Serum cystatin C and emphysema: results from the National Health and Nutrition Examination Survey (NHANES)

The Causal Relationship Between Gut and Skin Microbiota and Chronic Obstructive Pulmonary Disease:A Bidirectional Two-Sample Mendelian Randomization Analysis

Background

Recently, numerous studies have explored the potential impact of gut microbiota on Chronic Obstructive Pulmonary Disease (COPD). However, the causal relationship between skin microbiota and COPD, as well as the differences and similarities between the relationships of gut microbiota and COPD, has not been thoroughly studied.

Methods

We conducted a comprehensive two-sample Mendelian randomization (MR) analysis to investigate the relationships between gut and skin microbiota and COPD. The inverse variance weighted (IVW) method was used as the primary approach. MR-Egger, weighted median, and MR-PRESSO methods were used as supplementary approaches. Various sensitivity and stability analyses were conducted to validate the results. Genetic variations of gut microbiota were obtained from the FR02 cohort study. Genetic variations of skin microbiota were derived from the KORA FF4 and PopGen cohorts, with a total of 1,656 skin samples. GWAS data for COPD were obtained from the FinnGen consortium, including 18,266 COPD cases and 311,286 controls from European cohorts.

Results

The results of IVW method of MR analysis showed that 10 gut microbiotas and 4 skin microbiotas were negatively associated with COPD [p < 0.05, odds ratio (OR) < 1]; 3 gut microbiotas and 6 skin microbiotas were positively associated with COPD (p < 0.05, OR > 1). None of them were heterogeneous or horizontally pleiotropic (p > 0.05) or reverse causality.

Conclusion

This study revealed the causal relationships between gut and skin microbiota and COPD, offering fresh perspectives for the prevention, diagnosis, and management of COPD.

Association between Serum Cys C and PTB Cavitation

Background

Cystatin C (Cys C) not only regulates the body's immune defenses but also contributes to tissue degradation and destruction by causing an imbalance between protease and antiprotease in infectious diseases. Is Cys C involved in pulmonary tuberculosis (PTB) infection and cavitation? We therefore conducted a retrospective study on this question to provide a basis for further studies.

Methods

Cavitary PTB patients, noncavitary PTB patients, and healthy controls were recruited in our study. Serum Cys C, CRP, BUN, UA, and CR were measured in all subjects, and the Kruskal-Wallis test was used to compare medians of these clinical parameters in different groups. The Spearman rank correlation test was used to determine correlations between variables. In addition, a multivariate analysis using binary logistic regression was used to identify factors associated with PTB cavitation.

Results

In our study, elevated serum Cys C levels were found in cavitary PTB patients compared to healthy controls and noncavitary patients (p = 0.022). Serum Cys C levels were statistically correlated with serum BUN and CR concentrations (r = 0.278, p = 0.005; r = 0.281, p = 0.004) in PTB patients. The binary logistic regression analysis showed that elevated serum Cys C levels were correlated with pulmonary cavitation in PTB patients (OR = 1.426, 95% CI: 1.071-1.898).

Conclusion

Elevated serum levels of Cys C are associated with pulmonary cavitation in PTB patients.

Dynamic immune response characteristics of piglets infected with Actinobacillus pleuropneumoniae through omic

Porcine infectious pleuropneumonia is characterized by a high-rate of carriage and mixed infection with other pathogens. The host immune response induced by Actinobacillus pleuropneumoniae (APP) is the basis for elucidating pathogenesis and controlling disease. However, there is currently no comprehensive and dynamic data characterising the host immune response. In this study, piglets were infected with APP and differentially expressed proteins of bronchoalveolar lavage fluid (BALF) and peripheral serum were identified by iTRAQ-LC-MS/MS, and differentially expressed genes of peripheral blood mononuclear cells (PBMC) by RNA-seq. The results of the integrated analysis of serum, BALF and PBMC showed significant metabolism and local immune responses in BALF, the general immune response in PBMC mainly involves cytokines, while that in serum mainly involves biosynthesis, phagosome, and complement and coagulation cascades. Furthermore, immune responses in PBMCs and serum were rapid and maintained compared to the lung where metabolism and cell adhesion activities were enriched. Some innate immunity pathways of the cellular response to ROS, neutrophil mediated immunity, granulocyte activation and leukocyte cell-cell adhesion were identified as central points, connecting multiple signaling pathways to form an integrated large network. At 24 h post-infection, 14 molecules were up regulated in BALF, 10 of which were shared with PBMC, but at 120 h, 20 down-regulated molecules were identified in BALF, 11 of them still up- regulated in PBMC. We conclude that, the immune response in the lung is different from that in blood, but there is a similarity in response in PBMC and serum.

