Understanding Changes in High Density Lipoproteins During the Acute Phase Response

Pharmacological rationale for the very early treatment of acute coronary syndrome with monoclonal antibodies anti-PCSK9

Immediate and aggressive lipid lowering therapies after acute coronary syndromes (ACS) and percutaneous coronary interventions (PCI) are supported by the ESC/EAS dyslipidemia guidelines, recommending the initiation of high-intensity statin therapy within the first 1-4 days of hospitalization. However, whether non statin lipid-lowering agents, added to statin treatment, could produce a further reduction in the risk of major adverse cardiovascular events (MACE) is still unknown. Thus, the efficacy of early treatment post-ACS with monoclonal antibodies (mAbs) anti PCSK9, evolocumab and alirocumab, is under investigation. The rationale to explore the rapid and aggressive pharmacological intervention with PCSK9 mAbs is supported by at least five confirmatory data in ACS: 1) circulating PCSK9 levels are raised during ACS 2) PCSK9 may stimulate platelet reactivity, this last being pivotal in the recurrence of ischemic events; 3) PCSK9 is associated with intraplaque inflammation, macrophage activation and endothelial dysfunction; 4) PCSK9 concentrations are associated with inflammation in the acute phase of ACS; and 5) statins raise PCSK9 levels promptly and, at times, dramatically. In this scenario, appropriate pharmacodynamic characteristics of anti PCSK9 therapies are a prerequisite for an effective response. Monoclonal antibodies act on circulating PCSK9 with a direct and rapid binding by blocking the interaction with the low-density lipoprotein receptor (LDLR). Evolocumab and alirocumab show a very rapid (within 4 h) and effective suppression of circulating unbound PCSK9 (- 95 % ÷ - 97 %). This inhibition results in a significant reduction of LDL-cholesterol (LDL-C) after 48 h (- 35 %) post injection with a full effect after 7-10 days (55-75 %). The complete and swift inhibitory action by evolocumab and alirocumab could have a potential clinical impact in ACS patients, also considering their potential inhibition of PCSK9 within the atherosclerotic plaque. Thus, administration of evolocumab or alirocumab is effective in lowering LDL-C levels in ACS, although the efficacy to prevent further cardiovascular (CV) events is still undetermined. The answer to this question will be provided by the ongoing clinical trials with evolocumab and alirocumab in ACS. In the present review we will discuss the pharmacological and biological rationale supporting the potential use of PCSK9 mAbs in ACS patients and the emerging evidence of evolocumab and alirocumab treatment in this clinical setting.

Lower LDL-cholesterol levels associated with increased inflammatory burden in patients with acute ST-segment elevation myocardial infarction

OBJECTIVE

Association of low-density lipoprotein cholesterol and highly sensitive C-reactive protein in ST-elevation myocardial infarction patients was assessed in this study.

METHODS

591 consecutive patients who were hospitalized with a diagnosis of ST-elevation myocardial infarction were enrolled and assigned into tertiles according to their serum low-density lipoprotein cholesterol levels. Differences in highly sensitive C-reactive protein among low-density lipoprotein cholesterol tertiles and correlations between highly sensitive C-reactive protein and low-density lipoprotein cholesterol were assessed.

RESULTS

Highly sensitive C-reactive protein levels differed significantly among the groups (p<0.001) and found to be highest in the low-density lipoprotein cholesterol tertile 1 and lowest in the low-density lipoprotein cholesterol tertile 3 (post-hoc p-values: tertile 1 vs. 2 <0.001; tertile 1 vs. 3 <0.001; tertile 2 vs. 3=0.019). There was a negative correlation between hs-CRP and both low-density lipoprotein cholesterol (r=-0.332, p<0.001) and total cholesterol (r=-0.326, p<0.001). There was also a negative correlation between highly sensitive C-reactive protein and high-density lipoprotein cholesterol, though the strength of this relationship was weak (r=-0.103, p=0.014).

CONCLUSION

Lower low-density lipoprotein cholesterol levels are associated with higher inflammatory burden in patients with acute STEMI. Further studies are required to elucidate the significance of low-density lipoprotein cholesterol levels in ST-elevation myocardial infarction settings.

Functional Food and Bioactive Compounds on the Modulation of the Functionality of HDL-C: A Narrative Review

Cardiovascular diseases (CVD) remain a serious public health problem and are the primary cause of death worldwide. High-density lipoprotein cholesterol (HDL-C) has been identified as one of the most important molecules in the prevention of CVD due to its multiple anti-inflammatories, anti-atherogenic, and antioxidant properties. Currently, it has been observed that maintaining healthy levels of HDL-C does not seem to be sufficient if the functionality of this particle is not adequate. Modifications in the structure and composition of HDL-C lead to a pro-inflammatory, pro-oxidant, and dysfunctional version of the molecule. Various assays have evaluated some HDL-C functions on risk populations, but they were not the main objective in some of these. Functional foods and dietary compounds such as extra virgin olive oil, nuts, whole grains, legumes, fresh fish, quercetin, curcumin, ginger, resveratrol, and other polyphenols could increase HDL functionality by improving the cholesterol efflux capacity (CEC), paraoxonase 1 (PON1), and cholesteryl ester transfer protein (CETP) activity. Nevertheless, additional rigorous research basic and applied is required in order to better understand the association between diet and HDL functionality. This will enable the development of nutritional precision management guidelines for healthy HDL to reduce cardiovascular risk in adults. The aim of the study was to increase the understanding of dietary compounds (functional foods and bioactive components) on the functionality of HDL.

The Lipid Paradox as a Metabolic Checkpoint and Its Therapeutic Significance in Ameliorating the Associated Cardiovascular Risks in Rheumatoid Arthritis Patients

While the most common manifestations associated with rheumatoid arthritis (RA) are synovial damage and inflammation, the systemic effects of this autoimmune disorder are life-threatening, and are prevalent in 0.5–1% of the population, mainly associated with cardiovascular disorders (CVDs). Such effects have been instigated by an altered lipid profile in RA patients, which has been reported to correlate with CV risks. Altered lipid paradox is related to inflammatory burden in RA patients. The review highlights general lipid pathways (exogenous and endogenous), along with the changes in different forms of lipids and lipoproteins in RA conditions, which further contribute to elevated risks of CVDs like ischemic heart disease, atherosclerosis, myocardial infarction etc. The authors provide a deep insight on altered levels of low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) and triglycerides (TGs) in RA patients and their consequence on the cardiovascular health of the patient. This is followed by a detailed description of the impact of anti-rheumatoid therapy on the lipid profile in RA patients, comprising DMARDs, corticosteroids, anti-TNF agents, anti-IL-6 agents, JAK inhibitors and statins. Furthermore, this review elaborates on the prospects to be considered to optimize future investigation on management of RA and treatment therapies targeting altered lipid paradigms in patients.

