocyte sedimentation rate, and anti-dsDNA levels (all P<0.05), and positively correlated with complement C3 and C4 level (all P<0.05). Functionally, the overexpression of ALKBH5 promoted apoptosis and inhibited the proliferation of T cells (all P<0.05).

CONCLUSION

ALKBH5 expression is downregulated in SLE patients and could affect the apoptosis and proliferation of T cells, but the exact mechanism still needs to be further explored.

Baricitinib decreases anti-dsDNA in patients with systemic lupus erythematosus: results from a phase II double-blind, randomized, placebo-controlled trial

Background

Patients with systemic lupus erythematosus (SLE) have substantial unmet medical need. Baricitinib is a Janus kinase (JAK)1 and 2 inhibitor that was shown to have therapeutic benefit in patients with SLE in a phase II clinical trial. The purpose of this study was to evaluate the median change from baseline in conventional serologic biomarkers in subgroups and the overall population of baricitinib-treated patients with SLE, and the SLE Responder Index-4 (SRI-4) response by normalization of anti-dsDNA.

Methods

Data were assessed from the phase II trial I4V-MC-JAHH (NCT02708095). The median change from baseline in anti-dsDNA, IgG, and other conventional serologic markers was evaluated over time in patients who had elevated levels of markers at baseline, and in all patients for IgG. Median change from baseline for baricitinib treatments were compared with placebo. Among patients who were anti-dsDNA positive at baseline, SRI-4 responder rate was compared for those who stayed positive or achieved normal levels by week 24.

Results

Significant decreases of anti-dsDNA antibodies were observed in response to baricitinib 2 mg and 4 mg compared to placebo beginning at weeks 2 (baricitinib 2 mg = − 14.3 IU/mL, placebo = 0.1 IU/mL) and 4 (baricitinib 4 mg = − 17.9 IU/mL, placebo = 0.02 IU/mL), respectively, continuing through week 24 (baricitinib 2 mg = − 29.6 IU/mL, baricitinib 4 mg = − 15.1 IU/mL, placebo=3.0 IU/mL). Significant reductions from baseline of IgG levels were found for baricitinib 4 mg-treated patients compared to placebo at weeks 12 (baricitinib 4 mg = − 0.65 g/L, placebo = 0.09 g/L) and 24 (baricitinib 4 mg = − 0.60 g/L, placebo = − 0.04 g/L). For patients who were anti-dsDNA positive at baseline, no relationship between achieving SRI-4 responder and normalization of anti-dsDNA was observed by week 24.

Conclusions

Baricitinib treatment resulted in a rapid and sustained significant decrease in anti-dsDNA antibodies compared to placebo among those with positive anti-dsDNA antibodies at baseline, as well as a significant decrease in IgG levels in the 4 mg group at weeks 12 and 24. These data suggest that baricitinib may influence B cell activity in SLE. Further studies are needed to evaluate if reductions in anti-dsDNA levels with baricitinib treatment reflect the impact of baricitinib on B cell activity.

Trial registration

NCT02708095.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13075-022-02794-x.

The association between lupus serology and disease outcomes: A systematic literature review to inform the treat-to-target approach in systemic lupus erythematosus

INTRODUCTION

Serological markers such as anti-double stranded (ds)DNA antibodies and complement fractions C3/C4, are integral components of disease activity assessment in patients with systemic lupus erythematosus (SLE). However, it remains uncertain whether treatment should aim at restoration of serological abnormalities.

OBJECTIVES

To analyze and critically appraise the literature on the prognostic impact of active lupus serology despite clinical disease quiescence.

METHODS

A systematic literature review was performed in PubMed and EMBASE using the PICOT(S) (population, index, comparator, outcome(s), timing, setting) system to identify studies evaluating the association of serum anti-dsDNA, C3 and C4 levels assessed at the time of clinical remission or during the disease course, against the risk for impending flares and organ damage. Risk of bias was determined by the Quality in Prognosis Studies and ROB2 tools for observational and randomized controlled studies, respectively.