Correlation of serum cystatin C with inflammatory cytokines in patients with traumatic brain injury

Traumatic brain injury (TBI) is a world-wide leading health problem with high morbidity and mortality rates. Emerging studies have demonstrated that TBI is the consequence of a series of inflammatory responses in the body. The alteration of Cystatin C (Cys C) was reported in a variety of chronic inflammatory diseases and was also recommended as a biomarker for predicting renal diseases. In this study, we aimed to investigate the relationship between serum Cys C and TBI, and to evaluate the prognostic role of Cys C in TBI prediction. One hundred and seventy-six patients with TBI were recruited and 102 patients were finally analyzed, with 30 healthy control subjects. The concentrations of Cys C were significantly reduced in the healthy control group compared to the TBI group, and correlated with high GCS scores. The levels of hsCRP, counts of white blood cells, and levels of IL-6 and TNF-α were remarkably elevated in the TBI patients compared with the control group in a severity-dependent manner. Moreover, the concentration of Cys C was negatively correlated with TBI severity and positively correlated with inflammatory factors. In conclusion, serum Cys is an inflammatory cytokine-related factor and might indicate the severity of TBI thus serving as a prognostic biomarker.

Serum Cystatin C and Coronavirus Disease 2019: A Potential Inflammatory Biomarker in Predicting Critical Illness and Mortality for Adult Patients

This study aimed at determining the relationship between baseline cystatin C levels and coronavirus disease 2019 (COVID-19) and investigating the potential prognostic value of serum cystatin C in adult patients with COVID-19. 481 patients with COVID-19 were consecutively included in this study from January 2, 2020, and followed up to April 15, 2020. All clinical and laboratory data of COVID-19 patients with definite outcomes were reviewed. For every measure, COVID-19 patients were grouped into quartiles according to the baseline levels of serum cystatin C. The highest cystatin C level was significantly related to more severe inflammatory conditions, worse organ dysfunction, and worse outcomes among patients with COVID-19 (P values < 0.05). In the adjusted logistic regression analyses, the highest cystatin C level and ln-transformed cystatin C levels were independently associated with the risks of developing critically ill COVID-19 and all-cause death either in overall patients or in patients without chronic kidney disease (P values < 0.05). As a potential inflammatory marker, increasing baseline levels of serum cystatin C might independently predict adverse outcomes for COVID-19 patients. Serum cystatin C could be routinely monitored during hospitalization, which showed clinical importance in prognosticating for adult patients with COVID-19.

The association between cystatin C and COPD: a meta-analysis and systematic review

BACKGROUND

In recent years, many studies have discovered that cystatin C (Cys C) may play an important role in respiratory diseases, especially in chronic obstructive pulmonary disease (COPD). However, the findings of these studies were inconsistent. This systematic review and meta-analysis aimed to assess the relationship between serum Cys C and COPD.

METHODS

We conducted a systematic literature search in PubMed, Embase, Web of Science, Wanfang databases, and the China National Knowledge Infrastructure. The standardized mean difference (SMD), Fisher's Z-value and 95% confidence interval (CI) were calculated to investigate the effect sizes. Subgroup analyses were performed on disease status, ethnicity, assay method, and study design. Sensitivity was performed, and publication bias was assessed.

RESULTS

A total of 15 studies, including 4079 COPD patients and 5949 controls, were included in this meta-analysis. The results showed that serum Cys C levels in patients with COPD were significantly higher than those in controls (SMD = 0.99, 95% CI =0.62-1.37, P < 0.001), especially in AECOPD (SMD = 1.59, 95% CI =1.05-2.13, P < 0.001), and there were statistically different among AECOPD and SCOPD (SMD = 0.35, 95% CI =0.10-0.59, P = 0.005). The serum Cys C levels were negatively correlated with FEV1%pre (Z = - 0.45, 95%CI = -0.58--0.32, P = 0.011) and FEV1/FVC (Z = - 0.32, 95%CI = -0.50--0.14, P = 0.006). The serum Cys C levels were independent of ethnicity, assay method, and study design.

