C-reactive protein as a novel biomarker

Predictive value of C-reactive protein levels for the early and later detection of postoperative complications after cytoreductive surgery and HIPEC

Synopsis

C-reactive protein (CRP), white blood cells and procalcitonin (PCT) participate in the systemic response to inflammation and increase after postoperative infective complications. Postoperative complications after CRS and HIPEC could be predicted using the CRP cut-off value (169 mg/L at PODs 3-5 and 62 mg/L at PODs 7-10).

Background

Postoperative elevation of C-reactive protein (CRP) can be used in order to predict the postoperative complications in many indications. Cytoreduction surgery (CRS) associated with hyperthermic intraperitoneal chemotherapy (HIPEC) is associated with high morbidity.

Objectives

The aim of the study was to demonstrate the CRP predictive value for the occurrence of complications.

Methods

All patients who had CRS and HIPEC, regardless of the origin of peritoneal metastasis, were included in this retrospective study. Postoperative complications and CRP and white blood cell (WBC) counts were recorded from postoperative day (POD) 1 through 10.

Results

Among the 127 patients included, 58 (45.7%) had no complications (NCs), 53 (41.7%) had infective complications (ICs), and 16 (12.6%) had non-infective complications (NICs). The IC group had a higher CRP value than the NC group, which was statistically significant from POD7 to POD10 (41.1 versus 107.5 p = 0.023 and 77.8 versus 140 p = 0.047, respectively). A cut-off CRP value was 169 mg/L at PODs 3-5 and 62 mg/L at PODs 7-10. The area under the curve (AUC) at POD5 was 0.56 versus 0.76 at POD7, p=0.007. The sensibility, specificity, positive and negative predictive values of these cut-offs were 55%, 83%, 74% and 67%, respectively. Moreover, 17 patients (32%) with ICs had a CRP value higher than these cut-offs before the diagnosis was made by the medical team.

Conclusion

This study suggested that postoperative complications could be predicted using the CRP cut-off value on PODs 3-5 (169 mg/l) and PODs 7-10 (62 mg/l) after CRS and HIPEC.

Biomarkers of Cardiac Injury: An Update

Conventional and promising new markers of myocardial injury have become an important diagnostic tool and their prognostic significance is also recognized. In addition, they help identify patients who will derive the most benefit from therapeutic interventions. The literature was searched from the websites of the National Library of Medicine (http://www.ncbi.nlm.nih.gov/) and PubMed Central, the U.S. National Library of Medicine’s digital archive of life sciences journal literature (http://www.pubmedcentral.nih.gov/). The data were accessed from books and journals that published relevant articles in this field. The diagnosis of acute myocardial infarction (AMI) has traditionally relied on the combination of chest pain, ECG features, and elevation in serum markers. However, chest symptoms are frequently atypical or absent and ECG changes may be nonspecific or absent. Hence, the diagnosis of acute coronary syndromes has become increasingly dependent on serum markers of cardiac injury. Among them, creatine kinase (CK) is an effective and widely used test, with the recent CKMB assay offering greater specificity and sensitivity. Cardiac troponins facilitate early and rapid diagnosis, enable effective risk stratification in patients with AMI (with or without traditional criteria for MI), and identify those who will benefit from aggressive medical or surgical intervention. Recent data suggest the potential of myoglobin and CKMB isoforms as sensitive markers in the early hours after symptom onset. Cardiac-specific troponins help in rapid diagnosis, prognostication, and treatment of AMI. Troponins also facilitate early detection of recent infarction owing to their prolonged diagnostic window and also aid in the detection of “microinfarction.” CKMB is used to detect reinfarction or infarct extension, if levels rise again after declining. Finally, novel biochemical markers are receiving attention in ongoing trials. They may prove to be more effective in diagnosis and prognosis than their existing counterparts.

