C-X-C Motif Chemokine Ligand 16 Is a Potent Predictor of Outcomes in Dialysis Patients

INTRODUCTION

C-X-C motif chemokine ligand 16 (CXCL16) is an inflammatory marker that has been found to be predictive of outcomes in patients with cardiovascular disease. Our previous work has also demonstrated its relation to cardiac injury in dialysis patients. However, it is yet unclear whether there is an association between CXCL16 and adverse outcomes in dialysis patients. We aimed to evaluate its prognostic value along with several traditional inflammatory markers in the current study.

METHODS

This is a multicenter longitudinal study of prevalent dialysis patients. Circulating inflammatory markers including CXCL16, C-reactive protein (CRP), tumor necrosis factor-α, and interleukin-6 (IL-6) were measured using a multiplex assay. The primary outcomes were all-cause mortality and a composite of major adverse cardiovascular events (MACEs). The associations between biomarkers and outcomes were analyzed using Cox proportional hazards regression models.

RESULTS

Of the 366 participants with available plasma samples, the average age was 52.5 (±12.1) years, and there were 160 (43.7%) female participants. For all-cause mortality, logarithmically transformed CXCL16, IL-6, and CRP were independent predictors after adjustment for covariates. When the 3 markers were included in the same model, CXCL16 was the only one remaining its significance. For MACEs, logarithmically transformed CXCL16 and IL-6 were significant predictors when analyzed separately and CXCL16 was an independent predictor even after adjustment for IL-6. When the biomarkers were analyzed as categorical variables, only CXCL16 was associated with both outcomes. Adding CXCL16 to established risk factors improved risk prediction as revealed by Net Reclassification Index (NRI).

CONCLUSION

Using a multimarker approach, we determined that CXCL16 is a potent predictor of all-cause mortality and cardiovascular events in dialysis patients. Our data suggest CXCL16 may improve risk stratification and could be a potential interventional target.

Heightened Levels of Antimicrobial Response Factors in Patients With Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic progressive autoimmune disease leading to considerable disability over time. The disease can be characterized by the presence of multiple autoantibodies in the serum and synovial fluid. Microbial dysbiosis is proposed to play a role in the pathogenesis of RA. Increased systemic bacterial exposure leads to elevated levels of antimicrobial response factors (ARFs) in the circulation. In the present study, we tested whether RA patients have increased levels of ARFs by analyzing the levels of multiple ARFs in serum from RA patients and healthy age and sex-matched controls. The levels of soluble CD14 (sCD14), lysozyme, and CXCL16 were significantly elevated in RA patients compared to healthy controls. Lipopolysaccharide binding protein (LBP) levels remained unchanged in RA patients compared to healthy controls. A positive correlation of LBP with rheumatoid factor (RF) was also found in RA subjects. Interestingly, the levels of anti-endotoxin core antibodies (EndoCAb) IgM, total IgM, EndoCAb IgA, and total IgA were significantly elevated in RA patients compared to healthy controls. No significant changes in the levels of EndoCAb IgG and total IgG were observed in RA patients compared to healthy controls. Furthermore, lysozyme and CXCL16 levels were positively correlated with disease severity among RA subjects. Increases in the levels of several ARFs and their correlations with clinical indices suggest systemic microbial exposure in the RA cohort. Modulation of microbial exposure may play an important role in disease pathogenesis in individuals with RA.

CXC Motif Ligand 16 Promotes Nonalcoholic Fatty Liver Disease Progression via Hepatocyte-Stellate Cell Crosstalk

CONTEXT

Nonalcoholic fatty liver disease (NAFLD) is a focus of attention because of its prevalence. CXC motif ligand 16 (CXCL16) has been studied in inflammatory and metabolic diseases.

OBJECTIVE

To investigate the role of CXCL16 in steatosis and fibrosis in patients with NAFLD.

DESIGN

Liver specimens and sera of patients with NAFLD were collected from 2012 to 2017.

SETTING

Beijing 302 Hospital.

PARTICIPANTS

117 patients with NAFLD and 15 healthy controls.

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

The main outcome measures were CXCL16 levels in sera and biopsy specimens of patients with NAFLD.