CONCLUSION

Serum Cys C levels were associated with COPD and COPD exacerbation, and they were inversely correlated with FEV1%pre and FEV1/FVC.

Serum Cystatin C Levels in COPD: Potential Diagnostic Value and Relation between Respiratory Functions

BACKGROUND

The aim of this study was to determine the level of serum cystatin C (CysC) in patients with Chronic Obstructive Pulmonary Disease (COPD) during exacerbation and stable periods and to investigate its potential diagnostic value and the relationship between CysC levels and the pulmonary function test (PFT).

METHODS

One hundred twenty-six patients with COPD (68 in stable periods, 58 during exacerbation periods) and 50 healthy subjects were included in the study. PFT, body mass index (BMI), white blood cell counts, C-reactive protein (CRP), serum urea and creatinine levels were evaluated in both groups of patients. CysC levels were measured in all participants.

RESULTS

Serum CysC levels were statistically higher in both COPD groups than the control group (p<0.001 for both) although there was no statistically significant difference between COPD groups (p>0.05). CysC levels showed negative correlation with forced expiratory volume in 1 second (FEV1) and a positive correlation with C-reactive protein (CRP) levels in patients with stable COPD. There was a positive correlation between serum CysC levels and serum urea, creatinine, CRP levels in patients with COPD exacerbation (r=0.333, p=0.011; r=0.260, p=0.049; r=0.414, p<0.01 respectively). When stable COPD and control groups were evaluated, serum CysC had an area under the curve (AUC) in the receiver operating characteristic (ROC) curve of 0.951 (0.909-0.994 95% CI: p<0.001).

CONCLUSIONS

Our results showed that CysC levels increased in both COPD groups. Increased CysC levels may be related with lung function decline and inflammation in COPD patients. In addition, CysC levels may be a potential indicator for the diagnosis of COPD.

Matrix metalloproteinases in emphysema

Several studies have implicated a causative role for specific matrix metalloproteinases (MMPs) in the development and progression of cigarette smoke-induced chronic obstructive pulmonary disease (COPD) and its severe sequela, emphysema. However, the precise function of any given MMP in emphysema remains an unanswered question. Emphysema results from the degradation of alveolar elastin - among other possible mechanisms - a process that is often thought to be caused by elastolytic proteinases made by macrophages. In this article, we discuss the data suggesting, supporting, or refuting causative roles of macrophage-derived MMPs, with a focus on MMPs-7, -9, -10, -12, and 28, in both the human disease and mouse models of emphysema. Findings from experimental models suggest that some MMPs, such as MMP-12, may directly breakdown elastin, whereas others, particularly MMP-10 and MMP-28, promote the development of emphysema by influencing the proteolytic and inflammatory activities of macrophages.

Serum Cystatin C as an Inflammatory Marker in Exacerbated and Convalescent COPD Patients

Chronic obstructive pulmonary disease (COPD) is a common chronic inflammatory disease with high morbidity and mortality rates. Cystatin C (Cys C) is a sensitive indicator for various chronic inflammatory diseases. In this study, we aimed to evaluate the role of Cys C in COPD patients comparing with the other well-known inflammatory markers. Ninety patients with acute exacerbated COPD were studied and were reassessed when convalescent. Ninety controls were matched for age, gender, body mass index, smoking index, and comorbidity. Serum Cys C was significantly increased in convalescent COPD patients compared with healthy controls and further increased in COPD patients with an acute exacerbation. Serum Cys C was positively correlated with hsCRP both in the exacerbation and convalescence periods of COPD and negatively correlated with FEV1% predicted and FEV1/FVC in the convalescent COPD patients. In conclusion, serum Cys C is a positive acute-phase reactant in COPD patients and might indicate systemic inflammation during the progression of COPD.

