CXCL13 as a new biomarker of systemic lupus erythematosus and lupus nephritis – from bench to bedside?

Different studies over the last decade have linked the B cell-attracting chemokine CXC ligand 13 (CXCL13) to the autoimmune disease systemic lupus erythematosus (SLE). A pathogenetic role of this chemokine for disease manifestation in SLE was described initially in mouse models for SLE. Mechanisms of CXCL13 actions were also identified in SLE patients. Moreover, various clinical studies have identified CXCL13 serum levels as a useful biomarker in patients with SLE of different ethnicities for disease activity. In addition, CXCL13 seems to be a promising marker for the diagnosis of lupus nephritis, one of the most severe complications of SLE. However, its exact place within the mechanisms that lead to SLE remains to be defined. Further research is needed to resolve more details of the pathomechanism and the signalling pathway of CXCL13 in SLE. Blocking CXCL13 or the signal pathways of CXCL13 is seen as a promising therapeutic approach for SLE and will be addressed in the near future. This review summarizes all papers that linked CXCL13 to SLE and highlights its importance in the pathogenesis and diagnosis of SLE     

Angiogenin and SDF-1α serum concentration in patients with systemic sclerosis in relation to clinical status

Introduction

Systemic sclerosis (SSc) is a connective tissue disorder characterized by tissue hypoxia due to vascular changes and excessive fibrosis of the skin and internal organs. Damage to blood vessels and endothelium, as well as imbalance of vascular homeostasis, impairment of angiogenesis and vasculogenesis are observed in the course of the disease. The aim of the study was to investigate the pro-angiogenic factors angiogenin and SDF-1α in patients with SSc.

Material and methods

Serum samples were collected from 50 patients with dSSc (diffuse SSc) and lSSc (limited SSc) and from 38 patients used as a healthy control group. We explored: 1) how the serum concentrations of SDF-1α and angiogenin differ in the investigated groups; 2) the correlation among chemokines in SSc and the duration of the disease, Raynaud’s phenomenon, sclerosis of the skin and TSS (total skin score).

Results

Patients with SSc showed statistically significantly higher serum angiogenin concentration and there was no correlation between duration of the disease and Raynaud’s phenomenon, skin sclerosis or TSS. There was also no difference or no correlation between serum level of SDF-1α and the investigated groups.

Conclusions

The increase in angiogenin concentration in the serum in patients with SSc may confirm endothelial damage caused by hypoxia and reduced vascular perfusion due to the course of SSc without contributing to compensatory revascularization.     

Pathological significance and regulatory mechanism of lymphotoxin β receptor overexpression in T cells of patients with systemic lupus erythematosus

Systemic lupus erythematosus (SLE) is a typical autoimmune disease. Lymphotoxin β receptor (LTβR) signaling plays an important role in autoimmune inflammations. LTβR-Ig fusion protein, LTβR blocking agent, has been used to treat SLE, while its mechanism remains to be fully elucidated. In this study, to investigate the expression of LTβR in the T cells of SLE patients and its roles in the pathogenesis of SLE, we isolated the peripheral blood T cells of SLE patients and normal controls to detect expression of LTβR by flow cytometry and RNA assay. T cells were also stimulated with LIGHT, a ligand of LTβR, and then detected for their LTβR expressions and apoptosis by flow cytometry. Also, their expressions of inflammatory factors and receptors were determined by RNA assay. The results showed that LTβR positive cells were 22.75%
6.98% in CD3+ cells of SLE patients, while there were almost no LTβR positive cells in CD3+ cells of normal persons. Moreover, LTβR expression was remarkably higher in CD3, CD4 and CD8 positive T cells of active SLE patients than non/low active patients (all P < 0.05), and positively correlated with increased Ig level, decreased complement level and renal damage. Moreover, the stimulation of SLE T cells with LIGHT promoted higher expression of LTβR, IL-23R and IL-17A, and apoptosis of T cells. In conclusion, we demonstrated a high expression of LTβR in the T cells of SLE patients which may be associated with pathogenesis of SLE.     