RESULTS

Fifty-three studies were eligible, the majority having moderate (70.6%) or high (11.8%) risk of bias and not adequately controlling for possible confounders. C3 hypocomplementemia during stable/inactive disease was associated with increased risk (2.0 to 3.8-fold) for subsequent flare in three out of seven relevant studies. Three out of four studies reported a significant effect of C4 hypocomplementemia on flare risk, including one study in lupus nephritis (likelihood ratio-positive 12.0). An increased incidence of flares (2.0 to 2.8-fold) was reported in 11 out of 16 studies assessing the prognostic effect of high anti-dsDNA, and similarly, the majority of studies yielded significant relationships with renal flares. Six studies examined the effect of combined (rather than individual) serological activity, confirming the increased risk (2.0 to 2.7-fold) for relapses. No consistent association was found with organ damage.

CONCLUSION

Notwithstanding the heterogeneity and risk of bias, existing evidence indicates a modest association between abnormal serology and risk for flare in patients with stable/inactive SLE. These findings provide limited support for inclusion of serology in the treat-to-target approach but rationalize to further investigate their prognostic implications especially in lupus nephritis.

Laboratory evaluation of anti-dsDNA antibodies

Antibodies to dsDNA are an important laboratory parameter for diagnosis, monitoring and classification of systemic lupus erythematosus (SLE). In clinical laboratories, several techniques are used to detect and quantify anti-dsDNA antibodies. Each technique has its advantages and disadvantages regarding sensitivity, specificity, avidity and assay procedure. Assays differ with respect to the antigen source (native versus synthetic versus molecular biological) used and the way the antigen is presented (e.g. in solution, covalently linked to a solid phase,…). Consequently, correlation between assays can be poor and standardization of anti-dsDNA antibody tests is challenging. We here provide an overview of the currently available anti-dsDNA tests frequently used in clinical laboratories [Crithidiae luciliae immunofluorescence test (CLIFT), Enzyme linked immune sorbent assay (ELISA), fluoroenzyme immunoassay (FEIA), chemiluminescence (CIA), multiplexed bead-based assays and Farr-RIA] and their performance characteristics. From this literature study, we concluded that performance characteristics differ between assays. Often, a combination of techniques is necessary for the best result interpretation.

Comparisons of Anti-dsDNA Antibody Detection Methods by Chemiluminescent Immunoassay and Enzyme-Linked Immunosorbent Assay in Systemic Lupus Erythematosus

This study aimed to compare the test results of anti-double-stranded DNA (anti-dsDNA) antibodies obtained using chemiluminescent immunoassay (CIA) and enzyme-linked immunosorbent assay (ELISA), and investigate predictors of inconsistent results. This retrospective study included 502 patients who underwent CIA and ELISA to determine their anti-dsDNA antibody values within a year. We compared the diagnostic power for SLE, disease activity, and predictive power for lupus nephritis (LN). A multivariate analysis was performed to determine the predictors of inconsistencies. CIA and ELISA were moderately correlated in terms of their consistency (Cronbach’s α = 0.571), and yielded comparably favorable results in terms of SLE diagnostic power and SLE disease activity. However, if the patient had LN, CIA displayed higher predictive power than ELISA (0.620 vs. 0.555, p = 0.026). Compared with the CIA/ELISA double-positive group, the inconsistent group had lower anti-C1q circulating immune complexes (CIC) antibody values (OR: 0.42, 95% CI: 0.18–0.94, p = 0.036), and lower SLEDAI scores (≥4) (OR: 0.33, 95% CI: 0.14–0.79, p = 0.013). Anti-dsDNA antibody detection with CIA exhibited higher predictability for diagnosing LN than did ELISA. In the event of inconsistencies between anti-dsDNA methods, SLE disease activity and CIC test values should be considered simultaneously.

Lack of standardisation in interpretation and reporting of autoantibody assays: a survey analysis of Australasian laboratories with focus on line immunoassays

Autoantibody assays are reported in a variety of formats. Results only slightly above established cut-offs provide lower likelihood ratios; therefore, their clinical significance may be more uncertain, which is not readily communicated with dichotomous qualitative reporting. Line immunoassays (LIA) are a common method for detecting antibodies to extractable nuclear antigens (ENA) and myositis-associated antibodies. However, recommended positive cut-offs are contentious. We distributed a survey via e-mail to participants in the Royal College of Pathologists of Australasia Quality Assurance Program (RCPAQAP) Immunology modules and to a dedicated immunology mailing list in Australasia. Questions explored general viewpoints surrounding autoantibody reporting, as well as current laboratory practices, with particular focus on interpretation and reporting of the most commonly used ENA LIA manufactured by Euroimmun. There were 31 responders, representative of at least 17 unique laboratories across Australia (8 public, 5 private) and New Zealand (4 laboratories). Responses suggest that autoantibody reporting is not standardised; there was variation in general viewpoints and reporting practices, particularly regarding the interpretation of and positive cut-offs used for the Euroimmun ENA LIA, which were contrary to the manufacturer's guidelines in a majority of the responses. Interpretative qualitative reporting based on results from other investigations and the clinical history was a common theme. There is large variation in the reporting of autoantibody assays within Australasia, especially by LIA. A majority of respondents report the most commonly used ENA LIA contrary to manufacturer's guidelines; alternative positive cut-offs are commonly utilised. LIA reports should indicate the level of positivity to enhance their relevance in the clinical decision-making process.

