Bibliometric analysis of global research on air pollution and cardiovascular diseases: 2012-2022.

Background: The relationship between air pollution and cardiovascular diseases (CVDs) has garnered significant interest among researchers globally. This study employed bibliometric analysis to provide an overview of current research on the association between air pollution and CVDs, offering a comprehensive analysis of global research trends in this area. Methods: An exhaustive scrutiny of literature pertaining to the nexus between air pollution and CVDs from 2012 to 2022 was conducted through rigorous screening of the Web of Science Core Collection (WoSCC). Publications were exclusively considered in English. Subsequently, sophisticated analytical tools including CiteSpace 6.2.4R, Vosviewer 1.6.19, HistCite 2.1, Python 3.7.5, Microsoft Charticulator, and Bibliometrix Online Analysis Platform were deployed to delineate research trends in this domain. Results: The analysis of the dataset, comprising 1710 documents, unveiled a consistent escalation in scientific publications, peaking in 2022 with a total of 248 publications. Moreover, Environmental Science and Toxicology stood out as the predominant categories. Examination of keyword frequency highlighted the terms 'air pollution', 'cardiovascular disease', and 'particulate matter' as the most prevalent. Notably, the most prolific entities, in terms of authors, journals, organizations, and countries, were identified as Robert D. Brook, Environmental Health Perspectives, Harvard University, and the United States, respectively. Conclusion: The findings presented a notable increase in high-quality publications on this topic over the past 11 years, suggesting a positive outlook for future research. The study concluded with an examination of three key themes in research trends related to air pollution and CVDs: the initial physiological response to pollutant exposure, the pathways through which pollutants are transmitted, and the subsequent effects on target organs. Additionally, various air pollutants, such as particulate matter, nitric dioxide, and ozone, could contribute to multiple CVDs, including coronary heart disease, hypertension, and heart failure. Although some hypotheses have been put forward, the mechanisms of air pollution-related CVDs still need to be explored in the future.

A novel approach with tofacitinib for the management of keratoderma blennorrhagicum in reactive arthritis: a case report.

Reactive arthritis(ReA), a form of arthritis occurring post-infection, manifests with antecedent infection symptoms, arthritis, and extra-articular manifestations, categorizing it as spondyloarthritis. "Keratoderma blennorrhagicum" (characterized by pustular hyperkeratosis on palms and soles, resembling pustular psoriasis) represents the most typical skin manifestation of ReA, occurring in acute or chronic phases. Severe lesions necessitate systemic disease modifying anti-rheumatic drugs (DMARDs) or biologic therapies. This article reports a case of ReA with sacroiliitis and widespread pustular eruptions following a urinary tract infection. Treatment with sulfasalazine and thalidomide significantly improved sacroiliitis, but the skin rash remained persistent and recurring. Subsequent use of adalimumab and secukinumab resulted in worsening skin rash, prompting a switch to tofacitinib, leading to a remarkable improvement in pustular eruptions after 20 days of treatment. This case demonstrates successful application of tofacitinib in treating severe keratoderma blennorrhagicum refractory to conventional DMARDs and biologics, offering insights into JAK inhibition for challenging rheumatic diseases with skin involvement.

MICROVASCULATURE ALTERATIONS OF PERIPAPILLARY RETINA AND MACULA IN SYSTEMIC LUPUS ERYTHEMATOSUS PATIENTS WITHOUT OCULAR INVOLVEMENT BY OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY.