Native matrix-based human lung alveolar tissue model in vitro: studies of the reparatory actions of mesenchymal stem cells

Studies of lung diseases in vitro often rely on flat, plastic-based monocultures, due to short lifespan of primary cells, complicated anatomy, lack of explants, etc. We hereby present a native 3D model with cues for repopulating epithelial cells. Abilities of mesenchymal stem cells (MSC) to modulate bacterial lipopolysaccharide (LPS) and cigarette smoke-induced injury to pulmonary epithelium were tested in our model. Post-mortem human lung tissue was sliced, cut and decellularized. Resulting matrix pads were reseeded with pulmonary epithelium (A549 line). Markers of the layer integrity and certain secreted proteins in the presence of cigarette smoke extract (CSE) and LPS were assessed via Western blot, ELISA and RT-PCR assays. In parallel, the effects of MSC paracrine factors on exposed epithelial cells were also investigated at gene and protein levels. When cultured on native 3D matrix, A549 cells obtain dual, type I- and II-like morphology. Exposure to CSE and LPS leads to downregulation of several epithelial proteins and suppressed proliferation rate. MSC medium added to the model restores proliferation rate and some of the epithelial proteins, i.e. e-cadherin and beta-catenin. CSE also increases secretion of pro-inflammatory cytokines by epithelial cells and upregulates transcription factor NFκB. Some of these effects might be counteracted by MSC in our model. We introduce repopulated decellularized lung matrix that highly resembles in vivo situation and is convenient for studies of disease pathogenesis, cytotoxicology and for exploring therapeutic strategies in the human lung context in vitro. MSC paracrine products have produced protecting effects in our model.

Plasma Cathepsin S and Cathepsin S/Cystatin C Ratios Are Potential Biomarkers for COPD

Purpose. This study aimed to examine whether plasma levels of cathepsin S or its inhibitor, cystatin C, may serve as biomarkers for COPD. Patients and Methods. We measured anthropometrics and performed pulmonary function tests and chest CT scans on 94 patients with COPD and 31 subjects with productive cough but no airflow obstruction (“at risk”; AR). In these subjects and in 52 healthy nonsmokers (NS) and 66 healthy smokers (HS) we measured plasma concentrations of cathepsin S and cystatin C using an ELISA. Data were analyzed using simple and logistic regression and receiver operating characteristic analyses. Results. Cathepsin S and cystatin C plasma levels were significantly higher in the COPD and AR groups than in the NS and HS groups (p < 0.01). Among the COPD patients and AR subjects, plasma cathepsin S levels and cathepsin S/cystatin C ratios, but not cystatin C levels, were negatively related to severe airflow limitation (% FEV₁ predicted < 50%; p = 0.005) and severe emphysema as assessed by low attenuation area (LAA) score on chest CT scans (LAA ≥ 8.0; p = 0.001). Conclusion. Plasma cathepsin S and cathepsin S/cystatin C ratios may serve as potential biomarkers for COPD.

Pollutional haze and COPD: etiology, epidemiology, pathogenesis, pathology, biological markers and therapy

In recent years, serious pollutional haze occurs in the mainland of China thanks to the development of urbanization and industrialization. There is a close relationship between air pollution and the occurrence and development of chronic obstructive pulmonary disease (COPD), but there are some new characteristics in some aspects of COPD associated with pollutional haze compared with COPD induced by traditional physical and chemical factors. This article attempts to summarize the new progress from these new features of COPD related to pollutional haze, focus on etiology, epidemiology, pathogenesis, pathology, biological markers and therapy.

Antimicrobial proteins and peptides in human lung diseases: A friend and foe partnership with host proteases

Lung antimicrobial proteins and peptides (AMPs) are major sentinels of innate immunity by preventing microbial colonization and infection. Nevertheless bactericidal activity of AMPs against Gram-positive and Gram-negative bacteria is compromised in patients with chronic obstructive pulmonary disease (COPD), cystic fibrosis (CF) and asthma. Evidence is accumulating that expression of harmful human serine proteases, matrix metalloproteases and cysteine cathepsins is markedely increased in these chronic lung diseases. The local imbalance between proteases and protease inhibitors compromises lung tissue integrity and function, by not only degrading extracellular matrix components, but also non-matrix proteins. Despite the fact that AMPs are somewhat resistant to proteolytic degradation, some human proteases cleave them efficiently and impair their antimicrobial potency. By contrast, certain AMPs may be effective as antiproteases. Host proteases participate in concert with bacterial proteases in the degradation of key innate immunity peptides/proteins and thus may play immunomodulatory activities during chronic lung diseases. In this context, the present review highlights the current knowledge and recent discoveries on the ability of host enzymes to interact with AMPs, providing a better understanding of the role of human proteases in innate host defense.

