Association of Sepsis-Related Mortality with Early Increase of TIMP-1/MMP-9 Ratio

Objective

Higher circulating levels of tissue inhibitor of matrix metalloproteinases (TIMP)-1 at the time of severe sepsis diagnosis have been reported in nonsurviving than in surviving patients. However, the following questions remain unanswered: 1) Does TIMP-1/MMP-9 ratio differ throughout the first week of intensive care between surviving and non-surviving patients? 2) Is there an association between TIMP-1/MMP-9 ratio and sepsis severity and mortality during such period? 3) Could TIMP-1/MMP-9 ratio during the first week be used as an early biomarker of sepsis outcome? 4) Is there an association between TIMP-1/MMP-9 ratio and coagulation state and circulating cytokine levels during the first week of intensive care in these patients? The present study sought to answer these questions.

Methods

Multicenter, observational and prospective study carried out in six Spanish Intensive Care Units (ICUs) of 295 patients with severe sepsis. Were measured circulating levels of TIMP-1, MMP-9, tumour necrosis factor (TNF)-alpha, interleukin (IL)-10 and plasminogen activator inhibitor (PAI)-1 at day 1, 4 and 8. End-point was 30-day mortality.

Results

We found higher TIMP-1/MMP-9 ratio during the first week in non-surviving (n = 98) than in surviving patients (n = 197) (p<0.01). Logistic regression analyses showed that TIMP-1/MMP-9 ratio at days 1, 4 and 8 was associated with mortality. Receiver operating characteristic (ROC) curves showed that TIMP-1/MMP-9 ratio at days 1, 4 and 8 could predict mortality. There was an association between TIMP-1/MMP-9 ratio and TNF-alpha, IL-10, PAI-1 and lactic acid levels, SOFA score and platelet count at days 1, 4 and 8.

Conclusions

The novel findings of our study were that non-surviving septic patients showed persistently higher TIMP-1/MMP-9 ratio than survivors ones during the first week, which was associated with severity, coagulation state, circulating cytokine levels and mortality; thus representing a new biomarker of sepsis outcome.     

Differential Regulation of Matrix-Metalloproteinases and Their Tissue Inhibitors in Patients with Aneurysmal Subarachnoid Hemorrhage

Background

Matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) are involved in vascular remodeling, (neuro)inflammation, blood-brain barrier breakdown and neuronal apoptosis. Proinflammatory mechanisms are suggested to play an important role during early brain injury and cerebral vasospasm after aneurysmal subarachnoid hemorrhage (SAH). This study aimed to analyze MMP-3, MMP-9, TIMP-1 and TIMP-3 in patients with SAH and their respective association with cerebral vasospasm (CVS).

Methods

Blood samples were collected in 20 SAH patients on days 1 to 7, 9, 11, 13 and 15 and 20 healthy age and gender matched volunteers. Serum MMPs and TIMPs were analyzed using enzyme-linked immunosorbent assay. Doppler sonographic CVS was defined as a mean blood flow velocity above 120 cm/sec in the middle cerebral artery. When discharged from hospital and at 6 month follow-up neurological outcome was evaluated using the Glasgow Outcome Score and the modified Rankin Scale.

Results

MMP-9 was higher in SAH patients compared to healthy controls (p<0.001). Patients with CVS (n = 11) had elevated MMP-9 serum levels compared to patients without CVS (n = 9, p<0.05). Higher MMP-9 was observed in the presence of cerebral ischemia associated with cerebral vasospasm (p<0.05). TIMP-1 was increased in patients with SAH on day 4 (p<0.05). There was an imbalance of the MMP-9/TIMP-1 ratio in favor of MMP-9 in SAH patients, in particular those with CVS (p<0.001). MMP-3 and TIMP-3 were significantly lower in SAH patients throughout day 4 and day 7, respectively (p<0.05). We did not find an association between MMP-, TIMP levels and neurological outcome after 6 months.

Conclusions

MMP-3 and -9 are differentially regulated in SAH patients with both enzymes showing peak levels correlating with the development of CVS. The inhibitors TIMP-1 and -3 were low during the acute phase after SAH and increased later on which might suggest a preponderance of pro-inflammatory mechanisms.     

Biomarkers of extracellular matrix metabolism (MMP-9 and TIMP-1) and risk of stroke, myocardial infarction, and cause-specific mortality: cohort study

Objective

Turnover of the extracellular matrix in all solid organs is governed mainly by a balance between the degrading matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs). An altered extracellular matrix metabolism has been implicated in a variety of diseases. We investigated relations of serum levels of MMP-9 and TIMP-1 to mortality risk from an etiological perspective.

