Cytokines decrease apolipoprotein accumulation in medium from Hep G2 cells

Eye on the horizon: The metabolic landscape of the RPE in aging and disease

To meet the prodigious bioenergetic demands of the photoreceptors, glucose and other nutrients must traverse the retinal pigment epithelium (RPE), a polarised monolayer of cells that lie at the interface between the outer retina and the choroid, the principal vascular layer of the eye. Recent investigations have revealed a metabolic ecosystem in the outer retina where the photoreceptors and RPE engage in a complex exchange of sugars, amino acids, and other metabolites. Perturbation of this delicate metabolic balance has been identified in the aging retina, as well as in age-related macular degeneration (AMD), the leading cause of blindness in the Western world. Also common in the aging and diseased retina are elevated levels of cytokines, oxidative stress, advanced glycation end-products, increased growth factor signalling, and biomechanical stress - all of which have been associated with metabolic dysregulation in non-retinal cell types and tissues. Herein, we outline the role of these factors in retinal homeostasis, aging, and disease. We discuss their effects on glucose, mitochondrial, lipid, and amino acid metabolism in tissues and cell types outside the retina, highlighting the signalling pathways through which they induce these changes. Lastly, we discuss promising avenues for future research investigating the roles of these pathological conditions on retinal metabolism, potentially offering novel therapeutic approaches to combat age-related retinal disease.

Adrenal insufficiency in liver diseases - pathophysiology and underlying mechanisms

Relative adrenal insufficiency (RAI) is common in critically ill patients with cirrhosis, but it has been also documented in non-critically ill patients. Its pathophysiology is complex and not well understood yet. In this review, we aimed to present potential mechanisms and causal pathways implicated in the pathogenesis of RAI in cirrhosis. There is accumulating evidence supporting a suboptimal baseline adrenal function in cirrhosis mainly due to decreased cortisol synthesis and metabolism rates from the adrenal gland. Apart from this peripheral impairment, more recent studies suggest that there is a greater defect in the central stimulation of the hypothalamic-pituitary-adrenal (HPA) axis (hypothalamus/pituitary gland). Pro-inflammatory mediators, which are elevated in cirrhosis, have been also implicated through suppression of the HPA axis, decrease in cortisol synthesis and tissue glucocorticoid resistance. All abovementioned support the hepatoadrenal syndrome hypothesis that during episodes of acute decompensation there is suboptimal adrenocortical response that leads to worse outcomes. In conclusion, the complex pathophysiology of adrenal dysfunction in cirrhosis has not been fully elucidated yet and further research is needed in order to better understand this rather common entity in cirrhosis.

Tumor Necrosis Factor Alpha Inhibitors and Cardiovascular Risk in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory disease characterized by an increased risk of cardiovascular events, due to the complex interplay between traditional and disease-related risk factors. Chronic inflammation and persistent disease activity are the key determinants of this risk, but despite great improvement in the disease management and prognosis, cardiovascular events are still the main cause of morbidity and mortality in RA cohorts1. In the last decades, the advent of new biological and targeted-synthetic DMARDs was accompanied by an improvement in disease activity control, but the role of each class of drugs on CVD risk is still a matter a debate. Since their approval for RA treatment, tumor necrosis factor alpha (TNFα) inhibitors have been widely investigated to better understand their effects on cardiovascular outcomes. The hypothesis that the reduction of chronic inflammation with any treatment may reduce the cardiovascular risk has been recently confuted by the direct comparison of TNFα-inhibitors and JAK inhibitors in patients with RA and coexisting risk factors for cardiovascular disease. The aim of this literature review is to add to the available evidence to analyze the relationship between TNFα-inhibitors and CVD risk in patients with RA and also provide some clinical scenarios to better explain the treatment dilemmas. In particular, while data on major cardiovascular events and thromboembolism seem consistent with an inflammation-mediated benefit with TNFα-inhibitors, there remain concerns about the use of this class of bDMARDs in patients with chronic heart failure.

Paradoxical Effects of Prolonged Insufficient Sleep on Lipid Profile: A Pooled Analysis of 2 Randomized Trials

Background Insufficient sleep is associated with increased cardiovascular disease risk, but causality is unclear. We investigated the impact of prolonged mild sleep restriction (SR) on lipid and inflammatory profiles. Methods and Results Seventy-eight participants (56 women [12 postmenopausal]; age, 34.3±12.5 years; body mass index, 25.8±3.5 kg/m2) with habitual sleep duration 7 to 9 h/night (adequate sleep [AS]) underwent two 6-week conditions in a randomized crossover design: AS versus SR (AS-1.5 h/night). Total cholesterol, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol, triglycerides, and inflammatory markers (CRP [C-reactive protein], interleukin 6, and tumor necrosis factor-α) were assessed. Linear models tested effects of SR on outcomes in the full sample and by sex+menopausal status (premenopausal versus postmenopausal women+men). In the full sample, SR increased high-density lipoprotein cholesterol compared with AS (β=1.2±0.5 mg/dL; P=0.03). Sex+menopausal status influenced the effects of SR on change in total cholesterol (P-interaction=0.04), LDL-C (P-interaction=0.03), and interleukin 6 (P-interaction=0.07). Total cholesterol and LDL-C decreased in SR versus AS in premenopausal women (total cholesterol: β=-4.2±1.9 mg/dL; P=0.03; LDL-C: β=-6.3±2.0 mg/dL; P=0.002). Given paradoxical effects of SR on cholesterol concentrations, we explored associations between changes in inflammation and end point lipids under each condition. Increases in interleukin 6 and tumor necrosis factor-α during SR tended to relate to lower LDL-C in premenopausal women (interleukin 6: β=-5.3±2.6 mg/dL; P=0.051; tumor necrosis factor-α: β=-32.8±14.2 mg/dL; P=0.027). Conclusions Among healthy adults, prolonged insufficient sleep does not increase atherogenic lipids. However, increased inflammation in SR tends to predict lower LDL-C in premenopausal women, resembling the "lipid paradox" in which low cholesterol associates with increased cardiovascular disease risk in proinflammatory conditions. Registration URL: https://www.clinicaltrials.gov; Unique identifiers: NCT02835261, NCT02960776.

Association of serum lipids with inflammatory bowel disease: a systematic review and meta-analysis

Background

Serum lipid levels seem to be abnormal in Inflammatory bowel disease (IBD). However, the specific manifestation of abnormal serum lipid levels in IBD are heterogeneous among studies and have not been sufficiently determined yet.

Methods

PubMed, EMBASE, and Cochrane Library databases were searched. Serum lipid levels were compared between IBD patients and Health individuals, Crohn's (CD) and ulcerative colitis (UC), active and inactive, mild and non-mild patients, respectively. Meta-analyses were performed by using a random-effect model. Weight mean difference (WMD) with 95% confidence intervals (CIs) were calculated.