Serial measurements of Paraoxonase-1 (PON-1) activity in horses with experimentally induced endotoxemia

Background

Paraoxonase-1 (PON-1) is an antioxidant enzyme, whose activity decreases during the acute phase response in many species. Little is known about PON-1 and its role as a negative acute phase protein during septic inflammation in horses, but promising findings about its utility in diagnosing SIRS and predicting the outcome in diseased horses, were recently highlighted. The objective of the study was to investigate the behaviour of PON-1 in horses after experimentally induced endotoxemia. To this aim, PON-1 activity was measured on 66 plasma samples collected from six clinically healthy mares, previously included in another study, before and at multiple time points between 12 and 240 h after intravenous infusion of Escherichia coli O55:B5 lipopolysaccharide (LPS).

Results

Compared with baseline values, a progressive transient decrease of PON-1 activity was observed starting from 24 h post-infusion, with lowest values observed between 3 to 7 days post-infusion, followed by a normalisation to pre-infusion levels the tenth day.

Conclusions

The results of this study suggest that measurement and monitoring of PON-1 activity might be useful to evaluate progression and recovery from endotoxemia in horses. Further studies in horses with naturally occurring sepsis are warranted.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12917-020-02629-4.

Cardiovascular co-morbidity in patients with rheumatoid arthritis: a narrative review of risk factors, cardiovascular risk assessment and treatment

Cardiovascular disease (CVD) is markedly increased in patients with rheumatoid arthritis partly due to accelerated atherosclerosis from chronic inflammation. Traditional cardiovascular risk factors such as hypertension, hyperlipidemia, smoking, diabetes mellitus and physical inactivity are also highly prevalent among patients with rheumatoid arthritis (RA) and contribute to the CVD risk. The impact of traditional risk factors on the CVD risk appears to be different in the RA and non-RA population. However, hyperlipidemia, diabetes mellitus, body mass index and family history of CVD influence the CVD risk in RA patients the same way they do for the non-RA population. Despite that, screening and treatment of these risk factors is suboptimal among patients with RA. Recent guidelines from the European League Against Rheumatism (EULAR) recommend aggressive management of traditional risk factors in addition to RA disease activity control to decrease the CVD risk. Several CVD risk calculators are available for clinical use to stratify a patients' risk of developing a CVD event. Most of these calculators do not account for RA as a risk factor; thus, a multiplication factor of 1.5 is recommended to predict the risk more accurately. In order to reduce CVD in the RA population, national guidelines for the prevention of CVD should be applied to manage traditional risk factors in addition to aggressive control of RA disease activity. While current data suggests a protective effect of non-biologic disease modifying anti-rheumatic drugs (DMARDs) and biologics on cardiovascular events among patients with RA, more data is needed to define this effect more accurately.

Persistent Unresolved Inflammation in the Mecp2-308 Female Mutated Mouse Model of Rett Syndrome

Rett syndrome (RTT) is a rare neurodevelopmental disorder usually caused by mutations in the X-linked gene methyl-CpG-binding protein 2 (MECP2). Several Mecp2 mutant mouse lines have been developed recapitulating part of the clinical features. In particular, Mecp2-308 female heterozygous mice, bearing a truncating mutation, are a validated model of the disease. While recent data suggest a role for inflammation in RTT, little information on the inflammatory status in murine models of the disease is available. Here, we investigated the inflammatory status by proteomic 2-DE/MALDI-ToF/ToF analyses in symptomatic Mecp2-308 female mice. Ten differentially expressed proteins were evidenced in the Mecp2-308 mutated plasma proteome. In particular, 5 positive acute-phase response (APR) proteins increased (i.e., kininogen-1, alpha-fetoprotein, mannose-binding protein C, alpha-1-antitrypsin, and alpha-2-macroglobulin), and 3 negative APR reactants were decreased (i.e., serotransferrin, albumin, and apolipoprotein A1). CD5 antigen-like and vitamin D-binding protein, two proteins strictly related to inflammation, were also changed. These results indicate for the first time a persistent unresolved inflammation of unknown origin in the Mecp2-308 mouse model.

Paraoxonases and infectious diseases

The paraoxonases (PON1, PON2 and PON3) are an enzyme family with a high structural homology. All of them have lactonase activity and degrade lipid peroxides in lipoproteins and cells. As such, they play a role in protection against oxidation and inflammation. Infectious diseases are often associated with oxidative stress and an inflammatory response. Infection and inflammation trigger a cascade of reactions in the host, known as the acute-phase response. This response is associated with dramatic changes in serum proteins and lipoproteins, including a decrease in serum PON1 activity. These alterations have clinical consequences for the infected patient, including an increased risk for cardiovascular diseases, and an impaired protection against the formation of antibiotic-resistant bacterial biofilms. Several studies have investigated the value of serum PON1 measurement as a biomarker of the infection process. Low serum PON1 activities are associated with poor survival in patients with severe sepsis. In addition, preliminary studies suggest that serum PON1 concentration and/or enzyme activity may be useful as markers of acute concomitant infection in patients with an indwelling central venous catheter. Investigating the associations between paraoxonases and infectious diseases is a recent, and productive, line of research.

Evaluation of Lipid Profile Changes in Pediatric Patients with Acute Mononucleosis

BACKGROUND

Acute Epstein-Barr virus (EBV) infection could lead to atherogenic lipid profile changes in adults; while there is no evidence about the children with Infectious mononucleosis (IM). The aim of this study was to evaluate the lipid profile of the children in acute phase of mononucleosis and two months after the recovery.

MATERIALS AND METHODS

From 2010 through 2012, 36 children with IM aged 1-10 years were enrolled in a prospective cross-sectional study. Fasting serum total cholesterol, high density lipoprotein (HDL), low density lipoprotein (LDL), and triglyceride level were measured during acute phase of the disease and after 2 months of the recovery.