Design

The prospective Uppsala Longitudinal Study of Adult Men (ULSAM) cohort, followed from 1991–1995 for up to 18.1 years. A random population-based sample of 1,082 71-year-old men, no loss to follow-up. Endpoints were all-cause (n = 628), cardiovascular (n = 230), non-cardiovascular (n = 398) and cancer mortality (n = 178), and fatal or non-fatal myocardial infarction (n = 138) or stroke (n = 163).

Results

Serum MMP-9 and TIMP-1 levels were associated with risk of all-cause mortality (Cox proportional hazard ratio [HR] per standard deviation 1.10, 95% confidence interval [CI] 1.03–1.19; and 1.11, 1.02–1.20; respectively). TIMP-1 levels were mainly related to risks of cardiovascular mortality and stroke (HR per standard deviation 1.22, 95% CI 1.09–1.37; and 1.18, 1.04–1.35; respectively). All relations except those of TIMP-1 to stroke risk were attenuated by adjustment for cardiovascular disease risk factors. Relations in a subsample without cardiovascular disease or cancer were similar to those in the total sample.

Conclusion

In this community-based cohort of elderly men, serum MMP-9 and TIMP-1 levels were related to mortality risk. An altered extracellular matrix metabolism may be involved in several detrimental pathways, and circulating MMP-9 or TIMP-1 levels may be relevant markers thereof.     

The MMP-9 -1562 C/T Polymorphism in the Presence of Metabolic Syndrome Increases the Risk of Clinical Events in Patients with Coronary Artery Disease

Background and Objectives

Elevated levels of matrix metalloproteinase (MMP)-9 have been associated with the metabolic syndrome (MetS) and cardiovascular events. The MMP-9 −1562 C/T polymorphism has furthermore been shown as a risk factor for coronary artery disease (CAD). The non-favourable cardiometabolic state in MetS may increase the risk. We aimed to investigate the influence of MMP-9 −1562 C/T polymorphism in subjects with CAD and MetS.

Methods

Patients (n = 1000) with verified CAD stratified in Mets +/− (n = 244/756), were analyzed for the MMP-9 −1562 C/T polymorphism and related to clinical events after 2 years follow-up. Serum levels of total MMP-9 and tissue inhibitor of matrix metalloproteinases (TIMP)-1were analyzed in all, whereas MMP-9 activity, extracellular matrix metalloproteinase inducer (EMMPRIN), and expression of the two genes were analyzed in a subset of 240 randomly selected patients.

Results

Totally, 106 clinical endpoints were recorded. In MetS; the T-allele associated with 5.5 fold increase in event rate (p<0.0001), increased with number of MetS components, a 117% increase in total MMP-9 levels (TT homozygous, p = 0.05), significantly higher total- and endogenous active MMP-9 and TIMP-1 levels (p<0.01 all), and EMMPRIN was inversely correlated with pro- and endogenous active MMP-9 (p<0.05, both). In non-MetS; the T-allele was not associated with new events, nor higher MMP-9 levels. EMMPRIN was significantly correlated with total MMP-9 and TIMP-1 (p<0.01, both) and the two genes were inter-correlated (p<0.001).

Conclusion

In CAD patients with MetS, the MMP-9 T-allele increased the risk of clinical events, probably mediated through elevated MMP-9 levels and altered MMP-9 regulation.     

Imbalances between Matrix Metalloproteinases (MMPs) and Tissue Inhibitor of Metalloproteinases (TIMPs) in Maternal Serum during Preterm Labor

Background

Matrix metalloproteinases (MMPs) are involved in remodeling of the extracellular matrix (ECM) during pregnancy and parturition. Aberrant ECM degradation by MMPs or an imbalance between MMPs and their tissue inhibitors (TIMPs) have been implicated in the pathogenesis of preterm labor, however few studies have investigated MMPs or TIMPs in maternal serum. Therefore, the purpose of this study was to determine serum concentrations of MMP-3, MMP-9 and all four TIMPs as well as MMP:TIMP ratios during term and preterm labor.

Methods

A case control study with 166 singleton pregnancies, divided into four groups: (1) women with preterm birth, delivering before 34 weeks (PTB); (2) gestational age (GA) matched controls, not in preterm labor; (3) women at term in labor and (4) at term not in labor. MMP and TIMP concentrations were measured using Luminex technology.

Results

MMP-9 and TIMP-4 concentrations were higher in women with PTB vs. GA matched controls (resp. p = 0.01 and p<0.001). An increase in MMP-9:TIMP-1 and MMP-9:TIMP-2 ratio was observed in women with PTB compared to GA matched controls (resp. p = 0.02 and p<0.001) as well as compared to women at term in labor (resp. p = 0.006 and p<0.001). Multiple regression results with groups recoded as three key covariates showed significantly higher MMP-9 concentrations, higher MMP-9:TIMP-1 and MMP-9:TIMP-2 ratios and lower TIMP-1 and -2 concentrations for preterm labor. Significantly higher MMP-9 and TIMP-4 concentrations and MMP-9:TIMP-2 ratios were observed for labor.