Results

Overall, 53 studies were included. Compared with healthy controls, IBD patients had significantly lower TC (WMD = -0.506, 95%CI = -0.674 to -0.338, p < 0.001), HDL-c (WMD = -0.122, 95%CI = -0.205 to -0.039, p = 0.004), and LDL-c (WMD = -0.371, 95%CI = -0.547 to -0.194, p < 0.001) levels. CD groups had a significantly lower TC (WMD = -0.349, 95%CI = -0.528 to -0.170, p < 0.0001) level as compared to UC groups. Active IBD and non-mild UC groups had significantly lower TC (WMD = -0.454, 95%CI = -0.722 to -0.187, p = 0.001) (WMD =0.462, 95%CI = 0.176 to 0.748, p = 0.002) and LDL-c (WMD = -0.225, 95%CI = -0.445 to -0.005, p = 0.045) (WMD =0.346, 95%CI = 0.084-0.609, p = 0.010) levels as compared to inactive IBD and mild UC groups, respectively.

Conclusion

The overall level of serum lipids in IBD patients is lower than that of healthy individuals and is negatively associated with disease severity.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier: CRD42022383885.

The bidirectional interaction of COVID-19 infections and lipoproteins

COVID-19 infections decrease total cholesterol, LDL-C, HDL-C, and apolipoprotein A-I, A-II, and B levels while triglyceride levels may be increased or inappropriately normal for the poor nutritional status. The degree of reduction in total cholesterol, LDL-C, HDL-C, and apolipoprotein A-I are predictive of mortality. With recovery lipid/lipoprotein levels return towards pre-infection levels and studies have even suggested an increased risk of dyslipidemia post-COVID-19 infection. The potential mechanisms for these changes in lipid and lipoprotein levels are discussed. Decreased HDL-C and apolipoprotein A-I levels measured many years prior to COVID-19 infections are associated with an increased risk of severe COVID-19 infections while LDL-C, apolipoprotein B, Lp (a), and triglyceride levels were not consistently associated with an increased risk. Finally, data suggest that omega-3-fatty acids and PCSK9 inhibitors may reduce the severity of COVID-19 infections. Thus, COVID-19 infections alter lipid/lipoprotein levels and HDL-C levels may affect the risk of developing COVID-19 infections.

Relationship between Cholesterol-Related Lipids and Severe Acute Pancreatitis: From Bench to Bedside

It is well known that hypercholesterolemia in the body has pro-inflammatory effects through the formation of inflammasomes and augmentation of TLR (Toll-like receptor) signaling, which gives rise to cardiovascular disease and neurodegenerative diseases. However, the interaction between cholesterol-related lipids and acute pancreatitis (AP) has not yet been summarized before. This hinders the consensus on the existence and clinical importance of cholesterol-associated AP. This review focuses on the possible interaction between AP and cholesterol-related lipids, which include total cholesterol, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C) and apolipoprotein (Apo) A1, from the bench to the bedside. With a higher serum level of total cholesterol, LDL-C is associated with the severity of AP, while the persistent inflammation of AP is allied with a decrease in serum levels of cholesterol-related lipids. Therefore, an interaction between cholesterol-related lipids and AP is postulated. Cholesterol-related lipids should be recommended as risk factors and early predictors for measuring the severity of AP. Cholesterol-lowering drugs may play a role in the treatment and prevention of AP with hypercholesterolemia.

A Transient Inflammatory Response Induced by Lipopolysaccharide Infusion Lowers Markers of Endogenous Cholesterol and Bile Acid Synthesis in Healthy Normocholesterolemic Young Men

Inflammation is associated with changes in plasma lipids, lipoproteins, and cholesterol efflux capacity (CEC). It is unknown if the changes in lipids and lipoproteins during inflammation are related to changes in cholesterol absorption, synthesis, and bile acid synthesis. We, therefore, examined the effects of acute lipopolysaccharide (LPS)-induced transient systemic inflammation on lipids, lipoproteins, CEC, and markers of cholesterol metabolism. We also evaluated whether markers for cholesterol metabolism at baseline predict the intensity of the inflammatory response. Eight healthy young subjects received LPS infusion, and blood was sampled for the following 24 h. In addition to lipids, lipoproteins, and CEC, we also measured markers for cholesterol absorption and synthesis, bile acid synthesis, and inflammation. Compared with baseline, plasma total cholesterol, low-density lipoprotein cholesterol, and CEC decreased, while triglycerides increased in the 24 h following LPS infusion. TC-standardized levels of cholesterol synthesis markers (lathosterol, lanosterol, and desmosterol) and a bile acid synthesis marker (7α-OH-cholesterol) also decreased, with no changes in cholesterol absorption markers (campesterol, sitosterol, and cholestanol). Baseline TC-standardized levels of desmosterol and 7α-OH-cholesterol were positively correlated with concentrations of various inflammatory markers. Changes in TC-standardized desmosterol and 7α-OH-cholesterol were negatively correlated with concentrations of inflammatory markers. LPS infusion reduced endogenous cholesterol synthesis and bile acid synthesis in healthy young men.

A Modern Approach to Dyslipidemia

Lipid disorders involving derangements in serum cholesterol, triglycerides, or both are commonly encountered in clinical practice and often have implications for cardiovascular risk and overall health. Recent advances in knowledge, recommendations, and treatment options have necessitated an updated approach to these disorders. Older classification schemes have outlived their usefulness, yielding to an approach based on the primary lipid disturbance identified on a routine lipid panel as a practical starting point. Although monogenic dyslipidemias exist and are important to identify, most individuals with lipid disorders have polygenic predisposition, often in the context of secondary factors such as obesity and type 2 diabetes. With regard to cardiovascular disease, elevated low-density lipoprotein cholesterol is essentially causal, and clinical practice guidelines worldwide have recommended treatment thresholds and targets for this variable. Furthermore, recent studies have established elevated triglycerides as a cardiovascular risk factor, whereas depressed high-density lipoprotein cholesterol now appears less contributory than was previously believed. An updated approach to diagnosis and risk assessment may include measurement of secondary lipid variables such as apolipoprotein B and lipoprotein(a), together with selective use of genetic testing to diagnose rare monogenic dyslipidemias such as familial hypercholesterolemia or familial chylomicronemia syndrome. The ongoing development of new agents-especially antisense RNA and monoclonal antibodies-targeting dyslipidemias will provide additional management options, which in turn motivates discussion on how best to incorporate them into current treatment algorithms.