PURPOSE: To evaluate microvasculature alterations of the peripapillary retina and macula and to assess whether the changes can detect preclinical retinopathy in systemic lupus erythematosus patients. METHODS: Cross-sectional study of 32 systemic lupus erythematosus patients without retinopathy and 22 normal controls. Optical coherence tomography angiography was used to measure the microvasculature of the peripapillary retina and macula. Vessel densities (VD, %) and fractal dimensions of superficial capillary plexus (SCP) and deep capillary plexus were calculated. RESULTS: Compared with controls, macular vessel densities of the whole image SCP (macular vessel density of SCP-wi) and macular vessel density of inferior SCP (macular vessel density of SCP-i) were significantly reduced in systemic lupus erythematosus patients ( P < 0.05). The peripapillary vessel densities (peripapillary vessel density [pVD]) of a 2.5-mm circle of SCP (pVD of SCP Φ2.5 ), pVD of SCP Φ3.5 , and pVD of inferior region of the inner circle of SCP (pVD of SCP-ii) were significantly reduced in patients treated with hydroxychloroquine >5 years. Macular vessel density of SCP-wi declined with age (ß = -0.12; P < 0.01) and pVD of SCP-ii declined with hydroxychloroquine cumulative dose (ß = -0.01; P < 0.01). Macular vessel density of SCP-i had the best discrimination power of 0.77 ( P < 0.01). CONCLUSION: Systemic lupus erythematosus patients without ocular involvement had microvasculature alterations that were particularly evident in the SCP. Peripapillary retina microvasculature may be reduced in patients with longer hydroxychloroquine treatment.

Association Between Wait Time of Central Venous Pressure Measurement and Outcomes in Critical Patients With Acute Kidney Injury: A Retrospective Cohort Study.

Background: Hemodynamic management is of paramount importance in patients with acute kidney injury (AKI). Central venous pressure (CVP) has been used to assess volume status. We intended to identify the optimal time window in which to obtain CVP to avoid the incidence of adverse outcomes in patients with AKI. Methods: The study was based on the Medical Information Mart for Intensive Care (MIMIC) IV database. The primary outcome was in-hospital mortality. Secondary outcomes included the number of ICU-free days and norepinephrine-free days at 28 days after ICU admission, and total fluid input and fluid balance during the first and second day. A time-dose-response relationship between wait time of CVP measurement and in-hospital mortality was implemented to find an inflection point for grouping, followed by propensity-score matching (PSM), which was used to compare the outcomes between the two groups. Results: Twenty Nine Thousand and Three Hundred Thirty Six patients with AKI were enrolled, and the risk of in-hospital mortality increased when the CVP acquisition time was >9 h in the Cox proportional hazards regression model. Compared with 8,071 patients (27.5%) who underwent CVP measurement within 9 h and were assigned to the early group, 21,265 patients (72.5%) who delayed or did not monitor CVP had a significantly higher in-hospital mortality in univariate and multivariate Cox regression analyses. After adjusting for potential confounders by PSM and adjusting for propensity score, pairwise algorithmic, overlap weight, and doubly robust analysis, the results were still stable. The HRs were 0.58-0.72, all p < 0.001. E-value analysis suggested robustness to unmeasured confounding. Conclusions: Among adults with AKI in ICU, increased CVP wait time was associated with a greater risk of in-hospital mortality. In addition, early CVP monitoring perhaps contributed to shortening the length of ICU stays and days of norepinephrine use, as well as better fluid management.

A Multicenter Study of Viral Aetiology of Community-Acquired Pneumonia in Hospitalized Children in Chinese Mainland.

Community-acquired pneumonia (CAP) is one of the leading causes of morbidity and mortality in children worldwide. In this study, we aimed to describe the aetiology of viral infection of pediatric CAP in Chinese mainland. During November 2014 to June 2016, the prospective study was conducted in 13 hospitals. The hospitalized children under 18 years old who met the criteria for CAP were enrolled. The throat swabs or nasopharyngeal aspirates (NPAs) were collected which were then screened 18 respiratory viruses using multiplex PCR assay. Viral pathogens were present in 56.6% (1539/2721) of the enrolled cases, with the detection rate of single virus in 39.8% of the cases and multiple viruses in 16.8% of the cases. The most frequently detected virus was respiratory syncytial virus (RSV) (15.2%, 414/2721). The highest detection rate of virus was in < 6-month-age group (70.7%, 292/413). RSV, human metapneumovirus (HMPV), human parainfluenza viruses (HPIVs) and influenza B virus (Flu B) showed the similar prevalence patterns both in north and south China, but HPIVs, Flu A, human bocavirus (HBoV), human adenovirus (HAdV) and human coronaviruses (HCoVs) showed the distinct circulating patterns in north and south China. Human enterovirus/human rhinovirus (HEV/HRV) (27.6%, 27/98), HBoV (18.4%, 18/98), RSV (16.3%, 16/98) and HMPV (14.3%, 14/98) were the most commonly detected viruses in severe pneumonia cases with single virus infection. In conclusion, viral pathogens are frequently detected in pediatric CAP cases and may therefore play a vital role in the aetiology of CAP. RSV was the most important virus in hospitalized children with CAP in Chinese mainland.