RESULTS

From 36 patients enrolled, 25 (69.4%) cases were male and the mean age of the patients was 4.1 ± 2.0 years. The mean of the total cholesterol level in the acute phase and 2 months after the recovery were149.5 ± 35.3 mg/dL and 145.7±30.6, respectively (P = 0.38). However, the serum level of HDL cholesterol in patients after 2 months of recovery was significantly increased (37.9 ± 9.3 mg/dL vs. 28.5 ± 10.6 mg/dL, P < 0.001). The mean value of serum LDL cholesterol was significantly reduced, two months after recovery (81.4 ± 19.5 mg/dL, vs. 92.6 ± 28.8 mg/dL, P = 0.009). Furthermore, the serum triglyceride level was significantly reduced after the recovery (108.7 ± 36.9 mg/dL) compared with the acute phase (163.8 ± 114.3 mg/dL) (P = 0.004).

CONCLUSION

EBV infection in children could change lipid profile which is partially restored 2 months after the recovery.

Colorimetric and electrophoretic evaluation of lipoprotein fractions in healthy neonatal calves: Comparison with results from adult cows and from calves with inflammatory conditions

High density lipoproteins (HDLs) are pivotal in innate immunity and decrease in serum during inflammation. Several studies have been done about lipoprotein changes in transition cows but little is known about their changes in newborn calves. The aim of this study is to provide information about HDLs in newborn calves, by defining the possible age-related changes in healthy calves compared with adults and by assessing the possible differences in calves with inflammation. Lipoprotein electrophoretic separation (reported as percentages) and colorimetric measurement of HDL (HDL-C) were performed on healthy cows and calves in order to identify possible differences in the lipoprotein profile due to the age. Then, age-matched calves with inflammatory conditions were also evaluated. Results showed that in calves HDL% and VLDL% were lower (mean values±SD: 77.6%±8.6% and 2.6%±2.5%, respectively) and LDL% was higher (19.7%±7.4%) than in adults (89.0%±3.9%; 5.2±2.1% and 5.8%±3.1%, respectively). Sick calves revealed a decrease of both HDL% (mean values ± SD: 61.0%±22.1%) and HDL-C (22.8±11.6mg/dL) and an increase of VLDL% (12.1% ±13.1%) compared with controls (77.6%±8.6%; 41.5±11.2mg/dL and 2.6%±2.5%, respectively). Paraoxonase-1 activity, influenced by inflammation and oxidation, was measured, and it appeared correlated with HDL% and HDL-C in sick calves. In conclusion, this study revealed that HDLs concentration in healthy calves is lower than in adults, and further decreases in calves with inflammation, likely due to oxidation.

Associations between follicular fluid high density lipoprotein particle components and embryo quality among in vitro fertilization patients

PURPOSE

Follicular redox balance is likely to be important for embryo quality during in vitro fertilization (IVF), and the anti-oxidative high desity lipoprotein (HDL) particle is the sole lipoprotein measured in follicular fluid (FF). Therefore, we investigated FF HDL particle components as predictors of embryo quality during IVF.

METHODS

Two research follicles collected from each participant were individually tracked, and 103 women having at least one developed embryo were included in the analysis. Concentrations of 15 non-cholesterol HDL particle components and 26 HDL-cholesterol (HDL-C) particle size subfractions were determined. Embryo quality was assessed for embryo cell number, embryo fragmentation, and embryo symmetry. Multivariable Poisson regression with a sandwich variance estimator was used to evaluate associations between HDL particle components and embryo quality, adjusted for covariates.

RESULTS

Higher γ-tocopherol concentration was associated with less embryo fragmentation (relative risk [RR] = 4.43; 95 % confidence interval [CI] 1.78, 11.06), and higher apolipoprotein A-1 concentration was associated with full embryo symmetry (RR = 3.92; 95 % CI 1.56, 9.90). Higher concentrations of HDL-C subfractions in the large and medium particle size ranges were associated with poorer embryo quality.

CONCLUSIONS

FF HDL lipophilic micronutrients and protein components, as well as HDL-C particle size, may be important predictors of embryo quality during IVF.

Subfractions of high-density lipoprotein (HDL) and dysfunctional HDL in chronic kidney disease patients

A number of studies have shown that chronic kidney disease (CKD) is associated with increased risk for cardiovascular disease (CVD). Chronic kidney disease is characterized by significant disturbances in lipoprotein metabolism, including differences in quantitative and qualitative content of high-density lipoprotein (HDL) particles. Recent studies have revealed that serum HDL cholesterol levels do not predict CVD in CKD patients; thus CKD-induced modifications in high-density lipoprotein (HDL) may be responsible for the increase in CV risk in CKD patients. Various methods are available to separate several subclasses of HDL and confirm their atheroprotective properties. However, under pathological conditions associated with inflammation and oxidation, HDL can progressively lose normal biological activities and be converted into dysfunctional HDL. In this review, we highlight the current state of knowledge on subfractions of HDL and HDL dysfunction in CKD.

Levels of High-Density Lipoprotein Cholesterol are Associated With Biomarkers of Inflammation in Patients With Acute Coronary Syndrome

Pathologic conditions associated with inflammation show an inverse correlation between high-density lipoprotein cholesterol (HDL-C) and inflammatory biomarker levels. Our aim was to investigate, in patients with acute coronary syndrome (ACS), whether very low HDL-C levels are associated with inflammatory biomarkers. In a cross-sectional study, we included 6,134 patients with ACS; they were classified as having very low (<30 mg/dl), low (30 to 39.9 mg/dl), and normal HDL-C (≥ 40 mg/dl) levels. We analyzed the association of different categories of HDL-C levels with serum levels of inflammatory biomarkers, high-sensitivity C-reactive protein (hs-CRP), albumin, and white blood cell count at admission. Overall, 18.5% of patients had very low HDL-C levels. Patients with very low HDL-C levels, compared to patients with low or normal HDL-C levels, had the highest hs-CRP (median 17.8 [interquartile range 7.2 to 54.5] vs 12.6 [5.6 to 33.9] vs 12.0 [5.4 to 36.9] mg/L, respectively, p <0.001) and the lowest albumin levels (median 3.6 [IQR 3.3 to 4.0] vs 3.8 [3.5 to 4.0] vs 3.8 [3.5 to 4.1] g/dl, respectively, p <0.001). White blood cell count did not differ significantly (p = 0.40). The multivariate analysis showed that albumin ≤ 3.5 g/dl (odds ratio 2.16, 95% confidence interval 1.88 to 2.49, p <0.001) and hs-CRP ≥ 10 mg/L (odds ratio 1.35, 95% confidence interval 1.17 to 1.55, p <0.001) were independent predictors of very low HDL-C levels. Patients with very low HDL-C levels had the highest inhospital mortality rates compared with the other groups. In conclusion, in patients with ACS, hs-CRP and serum albumin were associated independently with very low HDL-C levels.