Cytometry by time of flight identifies distinct signatures in patients with systemic sclerosis,systemic lupus erythematosus and Sjögrens syndrome

Systemic sclerosis (SSc), systemic lupus erythematosus (SLE) and primary Sjögrens syndrome (pSS) are clinically distinct systemic autoimmune diseases (SADs) that share molecular pathways. We quantified the frequency of circulating immune-cells in 169 patients with these SADs and 44 healty controls (HC) using mass-cytometry and assessed the diagnostic value of these results. Alterations in the frequency of immune-cell subsets were present in all SADs compared to HC. Most alterations, including a decrease of CD56^hi NK-cells in SSc and IgM⁺ Bcells in pSS, were disease specific; only a reduced frequency of plasmacytoid dendritic cells was common between all SADs Strikingly, hierarchical clustering of SSc patients identified 4 clusters associated with different clinical phenotypes, and 9 of the 12 cell subset-alterations in SSc were also present during the preclinical-phase of the disease. Additionally, we found a strong association between the use of prednisone and alterations in B-cell subsets. Although differences in immune-cell frequencies between these SADs are apparent, the discriminative value thereof is too low for diagnostic purposes. Within each disease, mass cytometry analyses revealed distinct patterns between endophenotypes. Given the lack of tools enabling early diagnosis of SSc, our results justify further research into the value of cellular phenotyping as a diagnostic aid.     

Decreased serum paraoxonase 1 (PON1) activity: an additional risk factor for atherosclerotic heart disease in patients with PCOS?

BACKGROUND: Patients with polycystic ovary syndrome (PCOS) may have an increased risk for the development of hypertension and atherosclerotic heart disease (AHD), the pathophysiological mechanisms of which are not clear. Paraoxonase1 (PON1) is a high-density lipoprotein-associated enzyme that prevents oxidative modification of low-density lipoprotein. The aim of this study was to measure the serum levels of PON1 activity in patients with PCOS and to compare with those of regularly cycling controls. METHODS: Serum lipid parameters, malondialdehyde (MDA) levels and PON1 activity, were measured in PCOS patients (n = 23) and regularly cycling, age-, body mass index- and smoking status-matched controls (n = 23). All patients had normal glucose tolerance test as assessed by a 75 g oral glucose tolerance test. None of the patients had clinically evident hypertension or AHD. RESULTS: Apart from the mean serum PON1 activity, all parameters in the lipid profile including serum MDA levels were comparable between the two groups. There were no significant differences in respect to fasting glucose (4.64 +/- 0.5 versus 4.43 +/- 0.83 mmol/l) and fasting glucose insulin ratio (11.06 +/- 8.26 versus 11.49 +/- 4.90) among the two groups (P > 0.05). However, HOMA insulin resistance index was significantly higher in patients with PCOS compared with the controls (2.06 +/- 0.86 versus 1.51 +/- 0.49; P = 0.01). Also, mean serum PON1 activity was significantly lower in the PCOS group compared with the controls (151.2 +/- 90.8 versus 217.7 +/- 101.6, respectively; P = 0.027). CONCLUSIONS: Reduced serum PON1 activity might contribute to the increased susceptibility for the development of AHD in women with PCOS.     

Do biological agents improve health-related quality of life in patients with systemic lupus erythematosus? Results from a systematic search of the literature

Despite an unprecedented rise in the number of biological therapies developed for systemic lupus erythematosus (SLE) during the last decades, most randomised clinical trials (RCTs) have failed to reach their primary efficacy endpoint. These endpoints mainly constitute composite outcomes that encompass disease activity indices derived from clinician-reported and laboratory data and do not necessarily reflect the patient perspective, as symptoms that represent major concerns to patients, such as fatigue, are seldom part of the evaluation. To overcome this limitation, patient-reported outcomes (PROs) constitute useful tools for evaluating the effect of an intervention on facets that are particularly relevant for the patients. In the present review, we performed a systematic literature search aiming to examine the effect of biological therapies on SLE patients' health-related quality of life (HRQoL) and fatigue in RCT and real-life settings. We summarised results concerning 14 different biological agents, the majority of which targeting B cells or type I interferons, and discuss strategies that have been used to analyse HRQoL data, putting emphasis on minimal clinically important differences and the potential use of PROs as distinct targets in treat-to-target approaches. Lastly, we discuss differences between generic and disease-specific PRO measures and highlight the need of using a combination thereof aiming to capture the patient perspective in a comprehensive manner.     