Conclusions

Serum MMP-9:TIMP-1 and MMP-9:TIMP-2 balances are tilting in favor of gelatinolysis during preterm labor. TIMP-1 and -2 concentrations were lower in preterm gestation, irrespective of labor, while TIMP-4 concentrations were raised in labor. These observations suggest that aberrant serum expression of MMP:TIMP ratios and TIMPs reflect pregnancy and labor status, providing a far less invasive method to determine enzymes essential in ECM remodeling during pregnancy and parturition.     

Serum MMP-8: A Novel Indicator of Left Ventricular Remodeling and Cardiac Outcome in Patients after Acute Myocardial Infarction

Objective

Left ventricular (LV) remodeling following myocardial infarction (MI) is characterized by progressive alterations of structure and function, named LV remodeling. Although several risk factors such as infarct size have been identified, LV remodeling remains difficult to predict in clinical practice. Changes within the extracellular matrix, involving matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs), are an integral part of left ventricular (LV) remodeling after myocardial infarction (MI). We investigated the temporal profile of circulating MMPs and TIMPs and their relations with LV remodeling at 1 year and clinical outcome at 3 years in post-MI patients.

Methods

This prospective multicentre study included 246 patients with a first anterior MI. Serial echocardiographic studies were performed at hospital discharge, 3 months, and 1 year after MI, and analysed at a core laboratory. LV remodeling was defined as the percent change in LV end-diastolic volume (EDV) from baseline to 1 year. Serum samples were obtained at hospital discharge, 1, 3, and 12 months. Multiplex technology was used for analysis of MMP-1, -2, -3, -8, -9, -13, and TIMP-1, -2, -3, -4 serum levels.

Results

Baseline levels of MMP-8 and MMP-9 were positively associated with changes in LVEDV (P = 0.01 and 0.02, respectively). When adjusted for major baseline characteristics, MMP-8 levels remained an independent predictor LV remodeling (P = 0.025). By univariate analysis, there were positive relations between cardiovascular death or hospitalization for heart failure during the 3-year follow-up and the baseline levels of MMP-2 (P = 0.03), MMP-8 (P = 0.002), and MMP-9 (P = 0.03). By multivariate analysis, MMP-8 was the only MMP remaining significantly associated with clinical outcome (P = 0.02).

Conclusion

Baseline serum MMP-8 is a significant predictor of LV remodeling and cardiovascular outcome after MI and may help to improve risk stratification.     

Red Blood Cell Distribution Width during the First Week Is Associated with Severity and Mortality in Septic Patients

Objective

Higher values of red blood cell distribution width (RDW) have been found in non-surviving than in surviving septic patients. However, it is unknown whether RDW during the first week of sepsis evolution is associated with sepsis severity and early mortality, oxidative stress and inflammation states, and these were the aims of the study.

Methods

We performed a prospective, observational, multicenter study in six Spanish Intensive Care Units with 297 severe septic patients. We measured RDW, serum levels of malondialdehyde (MDA) to assess oxidative stress, and tumour necrosis factor (TNF)-α to assess inflammation at days 1, 4, and 8. The end-point was 30-day mortality.

Results

We found higher RDW in non-surviving (n = 104) than in surviving (n = 193) septic patients at day 1 (p = 0.001), day 4 (p = 0.001), and day 8 (p = 0.002) of ICU admission. Cox regression analyses showed that RDW at day 1 (p<0.001), 4 (p = 0.005) and 8 (p = 0.03) were associated with 30-day mortality. Receiver operating characteristic curves showed that RDW at day 1 (p<0.001), 4 (p<0.001), and 8 (p<0.001) could be used to predict 30-day mortality. RDW showed a positive correlation with serum MDA levels at day 1 and day 4, with serum TNF-α levels at days 4 and 8, and with SOFA score at days 1, 4 and 8.

Conclusions

The major findings of our study were that non-surviving septic patients showed persistently higher RDW during the first week of ICU stay than survivors, that RDW during the first week was associated with sepsis severity and mortality, that RDW during the first week could be used as biomarker of outcome in septic patients, and that there was an association between RDW, serum MDA levels, and serum TNF-α levels during the first week.     

Prognostic Value of Malondialdehyde Serum Levels in Severe Sepsis: A Multicenter Study

Objective

The oxidant/antioxidant state in septic patients has only been studied in small series. We wished to determine whether malondialdehyde (MDA) serum levels were associated with severity and 30-day mortality in a large series of patients with sepsis.