SGK1 enhances Th9 cell differentiation and airway inflammation through NF-κB signaling pathway in asthma.

This study aimed to explore the effect of Sgk1 on Th9 differentiation and the underlying mechanism in asthma. The asthmatic mouse model induced by ovalbumin (OVA) and CD4+T cells which were cultured with TGF-ß, IL-2, IL-4, and anti-IFN-γ were applied in vivo and in vitro, respectively. Flow cytometry, quantitative real-time PCR (qRT-PCR), and ELISA were performed to detect T-helper 9 (Th9) cells, IL-9 expression, and IL-9 release. Western blot was performed to examine phosphorylated(p)-IKKα, p-IκBα, p-p65, and IRF4 levels. Hematoxylin/eosin (H&E) staining was adopted to assess pathological changes of lung tissues. Inhibition of Sgk1 dramatically reversed elevated Th9 cells and IL-9 expression in the lung tissues of asthmatic mice. In vitro, Sgk1 promoted Th9 differentiation and elevated p-IKKα, p-IκBα, p-p65, and IRF4 levels, but inhibition of IKKα/IκBα/p65 pathway and IRF4 both reversed enhanced Th9 differentiation by Sgk1. Sgk1→IKKα/IκBα/NF-κBp65→IRF4→Th9 axis may be implicated in asthma development.

Serine/threonine phosphatase PP2A is essential for optimal B cell function.

Protein phosphatase 2A (PP2A), a serine/threonine phosphatase, has been shown to control T cell function. We found that in vitro-activated B cells and B cells from various lupus-prone mice and patients with systemic lupus erythematosus display increased PP2A activity. To understand the contribution of PP2A to B cell function, we generated a Cd19CrePpp2r1afl/fl (flox/flox) mouse which lacks functional PP2A only in B cells. Flox/flox mice displayed reduced spontaneous germinal center formation and decreased responses to T cell-dependent and T-independent antigens, while their B cells responded poorly in vitro to stimulation with an anti-CD40 antibody or CpG in the presence of IL-4. Transcriptome and metabolome studies revealed altered nicotinamide adenine dinucleotide (NAD) and purine/pyrimidine metabolism and increased expression of purine nucleoside phosphorylase in PP2A-deficient B cells. Our results demonstrate that PP2A is required for optimal B cell function and may contribute to increased B cell activity in systemic autoimmunity.

Diagnosis of nonexophytic nasopharyngeal lesion with endoscopy-guided core needle biopsy after narrow band imaging.

BACKGROUND: Due to the obstruction of the surrounding structures or stiff mucosa, the primary and recurrent nonexophytic nasopharyngeal carcinoma (NE-NPC) patients are difficult to be diagnosed histologically by traditional forceps biopsy. RESULTS: All the 15 cases had adequate biopsy for histological diagnosis. There were 5 cases of primary and 7 cases of recurrent NE-NPC, and 3 cases of inflammatory lesion. The histopathological diagnosis was consistent with the follow-up visit. The bleeding quantity during the CNB procedure ranged from 1 to 5 ml (mean 1.93 mL). The pain score during CNB were between 2 and 7 (mean 4.20). There were no serious complications. MATERIALS AND METHODS: From April 2009 to March 2016, after conventional white-light and novel narrow-band imaging, nasal endoscope-guided core needle biopsy (CNB) were performed on 15 cases of nonexophytic nasopharyngeal lesion with a semiautomatic biopsy gun. CONCLUSIONS: CNB is able to get adequate biopsy specimens and thus the diagnosis accuracy of CNB is high for NE-NPC. Nasal endoscope-guided CNB is the direct approach with a short distance in the tissue before reaching the tumor. It has the advantages of minimal trauma, short operative time, and no serious complications. It is simple, safe, and worth of application in clinic.