Association between arsenic exposure and thyroid function: data from NHANES 2007-2010

The association of arsenic variables in urine, total arsenic (UAS), arsenobetaine (UAB), dimethylarsinic acid (UDMA), and arsenic adjusted for arsenobetaine (UAAS) with thyroid-stimulating hormone (TSH), free and total serum thyroxine (FT4, TT4), free and total triiodothyronine (FT3, TT3), and thyroglobulin (TGN) was evaluated by analyzing data from 2007-2010 National Health and Nutrition Examination Survey. For iodine deficient males, there was a positive association between TSH and UDMA (p < 0.01) and a negative association between the levels of TT4 and UDMA (p < 0.01). Levels of UAAS were inversely associated with the levels of TT4 for both iodine-deficient (p = 0.054) and iodine-replete females (p < 0.01). For iodine-replete females, levels of both TSH and TGN increased with decrease in the levels of both UAB (p < 0.01) and UAS (p < 0.01). There was also a negative association between TSH and UAB as well as UAS (p < 0.01). For iodine-replete males, increased levels of UDMA were associated with decreasing levels of FT4 (p = 0.03).

Thyroid function and serum copper, selenium, and zinc in general U.S. population

Association of the levels of serum selenium (Se), zinc (Zn), and copper (Cu) with thyroid function was assessed by analyzing data from National Health and Nutrition Examination Survey for the cycle 2011-2012. Thyroid function variables analyzed were as follows: thyroid-stimulating hormone (TSH), free and total triiodothyronine (FT3, TT3), free and total thyroxine (FT4, TT4), and thyroglobulin (TGN). Regression models with log-transformed values of thyroid hormones as independent variables and age, race/ethnicity, smoking and iodine sufficiency status, respondents' education, and levels of Se, Zn, and Cu as dependent variables were fitted. For males, levels of Zn were associated with decreased levels of FT4 and TT4, and levels of Cu were associated with increased levels of FT4 and TT4. For females, levels of Cu were associated with increased levels of TT3 and TT4. Smoking was found to be associated with lower levels of TSH and higher levels of TGN in males. Smoking was found to be associated with lower levels of TT4 in females. Males had about 5-10% higher levels of both Se and Zn, but as much as 20% lower levels of Cu than females. Smoking was associated with lower levels of Zn, but higher levels of Cu in males.

Serum cystatin C and indices of lung function in elderly Chinese men with chronic obstructive pulmonary disease

OBJECTIVE

The aim of this cross-sectional case-control study was to determine the relationship between serum cystatin C (sCysC) levels and lung function in elderly male patients with chronic obstructive pulmonary disease (COPD).

METHODS

This study included 251 Chinese men (age ≥ 65 years) who were divided into COPD (n = 129) and non-COPD (n = 122) groups. Participants underwent lung function and laboratory testing, including measurement of sCysC levels. Relationships between sCysC concentration and indices of lung function were assessed by multiple regression analysis.

RESULTS

Participants in the COPD group displayed higher sCysC concentrations (P = 0.041) and lower lung function (P < 0.001) compared to participants in the non-COPD group. Multiple linear regression analyses revealed that the reciprocal of the sCysC concentration (1/sCysC) was positively associated with the predicted forced expiratory volume in 1 s in all subjects (β = 0.156, P = 0.009). The findings indicate that high sCysC levels were directly associated with decreased lung function in elderly Chinese men with COPD.

CONCLUSIONS

High sCysC concentration may be a potential indicator of impaired lung function, and its application may improve the diagnosis and assessment of COPD severity in elderly male patients.