Methods

We performed an observational, prospective, multicenter study in six Spanish Intensive Care Units. Serum levels of MDA were measured in a total of 228 patients (145 survivors and 83 non-survivors) with severe sepsis and 100 healthy controls.

Results

Serum levels of MDA were higher in severe septic patients than in healthy controls. Non-surviving septic patients had higher MDA values than survivors. MDA serum levels were associated with severity markers (lactic acid, SOFA, APACHE-II) and coagulation indices. Regression analysis showed that MDA serum levels were associated with 30-day survival (Hazard ratio = 1.05; 95% confidence interval = 1.009–1.091; p = 0.016). Receiver operating characteristic analysis showed that the area under curve of MDA serum levels to predict 30-day survival was 0.62 (95% CI = 0.56–0.69; P = 0.002). The risk of death in septic patients with MDA serum levels above 4.11 nmol/mL was higher than in patients with lower values (Hazard Ratio = 2.43; 95% CI = 1.49–3.94; p<0.001).

Conclusions

The novel findings of our study on severe septic patients, to our knowledge the largest series providing data on the oxidative state, are that elevated MDA serum levels probably represent an unbalanced oxidant state and are related with poor prognosis in patients with severe sepsis.     

Circulating Annexin A5 Levels after Atrial Switch for Transposition of the Great Arteries: Relationship with Ventricular Deformation and Geometry

Background

Inflammatory cytokines, cardiomyocyte apoptosis, and altered collagen turnover may contribute to unfavourable ventricular remodeling. This unfavourable ventricular remodelling is well documented in patients after atrial switch operation for complete transposition of the great arteries. We therefore tested if levels of circulating markers of inflammation, apoptosis, collagen synthesis, and extracellular matrix degradation are altered in patients after atrial switch operation for transposition of the great arteries.

Methods and Results

Circulating tumour necrosis factor (TNF)-α, annexin A5 (AnxA5), carboxy-terminal propeptide of type I procollagen (PICP), amino-terminal propeptide of type III procollagen (PIIINP), matrix metalloproteinase-1 (MMP-1), and tissue inhibitor of metalloproteinase-1 (TIMP-1) levels were determined in 27 patients aged 25.2±3.1 years and 20 controls. Ventricular myocardial deformation and left ventricular eccentricity index (EI) were determined by speckle tracking and two-dimensional echocardiography, respectively. Compared with controls, patients had significantly higher circulating AnxA5 (p<0.001) and TNF-α (p = 0.018) levels, but similar PICP, PIIINP, MMP-1 and TIMP-1 levels. For the whole cohort, plasma AnxA5 correlated with serum TNF-α (p = 0.002), systemic ventricular global longitudinal strain (GLS) and systolic and early diastolic strain rate (all p<0.001), and subpulmonary ventricular GLS and early diastolic strain rate (both p<0.001). In patients, plasma AnxA5 level correlated positively with subpulmonary ventricular EI (p = 0.027). Multiple linear regression analysis identified systemic ventricular GLS (β = −0.50, p<0.001) and serum TNF-α (β = 0.29, p = 0.022) as significant correlates of plasma AnxA5.

Conclusions

Elevated plasma AnxA5 level in patients after atrial switch operation is associated with impaired systemic myocardial deformation, increased subpulmonary ventricular eccentricity, and increased serum TNF-α level.     

Serum Levels of Caspase-Cleaved Cytokeratin-18 and Mortality Are Associated in Severe Septic Patients: Pilot Study

Objective

Apoptosis is increased in sepsis. Cytokeratin 18 (CK-18), a protein of the intermediate filament group present in most epithelial and parenchymal cells, is cleaved by the action of caspases and released into the blood as caspase-cleaved CK (CCCK)-18 during apoptosis. Circulating levels of CCCK-18 have scarcely been explored in septic patients. In one study with 101 severe septic patients, the authors reported higher serum CCCK-18 levels in non-survivors than in survivors; however, the sample size was too small to demonstrate an association between serum CCCK-18 levels and early mortality and whether they could be used as a biomarker to predict outcomes in septic patients. Thus, these were the objectives of this study with a large series of patients.

Methods

We performed a prospective, multicenter, observational study in six Spanish Intensive Care Units with 224 severe septic patients. Blood samples were collected at the time that severe sepsis was diagnosed to determine serum levels of CCCK-18, tumor necrosis factor (TNF)-alpha, interleukin (IL)-6 and IL-10. The end point was 30-day mortality.

