Lupus band test can be used in combination with anti-chromatin antibodies and complement analysis to predict transition from cutaneous to systemic lupus

The lupus band test (LBT) is frequently performed for patients with lupus erythematosus (LE) but its capacity to discriminate cutaneous (C)LE from systemic (S)LE is debated, as well as its association with serum antinuclear antibodies (ANA) and complement reduction. Among 158 patients, 56 received retrospectively a diagnosis of CLE, 37 have SLE and 65 other skin disorders. Considering 29 clinical, histopathologic, LBT, and serological parameters: 5 parameters were effective in distinguishing LE from other skin disorders (e.g. skin photosensitivity, LBT positivity, basal vacuolar changes, thickening of the basement membrane, and anti-SSA-60 kDa); and 8 parameters were able to separate SLE from CLE (e.g. arthritis, lupus nephritis, hematological manifestations, Raynaud/sicca manifestations, anti-chromatin, anti-dsDNA, and low levels of C3/4). A positive LBT was further determined to be associated with systemic manifestations when associated with anti-chromatin response and complement reduction in the profile of patients evolving to a systemic form of lupus.

IL-21 dependent Granzyme B production of B-cells is decreased in patients with lupus nephritis

OBJECTIVES

B-cells play a crucial role in the pathogenesis of lupus nephritis. Recently, a separate subset has been discovered characterized by expression of Granzyme B. The aim of this study is to investigate this subset in patients with systemic lupus erythematosus (SLE).

METHODS

Isolated PBMCs of SLE-patients (n=30) and healthy controls (n=21) were in vitro stimulated with CPG, IgG+IgM and IL-21. Patients were sub-grouped in patients with and without biopsy proven lupus nephritis. B-cells were analyzed for intracellular Granzyme B expression by flow cytometry.

RESULTS

The strongest stimulus for Granzyme B secretion of B-cells was IgG+IgM in presence of IL-21. SLE-patients had a significant decreased percentage of Granzyme B⁺ B-cells in particular SLE-patients with active disease and with lupus nephritis.

CONCLUSIONS

The frequency of GrB+ producing B-cells is reduced in SLE patients. This may contribute to an imbalanced B-cell regulation towards effector B-cells which might promote the development of lupus nephritis.

Decreased IL-10(+) regulatory B cells (Bregs) in lupus nephritis patients

OBJECTIVES

Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by B cell-dependent autoantibody production. Recently, a new B-cell subset was discovered that has a regulatory capacity. The aim of this study was to analyse regulatory B cells (Bregs) in SLE patients.

METHOD

Peripheral mononuclear blood cells (PBMCs) of 34 SLE patients fulfilling the American College of Rheumatology (ACR) criteria for SLE and 21 healthy controls (HC) were included. PBMCs were stained for CD19, CD24, and CD38 and analysed by flow cytometry. In vitro stimulated PBMCs with CpG and restimulated with phorbol 12-myristate 13-acetate (PMA) and ionomycin were investigated for IL-10(+) Bregs .

RESULTS

The percentages of circulating CD19(+)CD24(hi)CD38(hi) cells in HC were not different those in from SLE patients. The percentages of IL-10(+) Bregs were significantly decreased in SLE patients, in particular those with lupus nephritis (LN), compared to HC. The proportion was independent of disease activity.

CONCLUSIONS

This is the first study to demonstrate a decrease in IL-10-producing B cells in LN patients compared to HC, reflecting an impaired regulatory function.

Analysis of IL10 haplotypes in primary Sjögren's syndrome patients from Western Mexico: Relationship with mRNA expression, IL-10 soluble levels, and autoantibodies