Salivary Immunoglobulin Gamma-3 Chain C Is a Promising Noninvasive Biomarker for Systemic Lupus Erythematosus

We aimed to characterize the salivary protein components and identify biomarkers in patients with systemic lupus erythematosus (SLE). A proteomic analysis using two-dimensional gel electrophoresis and mass spectrometry was performed to determine the alterations of salivary proteins between patients with SLE and healthy controls, and the concentrations of the candidate proteins were measured through Western blot analysis and the enzyme-linked immunosorbent assay. The 10 differentially expressed protein spots were immunoglobulin gamma-3 chain C region (IGHG3), immunoglobulin alpha-1 chain C region, protein S100A8, lactoferrin, leukemia-associated protein 7, and 8-oxoguanine DNA glycosylase. The patients with SLE exhibited enhanced salivary IGHG3 (3.9 ± 2.15 pg/mL) and lactoferrin (4.7 ± 1.8 pg/mL) levels compared to patients with rheumatoid arthritis (1.8 ± 1.01 pg/mL and 3.2 ± 1.6 pg/mL, respectively; p < 0.001 for both) or healthy controls (2.2 ± 1.64 pg/mL and 2.2 ± 1.7 pg/mL, respectively; p < 0.001 for both). The salivary IGHG3 levels correlated with the erythrocyte sedimentation rate (r = 0.26, p = 0.01), anti-double-stranded DNA (dsDNA) antibody levels (r = 0.25, p = 0.01), and nephritis (r = 0.28, p = 0.01). The proteomic analysis revealed that the salivary IGHG3 levels were associated with SLE and lupus disease activity, suggesting that salivary IGHG3 may be a promising noninvasive biomarker for SLE.

Elevated Creatinine Clearance in Lupus Nephritis patients with Normal Creatinine

Objectives: The present study aimed to observe the differences in creatinine clearance (Ccr) in systemic lupus erythematosus (SLE) patients with normal serum creatinine at different levels of urinary protein. Method: The present cross-sectional study included 177 SLE patients with normal serum creatinine from Qilu Hospital of Shandong University between January 2010 and April 2020. The following data were collected: blood urea nitrogen (BUN), serum creatinine (Cr), serum total protein, serum albumin, immunoglobulin (Ig) G, IgA, IgM, complement 3, complement 4, anti-ds-DNA antibody, routine urine test, urine protein/creatinine ratio (UPCR) (g/g), and the SLE disease activity index. The estimated Ccr was calculated according to the Cockcroft formula. Results: 123 patients were with positive urinary protein (Lupus Nephritis, LN group) and 54 patients were with negative urinary protein (Non-LN group). Compared with the Non-LN group, the LN group had higher BUN (5.76±3.22 vs. 4.78±1.58, P=0.007) and Cr (62.36±19.53 vs. 54.83±11.09, P=0.001). There was a strong correlation between the UPCR and the semi-quantitative determination of urine protein in LN patients (r=0.9583, P=0.0417). The serum creatinine levels were significantly higher in patients with urine protein 3+ (72.97±25.16) or massive proteinuria (62.32±19.66) than the other groups. Patients with urinary protein ± exhibited a significantly elevated Ccr when compared to patients with urinary protein 3+ (130.6±44.15 vs. 110.5±33.50, P=0.02), and patients with UPCR<0.15 g/g had higher Ccr than other groups and showed significantly increased Ccr compared with patients with UPCR≥0.15 g/g (132.44±21.02 vs. 115.14±35.89, P=0.007). Conclusions: Early renal function impairment may be present in LN patients. The kidneys of LN patients with urinary protein ± or UPCR<0.15 g/g are in a state of hyperfunction.