Inflammation, adiposity, and atherogenic dyslipidemia in rheumatoid arthritis: is there a paradoxical relationship?

Dyslipidemia is highly prevalent in rheumatoid arthritis (RA) and appears to be present very early in the RA disease process, in some studies even before a diagnosis of clinical RA has been made. The association between lipid measures and the risk of cardiovascular disease (CVD) in RA appears to be paradoxical, whereby lower levels of total cholesterol (TC), low-density lipoprotein (LDL-C), and atherogenic ratios are associated with higher CVD risk. This may be due to the lipid-lowering effects of RA-related systemic inflammation. Therefore, standard CVD risk calculators have been shown to underperform in RA. Data also suggest that lipoprotein particle sizes and the apolipoprotein cargo of lipoproteins skew toward atherogenic dyslipidemia in RA and may contribute to the initiation and progression of atherosclerosis. Inflammatory burden in RA may also alter the anti-inflammatory and atheroprotective roles associated with high-density lipoprotein cholesterol (HDL-C). Adipose tissue is quantitatively increased in RA patients compared with matched non-RA controls and may be more inflamed and metabolically dysfunctional compared with an otherwise similar non-RA patient. In vitro, animal, and a handful of non-RA human, studies suggest that inflamed, metabolically dysfunctional adipose tissue contributes directly to lower HDL-C levels. In turn, lower HDL-C that has been altered functionally by inflammation may lead to expanded adipose mass and further adipose dysfunction and inflammation. In the last part of this review, we speculate how the RA disease state may recapitulate these processes.

Cholesteryl Ester Transfer Protein Inhibitors - Future Soon to be REVEALed

Reduction of the remaining residual cardiovascular risk is a clinical unmet need currently being addressed through a combination of further reduction of plasma concentrations of low-density lipoproteins (LDLs) and increasing plasma concentrations of high-density lipoproteins (HDLs). This brief review sets out the so-called HDL hypothesis and summarises the clinical results of the family of drugs, which function to raise plasma HDL concentration through inhibition of cholesteryl ester transfer proteins (CEPT).

[Atherosclerosis in systemic lupus erythematosus]

CONTEXT

Evidence from epidemiological studies demonstrates that patients with systemic lupus erythematosus (SLE) are at increased risk for the development of cardiovascular disease. Traditional cardiovascular risk factors' play an important role in this phenomenon but do not account for the entire risk in lupus patients.

OBJECTIVES

The incidence and prevalence of cardiovascular events and infraclinical atherosclerosis are reviewed. Combinations of traditional risk factors with lupus-specific and treatment-related variables are detailed.

RESULTS

Atherosclerosis is more prevalent and occurs prematurely in lupus patients. Relative risk of myocardial infarction is between 5 to 8 times greater that of general population, and may exceed 50 in women between 35 and 44 years old. SLE was also found as an independent risk factor for subclinical atherosclerosis, and more than one third of lupus patient show evidence of carotid plaques of coronary artery calcifications. Lupus patients have more frequent traditional risk factors compared with general population of similar age and sex. Besides the traditional risk factors, SLE specific risk factors have been identified among witch advanced age at diagnosis, current disease activity, duration of the disease and renal activity. Moreover, lipid abnormalities in patients with SLE are common and likely are one of the major causes of premature atherosclerosis in these patients; the dyslipoprotein associated increased triglycerides and depressed HDL-cholesterol with proinflammatory HDL production. Autoimmunity may have a part of responsibility, but data's in favour of this hypothesis are not strong. Other mechanisms such as vascular inflammation, oxidative stress, immune complexes and complement activation may also elicit endothelial damage and promote atherosclerosis are associated with the pathogenesis of both SLE and atherosclerosis. Steroids may have a true double-edged role with a pro-atherogenic risk regarding the exacerbation of metabolic risk factors and a "beneficial" anti-inflammatory role. It is becoming increasingly apparent that antimalarials treatment in SLE has an atheroprotective and a cardioprotective effect. The other immunosuppressive drugs may reduce progression of atherosclerosis and cardiovascular events but their precise role remains to be elucidated. Despite their role in primary prevention in target general population, for now, systematic prescription of statins does not show a great benefit in the cardiovascular risk in lupus patients.

CONCLUSION

Mechanisms of atherosclerosis in SLE remain elusive. It is partially explained by the interaction of traditional cardiovascular risk factors, lupus-specific factors and therapy specially corticosteroids. Management strategies of lupus should include early all those items.

Subclinical inflammatory status in Rett syndrome

Inflammation has been advocated as a possible common central mechanism for developmental cognitive impairment. Rett syndrome (RTT) is a devastating neurodevelopmental disorder, mainly caused by de novo loss-of-function mutations in the gene encoding MeCP2. Here, we investigated plasma acute phase response (APR) in stage II (i.e., “pseudo-autistic”) RTT patients by routine haematology/clinical chemistry and proteomic 2-DE/MALDI-TOF analyses as a function of four major MECP2 gene mutation types (R306C, T158M, R168X, and large deletions). Elevated erythrocyte sedimentation rate values (median 33.0 mm/h versus 8.0 mm/h, P < 0.0001) were detectable in RTT, whereas C-reactive protein levels were unchanged (P = 0.63). The 2-DE analysis identified significant changes for a total of 17 proteins, the majority of which were categorized as APR proteins, either positive (n = 6 spots) or negative (n = 9 spots), and to a lesser extent as proteins involved in the immune system (n = 2 spots), with some proteins having overlapping functions on metabolism (n = 7 spots). The number of protein changes was proportional to the severity of the mutation. Our findings reveal for the first time the presence of a subclinical chronic inflammatory status related to the “pseudo-autistic” phase of RTT, which is related to the severity carried by the MECP2 gene mutation.