RESULTS

CXCL16 serum level was markedly elevated in patients with NAFLD, especially in those at the S3 steatosis level according to the steatosis, activity, and fibrosis (SAF) scoring system. The different serum levels of CXCL16 between groups were due to data in patients with A or F scores ≥2, according to the SAF scoring system. CXCL16 accumulated around steatotic hepatocytes in biopsy specimens. In vitro, CXCL16 treatment led to severe steatosis of hepatocytes in the hepatocyte-stellate cell coculture system and suppressed the respiration rate of hepatocytes. Lipogenic gene expression and hepatic stellate cell activation indexes were increased in a CXCL16 overexpression system. In addition, ligands in the Hedgehog pathway cascade were downregulated in hepatocytes.

CONCLUSIONS

CXCL16 was highly expressed in patients with NAFLD, suggesting that it may contribute to steatotic and fibrotic progression. CXCL16 may be a potential noninvasive marker of NAFLD and a future potential therapeutic target to treat NAFLD.

Decreased Systemic Levels of Endocan-1 and CXCL16 in Psoriasis Are Restored following Narrowband UVB Treatment

BACKGROUND

In psoriasis, a common immune-mediated disease affecting 2-3% of the population worldwide, there is an increased prevalence of extracutaneous diseases including obesity, the metabolic syndrome, and cardiovascular disease. This is believed to be linked to systemic inflammation. In previous studies, we have explored various markers in plasma and serum to characterize the ongoing systemic inflammation in psoriasis patients compared to controls. We have identified several markers that were altered in psoriasis patients, but which all were unresponsive to narrowband UVB (NB-UVB) treatment.

OBJECTIVE

The objective of the study was to evaluate the effect of NB-UVB treatment on markers of cardiovascular risk and systemic inflammation in psoriasis.

METHODS

The levels of 17 potential biomarkers with an association with cardiovascular risk were quantitated in plasma from 37 age- and gender-matched psoriasis patients and controls at baseline and in 21 psoriasis patients after 12 weeks of NB-UVB treatment to identify a systemic treatment response.

RESULTS

We identified the mediators endocan-1, CXCL16, and sVEGFR1, which were systemically decreased in psoriasis at baseline, as well as FABP3, FABP4, and sIL-1R1, which showed normal baseline levels. After 10-12 weeks of NB-UVB treatment, endocan-1 and CXCL16 were restored to normal levels, while sVEGFR1, FABP3, FABP4, and sIL-1R1 showed a significant reduction.

CONCLUSION

The current study expands the number of potential biomarkers in psoriasis by including a greater number and variety of mediators, approaching the systemic inflammation from additional vantage points, including soluble immune receptors and adipocyte contribution, to provide a more complete picture of the systemic inflammatory state in psoriasis.

CXC chemokine ligand 16 is increased in gestational diabetes mellitus and preeclampsia and associated with lipoproteins in gestational diabetes mellitus at 5 years follow-up

BACKGROUND

Women with a history of gestational diabetes mellitus and preeclampsia are at increased risk of cardiovascular disease later in life, but the mechanism remains unclear. The aim of the study was to evaluate the association between CXC chemokine ligand 16 and indices of glucose metabolism, dyslipidemia and systemic inflammation in gestational diabetes mellitus and preeclampsia.

METHODS

This sub-study of the population-based prospective cohort included 310 women. Oral glucose tolerance test was performed during pregnancy and 5 years later along with lipid analysis. CXC chemokine ligand 16 was measured in plasma (protein) and peripheral blood mononuclear cells (messenger RNA) during pregnancy and at follow-up.

RESULTS

Circulating CXC chemokine ligand 16 was higher in gestational diabetes mellitus women early in pregnancy and at follow-up, while higher in preeclampsia women late in pregnancy compared to control women. Messenger RNA of CXC chemokine ligand 16 in peripheral blood mononuclear cells were lower in gestational diabetes mellitus and preeclampsia women compared to control women. Increased circulating CXC chemokine ligand 16 level was associated with a higher apolipoprotein B and low-density lipoprotein cholesterol in gestational diabetes mellitus women but not in normal pregnancy at follow-up.