Induction of tolerance to hepatitis B virus: can we ‘eat the disease’ and live with the virus?

Hepatitis B virus (HBV) is a major health problem, with over 300 million HBsAg carriers worldwide. The HBV itself is non-cytopathic, and it is widely accepted that the mechanism of hepatocellular injury is the host anti-viral immune response. Current treatments, including the newly developed therapeutic modalities, are either based on anti-viral drugs or focus on attempts to augment the anti-viral immune response. The results of these approaches have been largely disappointing. There is evidence, however, that subjects with a natural tolerance to HBV or a down-regulated immune response develop little or no liver injury, despite chronic viremia. Lately, it has been shown that it is possible to induce tolerance toward viruses by oral administration of major viral structural proteins. Here, we discuss the pathogenesis of HBV-mediated liver disease and approaches to down-regulate the immune response directed against liver cells by orally inducing tolerance toward the virus. We hypothesize that this acquired tolerance should turn chronic active hepatitis patients with deteriorating disease into ‘healthy’ virus carriers. The proposed new treatment strategy would redirect the focus from augmenting anti-viral immune response to inducing host tolerance towards the virus.     

Is an excretory urogram mandatory in patients with small to medium-sized renal and ureteric stones treated by extra corporeal shock wave lithotripsy?

Background  

An intravenous urogram (IVU) has traditionally been considered mandatory before treating renal and ureteric stones by extracorporeal shock wave lithotripsy (ESWL). This study was designed to see whether there is a difference in complications and the need for ancillary procedures in patients managed by ESWL for renal and ureteric calculi, according to preoperative imaging technique.     

Is serum uric acid a predictive factor of response to IFN‐treatment in patients with chronic hepatitis C infection?

Several factors, including metabolic profile, are predictive of response to standard antiviral therapy in patients with chronic hepatitis C. In a retrospective study, it was investigated whether uric acid, involved in metabolic syndrome, could be included. A total of 153 patients (56.2% males; mean age 45.7 +/- 11.3 years) treated with pegylated-interferon and ribavirin were included. Eighty-five were infected with hepatitis C virus (HCV) genotype 1 or 4 and 68 with genotype 2 or 3. Viral load was >1,000,000 IU/ml in 101, < or =1,000,000 IU/ml in 35 and unknown in 17 patients. Ishak fibrosis score was < or =4 in 81, >4 in 15 and unknown in 57 patients. Mean serum uric acid was 5.05 +/- 1.3 mg/dl. Sustained virological response (negative serum HCV-RNA 6 months after treatment cessation) was achieved in 102 patients (67%). In the final logistic model, serum uric acid level > or =5.8 mg/dl (OR = 0.46; 95% CI: 0.30-0.62), viral load (OR = 0.29; 95% CI: 0.09-0.92) and HCV genotype (OR = 0.23; 95% CI: 0.09-0.60) were identified as the most important factors independently influencing clinical outcome. The prognostic role of serum uric acid was confirmed on the sub-sample reporting Ishak fibrosis score (OR = 0.49; 95% CI: 0.28-0.85). Serum uric acid level > or =5.8 mg/dl is predictive of poor response to HCV treatment. Prospective studies are needed to clarify the issue.     

Is there an additional benefit from coronary revascularization in diabetic patients with acute coronary syndromes or stable angina who are already on optimal medical treatment?