Low total cholesterol predicts early death in children with hemophagocytic lymphohistiocytosis

BACKGROUND

Hemophagocytic lymphohistiocytosis (HLH) is a rapidly progressive and potentially life-threatening disorder. Identifying risk factors and timely adjustment of the given treatment regimens is critical to reducing the early mortality in HLH patients. Hypocholesterolemia has been reported to be associated with poor prognosis in a variety of critical illnesses. However, serum cholesterol is rarely studied in HLH patients, and its prognostic value is unclear.

METHODS

We conducted a retrospective cohort study in National Clinical Research Center for Child Health and Disorders (Chongqing), identifying pediatric HLH patients (including genetically confirmed pHLH and not genetically confirmed pHLH) diagnosed with the HLH-2004 protocol and treated with immunochemotherapy between January 2008 and December 2020. The patients' blood lipid levels at initial diagnosis of HLH, including triglycerides (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein-cholesterol (LDL-C), were reviewed based on electronic medical records. Both Cox and logistic regression models were used to estimate the effects of blood lipid indicators on early death (within 30 days after diagnosis).

RESULTS

A total of 353 patients were enrolled in the study, with a median age at diagnosis of 45 months. The observed 30-day mortality rate was 19.05% (64/336, 17 were lost to follow-up) and Kaplan-Meier-estimated 3-year survival rate was 61.67% (95% CI, 56.27%-67.59%). DNA-targeted sequencing of HLH-related genes was performed in 173 (49.0%, 173/353) patients (not all patients with suspected pHLH underwent genetic testing), and 29 patients were diagnosed with genetically confirmed pHLH. Lipid panel was performed in 349 patients: 91.98% (321/349) had TG ≥ 1.80 mmol/L, 62.75%(219/349) had TG ≥ 3.00 mmol/L, 92.84% (324/349) had HDL-C ≤ 1.04 mmol/L, 58.74% (205/349) had LDL-C ≤ 1.30 mmol/L and 24.64% (86/349) had TC ≤ 3.11 mmol/L. TC ≤ 3.11 mmol/L and BUN ≥ 7.14 mmol/L were the independent risk factors for 30-day mortality [HR(95%CI): 2.85(1.46, 5.57) and 2.90(1.48, 5.68), respectively]. The presence of one of these risk factors increased the 30-day mortality rate by 6-fold [HR = 6.24, 95%CI: (3.18, 12.22)] and the presence of two risk factors by nearly 10-fold [HR = 9.98, 95%CI: (4.23, 23.56)] compared with the patients with no risk factors.

CONCLUSION

Severe derangement of lipoproteins is common in children with HLH, and decreased TC is an independent risk factor for early death. Hypocholesterolemia should be included as a biomarker during the diagnosis and management of HLH patients.

COVID-19 and diabetes-Two giants colliding: From pathophysiology to management

Since December 2019, a new coronavirus, called severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has spread around the world, causing the coronavirus 2019 (COVID-19) pandemic. From the beginning, SARS-CoV-2 has put a strain on the health system. In fact, many patients have had severe forms of the disease with the need for hospitalization due to respiratory failure. To contain the pandemic, the most widely used approach has been lockdowns. Social restrictions have been reduced thanks to the development of vaccines and targeted therapies. However, fatal events still occur among people at high risk of serious infection, such as patients with concomitant diabetes. Different mechanisms have been proposed to explain the poor prognosis of patients with diabetes and COVID-19, but the specific cause is unclear. It is now known that insulin resistance, inflammation, and cytokine storm are involved. Moreover, SARS-CoV-2 uses the angiotensin-converting enzyme 2 receptors to enter cells. This receptor is expressed on pancreatic beta cells and, during infection, it appears that receptor involvement may induce hyperglycemia in patients with or without diabetes. In this study, we discuss the mechanisms underlying the poor prognosis in people with COVID-19 and diabetes and what may improve the outcome in these patients.

Association between high-density lipoprotein cholesterol and apolipoprotein A-I and severe acute pancreatitis: a case-control study

BACKGROUND

Evidence is limited concerning the association between serum concentrations of high-density lipoprotein cholesterol (HDL-C) and apolipoprotein A-I (APO A-I) and severe acute pancreatitis (SAP). This study was designed to explore whether HDL-C and APO A-I were independently correlated to SAP after adjusting for covariates.

METHODS

There were 1127 patients with acute pancreatitis who were recruited from a tertiary teaching hospital in Wenzhou from 1 January 2018 to 30 April 2020. The independent variables were baseline levels of HDL-C, and APO A-I collected within 24 h after admission. The dependent variable was the occurrence of SAP during hospitalization. Univariate and multivariate binary logistic regression were conducted to analyze the relationship between HDL-C and APO A-I and SAP. The receiver operating characteristic curve was applied to analyze the prediction power of lipid parameters and C-reactive protein for SAP.

RESULTS

The incidence of SAP was 11.5% among the 678 patients included in the final analysis. The serum levels of APO A-I and HDL-C were negatively related to SAP after adjusting for confounders with an odds ratio of 0.24 [95% confidence interval (CI): 0.06-0.95] and 0.16 (95% CI, 0.04-0.56), respectively. APO A-I (area under the curve = 0.69; 95% CI, 0.63-0.76) and HDL-C (area under the curve = 0.72; 95% CI, 0.66-0.79) showed higher predictive value for SAP compared with other lipid parameters.

CONCLUSIONS

Decreased serum concentrations of HDL-C and APO A-I are associated with SAP after adjusting for covariates.

Lipid profile as an indicator of COVID-19 severity: A systematic review and meta-analysis

Background

Coronavirus disease-2019 (COVID-19) is a global pandemic. Studies reported dyslipidemia in patients with COVID-19. Herein, we conducted a systematic review and meta-analysis of published articles to evaluate the association of the lipid profile with the severity and mortality in COVID-19 patients.

Methods

PubMed/Medline, Europe PMC, and Google Scholar were searched for studies published between January 1, 2020 and January 13, 2021. Random or Fixed effects models were used to calculate the mean difference (MD) and 95% confidence intervals (CIs). Statistical heterogeneity was assessed using Cochran's Q test and I² statistics.

Results

This meta-analysis included 19 studies. Of which, 12 studies were categorized by severity, 04 studies by mortality, and 03 studies by both severity and mortality. Our findings revealed significantly decreased levels of total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) in the severe group when compared with the non-severe group in a random effect model. Similarly, random effect model results demonstrated significantly lower levels of HDL-C and LDL-C in the non-survivor group when compared with the survivor group. The level of TC was also found to be decreased in the non-survivor group when compared to the survivor group in a fixed-effect model.

Conclusion

In conclusion, the lipid profile is associated with both the severity and mortality in COVID-19 patients. Hence, the lipid profile may be used for assessing the severity and prognosis of COVID-19.

Prospero registration number

CRD42021216316.