IL-33 and soluble ST2 levels as novel predictors for remission and progression of carotid plaque in early rheumatoid arthritis: A prospective study.

OBJECTIVES: To study the association between the baseline IL-33 and soluble ST2 (sST2) levels with disease remission and progression of carotid atherosclerosis in early rheumatoid arthritis (ERA) patients. METHODS: A total of 98 ERA patients were enrolled. Disease activity and the presence of carotid plaque were evaluated at baseline and 12 months later. Plasma IL-33 and sST2 levels were determined using enzyme-linked immunosorbent assay kits. RESULTS: Baseline IL-33 and sST2 levels were associated with inflammatory markers and cardiovascular (CV) risk factors. Overall, 44(45%), 18(18%), and 21(21%) patients achieved remission based on 28-joint disease activity score (DAS28), Boolean, and simplified disease activity score (SDAI) criteria at 12 months, respectively. Patients with detectable IL-33 at baseline were less likely to achieve DAS28 (P = 0.010) and SDAI remission (P = 0.021), while a lower baseline sST2 level was able to predict DAS28, Boolean, and SDAI remission (P = 0.005, 0.001, and <0.001, respectively). Using multivariate analysis, a lower baseline sST2 level independently predict Boolean (OR = 0.789; P = 0.005) and SDAI remission (0.812; P = 0.008). Regarding carotid atherosclerosis, 9/98(9.2%) patients had plaque progression at 12 months. Baseline IL-33 was detectable in 8/9(89%) and 42/83(51%) of patients with and without plaque progression respectively (P = 0.029). Baseline detectable IL-33 was an independent predictor for plaque progression after adjusting for traditional CV risk factors (P = 0.017). CONCLUSIONS: Lower baseline sST2 levels independently predict disease remission and baseline detectable IL-33 independently predicts carotid plaque progression in ERA patients. This study suggests that inflammation induced by the IL-33/ST2 axis may play a significant role in the development of cardiovascular disease in RA.

Effect of bifidobacterium on defensin-5 expression in intestinal injury of preweaning rats.

AIM: To investigate the protective effect of bifidobacterium in endotoxin-induced intestinal injury in preweaning rats. METHODS: Preweaning rats were randomly divided into three groups (n = 40 for each): a control group (group C), a model group (group E) and a treatment group (group T). Both groups E and T were intraperitoneally injected with lipopolysaccharide (LPS) at a dose of 5 mg/kg (5 mg/L in normal saline), and group T was intragastrically administrated with bifidobacterium suspension (2.0 × 10(9) CFU/mL, 0.5 mL each time, twice a day, until the end of the experiment) 7 d before LPS administration. Group C was intraperitoneally injected with normal saline. After intraperitoneal injection and intragastric administration, the rats were placed back to the initial cage to receive breast feeding. The rats were killed at 2, 6, 12, 24 or 72 h, respectively, after endotoxin or physiological saline injection to collect serum and ileal tissue samples. Myeloperoxidase (MPO) contents in serum and ileum were detected at different times, and expression of ileal defensin-5 mRNA was evaluated by reverse transcription-polymerase chain reaction. RESULTS: Serum and ileal MPO contents in group E were significantly higher than those in group C (serum contents: 107.50 ± 17.70 vs 157.14 ± 24.67, P < 0.05; ileal contents: 1.03 ± 0.21 vs 1.57 ± 0.33, P < 0.05), which peaked at 12 h and 6 h, respectively. MPO contents in group T were significantly lower than those in group E (serum contents: 114.38 ± 24.56 vs 145.25 ± 23.62, P < 0.05; ileal contents: 1.25 ± 0.24 vs 1.57 ± 0.33, P < 0.05). The expression of defensin-5 mRNA in group E was significantly higher than that in group C (0.953 ± 0.238 vs 0.631 ± 0.146, P < 0.05), which peaked at 2 h, and then decreased gradually. The expression of defensin-5 mRNA in group T was significantly lower than that in group E (0.487 ± 0.149 vs 0.758 ± 0.160, P < 0.05) apparently in 24 h. The expression of defensin-5 mRNA at 2 h in group T was significantly higher than that in group C (0.824 ± 0.158 vs 0.631 ± 0.146, P < 0.05). CONCLUSION: MPO and defensin-5 mRNA increase in preweaning rats with LPS-induced intestinal injury. Bifidobacterium protects the gut by inhibiting MPO activity, not by increasing defensin-5 secretion.