Primary Sjögren's syndrome (pSS) is an autoimmune disease characterized by lymphocytic infiltration of salivary and lacrimal glands. Interleukin-10 (IL-10) plays a role in autoimmune diseases by promoting B-cell activation and autoantibodies production. IL10-1082A>G, -819C>T, -592C>A polymorphisms and their haplotypes have been associated with IL-10 production. The aim of this study was to associate IL10 haplotypes with mRNA expression and soluble IL-10 levels with susceptibility to pSS in 111 Mexican patients and 111 healthy subjects (HS). Primary Sjögren's syndrome patients showed high levels of sIL-10 (p=0.0001 vs HS) correlating with anti-Ro and anti-La antibodies (p<0.05). In addition, IL10 mRNA expression in pSS was higher than HS (0.8 vs 0.1, p=0.1537). However, no difference was observed in sIL-10 levels between haplotypes. Patients carriers of GCC haplotype showed higher mRNA expression than ACC+ATA (1.4 vs 0.6, p=0.2424) and high foci number (p=0.04 vs ACC). Our results suggest a strong relationship of IL10 with pSS which is demonstrated by the increased mRNA expression and also high sIL-10 levels positively correlated with autoantibodies. Besides that, the GCC haplotype carriers expressed high mRNA. However, IL10 haplotypes were not associated with sIL-10 in pSS from Western Mexico which suggest that diverse biological factors may regulate the IL10 expression in pSS.

Lipopolysaccharide Attenuates CD40 Ligand-Induced Regulatory B10 Cell Expansion and IL-10 Production in Mouse Splenocytes

Toll-like receptors (TLRs) play a key role in B cell-mediated innate and adaptive immunity. It has been shown that interleukin 10 (IL-10)-producing regulatory B cells (B10 cells) can negatively regulate cellular immune responses and inflammation in autoimmune diseases. In this study, we determined the effect of TLR4 signaling on the CD40-activated B10 cell competency. The results demonstrated that LPS and CD40L synergistically stimulated proliferation of mouse splenocytes. The percentage of B10 cells in cultured splenocytes was significantly increased after CD40L stimulation but such increase was diminished by the addition of LPS. Such effects by LPS were only observed in cells from WT but not TLR4^−/− mice. IL-10 mRNA expression and protein production in B10 cells from cultured splenocytes were significantly up-regulated by CD40L stimulation but were inhibited after the addition of LPS in a TLR4-dependent manner. This study suggests that LPS-induced TLR4 signaling attenuate CD40L-activated regulatory B10 cell competency.

B-cell-targeted therapies in systemic lupus erythematosus and ANCA-associated vasculitis: current progress

B cells play a central role in the pathogenesis of systemic lupus erythematosus and anti-neutrophil cytoplasmic antibody-associated vasculitis. There are various strategies for targeting B cells including depletion, inhibition of survival factors, activation and inhibition of co-stimulatory molecules. Controlled trials in systemic lupus erythematosus have shown positive results for belimumab, promising results for epratuzumab and negative results for rituximab. The failure of rituximab in controlled trials has been attributed to trial design, sample size and outcome measures rather than true inefficacy. In anti-neutrophil cytoplasmic antibody-associated vasculitis, rituximab is effective for remission induction and in relapsing disease. However, the optimal long-term re-treatment strategy remains to be determined. Over the next 5 years, evidence will be available regarding the clinical efficacy of these novel therapies, biomarkers and their long-term safety.

MicroRNA-30a promotes B cell hyperactivity in patients with systemic lupus erythematosus by direct interaction with Lyn

OBJECTIVE

To investigate why the level of Lyn is significantly decreased in B cells from a majority of patients with systemic lupus erythematosus (SLE) and to determine the role of microRNA-30a (miR-30a) in SLE B cell hyperactivity.

METHODS

Luciferase reporter gene assays were performed to identify the interaction between miR-30a and the 3'-untranslated region (3'-UTR) of Lyn. Levels of miR-30a in B cells were determined by TaqMan quantitative polymerase chain reaction (qPCR), Lyn messenger RNA levels were tested with real-time qPCR, and protein levels of Lyn were determined using Western blotting. The quantity of IgG was determined by enzyme-linked immunosorbent assay. The proliferation of B cells was measured using (3) H-thymidine incorporation.

RESULTS

In B cell lines, miR-30a, but not miR-30b, miR-30c, miR-30d, or miR-30e, could specifically bind the 3'-UTR of Lyn, and overexpression of miR-30a inhibited the levels of Lyn. The level of miR-30a in B cells was significantly higher in SLE patients compared to healthy donors. The level of miR-30a was negatively associated with the level of Lyn in B cells. Overexpression of miR-30a was found to promote B cell proliferation and the production of IgG antibodies. The effect of miR-30a could be abrogated by inducing overexpression of Lyn in B cells.