Lipid and Lipoprotein Dysregulation in Sepsis: Clinical and Mechanistic Insights into Chronic Critical Illness

In addition to their well-characterized roles in metabolism, lipids and lipoproteins have pleiotropic effects on the innate immune system. These undergo clinically relevant alterations during sepsis and acute inflammatory responses. High-density lipoprotein (HDL) plays an important role in regulating the immune response by clearing bacterial toxins, supporting corticosteroid release, decreasing platelet aggregation, inhibiting endothelial cell apoptosis, reducing the monocyte inflammatory response, and inhibiting expression of endothelial cell adhesion molecules. It undergoes quantitative as well as qualitative changes which can be measured using the HDL inflammatory index (HII). Pro-inflammatory, or dysfunctional HDL (dysHDL) lacks the ability to perform these functions, and we have also found it to independently predict adverse outcomes and organ failure in sepsis. Another important class of lipids known as specialized pro-resolving mediators (SPMs) positively affect the escalation and resolution of inflammation in a temporal fashion. These undergo phenotypic changes in sepsis and differ significantly between survivors and non-survivors. Certain subsets of sepsis survivors go on to have perilous post-hospitalization courses where this inflammation continues in a low grade fashion. This is associated with immunosuppression in a syndrome of persistent inflammation, immunosuppression, and catabolism syndrome (PICS). The continuous release of tissue damage-related patterns and viral reactivation secondary to immunosuppression feed this chronic cycle of inflammation. Animal data indicate that dysregulation of endogenous lipids and SPMs play important roles in this process. Lipids and their associated pathways have been the target of many clinical trials in recent years which have not shown mortality benefit. These results are limited by patient heterogeneity and poor animal models. Considerations of sepsis phenotypes and novel biomarkers in future trials are important factors to be considered in future research. Further characterization of lipid dysregulation and chronic inflammation during sepsis will aid mortality risk stratification, detection of sepsis, and inform individualized pharmacologic therapies.

Effect of Tocilizumab on LDL and HDL Characteristics in Patients with Rheumatoid Arthritis. An Observational Study

BACKGROUND

In patients with rheumatoid arthritis (RA), qualitative alterations of low and high-density lipoproteins (LDL and HDL, respectively) might partially explain their increased cardiovascular risk. Tocilizumab has been associated with an increase in lipids, including triglyceride (TG) and cholesterol levels. The aim of this study is to evaluate the effect of tocilizumab on certain LDL and HDL characteristics (oxidized LDL levels, HDL-associated enzymes, chemical composition of both total HDL and HDL3c subpopulation, and their capacity to promote cellular cholesterol efflux) at baseline and 3 months after the start of treatment in patients with RA.

METHODS

Twenty-eight RA patients (ACR/EULAR 2010 criteria) with indication of treatment with tocilizumab were included in the present study. Clinical assessment [Health assessment questionnaire (HAQ)], disease activity score 28 (DAS28), high-sensitivity C reactive protein (hsCRP) concentration, lipid profile, and lipoprotein (a) [Lp(a)] levels were evaluated in all patients at baseline and after 3 months of treatment with tocilizumab. Lipoprotein characteristics were evaluated through the levels of oxidized LDL (OxLDL), the activity of paraoxonase (PON) 1, the composition of total HDL and small, dense HDL3c subpopulation, and their ability to promote cellular cholesterol efflux.

RESULTS

After 3 months of treatment with tocilizumab, HAQ (- 23%, p < 0.05), DAS28 (- 49%, p < 0.001), and hsCRP (- 94%, p < 0.01) levels decreased significantly. Total cholesterol (TC), LDL-C, non-HDL-C, and apo B levels showed a significant increase after treatment (TC: + 7.0%, p < 0.01; LDL-C: + 10%, p < 0.01; non-HDL-C: + 9.9%, p < 0.01; and apo B: + 9.6%, p < 0.05). Decreases in Lp(a) and OxLDL levels were also observed after treatment [Lp(a): - 50%, p < 0.01; and oxLDL: - 5.4%, p < 0.05]. The latter was in accordance with the increment detected in PON activity. No changes were observed in HDL capacity to promote cholesterol efflux (p > 0.05) in the whole group.

CONCLUSIONS

Treatment with tocilizumab reduced hsCRP levels and displayed positive effects on certain lipoprotein-related parameters, such as a potent decrease inLp(a) and a reduction in OxLDL levels. Moreover, HDL capacity to promote cellular cholesterol efflux was maintained after 3 months of treatment.

Lipid metabolism changes in patients with severe COVID-19

Background

We investigated the dynamic changes in lipid profiles and their correlations with disease severity and clinical outcome in patients with severe COVID-19.

Methods

We retrospectively reviewed 519 severe COVID-19 patients with confirmed outcomes (discharged or deceased), admitted to the West Court of Union Hospital in Wuhan, China, between 29 January and 8 April 2020.

Results

Altogether, 424 severe COVID-19 patients, including 34 non-survivors and 390 survivors, were included in the final analyses. During hospitalization, low-density lipoprotein cholesterol (LDL-C), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C) and apolipoprotein A-I (apoA-I) showed an increasing trend in survivors, but showed a downward trend in non-survivors. The serum concentrations of HDL-C and apoA-I were inversely correlated with C-reactive protein (CRP), length of hospital stay of survivors, and disease severity scores. For in-hospital deaths, the areas under the receiver operating characteristic curves (AUCs) of the ratios of CRP/HDL-C and CRP/apoA-I at admission were 0.84 and 0.83, respectively. Moreover, patients with high ratios of CRP/HDL-C (＞77.39) or CRP/apoA-I (＞72.37) had higher mortality rates during hospitalization (log-rank p < 0.001). Logistic regression analysis demonstrated that hypertension, lactate dehydrogenase, SOFA score, and High CRP/HDL-C ratio were independent predictors of in-hospital mortality.

Conclusions

During severe COVID-19, HDL-C and apoA-I concentrations are dramatically decreased in non-survivors. Moreover, High CRP/HDL-C ratio is significantly associated with an increase in mortality and a poor prognosis.

Period prevalence and mortality rates associated with hypocholesterolaemia in dogs and cats: 1,375 cases

To determine the period prevalence of hypocholesterolaemia and the associated mortality rates in dogs and cats at a university teaching hospital. The secondary aim was to identify disease processes associated with hypocholesterolaemia.

MATERIALS AND METHODS

Medical records over a 5-year period were reviewed to determine the severity of hypocholesterolaemia and its associated mortality rate. Medical records of animals with moderate to severe hypocholesterolaemia (<2.59 mmol/L in dogs, <1.81 mmol/L in cats) were analysed further. Animals with hospital-acquired hypocholesterolaemia were identified.