An Update on Antibodies to Necleosome Components as Biomarkers of Sistemic Lupus Erythematosus and of Lupus Flares

Systemic lupus erythematosus (SLE) is an autoimmune disease with variable clinical expression. It is a potentially devastating condition affecting mostly women and leading to clinically unpredictable outcomes. Remission and flares may, in fact, alternate over time and a mild involvement limited to few articular sites may be followed by severe and widespread organ damage. SLE is the prototype of any autoimmune condition and has, for this reason, attracted the interest of basic immunologists. Therapies have evolved over time and clinical prognosis has, in parallel, been improved. What clinicians still lack is the possibility to use biomarkers of the disease as predictors of outcome and, in this area, several studies are trying to find solutions. Circulating autoantibodies are clearly a milestone of clinical research and the concrete possibility is to integrate, in the future, classical markers of activation (like C3) with target organ autoantibodies. Anti-dsDNA antibodies represent a basic point in any predictive attempt in SLE and should be considered the benchmark for any innovative proposal in the wide field of target organ pathologies related to SLE. DNA is part of the nucleosome that is the basic unit of chromatin. It consists of DNA wrapped around a histone octamer made of 2 copies each of Histone 2A, 2B, 3, and 4. The nucleosome has a plastic organization that varies over time and has the potential to stimulate the formation of antibodies directed to the whole structure (anti-nucleosome) or its parts (anti-dsDNA and anti-Histones). Here, we present an updated review of the literature on antibodies directed to the nucleosome and the nucleosome constituents, i.e., DNA and Histones. Wetriedto merge the data first published more than twenty years ago with more recent results to create a balanced bridge between old dogma and more recent research that could serve as a stimulus to reconsider mechanisms for SLE. The formation of large networks would provide the chance of studying large cohorts of patients and confirm what already presented in small sample size during the last years.

Antinuclear Antibody Tests

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

Anti-double Stranded DNA Antibodies: Origin, Pathogenicity, and Targeted Therapies

Systemic lupus erythematosus (SLE) is characterized by high-titer serological autoantibodies, including antibodies that bind to double-stranded DNA (dsDNA). The origin, specificity, and pathogenicity of anti-dsDNA antibodies have been studied from a wider perspective. These autoantibodies have been suggested to contribute to multiple end-organ injuries, especially to lupus nephritis, in patients with SLE. Moreover, serum levels of anti-DNA antibodies fluctuate with disease activity in patients with SLE. By directly binding to self-antigens or indirectly forming immune complexes, anti-dsDNA antibodies can accumulate in the glomerular and tubular basement membrane. These autoantibodies can also trigger the complement cascade, penetrate into living cells, modulate gene expression, and even induce profibrotic phenotypes of renal cells. In addition, the expression of suppressor of cytokine signaling 1 is reduced by anti-DNA antibodies simultaneously with upregulation of profibrotic genes. Anti-dsDNA antibodies may even participate in the pathogenesis of SLE by catalyzing hydrolysis of certain DNA molecules or peptides in cells. Recently, anti-dsDNA antibodies have been explored in greater depth as a therapeutic target in the management of SLE. A substantial amount of data indicates that blockade of pathogenic anti-dsDNA antibodies can prevent or even reverse organ damage in murine models of SLE. This review focuses on the recent research advances regarding the origin, specificity, classification, and pathogenicity of anti-dsDNA antibodies and highlights the emerging therapies associated with them.

Analysis of clinical risk factors in relapsed patients with class IV lupus nephritis

The present study aimed to investigate risk factors for renal recurrence in patients with type IV lupus nephritis (LN). Univariate and multivariate analyses were conducted to using the Cox proportional hazard model and the Kaplan-Meier method. A total 244 patients were diagnosed with type IV LN; 100 (28.49%) relapsed and 144 (41.03%) recovered successfully. Kaplan-Meier method analysis indicated that patients with type IV LN affecting the digestive tract had high renal recurrence rates. Patients with hyperglobulinemia, positive anti-ribonucleoprotein and anti-Sjögren's syndrome type B (anti-SSB) antibodies, thrombus in the loop or non-inflammatory necrotizing vasculopathy also had a high recurrence rate. Furthermore, patients achieving partial remission had an increased recurrence rate compared with patients achieving complete remission. Patients undergoing maintenance treatment with glucocorticoids alone had a higher recurrence rate compared with patients who used alternative treatment schemes. Univariate and multivariate regression analyses by the Cox proportional hazard model determined that the effect of systemic lupus erythematosus in the gastrointestinal tract, increased serum globulin levels and positive anti-SSB antibody at onset were risk factors for the recurrence of LN type IV. The present study demonstrated that clinical risk factors of renal recurrence in patients with LN type IV include LN in the gastrointestinal tract, increased serum globulin levels, positive anti-SSB antibodies at onset and the use of glucocorticoid-only maintenance treatment.