CONCLUSION

Our study shows that women with gestational diabetes mellitus and preeclampsia had a dysregulated CXC chemokine ligand 16 during pregnancy, and in gestational diabetes mellitus, the increase in CXC chemokine ligand 16 early in pregnancy and after 5 years was strongly associated with their lipid profile.

The relationship between serum CXCL16 level and carotid vulnerable plaque in patients with ischemic stroke

OBJECTIVE

We investigated the relationship between the serum macrophage chemokine ligand 16 (CXCL16) levels and the vulnerable carotid plaque in patients with ischemic stroke.

PATIENTS AND METHODS

We successively selected 118 cases of patients with an initial diagnosis of acute ischemic stroke (time of onset < 72 h), recorded risk factors, including gender, age, family history, smoking, body mass index, blood glucose levels, blood lipid levels, average systolic pressure and diastolic blood pressure (DBP) and homocysteine levels. ELISA was used to detect the levels of serum CXCL16. GE-3000 color Doppler ultrasound diagnostic instrument was applied for the detection of the cervical artery (including a bilateral common carotid artery, internal carotid artery and external carotid artery) intima-media thickness (IMT), plaque number, size, nature (stable and vulnerable) and luminal stenosis rate. Delica EMS-9EBx2P type transcranial Doppler ultrasound (TCD) was used to detect micro-arterial micro-embolic signals (MES). Stroke, according to etiologic type, was divided into large artery atherosclerosis (LAA), small artery occlusion (SAA) and others.

RESULTS

Serum CXCL16 levels were not significantly correlated with sex, age, family history, smoking, BMI, blood glucose levels, blood lipid levels, mean systolic blood pressure, diastolic blood pressure, and homocysteine levels. Serum CXCL16 levels increased with an increase of IMT, plaque area and lumen stenosis rate. Serum CXCL16 levels of vulnerable plaques were significantly higher than those of stable plaques; differences were statistically significant (p<0.05). It has nothing to do with the number of atherosclerotic plaques. The levels of serum CXCL16 in MES positive group were significantly higher than that in MES negative group; differences were statistically significant (p<0.05). The serum CXCL16 levels of LAA patients were significantly higher than that of SAA and other types of patients; differences were statistically significant (p<0.05).

CONCLUSIONS

The levels of serum CXCL16 are not related to high-risk factors for acute stroke and closely related to characteristics of atherosclerotic plaque, micro-embolic signals and stroke subtypes.

Interaction of Soluble CXC Ligand 16 and Cardiac Injury Markers in Hemodialysis Patients

BACKGROUND

Recent data suggest that there is a pathogenic role for CXC ligand 16 (CXCL16) in cardiovascular diseases. Little is known about circulating CXCL16 in patients with kidney dysfunction. We explored the relationships of plasma CXCL16 with cardiac injury markers in a group of dialysis patients.

METHODS

Plasma CXCL16 and C-reactive protein (CRP) were measured in 366 patients who were on maintenance hemodialysis. Cardiac injury was evaluated via measurements of the circulating B-type natriuretic peptide (BNP), N-terminal prohormone of brain natriuretic peptide (NT proBNP), Troponin I (TnI), and Troponin T (TnT). Sixty healthy subjects who were frequency matched with the patients on the basis of age and gender were recruited as healthy controls.

RESULTS

The mean age of the patients was 52.5 ± 12.1 years and 56.3% were male. Circulating CXCL16 was significantly higher in the patients than in the controls (patients vs.

CONTROLS

477.3 (367.0-647.1) pg/mL vs. 229.5 (203.8-254.5) pg/mL; p < 0.001). The log-transformed (log-) CXCL16 level was correlated with all 4 cardiac markers (log-BNP, log-NTproBNP, log-TnI, and log-TnT) with high levels of significance (all p < 0.001), even after extensive controls for the covariates. In contrast, CRP was correlated only with BNP (marginally) and NT proBNP and was not correlated with troponins.

CONCLUSION

We showed, for the first time, highly significant relationships of circulating CXCL16 level with cardiac injury markers in dialysis patients. Our data suggest that circulating CXCL16 is possibly involved in the pathological process of cardiovascular damage in dialysis patients and may serve as a therapeutic target for cardiac protection in these patients.