RESULTS

Among 16,977 dogs and 3,788 cats that had at least one cholesterol measurement, the period prevalence of hypocholesterolaemia was 7.0% in dogs and 4.7% in cats. The mortality rate of hypocholesteraemic dogs and cats was 12% in both species which was significantly higher than that of animals with normal serum cholesterol. The degree of hypocholesterolaemia was significantly associated with mortality. Dogs, but not cats, with hospital-acquired hypocholesterolaemia had a higher mortality rate than those presenting with hypocholesterolaemia. Disease of hepatic, gastrointestinal and lymphoreticular systems were most commonly associated with hypocholesterolaemia, and infectious and neoplastic disease were the most commonly associated pathophysiologic processes in both species. Lymphoma was over-represented in dogs with neoplasia.

CLINICAL SIGNIFICANCE

Hypocholesterolaemia is not a frequent abnormality but was associated with mortality in this study and may be a negative prognostic indicator. It is not known if hypocholesterolaemia is simply a marker for disease severity, or if it is has active physiologic effects contributing to poor outcomes.

Cardiovascular risk in persons at risk of developing rheumatoid arthritis

Background

Rheumatoid arthritis (RA) is associated with an increased cardiovascular disease (CVD) risk which may start even before diagnosis. To explore this CVD risk prior to RA, we determined multiple risk factors and two 10-year clinical risk scores in a cohort of individuals at-risk of RA. We also analyzed associations with arthritis development and autoantibody status and compared a subset of at-risk individuals to an age and sex matched seronegative control group.

Methods

In a cohort of 555 consecutive arthralgia patients positive for rheumatoid factor (RF) and / or anti-citrullinated protein antibody (ACPA) we retrospectively identified patients with preclinical arthritis (i.e. those who developed arthritis), and non-arthritis patients (those without arthritis development during maximum 5 years follow up). Demographics, CVD risk factors and the 10-year cardiovascular risk according to the SCORE and QRISK3 system were determined at baseline.

Results

Preclinical arthritis patients (n = 188) had a higher heart rate (68 vs 63 bpm, p = 0.048) and lower cholesterol (5.2 mmol/l vs 5.5, p = 0.006), HDL (1.0 mmol/l vs 1.1, p0.003) and ApoB (0.85 g/l vs 0.91, p = 0.011) compared to non-arthritis patients (n = 367). Lipid levels were associated with ACPA status in both the preclinical arthritis and non-arthritis group. Ten-year CVD risk scores did not differ between preclinical arthritis and non-arthritis patients, in total, 7% (SCORE) and 8% (QRISK3) of seropositive arthralgia patients were classified as high risk. Seropositive at-risk patients (n = 71) had higher total cholesterol (5.4 vs 4.9, p<0.001), TC/HDL ratio (4.0 vs 3.0, p<0.001), triglycerides (1.4 vs 1.0, p = 0.001), ApoB (1.0 vs 0.9, p = 0.019) and 10-year risk scores (median SCORE 1.0 vs 0.0, p = 0.030 and median QRISK3 4.4 vs 3.1, p<0.001) compared to seronegative controls.

Conclusion

Our results suggest that lipid changes commence prior to RA diagnosis and that ACPAs might play a role.

IgG Anti-High Density Lipoprotein Antibodies Are Elevated in Abdominal Aortic Aneurysm and Associated with Lipid Profile and Clinical Features

High-density lipoproteins cholesterol (HDLc) levels are decreased in abdominal aortic aneurysm (AAA), which is hallmarked by autoimmunity and lipid aortic deposits. To investigate whether IgG anti-HDL antibodies were present in AAA and their potential association with clinical features, IgG anti-HDL and total IgG along with HDLc plasma levels were measured in 488 AAA patients and 184 controls from the Viborg Vascular (VIVA) study, and in tissue-conditioned media from AAA intraluminal thrombus and media layer samples compared to control aortas. Higher IgG anti-HDL levels were found in AAA compared to controls, even after correcting for total IgG, and after adjusting for potential confounders. IgG anti-HDL levels were correlated with aortic diameter in univariate and adjusted multivariate analyses. IgG anti-HDL antibodies were negatively associated with HDLc levels before and after correcting for potential confounders. Increased anti-HDL antibodies were identified in tissue-conditioned media from AAA samples compared to healthy aortas, with higher levels being observed in the media layer. In conclusion, increased IgG anti-HDL levels (both in plasma and in tissue) are linked to AAA, associated with aortic diameter and HDLc levels. These data suggest a potential immune response against HDL in AAA and support an emerging role of anti-HDL antibodies in AAA.

Endocrine Diseases and the Liver: An Update

The endocrine system is a complex interconnected system of organs that control corporeal processes and function. Primary endocrine organs are involved in hormonal production and secretion but rely on a bevy of signals from the hypothalamic-pituitary axis and secondary endocrine organs, such as the liver. In turn, proper hepatic function is maintained through hormonal signaling. Thus, the endocrine system and liver are codependent, and diseases affecting either organs can lead to alterations in function within their counterparts. This article explores the hepato-endocrine relationship, including the effects on endocrine diseases on the liver.

Retrospective evaluation of plasma cholesterol concentration in septic dogs and its association with morbidity and mortality: 51 cases (2005-2015)

OBJECTIVE

To determine whether plasma cholesterol concentrations in dogs with sepsis is associated with morbidity or in-hospital mortality.

DESIGN

Retrospective cohort study from 2005-2015.

SETTING

Two private referral centers.

ANIMALS

Fifty-one dogs diagnosed with sepsis.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Dogs were classified as septic if they displayed ≥2 criteria of the systemic inflammatory response syndrome in conjunction with a documented underlying infectious cause. Dogs were excluded if they had been diagnosed previously with any concurrent illness reported to alter plasma cholesterol concentrations. Plasma cholesterol concentrations at the time of sepsis diagnosis were statistically analyzed for association with morbidity, as measured by the presence of organ dysfunction, the number of dysfunctional organs, duration of hospitalization, cost of hospitalization, and in-hospital mortality. Twenty-eight (55%) dogs survived to discharge, 15 (29%) were euthanized during hospitalization, and 8 (16%) died despite treatment. While median cholesterol concentrations were significantly different when comparing survivors to discharge versus nonsurvivors who died naturally despite treatment (P = 0.0245), they were not significantly different when comparing survivors to all nonsurvivors (P = 0.1821). Receiver operating characteristic curve analysis showed a cholesterol cutoff of 4.5 mmol/L (174 mg/dL) with a sensitivity of 75% and a specificity of 50% for predicting in-hospital mortality. For surviving dogs, plasma cholesterol concentrations were not associated with increased length of hospital stay. Number of dysfunctional organs and plasma cholesterol concentration were the 2 most significant individual predictors for survival, and when incorporated into a multivariate logistic regression model used for prediction, the model yielded a sensitivity of 94% and specificity of 63%.