Repeat Testing of Antibodies and Complements in Systemic Lupus Erythematosus: When Is It Enough?

OBJECTIVE

Patients with systemic lupus erythematosus (SLE) frequently undergo repeat testing for antibodies against extractable nuclear antigens (anti-ENA), but it is not known whether this is necessary or cost-effective. This study characterized the frequencies of changes in anti-ENA, anti-dsDNA, and complement C3 and C4 upon repeat testing.

METHODS

Chart review was done at one site of 130 patients with SLE enrolled in the 1000 Canadian Faces of Lupus prospective registry with annual antibody and complement testing. We determined the frequency of seroconversion (changes) on the next test and over the entire followup given 1 or multiple consistent results, and the cost to detect these changes.

RESULTS

Overall, 89.4% of patients had no changes in anti-ENA screening results from the first available test, 3.3% changed from negative to positive, and 7.3% from positive to negative. Following a single anti-ENA test, 3.9% of negative tests changed to positive and 4.2% of positive changed to negative on the next test. After multiple consistent tests, the frequencies of changes progressively declined. No changes from the first test were observed in anti-dsDNA, C3, and C4 in 60.8%, 83.3%, and 75.4% of patients, respectively. After 2 consistent anti-ENA tests, the cost to detect 1 change was above US$2000.

CONCLUSION

Anti-ENA results change infrequently, especially following 1 or more negative tests. The high cost and lack of evidence that changes affect management suggest that repeating anti-ENA tests routinely is unnecessary. Anti-dsDNA and complements change more frequently after an abnormal result, but less after a normal value.

Neutrophil CD64 expression, procalcitonin and presepsin are useful to differentiate infections from flares in SLE patients with SIRS

Background/Objective Differentiating systemic lupus erythematosus (SLE) activity from infections in febrile patients is difficult because of similar initial clinical presentation. The aim of this study is to evaluate the usefulness of a number of biomarkers for differentiating infections from activity in SLE patients admitted with systemic inflammatory response (SIRS). Methods Patients with SLE and SIRS admitted to the emergency room were included in this study. Measurements of different markers including procalcitonin, neutrophil CD64 expression and presepsin, were performed. Infection was considered present when positive cultures and/or polymerase chain reaction were obtained. Sensitivity and specificity were calculated for all biomarkers. Results Twenty-seven patients were admitted, 23 women (82.5%), mean age 33.2 years. An infectious disease was confirmed in 12 cases. Markers for SLE activity including anti-DNA titers by IIF ( p = 0.041) and enzyme-linked immunosorbent assay ( p = 0.009) were used for differentiating SLE flares from infection. On the contrary, increased procalcitonin ( p = 0.047), neutrophil CD64 expression by flow cytometry ( p = 0.037) and presepsin ( p = 0.037) levels were observed in infected SLE patients. Conclusions High neutrophil CD64 expression, presepsin and procalcitonin levels are useful to differentiate infections from activity in SLE patients. In most cases, a positive bioscore that includes these three markers demonstrate the presence of an infectious disease.

Predictive biological markers of systemic lupus erythematosus flares: a systematic literature review

BACKGROUND

The aim of this study was to identify the most reliable biomarkers in the literature that could be used as flare predictors in systemic lupus erythematosus (SLE).

METHODS

A systematic review of the literature was performed using two databases (MEDLINE and EMBASE) through April 2015 and congress abstracts from the American College of Rheumatology and the European League Against Rheumatism were reviewed from 2010 to 2014. Two independent reviewers screened titles and abstracts and analysed selected papers in detail, using a specific questionnaire. Reports addressing the relationships between one or more defined biological test(s) and the occurrence of disease exacerbation were included in the systematic review.