Triglyceride-induced macrophage cell death is triggered by caspase-1

Triglyceride (TG) induces macrophage cell death which contributes to the development of atherosclerosis. We confirmed that exogenous TG accumulates in human THP-1 macrophages and causes cell death. TG treated THP-1 macrophages exhibited no change in tumor necrosis factor (TNF)-α, interleukin (IL)-18, macrophage inflammatory protein (MIP)-1α, and IL-1R1 receptor mRNA expression. However, there was a marked decrease in IL-1β mRNA expression but an increase in IL-1β protein secretion. Decreased expression of IL-1β mRNA and increased secretion of IL-1β protein was not the direct cause of cell death. Until now, TG was assumed to induce necrotic cell death in macrophages. Since caspase-1 is known to be involved in activation and secretion of IL-1β protein and pyroptotic cell death, next we determined whether caspase-1 is associated with TG-induced macrophage cell death. We found an increase in caspase-1 activity in TG-treated THP-1 macrophages and inhibition of caspase-1 activity using a specific inhibitor partially rescued cell death. These results suggest activation of the pyroptotic pathway by TG. This is the first report implicating the activation of caspase-1 and the triggering of the pyroptosis pathway in TG-induced macrophage cell death.

Increased expression of interleukin-1β in triglyceride-induced macrophage cell death is mediated by p38 MAP kinase

Triglycerides (TG) are implicated in the development of atherosclerosis through formation of foam cells and induction of macrophage cell death. In this study, we report that addition of exogenous TG induced cell death in phorbol 12-myristate 13-acetate-differentiated THP-1 human macrophages. TG treatment induced a dramatic decrease in interleukin-1β (IL-1β) mRNA expression in a dose- and time-dependent manner. The expression of granulocyte macrophage colony-stimulating factor and platelet endothelial cell adhesion molecule remained unchanged. To identify signaling pathways involved in TG-induced downregulation of IL-1β, we added p38 MAPK, protein kinase C (PKC) or c-Raf1 specific inhibitors. We found that inhibition of p38 MAPK alleviated the TG-induced downregulation of IL-1β, whereas inhibition of PKC and c-Raf1 had no effect. This is the first report showing decreased IL-1β expression during TG-induced cell death in a human macrophage line. Our results suggest that downregulation of IL-1β expression by TG-treated macrophages may play a role during atherogenesis.

N-acetyl cysteine suppresses the foam cell formation that is induced by oxidized low density lipoprotein via regulation of gene expression

Foam cells derived from macrophages have been implicated as markers of early stage atherosclerosis development. In this study, we found that N-acetyl cysteine (NAC), a well-known inhibitor of reactive oxygen species (ROS), decreased the generation of ROS and suppressed foam cell formation in the presence of oxidized low density lipoprotein through down-regulation of cluster of differentiation 36 expression. We investigated gene expression profiles in order to determine the effects of NAC on foam cell formation using a microarray analysis. The level of apolipoprotein E, which is involved in lipid efflux, was increased and the levels of the antioxidant genes glutathione peroxidase 1 and 3 were also increased. The expression levels of the oxidative stress response and the DNA repair genes were decreased. These results were confirmed using quantitative real-time PCR. Our results indicate that oxidative stress plays an important role in foam cell formation, and that regulation of oxidation using antioxidants is a potential therapeutic method for blocking atherosclerosis development.

The association between work stress and inflammatory biomarkers in Jordanian male workers

The study aimed to establish the association of work stress, expressed as effort-reward imbalance (ERI), and C-reactive protein (CRP) in 152 healthy Jordanian male employees. Self-report work stress, anthropometric data, and blood for CRP analysis were collected. A significant correlation between ERI and CRP (r = 0.29, p < .01), and between waist circumference with CRP (r = 0.44, p < .01) was found. Central obesity explained most of the variance in CRP after controlling for various covariates, and ERI was not a significant predictor of CRP (ΔR2  = 0.02; β = 0.15, p = .052). However, when only the centrally obese group was considered, ERI accounted for 5.0% of the variability in the CRP (β = 0.24, p < .05). Results of this study confirm previous findings that obesity is significantly associated with CRP, and support the notion that higher ERI amongst obese workers is one small but significant predictor of increased levels of CRP.