Classification accuracy of serum Apo A-I and S100B for the diagnosis of mild traumatic brain injury and prediction of abnormal initial head computed tomography scan

The objective of the current study was to determine the classification accuracy of serum S100B and apolipoprotein (apoA-I) for mild traumatic brain injury (mTBI) and abnormal initial head computed tomography (CT) scan, and to identify ethnic, racial, age, and sex variation in classification accuracy. We performed a prospective, multi-centered study of 787 patients with mTBI who presented to the emergency department within 6 h of injury and 467 controls who presented to the outpatient laboratory for routine blood work. Serum was analyzed for S100B and apoA-I. The outcomes were disease status (mTBI or control) and initial head CT scan. At cutoff values defined by 90% of controls, the specificity for mTBI using S100B (0.899 [95% confidence interval (CI): 0.78-0.92]) was similar to that using apoA-I (0.902 [0.87-0.93]), and the sensitivity using S100B (0.252 [0.22-0.28]) was similar to that using apoA-I (0.249 [0.22-0.28]). The area under the receiver operating characteristic curve (AUC) for the combination of S100B and apoA-I (0.738, 95% CI: 0.71, 0.77), however, was significantly higher than the AUC for S100B alone (0.709, 95% CI: 0.68, 0.74, p=0.001) and higher than the AUC for apoA-I alone (0.645, 95% CI: 0.61, 0.68, p<0.0001). The AUC for prediction of abnormal initial head CT scan using S100B was 0.694 (95%CI: 0.62, 0.77) and not significant for apoA-I. At a S100B cutoff of <0.060 μg/L, the sensitivity for abnormal head CT was 98%, and 22.9% of CT scans could have been avoided. There was significant age and race-related variation in the accuracy of S100B for the diagnosis of mTBI. The combined use of serum S100B and apoA-I maximizes classification accuracy for mTBI, but only S100B is needed to classify abnormal head CT scan. Because of significant subgroup variation in classification accuracy, age and race need to be considered when using S100B to classify subjects for mTBI.

Human apolipoprotein A-I is associated with dengue virus and enhances virus infection through SR-BI

Diseases caused by dengue virus (DV) infection vary in severity, with symptoms ranging from mild fever to life threatening dengue hemorrhage fever (DHF) and dengue shock syndrome (DSS). Clinical studies have shown that significant decrease in the level of lipoproteins is correlated with severe illness in DHF/DSS patients. Available evidence also indicates that lipoproteins including high-density lipoprotein (HDL) and low-density lipoprotein (LDL) are able to facilitate cell entry of HCV or other flaviviruses via corresponding lipoprotein receptors. In this study, we found that pre-incubation of DV with human serum leads to an enhanced DV infectivity in various types of cells. Such enhancement could be due to interactions between serum components and DV particles. Through co-immunoprecipitation we revealed that apolipoprotein A-I (ApoA-I), the major protein component in HDL, is associated with DV particles and is able to promote DV infection. Based on that observation, we further found that siRNA knockdown of the scavenger receptor class B type I (SR-BI), the cell receptor of ApoA-I, abolished the activity of ApoA-I in enhancement of DV infection. This suggests that ApoA-I bridges DV particles and cell receptor SR-BI and facilitates entry of DV into cells. FACS analysis of cell surface dengue antigen after virus absorption further confirmed that ApoA-I enhances DV infection via promoting initial attachment of the virus to cells. These findings illustrate a novel entry route of DV into cells, which may provide insights into the functional importance of lipoproteins in dengue pathogenesis.

High-density lipoprotein in uremic patients: metabolism, impairment, and therapy

Several studies have shown that HDL has altered antioxidant and anti-inflammatory effects in chronic uremia, either by the reduction in its antioxidant enzymes or by the impairment of their activity. Systemic oxidative stress, which is highly prevalent in chronic kidney disease (CKD) patients, has been shown to decrease antioxidant and anti-inflammatory effects of HDL and even transform it into a pro-oxidant and pro-inflammatory agent. For this reason, we believe that the propensity for accelerated cardiovascular disease in CKD is facilitated by a few key features of this disease, namely, oxidative stress, inflammation, hypertension, and disorders of lipid metabolism. In a nutshell, oxidative stress and inflammation enhance atherosclerosis leading to increased cardiovascular mortality and morbidity in this population. In this detailed review, we highlight the current knowledge on HDL dysfunction and impairment in chronic kidney disease as well as the available therapy.

SAA does not induce cytokine production in physiological conditions

SAA has been shown to have potential proinflammatory properties in inflammatory diseases such as atherosclerosis. These include induction of tumor necrosis factor α, interleukin-6, and monocyte chemoattractant protein 1 in vitro. However, concern has been raised that these effects might be due to use of recombinant SAA with low level of endotoxin contaminants or its non-native forms. Therefore, physiological relevance has not been fully elucidated. In this study, we investigated the role of SAA in the production of inflammatory cytokines. Stimulation of mouse monocyte J774 cells with lipid-poor recombinant human SAA and purified SAA derived from cardiac surgery patients, but not ApoA-I and ApoA-II, elicited pro-inflammatory cytokines like granulocyte colony stimulating factor (G-CSF). However, HDL-associated SAA failed to stimulate production of these cytokines. Using neutralizing antibodies against toll like receptor (TLR) 2 and 4, we could evaluate that TLR 2 is responsible for G-CSF production by lipid-poor SAA. To confirm these data in vivo, we expressed mouse SAA in SAA deficient C57BL/6 mice using an adenoviral vector. G-CSF was identically expressed in SAA-Adenoviral infected mice as well as in control null-Adenoviral mice at the early time points (4-8h) and could not be detected in plasma 24h after infection when plasma SAA levels were maximally elevated, indicating that adenoviral vector rather than SAA affected G-CSF levels. Taken together, our findings suggest that lipid-poor SAA, but not HDL-associated SAA, stimulates G-CSF production and this stimulation is mediated through TLR 2 in J774 cells. However, its physiological role in vivo remains ambiguous.

Atherosclerosis and rheumatoid arthritis: more than a simple association

In the last decades a large amount of evidence linked rheumatoid arthritis (RA) to atherosclerosis. In fact, RA patients have an increased risk of cardiovascular events that is not fully explained by other classic cardiovascular risk factors. RA and atherosclerosis may share several common pathomechanisms and inflammation undoubtedly plays a primary role. The proinflammatory cytokines such as tumor necrosis factor alpha and interleukin-6, involved in the pathogenesis of RA, are also independently predictive of subsequent cardiovascular disease (CVD). In RA, inflammation alters HDL constituents and the concentration of LDL and HDL, thus facilitating atherosclerosis and CVD events. On the other hand, also the increase of oxidative processes, frequently observed in RA, induces atherosclerosis. Interestingly, some genetic polymorphisms associated with RA occurrence enhance atherosclerosis, however, other polymorphisms associated with RA susceptibility do not increase CVD risk. Several other mechanisms may influence atherosclerotic processes in RA. Moreover, atherosclerosis may be directly mediated also by underlying autoimmune processes, and indirectly by the occurrence of metabolic syndrome and impaired physical activity. Finally, the effects of RA therapies on cardiovascular system in general and on atherosclerosis in particular are really wide and different. However, the starting point of every RA treatment is that disease control, or better remission, is the best way we have for the reduction of CVD occurrence.