CONCLUSION

Plasma cholesterol concentration can provide prognostic information in dogs with sepsis. Further prospective studies investigating the role of cholesterol in sepsis are needed.

Hypothalamus-Pituitary-Adrenal Dysfunction in Cholestatic Liver Disease

The Hypothalamic-Pituitary-Adrenal (HPA) axis has an important role in maintaining the physiological homeostasis in relation to external and internal stimuli. The HPA axis dysfunctions were extensively studied in neuroendocrine disorders such as depression and chronic fatigue syndrome but less so in hepatic cholestasis, cirrhosis or other liver diseases. The HPA axis controls many functions of the liver through neuroendocrine forward signaling pathways as well as negative feedback mechanisms, in health and disease. This review describes cell and molecular mechanisms of liver and HPA axis physiology and pathology. Evidence is presented from clinical and experimental model studies, demonstrating that dysfunctions of HPA axis are correlated with liver cholestatic disorders. The functional interactions of HPA axis with the liver and immune system in cases of bacterial and viral infections are also discussed. Proinflammatory cytokines stimulate glucocorticoid (GC) release by adrenals but they also inhibit bile acid (BA) efflux from liver. Chronic hepatic inflammation leads to cholestasis and impaired GC metabolism in the liver, so that HPA axis becomes depressed. Recently discovered interactions of GC with self-oscillating transcription factors that generate circadian rhythms of gene expression in brain and liver, in the context of GC replacement therapies, are also outlined.

Admission levels of high-density lipoprotein and apolipoprotein A-1 are associated with the neurologic outcome in patients with out-of-hospital cardiac arrest

Objective

To investigate whether serum levels of high-density lipoprotein (HDL) and apolipoprotein A-1 (ApoA1), after the return of spontaneous circulation, can predict the neurologic outcome in patients with out-of-hospital cardiac arrest (OHCA).

Methods

This was a retrospective observational study conducted in a single tertiary hospital intensive care unit. All adult OHCA survivors with admission lipid profiles were enrolled from March 2013 to December 2015. Good neurologic outcome was defined as discharge cerebral performance categories 1 and 2.

Results

Among 59 patients enrolled, 13 (22.0%) had a good neurologic outcome. Serum levels of HDL (56.7 vs. 40 mg/dL) and ApoA1 (117 vs. 91.6 mg/dL) were significantly higher in patients with a good outcome. Areas under the HDL and ApoA1 receiver operating curves to predict good outcomes were 0.799 and 0.759, respectively. The proportion of good outcome was significantly higher in patients in higher tertiles of HDL and ApoA1 (test for trend, both P=0.003). HDL (P=0.018) was an independent predictor in the multivariate logistic regression model.

Conclusion

Admission levels of HDL and ApoA1 are associated with neurologic outcome in patients with OHCA. Prognostic and potential therapeutic values of HDL and ApoA1 merit further evaluation in the post-cardiac arrest state, as in other systemic inflammatory conditions such as sepsis.

Regulation of low-density lipoprotein cholesterol by intestinal inflammation and the acute phase response

Systemic inflammation, induced by disease or experimental intervention, is well established to result in elevated levels of circulating triglycerides, and reduced levels of high-density lipoprotein-cholesterol (HDL-C), in most mammalian species. However, the relationship between inflammation and low-density lipoprotein-cholesterol (LDL-C) concentrations is less clear. Most reports indicate that systemic inflammation, as observed during sepsis or following high dose experimental endotoxaemia, lowers total, and LDL-C in man. However, isolated reports have suggested that certain inflammatory conditions are associated with increased LDL-C. In this review, we summarize the emerging evidence that low-grade inflammation specifically of intestinal origin may be associated with increased serum LDL-C levels. Preliminary insights into potential mechanisms that may mediate these effects, including those connecting inflammation to trans-intestinal cholesterol efflux (TICE), are considered. We conclude that this evidence supports the potential downregulation of major mediators of TICE by inflammatory mediators in vitro and during intestinal inflammation in vivo. The TICE-inflammation axis therefore merits further study in terms of its potential to regulate serum LDL-C, and as a readily druggable target for hypercholesterolaemia.

Early prediction of persistent organ failure by serum apolipoprotein A-I and high-density lipoprotein cholesterol in patients with acute pancreatitis

BACKGROUND

Early identification of acute pancreatitis (AP) patients at high-risk of developing persistent organ failure (persistent OF) is a vital clinical goal. This research intends to assess the ability of apolipoprotein A-I (APO A-I) and high-density lipoprotein cholesterol (HDL-C) to predict persistent OF.

METHODS

Between January 2011 and September 2016, a total of 102 adult AP patients with organ failure, local complications or deterioration of former comorbidities disease during hospitalization were included in this study retrospectively. Serum lipids were tested and computed the correlation with clinical outcomes or scoring systems. The AUCs to predict persistent OF were also calculated and compared with each other.

RESULTS

Serum APO A-I and HDL-C levels were negatively associated with scoring systems. Meanwhile, serum lipids were negatively correlated with poor clinical outcomes. The AUCs of APO A-I, HDL-C, the combination of APO A-I and BISAP, or the combination of APO A-I and MCTSI to predict persistent OF among Moderately severe acute pancreatitis (MSAP) and Severe acute pancreatitis (SAP) patients were 0.886, 0.811, 0.912, and 0.900 or among those with organ failure were 0.915, 0.859, 0.933, and 0.933, respectively.

CONCLUSIONS

The concentrations of APO A-I, HDL-C, and the combinations of APO A-I and scoring systems have high predictive value to predict persistent OF.

Plasma cholesterol homeostasis, HDL remodeling and function during the acute phase reaction

Acute phase reaction (APR) is a systemic inflammation triggered by several conditions associated with lipid profile alterations. We evaluated whether APR also associates with changes in cholesterol synthesis and absorption, HDL structure, composition, and cholesterol efflux capacity (CEC). We analyzed 59 subjects with APR related to infections, oncologic causes, or autoimmune diseases and 39 controls. We detected no difference in markers of cholesterol synthesis and absorption. Conversely, a significant reduction of LpA-I- and LpAI:AII-containing HDL (-28% and -44.8%, respectively) and of medium-sized HDL (-10.5%) occurred in APR. Total HDL CEC was impaired in APR subjects (-18%). Evaluating specific CEC pathways, we found significant reductions in CEC by aqueous diffusion and by the transporters scavenger receptor B-I and ABCG1 (-25.5, -41.1 and -30.4%, respectively). ABCA1-mediated CEC was not affected. Analyses adjusted for age and gender provided similar results. In addition, correcting for HDL-cholesterol (HDL-C) levels, the differences in aqueous diffusion total and ABCG1-CEC remained significant. APR subjects displayed higher levels of HDL serum amyloid A (+20-folds; P = 0.003). In conclusion, APR does not associate with cholesterol synthesis and absorption changes but with alterations of HDL composition and a marked impairment of HDL CEC, partly independent of HDL-C serum level reduction.