[Correlation of diffusion tensor imaging between the cerebral cortex and speech discrimination in presbycusis].

OBJECTIVE: To investigate the relationship between pure-tone average (PTA), the fractional anisotropy (FA) of the auditory pathway, cognitive cortex and auditory cortex in presbycusis. METHOD: Twenty-five elderly subjects with presbycusis were participated in the study. PTA, speech discrimination abilities were evaluated in each subject. Diffusion tensor imaging (DTI) was applied to access the FA of the IC, the superior frontal gyrus and the Heschl's gyrus. Compare the difference between two sides of the values of FA in the three areas. Bivariate correlation analysis was performed to evaluate the effects of PTA and FA of the inferior colliculus (IC), the superior frontal gyrus and the Heschl's gyrus on speech discrimination abilities. RESULT: There were no significant differences between the left and right side of the inferior colliculus (P > 0.05). Higher FA values were recorded at the left side of the Heschl's gyrus and the superior frontal gyrus (P < 0.05). Both PTA and the FA of the superior frontal gyrus have a negative association with speech discrimination abilities (P < 0.01, P < 0.05), while the FA of the Heschl's gyrus has a positive association with speech discrimination abilities (P < 0.05). CONCLUSION: Our findings indicated that the speech discrimination abilities of the elderly is not only related to the peripheral auditory function, but also to the central auditory and cognitive function.

The alarmin functions of high-mobility group box-1 and IL-33 in the pathogenesis of systemic lupus erythematosus.

'Alarmins' are a group of endogenous proteins or molecules that are released from cells during cellular demise to alert the host innate immune system. Two of them, high-mobility group box-1 (HMGB1) and IL-33 shared many similarities of cellular localization, functions and involvement in various inflammatory diseases including systemic lupus erythematosus (SLE). The expressions of HMGB1 and IL-33, and their corresponding receptors RAGE (receptor for advanced glycation end products) and ST2, respectively, are substantially upregulated in patients with lupus nephritis (LN). This review highlights the emerging roles of alarmin proteins in various pathologies of LN, by focusing on classical HMGB1 and a newly discovered alarmin IL-33.

Serum soluble receptor for advanced glycation end products levels and aortic augmentation index in early rheumatoid arthritis--a prospective study.

OBJECTIVE: We assessed whether a serum soluble receptor for advanced glycation end product (sRAGE) levels were associated with a progression of carotid atherosclerosis and arterial stiffness indexes in a cohort of early rheumatoid arthritis (RA) patients. METHODS: RA patients with symptoms onset <2 years were recruited. Vascular assessments and serum sRAGE levels were measured at baseline and 1 year later. Arterial stiffness was determined by pulse wave velocity and aortic augmentation index (AIx). Carotid intima-media thickness was measured using high-resolution ultrasound. RESULTS: Ninety-four patients completed the 1-year study. Fifty-three (56.4%) achieved disease remission [28-joint disease activity score (DAS28 < 2.6)] at 12 months. Improvement in arterial stiffness was observed as reflected by the significant reductions in AIx and pulse wave velocity. At 12 months, the sRAGE levels increased significantly compared with baseline (939.8 ± 517.7 pg/ml to 1272.1 ± 567.3 pg/ml, P < 0.001). Changes in sRAGE levels were significantly higher in men compared to women (768 ± 510 pg/ml versus 271 ± 490 pg/ml, P < 0.05) and was negatively associated with the change in AIx (r = -0.259, P = 0.023). Changes in sRAGE level were not associated with other demographic, clinical, cardiovascular risk factors or treatment. Using multivariate analysis, the change in sRAGE levels and baseline high-density lipoprotein were independent predictors associated with the change in AIx. CONCLUSIONS: Arterial stiffness improved significantly in patients with early RA after effective control of inflammation. Increase in sRAGE level was associated with a decrease in AIx, suggesting that sRAGE may play an important role in the ligand-soluble receptor for advanced glycation end product interaction propagated inflammation and vascular stiffness in these patients.