RESULTS

From all of the databases, 4668 records were retrieved, of which 69 studies or congress abstracts were selected for the systematic review. The performance of seven types of biomarkers performed routinely in clinical practice and nine types of novel biological markers was evaluated. Despite some encouraging results for anti-double-stranded DNA antibodies, anti-C1q antibodies, B-lymphocyte stimulator and tumour necrosis factor-like weak inducer of apoptosis, none of the biomarkers stood out from the others as a potential gold standard for flare prediction. The results were heterogeneous, and a lack of standardized data prevented us from identifying a powerful biomarker.

CONCLUSIONS

No powerful conclusions could be drawn from this systematic review due to a lack of standardized data. Efforts should be undertaken to optimize future research on potential SLE biomarkers to develop validated candidates. Thus, we propose a standardized pattern for future studies.

Vitamin D supplementation and disease activity in patients with immune-mediated rheumatic diseases: A systematic review and meta-analysis

BACKGROUND

Vitamin D serum levels and the presence and activity of rheumatic conditions have been associated. However, many studies are merely observational, and the existent randomized clinical trials were never systematically analyzed. Therefore, this study aims to provide a systematic review and meta-analysis of such a topic.

METHODS

MEDLINE, EMBASE, LILACS, COCHRANE, and CINAHL were explored to identify randomized trials that investigated clinical repercussions of vitamin D (or analogs) supplementation for at least 3 months in rheumatic diseases. Standardized clinical and/or laboratorial outcomes related to disease activity were analyzed according to each disease before and after supplementation.

RESULTS

Database searches rendered 668 results; 9 were included-5 on rheumatoid arthritis, 3 on systemic lupus erythematosus, and 1 on systemic sclerosis. Seven of the studies were meta-analyzed. After vitamin D supplementation, rheumatoid arthritis recurrence decreased; however, not significantly (risk difference = -0.10, 95% CI = -0.21, 0.00, P = .05). No statistical significance was observed regarding visual analog scale (mean difference = 2.79, 95% CI = -1.87, 7.44, P = .24) and disease activity score28 (mean difference = -0.31, 95% CI = -0.86, 0.25, P = .28). Regarding systemic lupus erythematosus, anti-dsDNA positivity was significantly reduced (risk difference = -0.10, 95% CI = -0.18, -0.03; P = .005).

CONCLUSION

Vitamin D supplementation reduced anti-dsDNA positivity on systemic lupus erythematosus and could possibly reduce rheumatoid arthritis recurrence, although novel randomized clinical trials are needed to confirm and extend the benefits of this hormone in immune-mediated rheumatic diseases.

What Causes Lupus Flares?

Systemic lupus erythematosus (SLE), the prototypic systemic autoimmune disease, follows a chronic disease course, punctuated by flares. Disease flares often occur without apparent cause, perhaps from progressive inherent buildup of autoimmunity. However, there is evidence that certain environmental factors may trigger the disease. These include exposure to UV light, infections, certain hormones, and drugs which may activate the innate and adaptive immune system, resulting in inflammation, cytotoxic effects, and clinical symptoms. Uncontrolled disease flares, as well as their treatment, especially with glucocorticoids, can cause significant organ damage. Tight surveillance and timely control of lupus flares with judicial use of effective treatments to adequately suppress the excessive immune system activation are required to bring about long term remission of the disease. We hope that new clinical trials will soon offer additional effective and target-specific biologic treatments for SLE.

The Diagnosis and Treatment of Systemic Lupus Erythematosus

BACKGROUND

Systemic lupus erythematosus (SLE) is an autoimmune disease with a prevalence of 36.7/100 000 in Germany and a female/male ratio of 4:1. The clinical course is variable, with a broad spectrum of organ manifestations; lupus nephritis develops in about half of all patients.

METHODS

This review is based on a selective search of PubMed and the Cochrane Library, including current guidelines and expert recommendations.

RESULTS

Assessment of clinical symptoms, laboratory findings, and optional biopsy results are the basis for early diagnosis of SLE. All patients should be treated with antimalarials as soon as the diagnosis is confirmed. In particular, hydroxychloroquine is associated with a higher rate of remission, fewer relapses, and reduced damage in the course of the disease, even in lupus nephritis. High-dose glucocorticoids should be given only when acutely indicated; immunosuppressives such as azathioprine, methotrexate, or mycophenolate mofetil may be administered to reduce glucocorticoids, according to the EULAR recommendations. Belimumab was recently approved as add-on therapy in autoantibody-positive SLE patients with high disease activity unresponsive to standard treatment. Short-term induction pulse therapy with low-dose intravenous cyclophosphamide, as well as continued mycophenolate mofetil treatment are advances in lupus nephritis.