Salutary effects of hemodialysis on low-density lipoprotein proinflammatory and high-density lipoprotein anti-inflammatory properties in patient with end-stage renal disease

End-stage renal disease (ESRD) causes oxidative stress, inflammation, low-density lipoprotein (LDL) oxidation, high-density lipoprotein (HDL) deficiency and accelerated atherosclerosis. Uptake of oxidized LDL by macrophages results in foam cell and plaque formation. HDL mitigates atherosclerosis via reverse cholesterol transport and inhibition of LDL oxidation. ESRD heightens LDL inflammatory activity and suppresses HDL anti-inflammatory activity. The effect of hemodialysis on the LDL and HDL inflammatory properties is unknown. By removing the potential pro-oxidant/proinflammatory uremic toxins, dialysis may attenuate LDL inflammatory and HDL anti-inflammatory properties. Conversely, exposure to dialyzer membrane and tubing and influx of impurities from dialysate can intensify LDL and HDL inflammatory activities. This study examined the effect of hemodialysis on LDL and HDL inflammatory activities. Plasma samples were obtained from 12 normal control and 26 ESRD patients before and after hemodialysis with (16 patients) or without (10 patients) heparinization. HDL and LDL were isolated and tested for monocyte chemotactic activity in cultured endothelial cells. ESRD patients had increased LDL chemotactic activity, reduced HDL anti-inflammatory activity, paraoxonase and glutathione peroxidase levels, and elevated plasma IL-6 before dialysis. Hemodialysis partially improved LDL inflammatory and HDL anti-inflammatory activities and enhanced patients' HDL ability to suppress their LDL inflammatory activity. The salutary effect on LDL inflammatory activity was significantly greater in patients dialyzed with than those without heparin. ESRD heightens LDL inflammatory and impairs HDL anti-inflammatory activities. Hemodialysis partially improves LDL and HDL inflammatory activities. The salutary effects of hemodialysis are in part mediated by heparin, which is known to possess lipolytic and antioxidant properties.

Lipotoxicity and impaired high density lipoprotein-mediated reverse cholesterol transport in chronic kidney disease

Chronic kidney disease (CKD) is associated with a high risk of death from cardiovascular disease. Inflammation, oxidative stress, and dyslipidemia, which are common consequences of CKD, contribute to the pathogenesis of atherosclerosis and cardiovascular disease in this population. Dyslipidemia of CKD is characterized by diminished plasma high density lipoprotein (HDL) concentration, impaired HDL anti-oxidant and anti-inflammatory activities, and elevated plasma triglyceride, very low density lipoprotein (VLDL), intermediate density lipoprotein, chylomicron remnants, and oxidized lipids and lipoproteins. The constellation of inflammation, HDL deficiency, and oxidative modification of lipoproteins can cause atherosclerosis and progression of renal disease. We have recently found lipid accumulation in the remnant kidney and the wall of aorta in rats with CKD induced by 5/6 nephrectomy. This was mediated by up-regulation of scavenger receptors involved in the influx of oxidized lipids or lipoproteins, tubular reabsorption of lipid binding proteins through megalin-cubilin complexes, upregulation of fatty acid synthesis, and downregulation of fatty acid oxidation pathways. The combination of increased lipid influx, elevated production and reduced catabolism of lipids, and impaired HDL-mediated reverse cholesterol transport can promote atherosclerosis, glomerulosclerosis, and tubulointerstitial damage. Although statins can be effective in slowing CKD progression in patients with mild-to-moderate CKD, they have consistently failed to mitigate oxidative stress, inflammation, HDL deficiency, or cardiovascular mortality in the end-stage renal disease populations. Similarly, high doses of antioxidant vitamins have failed to either ameliorate oxidative stress, inflammation, or improve overall mortality in end-stage renal disease. This article is intended to provide a brief review of the effects of CKD on HDL structure and function and pathways of lipid influx, efflux, synthesis, and catabolism in the artery wall and the diseased kidney.

An altered pattern of liver apolipoprotein A-I isoforms is implicated in male chronic hepatitis B progression

Chronic hepatitis B (CHB) appears to progress more rapidly in males than in females, and CHB-related hepatic cirrhosis and hepatocellular carcinoma are predominately diseases that tend to occur in men and postmenopausal women. To obtain more insight into the underlying mechanisms of gender disparity of CHB progress, two-dimensional difference gel electrophoresis was employed to compare liver proteome of C57BL/6 and HBV transgenic (HBV-Tg) mice both in male and female groups. We identified 8 differently expressed proteins in male HBV-Tg mice and 12 in female HBV-Tg mice. Apolipoprotein A-I (Apo A-I) was found to be down-regulated in male and female HBV-Tg mouse liver. It is more interesting that the pattern of liver Apo A-I isoforms was altered in male HBV-Tg mice but not in female HBV-Tg mice. Our further results indicated that the basic Apo A-I isoform, based on pI positions from serum 2-dimensional Western blotting, increased in male CHB patient sera but not in female CHB patient sera. Finally, we identified that the oxidative modification Apo A-I mainly reside in basic isoform. This pattern of selectively modified Apo A-I isoforms may be considered as a pathological hallmark that may extend our knowledge of the molecular pathogenesis of CHB progression.

HDL metabolism and activity in chronic kidney disease

Chronic kidney disease (CKD) is associated with development of atherosclerosis and premature death from cardiovascular disease. The predisposition of patients with CKD to atherosclerosis is driven by inflammation, oxidative stress and dyslipidemia, all of which are common features of this condition. Markers of dyslipidemia in patients with advanced CKD are impaired clearance and heightened oxidation of apolipoprotein-B-containing lipoproteins and their atherogenic remnants, and a reduction of the plasma concentration, antioxidant, and anti-inflammatory properties of high-density lipoprotein (HDL). Studies in animal models of CKD indicate that the disease promotes lipid accumulation in the artery wall and kidney, leading to atherosclerosis, glomerulosclerosis and tubulointerstitial injury. These effects seem to be mediated by an increased cellular influx of lipids, elevated cellular production and reduced cellular catabolism of fatty acids, and impaired antioxidant, anti-inflammatory and reverse lipid transport properties of HDL. Available pharmacological therapies have been largely ineffective in ameliorating oxidative stress, inflammation, HDL deficiency and/or dysfunction, and the associated atherosclerosis and cardiovascular disease in patients with end-stage renal disease. This Review aims to provide an overview of the mechanisms and consequences of CKD-induced HDL deficiency and dysfunction.