Infliximab is associated with improvement in arterial stiffness in patients with early rheumatoid arthritis -- a randomized trial.

OBJECTIVE: To determine the efficacy of methotrexate (MTX) with infliximab (IFX) compared with MTX alone in the prevention of atherosclerosis and arterial stiffness in patients with early rheumatoid arthritis (RA). METHODS: A randomized, open-label study in which early RA patients with active disease were treated with MTX alone (n = 20) and MTX plus IFX (n = 20) for 6 months. Patients were assessed every 3 months. Patients from the MTX-alone group who failed to achieve 28-joint Disease Activity Score remission (DAS28 ≤ 2.6) at 6 months were permitted to escape to open-label IFX. Intima-media thickness (IMT), pulse wave velocity (PWV), and augmentation index (AIx) were measured at baseline, 6 months, and 12 months. RESULTS: At 6 months, there was a significantly greater reduction in PWV in the MTX-alone group (0.18 ± 1.59 m/s) compared with the MTX plus IFX group (-0.78 ± 1.13 m/s; p = 0.044), accompanied by significantly greater reduction in patient's global assessment, number of swollen joints, C-reactive protein, and DAS28 in the MTX plus IFX group compared to the MTX-alone group. The changes in IMT and AIx were similar between the 2 groups. At 12 months, there was a trend favoring early combination treatment with regard to the reduction in PWV (p = 0.06). CONCLUSION: MTX plus IFX causes a more significant reduction in PWV than MTX alone in patients with early RA after 6-month treatment, and further improvement may be achieved in patients who continued on longterm tumor necrosis factor-α blockers, suggesting that early, effective suppression of inflammation may prevent progression of atherosclerosis by improving vascular function.

Antagonist-mediated down-regulation of Toll-like receptors increases the prevalence of human papillomavirus infection in systemic lupus erythematosus.

INTRODUCTION: Prevalence of an abnormal Papanicolaou smear was significantly increased in lupus patients in cross-sectional studies, associated with a higher prevalence of high-risk human papillomavirus (HPV) infection. The nucleic acid-specific Toll-like receptors (TLRs) locate at the endolysosomal compartments and trigger the induction of cytokines for the innate immune response. This study evaluated whether abnormal host innate immune response in lupus patients may enhance HPV persistence. METHODS: Protein levels of TLRs 3, 7, 8 and 9 in cervical epithelial cells of lupus patients and controls with or without HPV infection were assessed using flow cytometry. Characteristics associated with the differential expression of TLRs in systemic lupus erythematosus (SLE) were elucidated. The effect and interferon-stimulated genes (ISGs) (ISG15 and Mx-1) gene expressions were then measured in oncogenic HeLa (HPV18), CaSki (HPV) and C33A (HPV negative) cell lines using flow cytometry and quantitative real-time PCR. Ex vivo productions of cytokines and interferon-gamma (IFN-γ) upon TLR ligands stimulations were subsequently measured using cytometric bead array and ELISA. RESULTS: For subjects with HPV infection, levels of TLR3 and TLR7 were significantly lower in lupus patients compared with controls. Significantly decreased TLRs 7, 8 and 9 levels were observed in HPV-negative SLE compared to healthy controls. For SLE with and without HPV infection, TLR7 and 9 levels were significantly lower in infected SLE than those in HPV-negative patients. Independent explanatory variables associated with down-regulation of TLR7 level included HPV infection and a higher cumulative dose of prednisolone; while a higher cumulative dose of hydroxychloroquine and HPV infection were associated with down-regulation of TLR9 level. In cervical cell lines, TLRs 3, 7, 8, 9 protein levels and antiviral ISG15 and Mx-1 gene expressions were inhibited in two oncogenic HPV types. Functional data showed that the induction of pro-inflammatory cytokines by TLR ligands (R837, ssRNA and ODN2395) was greatly impaired in CaSki and HeLa than C33A cells. CONCLUSIONS: In conclusion, prednisolone and TLR antagonist (hydroxychloroquine) may down-regulate protein levels of TLR7 and TLR9 in lupus patients, thereby decreasing the innate immune response against HPV infection. Upon infection, HPV further down-regulate TLR7 and 9 levels for viral persistence. Furthermore, reduction of nucleic acid-sensing TLRs 7, 8 and 9 in carcinogenic HPVs ensures that the expression of inducible pro-inflammatory cytokines is minimized to prevent the expression of antiviral ISGs (ISG15 and Mx-1) on a biologically relevant antiviral response.