Cardiovascular disease (CVD) is common in patients with diabetes mellitus (DM) and related clinical outcomes are worse compared with non-diabetics. The optimal treatment in diabetic patients with coronary heart disease (CHD) is currently not established. We searched MEDLINE (1975-2010) using the key terms diabetes mellitus, coronary heart disease, revascularization, coronary artery bypass, angioplasty, coronary intervention and medical treatment. Most studies comparing different revascularization procedures in patients with CHD favoured coronary artery bypass graft (CABG) surgery in patients with DM. However, most of this evidence comes from subgroup analyses. Recent evidence suggests that advanced percutaneous coronary intervention (PCI) techniques along with best medical treatment may be non-inferior and more cost-effective compared with CABG. Treatment of vascular risk factors is a key option in terms of improving CVD outcomes in diabetic patients with CHD. The choice between medical therapy and revascularization warrants further assessment.     

Helicobacter pylori infection and autoimmune diseases; Is there an association with systemic lupus erythematosus,rheumatoid arthritis,autoimmune atrophy gastritis and autoimmune pancreatitis? A systematic review and meta-analysis study

Autoimmune diseases are considered as one of the most important disorders of the immune system, in which the prolonged and chronic processes eliminate self-tolerance to the auto-antigens. The prevalence of autoimmune diseases has been increasing worldwide in the recent years. According to the literature, biological processes such as the host genome, epigenetic events, environmental condition, drug consumption, and infectious agents are the most important risk factors that make the host susceptible to the development of autoimmune diseases. In the recent years, the role of Helicobacter pylori in the induction of autoimmune diseases has attracted extensive attention. Via molecular mimicry, epitope spreading, bystander activation, polyclonal activation, dysregulation in immune response, and highly immune-dominant virulence, such as cagA, H. pylori causes tissue damage, polarity, and proliferation of the host cells leading to the modulation of host immune responses. Moreover, given the large population worldwide infected with H. pylori, it seems likely that the bacterium may develop into autoimmune diseases through dysregulation of the immune response. The frequency and relationship between H. pylori infection and systemic lupus erythematosus, rheumatoid arthritis, autoimmune atrophy gastritis, and autoimmune pancreatitis were evaluated using the data from 43 studies involving 5052 patients. According to statistical analysis it is probable that infection with more virulent strains of H. pylori (such as H. pylori cagA positive) can increase the risk of autoimmune diseases. In addition, it was shown that infection with H. pylori can prevent the development of atrophic gastritis by stimulating inflammation in the gastric antrum. However, future studies should confirm the validity of this study.     

Elevated immunoglobulin G antibodies to the proline-rich amino-terminal region of Epstein-Barr virus nuclear antigen-2 in sera from patients with systemic connective tissue diseases and from a subgroup of Sjögren's syndrome patients with pulmonary involvements

Associations of Epstein-Barr virus (EBV) and autoimmune diseases have been hypothesized. We have analysed IgG antibodies to EBV nuclear antigen (EBNA)-2 in sera from Japanese patients with autoimmune systemic connective tissue diseases (CTD), exemplified by systemic lupus erythematosus (SLE), primary Sjogren's syndrome (SS), rheumatoid arthritis (RA), systemic sclerosis (SSc) and secondary SS (classical CTDs complicated with SS). An enzyme-linked immunosorbent assay (ELISA) which uses glutathione-S-transferase polypeptides fused to EBV nuclear antigen (EBNA)-2 and EBNA-1 was developed. Ratios of IgG antibody reactivity to whole IgG concentrations of sera were calculated to normalize EBNA-2 and EBNA-1 antibody levels to the hypergammaglobulinaemia that occurs in CTD. The ELISA optical density OD(450) readings of IgG antibodies to both the amino-terminal aa 1-116 of EBNA-2 and carboxyl-terminal aa 451-641 of EBNA-1 were elevated significantly in patients with SLE, primary SS, RA, SSc and secondary SS when compared to EBNA-1. The OD readings were divided by serum IgG concentrations to normalize for the hypergammaglobulinaemia. The specific levels of IgG antibodies to the amino-terminal region of EBNA-2 were elevated in patients with SLE, primary SS or RA, as well as those with secondary SS complicated with SLE or RA. The EBNA-2 amino-terminal region contains a polyproline tract and a proline-rich sequence and has considerable amino acid sequence homology with many cellular proline-rich proteins. High ratios of EBNA-2 aa 1-116 to EBNA-1 aa 451-641 IgG antibody levels which probably suggest reactivation of EBV latent infection were associated significantly with pulmonary involvement in SS patients. These results are consistent with the hypothesis that the sequence similarity between the amino-terminal region of EBNA-2 and proline-rich cellular proteins is associated with pathogenesis in a subpopulation of CTD patients, possibly by the molecular mimicry-epitope shift mechanism.     