Lipoprotein (a) as an acute phase reactant in patients on chronic hemodialysis

Lipoprotein (a) [Lp(a)], is an independent risk factor for atherosclerotic cardiovascular disease in patients on chronic hemodialysis. A low concentration of high density lipoprotein cholesterol (HDL-C) and serum albumin are another potential risk factors. The purpose of this study was to explore in patients on chronic hemodialysis, whether Lp(a) elevated levels are influenced by activated acute phase response (APR) and the correlation of Lp(a) with HDL-C and serum albumin. In 69 hemodialysis patients with C-reactive protein (CRP) levels over than 10 mg/L and 101 hemodialysis patients with CRP levels in the normal range, Lp(a), HDL-C and serum albumin were determined in relation to CRP, as a sensitive marker of an APR. Results showed that serum concentration of CRP in 69 hemodialysis patients was significantly higher than in controls (44,62 mg/L versus 8,75 mg/L, p<0,01).Patients with elevated CRP had significantly higher serum levels of Lp(a) and lower serum levels of HDL-C and albumin, than patients with CRP in the normal range ( 35,39 mg/dl versus 28,6 mg/dl, p<0,01, 0,91 mmol/L versus 1,29 mmol/L, p<0,01 and 33,56 g/L versus 35,86 g/L, p<0,01). Lp(a) levels correlated positively with CRP and negatively with HDL-C and serum albumin, in patients with elevated CRP, but not in healthy controls. According to the results Lp(a) reacts as an acute phase protein, in patients with APR.

Role of adhesion in arthropod immune recognition

The recognition and inactivation of toxins and pathogens are mediated by a combination of cell-free and cellular mechanisms. A number of soluble and membrane-bound pattern recognition molecules interact with elicitors to become involved in both cell-free inactivation as well as cellular uptake reactions. Here we describe the possible recognition and effector function of key arthropod immune proteins, such as peroxinectin, hemolin, and hemomucin, as an outcome of changes in adhesiveness, which drive self-assembly reactions leading to cell-free coagulation and cellular uptake reactions. The fact that some of these proteins are essential for immune and developmental functions in some species, but are not found in closely related species, may point to the existence of multiprotein assemblies, which are conserved at the mechanistic level and can function with more than one combination of protein constituents.

PON1 is a longevity gene: results of a meta-analysis

Paraoxonase 1 (PON1) is one of the most studied genes regarding cardiovascular risk, oxidative stress and inflammation. Several lines of evidence suggests that PON1 promotes an atheroprotective effect. Patients carrying PON1 codon 192 QQ genotype display a higher risk of cardiovascular events, the major cause of mortality in the elderly: it can be predicted that gene variants increasing the risk of mortality will be under-represented in long-living individuals. We first reported that PON1 R allele (R+) carriers are significantly more represented in Italian centenarians; subsequently this topic has been addressed by many other groups, and here we report a meta-analysis on 11 studies in different populations selected by a review of the literature available in PubMed and testing the effect of the Q192R polymorphism on human ageing. QUORUM guidelines for meta-analysis have been followed, and a total number of 5962 subjects have been included: 2795 young controls (<65 years of age) and 3167 old subjects (>65 years of age). The Mantel-Haenszel weighting for pooling in presence of a fixed effects model has been applied. The meta-analysis of R carriers showed a significant result with an overall OR of 1.16 (1.04-1.30, 95% CI, p=0.006). The meta-analysis of QR genotype also showed a significant result, with an overall OR of 1.14 (1.02-1.27, 95% CI, p=0.016). The results show that PON1 gene variants at codon 192 impact on the probability of attaining longevity, and that subjects carrying RR and QR genotypes (R+ carriers) are favoured in reaching extreme ages. These results likely represent the counterpart of the effects observed on cardiovascular diseases (CVD), as centenarians and nonagenarians escaped or delayed the onset of the major age-related diseases, including CVD.

Nevirapine Increases High-Density Lipoprotein Cholesterol Concentration by Stimulation of Apolipoprotein A-I Production

Objective— The purpose of this study was to investigate the mechanism by which the nonnucleoside reverse transcriptase inhibitor (NNRTI) nevirapine (NVP) increases high-density lipoprotein cholesterol (HDLc) in treatment-experienced human immunodeficiency virus-1 (HIV-1)–infected patients.

Methods and Results— Twelve HIV-1 infected patients, with stably suppressed HIV-1 viral load using AZT/3TC/abacavir for ≥6 months, added NVP to their current antiretroviral regimen. Patients received a primed bolus infusion of the stable isotope L-[1- 13 C]-valine for 12 hours before, as well as 6 and 24 weeks after, the addition of NVP to study apolipoprotein A-I (apoA-I) kinetics. Absolute production rate (APR) and fractional catabolic rate (FCR) of apoA-I were calculated using SAAM-II modeling. Major HDLc-modulating enzymes were assessed. Plasma apoA-I and HDLc levels increased significantly after 24 weeks of treatment by, respectively, 13±4% ( P =0.01) and 16±6% ( P =0.015). Concomitantly, apoA-I production rate at 24 weeks increased by 17±7% ( P =0.04). ApoA-I catabolism did not change. A modest increase of lecithin:cholesterol acyltransferase and cholesteryl ester transfer protein activity was observed.

Conclusions— NVP increases apoA-I production, which contributes to the HDLc increase after introduction of NVP-containing regimens. In view of the potent antiatherogenic effects of apoA-I, the observed increase may contribute to the favorable cardiovascular profile of NVP.

The relationship between serum lipids and periodontitis in elderly non-smokers

BACKGROUND

There are common risk factors for periodontal disease and cardiovascular disease in elderly patients. Some studies reported that a low total cholesterol (TC) serum level is associated with a higher level of death in the elderly. The purpose of this study was to investigate the relationship between serum lipids and periodontal disease in non-smoking elderly patients.

METHODS

Two hundred thirty-four non-smokers (63 males and 171 females) participated in this study. Multiple regression analysis was performed to evaluate the relationship between serum lipids and periodontitis and between serum lipids and inflammatory factors. The percentage of sites with probing depth (PD) > or =4 mm, clinical attachment level (CAL) > or =4 mm, and bleeding on probing (BOP) were used as dependent variables. TC, high-density lipoprotein cholesterol (HDL-C), gender, and the number of teeth present were included in the model as independent variables in the first analysis. TC, HDL-C, and low-density lipoprotein cholesterol (LDL-C) were used as dependent variables. Albumin, inorganic phosphorus, calcium, and C-reactive protein were used as independent variables in the second analysis.