Results

Non-surviving patients (n = 80) showed higher serum CCCK-18 levels (P<0.001) than survivors (n = 144). Multiple logistic regression analysis showed that serum CCCK-18 levels>391 u/L were associated with 30-day survival (Odds ratio = 2.687; 95% confidence interval = 1.449–4.983; P = 0.002), controlling for SOFA score, serum lactic acid levels and age. Kaplan-Meier survival analysis showed that the risk of death in septic patients with serum CCCK-18 levels >391 u/L was higher than in patients with lower values (Hazard Ratio = 3.1; 95% CI = 1.96–4.84; P<0.001). Serum CCCK-18 levels were positively associated with serum levels of IL-6 and lactic acid, and with SOFA and APACHE scores.

Conclusions

The major novel finding of our study, the largest cohort of septic patients providing data on circulating CCCK-18 levels, was that serum CCCK-18 levels are associated with mortality in severe septic patients.     

Correlation of Circulating MMP-9 with White Blood Cell Count in Humans: Effect of Smoking

Background

Matrix metalloproteinase-9 (MMP-9) is an emerging biomarker for several disease conditions, where white blood cell (WBC) count is also elevated. In this study, we examined the relationship between MMP-9 and WBC levels in apparently healthy smoking and non-smoking human subjects.

Methods

We conducted a cross-sectional study to assess the relationship of serum MMP-9 with WBC in 383 men and 356 women. Next, we divided the male population (women do not smoke in this population) into three groups: never (n = 243), current (n = 76) and former (n = 64) smokers and compared the group differences in MMP-9 and WBC levels and their correlations within each group.

Results

Circulating MMP-9 and WBC count are significantly correlated in men (R² = 0.13, p<0.001) and women (R² = 0.19, p<0.001). After stratification by smoking status, MMP-9 level was significantly higher in current smokers (mean ± SE; 663.3±43.4 ng/ml), compared to never (529.7±20.6) and former smokers (568±39.3). WBC count was changed in a similar pattern. Meanwhile, the relationship became stronger in current smokers with increased correlation coefficient of r = 0.45 or R² = 0.21 (p<0.001) and steeper slope of ß = 1.16±0.30 (p<0.001) in current smokers, compared to r = 0.26 or R² = 0.07 (p<0.001) and ß = 0.34±0.10 (p<0.001) in never smokers.

Conclusions

WBC count accounts for 13% and 19% of MMP-9 variance in men and women, respectively. In non-smoking men, WBC count accounts for 7% of MMP-9 variance, but in smoking subjects, it accounts for up to 21% of MMP-9 variance. Thus, we have discovered a previously unrecognized correlation between the circulating MMP-9 and WBC levels in humans.     

Serum metalloproteinase-9 is related to COPD severity and symptoms - cross-sectional data from a population based cohort-study

Background

Chronic obstructive pulmonary disease, COPD, is an increasing cause of morbidity and mortality worldwide, and an imbalance between proteases and antiproteases has been implicated to play a role in COPD pathogenesis. Matrix metalloproteinases (MMP) are important proteases that along with their inhibitors, tissue inhibitors of metalloproteinases (TIMP), affect homeostasis of elastin and collagen, of importance for the structural integrity of human airways. Small observational studies indicate that these biomarkers are involved in the pathogenesis of COPD. The aim of this study was to investigate serum levels of MMP-9 and TIMP-1 in a large Swedish population-based cohort, and their association with disease severity and important clinical symptoms of COPD such as productive cough.

Methods

Spirometry was performed and peripheral blood samples were collected in a populations-based cohort (median age 67 years) comprising subjects with COPD (n = 594) and without COPD (n = 948), in total 1542 individuals. Serum MMP-9 and TIMP-1 concentrations were measured with enzyme linked immunosorbant assay (ELISA) and related to lung function data and symptoms.

Results

Median serum MMP-9 values were significantly higher in COPD compared with non-COPD 535 vs. 505 ng/ml (P = 0.017), without any significant differences in serum TIMP-1-levels or MMP-9/TIMP-1-ratio. In univariate analysis, productive cough and decreasing FEV₁% predicted correlated significantly with increased MMP-9 among subjects with COPD (P = 0.004 and P = 0.001 respectively), and FEV₁% predicted remained significantly associated to MMP-9 in a multivariate model adjusting for age, sex, pack years and productive cough (P = 0.033).

Conclusion

Productive cough and decreasing FEV₁ were each associated with MMP-9 in COPD, and decreasing FEV₁ remained significantly associated with MMP-9 also after adjustment for common confounders in this population-based COPD cohort. The increased serum MMP-9 concentrations in COPD indicate an enhanced proteolytic activity that is related to disease severity, and further longitudinal studies are important for the understanding of MMP-9 in relation to the disease process and the pathogenesis of different COPD phenotypes.     