Endothelial cell biology: role in the inflammatory response

Human endothelial cells are multifunctional cells that line blood vessels and are capable of secreting a variety of biologically active mediators. They normally maintain vascular hemostasis and prevent thrombotic complications. When affected by infection, stress, hypertension, dyslipidemia, or high homocysteine levels, endothelial cells undergo changes resulting in "dysfunction," characterized typically by decreased endothelial expression of nitric oxide, enhanced expression of cell adhesion molecules, and associated increased binding of circulating leukocytes to these cells. There is accompanying cytokine and chemokine elaboration, resulting in cellular recruitment and the orchestration of an acute inflammatory response that can culminate in chronic inflammation if reparative mechanisms are not operative. This review will address the basic biology of endothelial cells; the expression and regulation of endothelial-derived cytokines, chemokines, and growth factors; the transcriptional regulation of these genes in endothelial cells; and the role played by these fascinating cells in human disease.

Proteomic analysis of differential protein expression in atherosclerosis

Although recent studies have shown that several pro-inflammatory proteins can be used as biomarkers for atherosclerosis, the mechanism of atherogenesis is unclear and little information is available regarding proteins involved in development of the disease. Atherosclerotic tissue samples were collected from patients in order to identify the proteins involved in atherogenesis. The protein expression profile of atherosclerosis patients was analysed using two-dimensional electrophoresis-based proteomics. Thirty-nine proteins were detected that were differentially expressed in the atherosclerotic aorta compared with the normal aorta. Twenty-seven of these proteins were identified in the MS-FIT database. They are involved in a number of biological processes, including calcium-mediated processes, migration of vascular smooth muscle cells, matrix metalloproteinase activation and regulation of pro-inflammatory cytokines. Confirmation of differential protein expression was performed by Western blot analysis. Potential applications of the results include the identification and characterization of signalling pathways involved in atherogenesis, and further exploration of the role of selected identified proteins in atherosclerosis.

C-reactive protein, stroke, and statins

C-reactive protein (CRP) is an important indicator and player in inflammatory diseases such as stroke. It may be involved in the earliest stages of stroke. Monitoring the levels of CRP may help in the prevention and treatment of stroke. Statin drugs may be useful in lowering CRP levels and the incidence of stroke.

Plasma total homocysteine levels in children with type 1 diabetes: relationship with vitamin status, methylene tetrahydrofolate reductase genotype, disease parameters and coronary risk factors

The objectives of this study were: to determine plasma total homocysteine tHcy levels and the prevalence of hyperhomocysteinemia in children with type 1 diabetes, to determine correlates of plasma tHcy levels with nutritional factor such as serum folic acid and vitamin B12 levels, genetic factors as methylenetetrahydrofolate reductase MTHFR gene polymorphism (C677T and A1298C), to attempt to identify possible dependencies between tHcy and the degree of metabolic control, the duration of the disease and presence of complications, and also to determine the relationship between other coronary risk factors. Plasma tHcy levels and other related parameters performed in 32 children with type 1 diabetes and 23 age-sex matched healthy children. Median tHcy level was higher in the patient group (11.38, 3.28 to 66.01 micromol/l) than the control group (8.78, 1.06 to 13.66 mol/l) (p < 0.05). A 28.1 per cent (n = 9) of the diabetic patients had hyperhomocysteinemia, four case with mild and five case with moderate. Plasma tHcy levels were positively correlated with disease duration and C-reactive protein CRP levels and negatively correlated with disease onset age. The hyperhomocysteinemic group had higher CRP levels, longer disease duration and early onset of disease than non-hyperhomocysteinemic group (p < 0.05 in both), respectively. The hyperhomocysteinemic group had significantly higher CRP, total cholesterol, triglyceride, apolipoprotein B, systolic blood pressure, blood urea nitrogen and creatinine levels and lower folate, apolipoprotein A1 levels and glomerular filtration rate values than the control group. Plasma tHcy levels were higher in diabetic children with poor metabolic control. Because of hyperhomocysteinemia is common in diabetic children and plasma tHcy levels correlated with early onset of the disease and disease duration, we recommend the usage of plasma tHcy levels as a risk indicator parameter with other coronary risk factor for detecting and preventing cardiovascular disease in diabetic children.