Link Between ER-Stress, PPAR-Alpha Activation, and BET Inhibition in Relation to Apolipoprotein A-I Transcription in HepG2 Cells

Activating transcription factor peroxisome proliferator-activated receptor alpha (PPARα) may increase apoA-I transcription. Furthermore, Bromodomain and Extra-Terminal domain (BET) protein inhibitors increase, whereas Endoplasmic Reticulum (ER) stress decreases apoA-I transcription. We examined possible links between these processes as related to apoA-I transcription in HepG2 cells. JQ1(+), thapsigargin, and GW7647 were used to induce, respectively BET inhibition, ER-stress, and PPARα activation. Expression of ER-stress markers (CHOP, XBP1s) was analyzed by western blotting. PPARα, KEAP1 (marker for BET inhibition), and apoA-I mRNAs were measured using qPCR. ER-stress and BET inhibition both decreased PPARα mRNA expression and activity, but did not interfere with each other, as ER-stress did not change KEAP1 and JQ1(+) did not influence ER-stress marker production. Interestingly, PPARα activation and BET-inhibition diminished ER-stress marker production and rescued apoA-I transcription during existing ER-stress. We conclude that the ER-stress mediated reduction in apoA-I transcription could be partly mediated via the inhibition of PPARα mRNA expression and activity. In addition, BET inhibition increased apoA-I transcription, even if PPARα production and activity were decreased. Finally, both BET inhibition and PPARα activation ameliorate the apoA-I lowering effect of ER-stress and are therefore interesting targets to elevate apoA-I transcription. J. Cell. Biochem. 118:2161-2167, 2017. © 2016 Wiley Periodicals, Inc.

Lipid Metabolism in Patients with Anti-N-Methyl-D-Aspartate Receptor Encephalitis

OBJECTIVE

Lipid metabolism has been implicated in autoimmune disorders, but its relationship with anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is unclear. This study examined the association of serum lipids with anti-NMDAR encephalitis.

METHODS

Serum lipid profiles and C-reactive protein (CRP) were evaluated in 68 patients with anti-NMDAR encephalitis, and 68 age- and sex-matched healthy controls (CTLs). Follow-up evaluations were conducted 3 months after admission in 32 of the 68 patients. Modified Rankin scale (mRS) scores and clinical and cerebrospinal fluid parameters were evaluated in all patients.

RESULTS

Compared with CTLs, patients with anti-NMDAR encephalitis had significantly lower serum high-density lipoprotein cholesterol (HDL-C) and apolipoprotein A-I (apoA-I) levels but significantly higher serum apoB levels and apoB/apoA-I ratios. Serum HDL and apoA-I were significantly and negatively associated with serum CRP levels, whereas serum aopB levels and apoB/apoA-I ratios were positively associated with age, CRP levels, and mRS scores. Follow-up evaluations revealed that serum total cholesterol, apoA-I, and HDL-C levels were significantly higher but mRS scores were significantly lower than those before treatment, and that the increased HDL-C levels were significantly and negatively correlated with decreased mRS scores.

CONCLUSION

Serum HDL-C and apoA-I levels are reduced in the initial phase of anti-NMDAR encephalitis and recover after treatment. Further studies about the role of serum lipid in anti-NMDAR encephalitis are needed.

Effect of inflammation on HDL structure and function

PURPOSE OF REVIEW

Studies have shown that chronic inflammatory disorders, such as rheumatoid arthritis, systemic lupus erythematosus, and psoriasis are associated with an increased risk of atherosclerotic cardiovascular disease. The mechanism by which inflammation increases cardiovascular disease is likely multifactorial but changes in HDL structure and function that occur during inflammation could play a role.

RECENT FINDINGS

HDL levels decrease with inflammation and there are marked changes in HDL-associated proteins. Serum amyloid A markedly increases whereas apolipoprotein A-I, lecithin:cholesterol acyltransferase, cholesterol ester transfer protein, paraoxonase 1, and apolipoprotein M decrease. The exact mechanism by which inflammation decreases HDL levels is not defined but decreases in apolipoprotein A-I production, increases in serum amyloid A, increases in endothelial lipase and secretory phospholipase A2 activity, and decreases in lecithin:cholesterol acyltransferase activity could all contribute. The changes in HDL induced by inflammation reduce the ability of HDL to participate in reverse cholesterol transport and protect LDL from oxidation.

SUMMARY

During inflammation multiple changes in HDL structure occur leading to alterations in HDL function. In the short term, these changes may be beneficial resulting in an increase in cholesterol in peripheral cells to improve host defense and repair but over the long term these changes may increase the risk of atherosclerosis.

Emerging hepatic syndromes: pathophysiology, diagnosis and treatment

Liver cirrhosis is a major cause of morbidity and mortality worldwide, mainly due to complications of portal hypertension. In this article, we review the current understanding on the pathophysiology, the diagnostic criteria and the available therapeutic options for patients with emerging hepatic syndromes in cirrhosis, namely the hepatorenal, hepato-adrenal and hepatopulmonary syndrome. The hepatorenal syndrome is a well-recognized complication of advanced cirrhosis and is usually associated with an accelerated course to death unless liver transplantation is performed. The hepatopulmonary syndrome is often missed in the evaluation of patients with cirrhosis; however, early recognition is essential for the efficient management of individual patients. The hepato-adrenal syndrome, although not fully characterized, offers an exciting field for research and potential therapeutic interventions.

[Interleukin-6 inhibition and cardiovascular disease in patients with rheumatoid arthritis]

Rheumatoid arthritis (RA) is a' disease conferring high risk for cardiovascular events (CVE). Systemic inflammation underlying RA favors development of CVE. The safety of biological agents, acting on the cardiovascular system has been inadequately investigated. On the one hand, they decrease RA activity and, on the other, may increase the risk of CVE. This review analyzes' the literature data predominantly published in recent years on the effect of an IL-6 receptor inhibitor on the cardiovascular system. Tocilizumab is shown to be a promising agent to reduce cardiovascular risk the findings need to be clinically verified. Long-term prospective investigations should be conducted to determine more exactly the impact of IL-6 receptor inhibition on. the development of CVE.