Developmental regulation of synthesis and dimerization of the amyloidogenic protease inhibitor cystatin C in the hematopoietic system

The cysteine protease inhibitor cystatin C is thought to be secreted by most cells and eliminated in the kidneys, so its concentration in plasma is diagnostic of kidney function. Low extracellular cystatin C is linked to pathologic protease activity in cancer, arthritis, atherosclerosis, aortic aneurism, and emphysema. Cystatin C forms non-inhibitory dimers and aggregates by a mechanism known as domain swapping, a property that reportedly protects against Alzheimer disease but can also cause amyloid angiopathy. Despite these clinical associations, little is known about the regulation of cystatin C production, dimerization, and secretion. We show that hematopoietic cells are major contributors to extracellular cystatin C levels in healthy mice. Among these cells, macrophages and dendritic cells (DC) are the predominant producers of cystatin C. Both cell types synthesize monomeric and dimeric cystatin C in vivo, but only secrete monomer. Dimerization occurs co-translationally in the endoplasmic reticulum and is regulated by the levels of reactive oxygen species (ROS) derived from mitochondria. Drugs or stimuli that reduce the intracellular concentration of ROS inhibit cystatin C dimerization. The extracellular concentration of inhibitory cystatin C is thus partly dependent on the abundance of macrophages and DC, and the ROS levels. These results have implications for the diagnostic use of serum cystatin C as a marker of kidney function during inflammatory processes that induce changes in DC or macrophage abundance. They also suggest an important role for macrophages, DC, and ROS in diseases associated with the protease inhibitory activity or amyloidogenic properties of cystatin C.

Association between thyroid function and selected organochlorine pesticides: data from NHANES 2001-2002

Exposure to organochlorine pesticides (OCP) has been shown to be associated with adverse thyroid function. The impact of exposure to selected OCPs on total serum thyroxine (TT4) and thyroid stimulating hormone (TSH) was evaluated by analyzing data from the 2001-2002 National Health and Nutrition Examination Survey. Oxychlordane, p,p'-DDE, trans-nonachlor, and heptachlor epoxide were selected for analysis. Regression models with logs of TSH and TT4 as dependent variables and OCP exposure, race/ethnicity, iodine and smoking status, total lipids and others as independent variables were fitted. TSH levels increased (p < 0.05) with increase in trans-nonachlor exposure for 20-39 year old iodine deficient males. TSH levels were higher when oxychlordane exposure was low than when the exposure was medium or high for 20-39 year old iodine deficient females (p < 0.05). For iodine deficient females, TT4 levels were lower when p,p'-DDE exposure was low than when it was medium (p < 0.05). For non-Hispanic blacks (NHB), TT4 levels decreased with increase in exposure to heptachlor epoxide (p < 0.05). For iodine replete males, TSH levels increased with increase in trans-nonachlor exposure (p < 0.05). For iodine replete females, (i) Mexican Americans (MA) had higher TSH levels when the exposure to oxychlordane was medium than when the exposure was low; (ii) for 60+years old, there was a positive association between TSH and heptachlor epoxide levels; and (iii) TT4 levels had an inverse association with trans-nonachlor and oxychlordane. In general though not always, (i) TSH and TT4 levels were lowest for the 20-39 years old and highest for the 60+years old (p < = 0.05), (ii) TSH and TT4 levels for iodine deficient males and females were lowest for NHB, highest for MA, and in-between for non-Hispanic white, and (iii) non-smokers had higher TSH and TT4 levels than smokers and in general, statistically significantly so.

Association between cystatin C and arteriosclerosis in the absence of chronic kidney disease

AIM

Chronic kidney disease (CKD) is a known risk factor for cardiovascular disease (CVD). Cystatin C was recently reported to be an endogenous surrogate of kidney function, and a high level of cystatin C is reported to be a strong predictor of CVD; however, the association between cystatin C and arteriosclerosis in a non-CKD population is unclear. This study aimed to clarify the association between cystatin C and arteriosclerosis in a non-CKD population.

METHODS

Of the 637 Japanese adults (264 men, 373 women) enrolled, we analyzed 446 participants with an estimated glomerular filtration rate (eGFR) >60 mL/min and no proteinuria (177 men, 269 women) without a history of CVD. Kidney function was evaluated according to serum cystatin C levels and eGFR. Arteriosclerosis was evaluated on the basis of the cardio-ankle vascular index (CAVI) and carotid intima-media thickness (CIMT).

RESULTS

The mean age of our subjects was 67.0±10.0 years. No variables showed any significant differences according to gender. The results of multiple linear regression analysis showed a significant correlation between serum cystatin C and CAVI only in women, but not CIMT.

CONCLUSION

We observed a significant correlation between cystatin C and CAVI, which is a marker of early-stage arteriosclerosis, in women in a non-CKD population with no proteinuria and eGFR>60 mL/min.