CONCLUSION

These results reveal that elevated expression of miR-30a is responsible for the reduction in levels of Lyn in B cells from patients with SLE, suggesting that miR-30a plays an important role in B cell hyperactivity.

Gene expression profiles in a rabbit model of systemic lupus erythematosus autoantibody production

We previously reported the establishment of a rabbit (Oryctolagus cuniculus) model in which peptide immunization led to production of lupus-like autoantibodies including anti-Sm, -RNP, -SS-A, -SS-B, and -dsDNA characteristic of those produced in systemic lupus erythematosus (SLE) patients. Some neurologic symptoms in the form of seizures and nystagmus were observed. The animals used in the previous and in the current study were from a National Institute of Allergy and Infectious Diseases colony of rabbits that were pedigreed, Ig-allotype defined, but not inbred. Their genetic heterogeneity may correspond to that found among patients of a given ethnicity. We extended the information about this rabbit model by microarray-based expression profiling. We first demonstrated that human expression arrays could be used with rabbit RNA to yield information on molecular pathways. We then designed a study evaluating gene expression profiles in eight groups of control and treated rabbits (47 rabbits in total). Genes significantly upregulated in treated rabbits were associated with NK cytotoxicity, Ag presentation, leukocyte migration, cytokine activity, protein kinases, RNA spliceosomal ribonucleoproteins, intracellular signaling cascades, and glutamate receptor activity. These results link increased immune activation with upregulation of components associated with neurologic and anti-RNP responses, demonstrating the utility of the rabbit model to uncover biological pathways related to SLE-induced clinical symptoms, including neuropsychiatric lupus. Our finding of distinct gene expression patterns in rabbits that made anti-dsDNA compared with those that only made other anti-nuclear Abs should be further investigated in subsets of SLE patients with different autoantibody profiles.

Increased expression of ganglioside GM1 in peripheral CD4+ T cells correlates soluble form of CD30 in Systemic Lupus Erythematosus patients

Gangliosides GM1 is a good marker of membrane microdomains (lipid rafts) with important function in cellular activation processes. In this study we found that GM1 expression on CD4+ T cells and memory T cells (CD45RO/CD4) were dramatic increased after stimulation with phytohaemagglutinin in vitro. Next, we examined the GM1 expression on peripheral blood CD4+ T cells and CD8+ T cells from 44 patients with SLE and 28 healthy controls by flow cytometry. GM1 expression was further analyzed with serum soluble CD30 (sCD30), IL-10, TNF-alpha and clinical parameters. The mean fluorescence intensity of GM1 on CD4+ T cells from patients with SLE was significantly higher than those from healthy controls, but not on CD8+ T cells. Increased expression of GM1 was more marked on CD4+/CD45RO+ memory T cells from active SLE patients. Patients with SLE showed significantly elevated serum sCD30 and IL-10, but not TNF-alpha levels. In addition, we found that enhanced GM1 expression on CD4+ T cells from patients with SLE positively correlated with high serum levels of sCD30 and IgG as well as disease activity (SLEDAI scores). Our data suggested the potential role of aberrant lipid raft/GM1 on CD4+ T cells and sCD30 in the pathogenesis of SLE.

Monoclonal Antibodies for Systemic Lupus Erythematosus (SLE)

A number of monoclonal antibodies (mAb) are now under investigation in clinical trials to assess their potential role in Systemic Lupus Erythematosus (SLE). The most frequently used mAb is rituximab, which is directed against CD20, a membrane protein expressed on B lymphocytes. Uncontrolled trials reported an improvement of SLE activity in non-renal patients and other studies even reported an improvement of severe lupus nephritis unresponsive to conventional treatments. However two randomized trials failed to show the superiority of rituximab over conventional treatment in non renal SLE and in lupus nephritis. Preliminary trials reported promising results with epratuzumab, a humanized mAb directed against CD22, and with belimumab, a human mAb that specifically recognizes and inhibits the biological activity of BLyS a cytokine of the tumornecrosis-factor (TNF) ligand superfamily. Other clinical trials with mAb directed against TNF-alpha, interleukin-10 (Il-10), Il-6, CD154, CD40 ligand, IL-18 or complement component C5 are under way. At present, however, in spite of good results reported by some studies, no firm conclusion on the risk-benefit profile of these mAbs in patients with SLE can be drawn from the available studies.