FEV1 inversely correlates with metalloproteinases 1, 7, 9 and CRP in COPD by biomass smoke exposure

Background

Matrix metalloproteinases (MMPs) and C-reactive protein (CRP) are involved in chronic obstructive pulmonary disease (COPD) pathogenesis. The aim of the present work was to determine plasma concentrations of MMPs and CRP in COPD associated to biomass combustion exposure (BE) and tobacco smoking (TS).

Methods

Pulmonary function tests, plasma levels of MMP-1, MMP-7, MMP-9, MMP-9/TIMP-1 and CRP were measured in COPD associated to BE (n = 40) and TS (n =40) patients, and healthy non-smoking (NS) healthy women (controls, n = 40).

Results

Plasma levels of MMP-1, MMP-7, MMP-9, and MMP-9/TIMP-1 and CRP were higher in BE and TS than in the NS healthy women (p <0.01). An inverse correlation between MMP-1, MMP-7, MMP-9, MMP-9/TIMP-1 and CRP plasma concentrations and FEV₁ was observed.

Conclusions

Increase of MMPs and CRP plasma concentrations in BE suggests a systemic inflammatory phenomenon similar to that observed in COPD associated to tobacco smoking, which may also play a role in COPD pathogenesis.     

Increased Expression of Intranuclear Matrix Metalloproteinase 9 in Atrophic Renal Tubules Is Associated with Renal Fibrosis

Background

Reduced turnover of extracellular matrix has a role in renal fibrosis. Matrix metalloproteinases (MMPs) is associated with many glomerular diseases, but the histological association of MMPs and human renal fibrosis is unclear.

Methods

This is a retrospective study. Institutional Review Board approval was obtained for the review of patients’ medical records, data analysis and pathological specimens staining with waiver of informed consents. Specimens of forty-six patients were examined by immunohistochemical stain of MMP-9 in nephrectomized kidneys, and the association of renal expression of MMP-9 and renal fibrosis was determined. MMP-9 expression in individual renal components and fibrosis was graded as high or low based on MMP-9 staining and fibrotic scores.

Results

Patients with high interstitial fibrosis scores (IFS) and glomerular fibrosis scores (GFS) had significantly higher serum creatinine, lower estimated glomerular filtration rate (eGFR), and were more likely to have chronic kidney disease (CKD) and urothelial cell carcinoma. Univariate analysis showed that IFS and GFS were negatively associated with normal and atrophic tubular cytoplasmic MMP-9 expression and IFS was positively correlated with atrophic tubular nuclear MMP-9 expression. Multivariate stepwise regression indicated that MMP-9 expression in atrophic tubular nuclei (r = 0.4, p = 0.002) was an independent predictor of IFS, and that MMP-9 expression in normal tubular cytoplasm (r = −0.465, p<0.001) was an independent predictor of GFS.

Conclusions

Interstitial fibrosis correlated with MMP-9 expression in the atrophic tubular nuclei. Our results indicate that renal fibrosis is associated with a decline of MMP-9 expression in the cytoplasm of normal tubular cells and increased expression of MMP-9 in the nuclei of tubular atrophic renal tubules.     

Early Elevation of Serum MMP-3 and MMP-12 Predicts Protection from World Trade Center-Lung Injury in New York City Firefighters: A Nested Case-Control Study

Objective

After 9/11/2001, some Fire Department of New York (FDNY) workers had excessive lung function decline. We hypothesized that early serum matrix metalloproteinases (MMP) expression predicts World Trade Center-Lung Injury (WTC-LI) years later.

Methods

This is a nested case-control analysis of never-smoking male firefighters with normal pre-exposure Forced Expiratory Volume in one second (FEV₁) who had serum drawn up to 155 days post 9/11/2001. Serum MMP-1, 2,3,7,8, 9, 12 and 13 were measured. Cases of WTC-LI (N = 70) were defined as having an FEV1 one standard deviation below the mean (FEV₁≤77%) at subspecialty pulmonary evaluation (SPE) which was performed 32 months (IQR 21–53) post-9/11. Controls (N = 123) were randomly selected. We modeled MMP''s ability as a predictor of cases status with logistic regression adjusted for time to blood draw, exposure intensity, weight gain and pre-9/11 FEV₁.

Results

Each log-increase in MMP-3 and MMP-12 showed reduced odds of developing WTC-LI by 73% and 54% respectively. MMP-3 and MMP-12 consistently clustered together in cases, controls, and the cohort. Increasing time to blood draw significantly and independently increased the risk of WTC-LI.

Conclusions

Elevated serum levels of MMP-3 and MMP-12 reduce the risk of developing WTC-LI. At any level of MMP-3 or 12, increased time to blood draw is associated with a diminished protective effect.     