Interleukin (IL)‐10, IL‐1ra and IL‐12 profiles in active and quiescent systemic lupus erythematosus: could longitudinal studies reveal patient subgroups of differing pathology?

Several cytokines have been implicated individually in the pathogenesis of systemic lupus erythematosus (SLE) and some, including interleukin (IL)-10, IL-12 and IL-1ra are raised during flares of disease activity. Few studies have been directed at examining the interactions between these cytokines and how their combined profile relates to disease activity. We have examined serum levels of IL-10, IL-12 and IL-1ra in a cohort of SLE patients obtained from the Queen Elizabeth Hospital, Birmingham in cross-sectional and, in a smaller group, longitudinal analyses. In the cross-sectional study, there were significant correlations between levels of the three cytokines. There were also significant correlations between levels of each cytokine and measures of disease activity. IL-10 levels correlated with ESR, anti-dsDNA antibody titres and C3D, IL-12 levels with anti-dsDNA antibody titres and IL-1ra levels with ESR, anti-dsDNA antibody titres and C3D. IL-1ra levels also correlated with CRP. Circulating IL-10 and IL-1ra levels were higher in patients with SLE than in normal controls, although in this study group they did not reach significance. Circulating IL-12 levels were, however, significantly higher in SLE compared to controls. This was true both in patients with active disease and those sampled during a quiescent phase. These data add to the evidence that cytokines such as IL-10, IL-12 and IL-1ra are important in SLE pathogenesis. In a retrospective study of serial serum samples from seven patients, we found two patients whose cytokine profile was very different from the rest of the group. In most patients normalized IL-10, IL-12 and IL-1ra levels mirrored BILAG scores closely, but in these two patients, IL-10, IL-12 and IL-1ra levels did not fluctuate with disease activity. It is possible that there is a subgroup of SLE patients whose cytokine profile could be an important indicator of their pathology. In order to confirm this and determine the frequency of such patients this study needs to be repeated with a much larger subject group. The coexistence of patient groups with different patterns of cytokine activity might explain conflicting reports of associations of levels of particular cytokines with SLE. As the observed differences could reflect different aetiologies of SLE, this information could reveal valuable endophenotypes for genetic and functional studies of SLE and might, ultimately, inform therapeutic management.     

Brain α-endosulfine is manifold decreased in brains from patients with Alzheimer's disease: a tentative marker and drug target?

α-Endosulfine has the sulfonylurea-like ability to block ATP-sensitive potassium (K_ATP) channels, which can stimulate insulin secretion in β cell. Although the blockade of K_ATP channels has been reported to be involved in neurotransmitter release, the neurobiological role of α-endosulfine has not been studied yet. We examined the protein levels of α-endosulfine in frontal cortex and cerebellum from patients with Alzheimer's disease (AD). α-Endosulfine was extremely decreased in both regions of AD compared to controls. This could result in the continuous opening of K_ATP channels with subsequent decrease of neurotransmitter release and change of potassium fluxes. This study is of great significance for providing a neurobiological function of brain α-endosulfine and furthermore, α-endosulfine could serve as a useful marker for the diagnosis of AD and a target for drug treatment.