RESULTS

According to the results of the multiple linear regression analysis, TC was associated with the percentage of sites with PD > or =4 mm (P <0.01; beta = -0.19), CAL > or =4 mm (P <0.01; beta = -0.20), and BOP (P = 0.03; beta = -0.16). HDL-C and LDL-C have a significant association with inflammatory markers and inorganic phosphorus and calcium, respectively.

CONCLUSION

Higher TC is associated with a lower prevalence of periodontitis in non-smoking elderly patients.

The paraoxonases: role in human diseases and methodological difficulties in measurement

Research into the paraoxonase (PON) gene family has flourished over the past few years. In the 1970s and 1980s, only PON1 was known, and the investigations were conducted, essentially, by toxicologists focusing on protection against organophosphate poisoning. Since then, two new members of the family, PON2 and PON3, have been identified, both being shown to play antioxidant and anti-inflammatory roles. Evidence exists indicating that the PON family is central to a wide variety of human illnesses such as cardiovascular disease, diabetes mellitus, metabolic syndrome, obesity, non-alcoholic steatohepatitis, and several mental disorders. However, research is hampered considerably by the methods currently available to measure the activity of these enzymes. In this review, we summarize the state of knowledge on PON biochemistry and function, the influence of genetic variations, and the involvement of PON in several diseases. The problems associated with PON measurement, such as sample acquisition, lack of reference methods, and variety of substrates, will be presented. Also, we cover some of the present lines of research and propose some others for future progress in this field.

Impaired antioxidant activity of high-density lipoprotein in chronic kidney disease

Chronic kidney disease (CKD) is associated with accelerated atherosclerosis and increased mortality from cardiovascular disease. CKD results in oxidative stress, inflammation, and high-density lipoprotein (HDL) deficiency, which work in concert to promote atherosclerosis. Normal HDL confers protection against atherosclerosis by inhibiting the oxidation of lipids and lipoproteins and by retrieving surplus cholesterol and phospholipids from lipid-laden cells in the artery wall for disposal in the liver (reverse cholesterol transport). The plasma level of oxidized low-density lipoprotein (LDL) is increased, plasma HDL-cholesterol is reduced, and HDL maturation is impaired in CKD. This study was designed to examine the antioxidant properties of HDL in patients with CKD. In all, 32 stable hemodialysis-dependent patients and 13 age-matched controls were studied. HDL was isolated and used for determination of in vitro antioxidant activity. In addition, the plasma level of key components of HDL, namely paraoxonase (PON), glutathione peroxidase (GPX), platelet activating factor acetylhydrolase (PAF-AH), lecithin cholesterol acyltransferase (LCAT), and apolipoprotein A-I (ApoA-I), were measured. The end-stage renal disease (ESRD) patients exhibited significant reductions of HDL-cholesterol, ApoA-I (-41%), GPX (-50%), and LCAT (-60%) concentrations, and a decrease in PON (-30%) and GPX (-50%) activities. These results were accompanied by a marked reduction of antioxidant activity of HDL (-127%), which was unaffected by the hemodialysis procedure. Thus, in addition to diminished plasma HDL concentration, the composition and antioxidant activity of HDL are altered in CKD; these events can contribute to a heightened risk of atherosclerosis.

Serological proteomics of gastritis: degradation of apolipoprotein A-I and alpha1-antitrypsin is a common response to inflammation irrespective of Helicobacter pylori infection

Proteomic technology was employed to analyze serum samples from healthy subjects (10 cases) and gastritis patients with negative and positive Helicobacter pylori (Hp) infection (15 cases each). The serum proteins were separated by two-dimensional (2-D) gel electrophoresis and analyzed by a computer-aided program. The altered proteins in expression were then identified by mass spectrometry and validated by Western blotting. Compared to those in normal control, proteins in at least six areas of 2-D gels were found to significantly increase their expression levels in both Hp-negative and Hp-positive serum samples. These proteins were identified by mass peptide fingerprinting and confirmed by Western blotting to be the truncated or cleaved protein fragments of apolipoprotein A-I and alpha-1 antitrypsin, two well-known acute-phase proteins. We conclude that the degradation or metabolization of acute-phase proteins, apolipoprotein A-I, and alpha1-antitrypsin, is a common response to gastric inflammation irrespective of Hp infection.

Altered lipoprotein metabolism in chronic inflammatory states: proinflammatory high-density lipoprotein and accelerated atherosclerosis in systemic lupus erythematosus and rheumatoid arthritis

In this review, the authors discuss the formation and structure of high-density lipoproteins (HDLs) and how those particles are altered in inflammatory or stress states to lose their capacity for reverse cholesterol transport and for antioxidant activity. In addition, abnormal HDLs can become proinflammatory (piHDLs) and actually contribute to oxidative damage. The assay by which piHDLs are identified involves studying the ability of test HDLs to prevent oxidation of low-density lipoproteins. Finally, the authors discuss the potential role of piHDLs (found in some 45% of patients with systemic lupus erythematosus and 20% of patients with rheumatoid arthritis) in the accelerated atherosclerosis associated with some chronic rheumatic diseases.

Paraoxonases are associated with intestinal inflammatory diseases and intracellularly localized to the endoplasmic reticulum

We demonstrated previously that the paraoxonase (PON1/2/3) genes and proteins are expressed in human intestinal biopsies and in Caco-2 cells. The current study aims were to explore whether PON1/2/3 expression is different in inflammatory bowel diseases (IBD) or celiac disease compared to healthy controls, and to explore the intracellular localization of PON1/2/3. Our results showed that significantly fewer biopsies expressed PON1 and PON3 in the duodenum of celiac patients (PON1, P<0.0001; PON3, P=0.03), in the terminal ileum of Crohn's patients (PON1, P=0.001; PON3, P=0.008), and in the colon of UC patients (PON1, P=0.02; PON3, P=0.06) compared to controls. Since all three disorders share markedly elevated inflammatory mediators we explored the PON1/2/3 mRNA expression on cytokine stimulation. No changes were observed in Caco-2 and HT29 cells. Immunofluorescence experiments localized PON1/2/3 exclusively to the endoplasmic reticulum (ER) in both CaCo-2 and HT29 cells. These results demonstrate for the first time a novel relationship between PON1 and PON3 expression and several inflammatory gastrointestinal disorders. Together with the localization of PON1/2/3 enzymes to the ER, it may be suggested that PON1/2/3 may have extracellular functions as part of the host response in IBD and celiac disease.