Acute exacerbations of COPD are associated with significant activation of matrix metalloproteinase 9 irrespectively of airway obstruction,emphysema and infection

Background

Acute exacerbations of chronic obstructive pulmonary disease (AE-COPD) are associated with accelerated aggravation of clinical symptoms and deterioration of pulmonary function. The mechanisms by which exacerbations may contribute to airway remodeling and declined lung function are poorly understood. In this study, we investigated if AE-COPD are associated with differential expression of matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) in bronchoalveolar lavage (BAL).

Methods

COPD patients undergoing diagnostic bronchoscopy, with either stable disease (n = 53) or AE-COPD (n = 44), matched for their demographics and lung function parameters were included in this study. Protein levels of MMP-2,–9,–12 and of TIMP-1 and -2 in BAL were measured by ELISA. Enzymatic activity of MMP-2 and -9 was assessed by gelatin zymography.

Results

We observed that MMP-9, TIMP-1 and TIMP-2 were significantly increased in BAL during AE-COPD. Furthermore, there was a significant negative correlation of MMP-9, TIMP-1 and TIMP-2 with FEV1% predicted and a significant positive correlation of TIMP-1 and TIMP-2 with RV% predicted in AE-COPD. None of MMPs and TIMPs correlated with DLCO% predicted, indicating that they are associated with airway remodeling leading to obstruction rather than emphysema. In AE-COPD the gelatinolytic activity of MMP-2 was increased and furthermore, MMP-9 activation was significantly up-regulated irrespective of lung function, bacterial or viral infections and smoking.

Conclusions

The results of this study indicate that during AE-COPD increased expression of TIMP-1, TIMP-2, and MMP-9 and activation of MMP-9 may be persistent aggravating factors associated with airway remodeling and obstruction, suggesting a pathway connecting frequent exacerbations to lung function decline.

Electronic supplementary material

The online version of this article (doi:10.1186/s12931-015-0240-4) contains supplementary material, which is available to authorized users.     

Effect of Statin Therapy in the Outcome of Bloodstream Infections Due to Staphylococcus aureus: A Prospective Cohort Study

Introduction

Statins have pleiotropic effects that could influence the prevention and outcome of some infectious diseases. There is no information about their specific effect on Staphylococcus aureus bacteremia (SAB).

Methods

A prospective cohort study including all SAB diagnosed in patients aged ≥18 years admitted to a 950-bed tertiary hospital from March 2008 to January 2011 was performed. The main outcome variable was 14-day mortality, and the secondary outcome variables were 30-day mortality, persistent bacteremia (PB) and presence of severe sepsis or septic shock at diagnosis of SAB. The effect of statin therapy at the onset of SAB was studied by multivariate logistic regression and Cox regression analysis, including a propensity score for statin therapy.

Results

We included 160 episodes. Thirty-three patients (21.3%) were receiving statins at the onset of SAB. 14-day mortality was 21.3%. After adjustment for age, Charlson index, Pitt score, adequate management, and high risk source, statin therapy had a protective effect on 14-day mortality (adjusted OR = 0.08; 95% CI: 0.01–0.66; p = 0.02), and PB (OR = 0.89; 95% CI: 0.27–1.00; p = 0.05) although the effect was not significant on 30-day mortality (OR = 0.35; 95% CI: 0.10–1.23; p = 0.10) or presentation with severe sepsis or septic shock (adjusted OR = 0.89; CI 95%: 0.27–2.94; p = 0.8). An effect on 30-day mortality could neither be demonstrated on Cox analysis (adjusted HR = 0.5; 95% CI: 0.19–1.29; p = 0.15).

Conclusions

Statin treatment in patients with SAB was associated with lower early mortality and PB. Randomized studies are necessary to identify the role of statins in the treatment of patients with SAB.     

PRO-C3-Levels in Patients with HIV/HCV-Co-Infection Reflect Fibrosis Stage and Degree of Portal Hypertension

Background

Liver-related deaths represent the leading cause of mortality among patients with HIV/HCV-co-infection, and are mainly related to complications of fibrosis and portal hypertension. In this study, we aimed to evaluate the structural changes by the assessment of extracellular matrix (ECM) derived degradation fragments in peripheral blood as biomarkers for fibrosis and portal hypertension in patients with HIV/HCV co-infection.

Methods

Fifty-eight patients (67% male, mean age: 36.5 years) with HIV/HCV-co-infection were included in the study. Hepatic venous pressure gradient (HVPG) was measured in forty-three patients. The fibrosis stage was determined using FIB4 -Score. ECM degraded products in peripheral blood were measured using specific ELISAs (C4M, MMP-2/9 degraded type IV collagen; C5M, MMP-2/9 degraded type V collagen; PRO-C3, MMP degraded n-terminal propeptide of type III collagen).