Immunopathological roles of cytokines, chemokines, signaling molecules, and pattern-recognition receptors in systemic lupus erythematosus.

Systemic lupus erythematosus (SLE) is an autoimmune disease with unknown etiology affecting more than one million individuals each year. It is characterized by B- and T-cell hyperactivity and by defects in the clearance of apoptotic cells and immune complexes. Understanding the complex process involved and the interaction between various cytokines, chemokines, signaling molecules, and pattern-recognition receptors (PRRs) in the immune pathways will provide valuable information on the development of novel therapeutic targets for treating SLE. In this paper, we review the immunopathological roles of novel cytokines, chemokines, signaling molecules, PRRs, and their interactions in immunoregulatory networks and suggest how their disturbances may implicate pathological conditions in SLE.

Down-regulated NOD2 by immunosuppressants in peripheral blood cells in patients with SLE reduces the muramyl dipeptide-induced IL-10 production.

BACKGROUND: Pattern recognition receptors (PRRs) such as Toll-like receptors are aberrantly expressed of peripheral blood mononuclear cells (PBMCs) in systemic lupus erythematosus (SLE) patients, for playing immunopathological roles. METHODOLOGY/PRINCIPAL FINDINGS: We investigated the expression and function of the PRR nucleotide-binding oligomerization domain (NOD2) in SLE. NOD2 expression in T, B lymphocytes, monocytes, myeloid dendritic cells (mDCs) and plasmacytoid dendritic cells (pDCs) was assessed in SLE patients and healthy controls (HCs) using flow cytometric analysis. Ex vivo production of cytokines from PBMCs upon NOD2 agonist muramyl dipeptide (MDP) stimulation was assessed using Cytometric Bead Array. Over-expression of NOD2 in monocytes was observed in immunosuppressant naïve SLE patients, and was positively associated with longer disease duration. Immunosuppressive therapy was an independent explanatory variable for downregulating NOD2 expression in CD8+ T, monocytes, mDCs and pDCs. Ex vivo basal productions of cytokines (IL-6, IL-8 and IL-10) were significantly increased in immunosuppressant naïve patients and patients with active disease despite immunosuppressants compared with HCs. Upon MDP stimulaiton, relative induction (%) of cytokines (IL-1ß) from PBMC was significantly increased in immunosuppressant naïve patients with inactive disease, and patients with active disease despite immunosuppressant treatment compared with HCs. Immunosuppressant usage was associated with a decreased basal production and MDP induced relative induction (%) of IL-10 in patients with inactive disease compared with immunosuppressant naïve patients and HCs. CONCLUSIONS/SIGNIFICANCE: Bacterial exposure may increase the NOD2 expression in monocytes in immunosuppressant naïve SLE patients which can subsequently lead to aberrant activation of PBMCs to produce proinflammatory cytokines, implicating the innate immune response for extracellular pathogens in the immunopathological mechanisms in SLE. Immunosuppressant therapy may downregulate NOD2 expression in CD8+ T lymphocytes, monocytes, and DCs in SLE patients which subsequently IL-10 reduction, contributing towards the regulation of immunopathological mechanisms of SLE, at the expense of increasing risk of bacterial infection.