CONCLUSION

The long-term prognosis for SLE has improved markedly in recent decades because of earlier diagnosis and optimized treatment. Further research and randomized controlled trials are needed for the development of specifically targeted therapies.

Autoantibodies against Modified Histone Peptides in SLE Patients Are Associated with Disease Activity and Lupus Nephritis

Persistent exposure of the immune system to death cell debris leads to autoantibodies against chromatin in patients with systemic lupus erythematosus (SLE). Deposition of anti-chromatin/chromatin complexes can instigate inflammation in multiple organs including the kidney. Previously we identified specific cell death-associated histone modifications as targets of autoantibodies in SLE. In this study we addressed, in a large cohort of SLE patients and controls, the question whether plasma reactivities with specific histone peptides associated with serology and clinical features. Plasma from SLE patients with and without lupus nephritis, disease controls, and healthy controls, were tested in ELISA with histone H4 peptide acetylated at lysines 8, 12 and 16 (H4p^ac), H2B peptide acetylated at lysine 12 (H2Bp^ac), H3 peptide trimethylated at lysine 27 (H3p^me), and their unmodified equivalents. SLE patients displayed a higher reactivity with the modified equivalent of each peptide. Reactivity with H4p^ac showed both a high sensitivity (89%) and specificity (91%) for SLE, while H2Bp^ac exhibited a high specificity (96%) but lower sensitivity (69%). Reactivity with H3p^me appeared not specific for SLE. Anti-H4p^ac and anti-H2Bp^ac reactivity demonstrated a high correlation with disease activity. Moreover, patients reacting with multiple modified histone peptides exhibited higher SLEDAI and lower C3 levels. SLE patients with renal involvement showed higher reactivity with H2B/H2Bp^ac and a more pronounced reactivity with the modified equivalent of H3p^me and H2Bp^ac. In conclusion, reactivity with H4p^ac and H2Bp^ac is specific for SLE patients and correlates with disease activity, whereas reactivity with H2Bp^ac is in particular associated with lupus nephritis.

Clinical Application of a Modular Genomics Technique in Systemic Lupus Erythematosus: Progress towards Precision Medicine

Monitoring disease activity in a complex, heterogeneous disease such as lupus is difficult. Both over- and undertreatment lead to damage. Current standard of care serologies are unreliable. Better measures of disease activity are necessary as we move into the era of precision medicine. We show here the use of a data-driven, modular approach to genomic biomarker development within lupus-specifically lupus nephritis.

Anti-dsDNA Antibodies are one of the many autoantibodies in systemic lupus erythematosus

Anti-dsDNA antibodies are the most studied antibodies of the lupus-related autoantibodies. The dogma is that these are the most important autoantibodies in systemic lupus erythematosus. In this review, evidence is presented to show that these antibodies (as measured by modern clinical laboratories) are not the most important autoantibodies in the diagnosis of systemic lupus erythematosus, and are of limited value in clinical correlation and in predicting disease flares. In addition, they are not likely to be the initiating autoantibodies in lupus nephritis. Thus, several pervasively held beliefs on anti-dsDNA antibodies are not valid. We suggest that anti-dsDNA antibodies should be considered as just one of the many autoantibodies associated with systemic lupus erythematosus.

Role of autoantibody testing

Autoantibodies are the serological hallmark of autoimmune disease. Though their pathogenic role is debatable, they play an important role in the management of a patient with rheumatic disease. However, due to their presence in the general population as well as in multiple autoimmune diseases, the presence of an autoantibody alone does not make a diagnosis; the result has to be interpreted along with clinical findings. Similarly, the absence of autoantibody does not exclude a disease. The common autoantibodies used in clinical practice include rheumatoid factor, anti-CCP antibodies, antinuclear antibodies (ANAs), anti-neutrophil cytoplasmic antibodies (ANCA) and anti-phospholipid antibodies. Once an autoantibody to a broad antigen is detected in a patient, sub-specificity analysis can improve the utility of the antibody. Autoantibodies are detected in the serum using different assays and results of which can vary; thus, it is important for a clinician to know the method used, its sensitivity and specificity to help in the proper interpretation of the laboratory results. This review will address these issues.