Results

As expected, HVPG showed strong and significant correlations with FIB4-index (r_s = 0.628; p = 7*10⁻⁷). Interestingly, PRO-C3 significantly correlated with HVPG (r_s = 0.354; p = 0.02), alanine aminotransferase (r_s = 0.30; p = 0.038), as well as with FIB4-index (r_s = 0.3230; p = 0.035). C4M and C5M levels were higher in patients with portal hypertension (HVPG>5 mmHg).

Conclusion

PRO-C3 levels reflect liver injury, stage of liver fibrosis and degree of portal hypertension in HIV/HCV-co-infected patients. Furthermore, C4M and C5M were associated with increased portal pressure. Circulating markers of hepatic ECM remodeling might be helpful in the diagnosis and management of liver disease and portal hypertension in patients with HIV/HCV coinfection.     

Metabolomic Derangements Are Associated with Mortality in Critically Ill Adult Patients

Objective

To identify metabolomic biomarkers predictive of Intensive Care Unit (ICU) mortality in adults.

Rationale

Comprehensive metabolomic profiling of plasma at ICU admission to identify biomarkers associated with mortality has recently become feasible.

Methods

We performed metabolomic profiling of plasma from 90 ICU subjects enrolled in the BWH Registry of Critical Illness (RoCI). We tested individual metabolites and a Bayesian Network of metabolites for association with 28-day mortality, using logistic regression in R, and the CGBayesNets Package in MATLAB. Both individual metabolites and the network were tested for replication in an independent cohort of 149 adults enrolled in the Community Acquired Pneumonia and Sepsis Outcome Diagnostics (CAPSOD) study.

Results

We tested variable metabolites for association with 28-day mortality. In RoCI, nearly one third of metabolites differed among ICU survivors versus those who died by day 28 (N = 57 metabolites, p<.05). Associations with 28-day mortality replicated for 31 of these metabolites (with p<.05) in the CAPSOD population. Replicating metabolites included lipids (N = 14), amino acids or amino acid breakdown products (N = 12), carbohydrates (N = 1), nucleotides (N = 3), and 1 peptide. Among 31 replicated metabolites, 25 were higher in subjects who progressed to die; all 6 metabolites that are lower in those who die are lipids. We used Bayesian modeling to form a metabolomic network of 7 metabolites associated with death (gamma-glutamylphenylalanine, gamma-glutamyltyrosine, 1-arachidonoylGPC(20:4), taurochenodeoxycholate, 3-(4-hydroxyphenyl) lactate, sucrose, kynurenine). This network achieved a 91% AUC predicting 28-day mortality in RoCI, and 74% of the AUC in CAPSOD (p<.001 in both populations).

Conclusion

Both individual metabolites and a metabolomic network were associated with 28-day mortality in two independent cohorts. Metabolomic profiling represents a valuable new approach for identifying novel biomarkers in critically ill patients.     

Use of the Delta Neutrophil Index as a Prognostic Factor of Mortality in Patients with Spontaneous Bacterial Peritonitis: Implications of a Simple and Useful Marker

Background

Spontaneous bacterial peritonitis (SBP) is a common and life-threatening infection in patients with advanced cirrhosis. The prognostic value of a novel marker, the delta neutrophil index (DNI), was investigated relative to mortality in patients with SBP.

Materials & Methods

Seventy-five patients with SBP were studied from April 2010 to May 2012. DNI at initial diagnosis of SBP was determined and compared with 30-day mortality rates.

Results

Of the patients, 87.7% were men, and the median age of all patients was 59.0 yrs. The area under the receiver-operating characteristic (ROC) curve of DNI for 30-day mortality was 0.701 (95% confidence interval [CI], 0.553–0.849; p = 0.009), which was higher than that of C-reactive protein (0.640, 95% CI, 0.494–0.786; p = 0.076) or the model for end-stage liver disease score (0.592, 95% CI, 0.436–0.748; p = 0.235). From the ROC curve, with the sum of sensitivity and specificity, the cutoff value of DNI was determined to be 5.7%. In the high-DNI group (DNI ≥5.7%), septic shock and 30-day mortality were more prevalent compared with the low-DNI group (84.2% vs. 48.2%, p = 0.007; 57.9% vs. 14.3%, p<0.001, respectively). Patients with an elevated DNI had a higher risk of 30-day mortality compared with those with a low DNI (4.225, 95% CI, 1.631–10.949; p = 0.003).

Conclusion

A higher DNI at the time of SBP diagnosis is an independent predictor of 30-day mortality in patients with SBP.