Dysregulation of the Low-Density Lipoprotein Receptor Pathway Is Involved in Lipid Disorder-Mediated Organ Injury

The low-density lipoprotein receptor (LDLR) pathway is a negative feedback system that plays important roles in the regulation of plasma and intracellular cholesterol homeostasis. To maintain a cholesterol homeostasis, LDLR expression is tightly regulated by sterol regulatory element-binding protein-2 (SREBP-2) and SREBP cleavage-activating protein (SCAP) in transcriptional level and by proprotein convertase subtilisin/kexin type 9 (PCSK9) in posttranscriptional level. The dysregulation of LDLR expression results in abnormal lipid accumulation in cells and tissues, such as vascular smooth muscle cells, hepatic cells, renal mesangial cells, renal tubular cells and podocytes. It has been demonstrated that inflammation, renin-angiotensin system (RAS) activation, and hyperglycemia induce the disruption of LDLR pathway, which might contribute to lipid disorder-mediated organ injury (atherosclerosis, non-alcoholic fatty liver disease, kidney fibrosis, etc). The mammalian target of rapamycin (mTOR) pathway is a critical mediator in the disruption of LDLR pathway caused by pathogenic factors. The mTOR complex1 activation upregulates LDLR expression at the transcriptional and posttranscriptional levels, consequently resulting in lipid deposition. This paper mainly reviews the mechanisms for the dysregulation of LDLR pathway and its roles in lipid disorder-mediated organ injury under various pathogenic conditions. Understanding these mechanisms leading to the abnormality of LDLR expression contributes to find potential new drug targets in lipid disorder-mediated diseases.

Decreased apolipoprotein A-I level indicates poor prognosis in extranodal natural killer/T-cell lymphoma, nasal type

Background

Extranodal natural killer (NK)/T-cell lymphoma, nasal type (ENKTL) is an invasive lymphoid malignancy with unfavorable survival, for which a prognostic model has not yet been validated. We hypothesized that serum apolipoprotein A-I (ApoA-I) may serve as a novel prognostic marker for ENKTL.

Patients and methods

A total of 236 newly diagnosed cases of ENKTL were analyzed retrospectively.

Results

The optimal cutoff value for the serum ApoA-I level was determined to be 0.95 g/L. A total of 154 and 82 cases were assigned to the high and low ApoA-I groups, respectively. Patients in the low ApoA-I group tended to present with poorer clinical features, a lower complete remission rate (P=0.001), and poor median progression-free survival (P<0.001) and overall survival (P<0.001). Multivariate analysis using Cox model showed that the serum ApoA-I level was an independent prognostic marker of overall survival (P<0.001) and progression-free survival (P<0.001) for ENKTL patients. For cases in the low-risk group, as assessed by International Prognostic Index, Prognosis Index for peripheral T-cell lymphoma, unspecified, and Korean Prognostic Index, the serum ApoA-I level was able to differentiate cases with poor outcomes from cases with good outcomes.

Conclusion

Our results showed that the baseline serum ApoA-I level was helpful for predicting ENKTL prognosis.

The Evaluation of Adrenal Function in Two Cases of Hypocortisolism Accompanied by Liver Cirrhosis

Adrenal insufficiency may occur in patients with liver cirrhosis. The assessment of hypothalamus-pituitary-adrenal function is important in such patients, but there is no consensus as to how it should be performed. We herein report the results of our evaluation of the adrenal function in two patients with hypocortisolism accompanied by liver cirrhosis. The patients lacked the typical features of hypocortisolism. One was diagnosed with hypocortisolism accompanied by liver cirrhosis while the other had secondary adrenal insufficiency caused by a hypothalamic disorder. Hypocortisolism accompanied by liver cirrhosis should be evaluated by endocrine tests to determine its pathogenesis. A low-dose adrenocorticotropic hormone test may be appropriate for non-critically ill cirrhotic patients.

Association of lipid profile alterations with severe forms of dengue in humans

Previous studies have shown a relationship between circulating lipids and dengue virus infection; however, the association of altered lipid profiles with severe dengue remains little studied. The aim of this study was to determine the association between circulating lipid content and severe dengue and/or platelet counts. Ninety-eight patients (2-66 years old) classified as having dengue without warning signs (DNWS), dengue with warning signs (DWWS), or severe dengue (SD) and 62 healthy individuals were studied. Blood samples were tested for NS1, anti-dengue IgM, platelet content, total cholesterol (TC), triglycerides (T), high-density lipoproteins (HDL), low-density lipoproteins (LDL) and very-low-density lipoproteins (VLDL). Lipid alterations were observed mainly in patients with SD. Increased T and VLDL was observed in SD, and increased HDL was observed in DWWS and SD. Decreased TC was found in all forms of dengue, and the lowest LDL values were found in SD. Platelet counts were significantly decreased in DWWS and SD when compare to DNWS. A positive correlation (p = 0.019) between LDL values and platelet counts and a negative correlation (p = 0.0162) between VLDL values and platelet counts were found. Lipid profile alterations were associated with severe dengue.

Serum levels of apolipoprotein A-I and high-density lipoprotein can predict organ failure in acute pancreatitis

Introduction

Predicting severity of pancreatitis is an important goal. Clinicians are still searching for novel and simple biomarkers that can better predict persistent organ failure (OF). Lipoproteins, especially high-density lipoprotein (HDL), and apolipoprotein A-I (APO A-I), have been shown to have anti-inflammation effects in various clinical settings. Severe acute pancreatitis (SAP) is associated with hypo-lipoproteinemia. We studied whether the concentrations of HDL and APO A-I can predict persistent OF in patients with predicted SAP admitted to the ICU.

Methods

In 66 patients with predicted SAP, we prospectively evaluated the relationship between lipid levels, inflammatory cytokines and clinical outcomes, including persistent OF and hospital mortality. Blood samples were obtained within 24 hours of admission to the ICU.

Results

HDL and APO A-I levels were inversely correlated with various disease severity scores. Patients with persistent OF had lower levels of HDL and APO A-I, while those with transient OF had lower levels of interleukin-6, tumor necrosis factor-α and lower rates of hospital mortality. Meanwhile, hospital non-survivors had lower concentrations of HDL, and APO A-I compared to the survivors. By using the area under the receiver operating characteristic (AUROC) curve, both HDL and APO A-I demonstrated an excellent discriminative power for predicting persistent OF among all patients (AUROC 0.912 and 0.898 respectively) and among those with OF (AUROC 0.904 and 0.895 respectively). Pair-wise comparison of AUROC showed that both HDL and APO A-I had better discriminative power than C-reactive protein to predict persistent OF.

Conclusions

Serum levels of HDL and APO A-I at admission to the ICU are inversely correlated with disease severity in patients with predicted SAP and can predict persistent OF in this clinical setting.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-015-0832-x) contains supplementary material, which is available to authorized users.

Modulation of autoimmunity and atherosclerosis - common targets and promising translational approaches against disease

Atherosclerosis is a chronic inflammatory disease of the arterial wall that is influenced by several risk factors, including hyperlipidemia and hypertension. Autoimmune diseases substantially increase the risk for cardiovascular disease (CVD). Although atherosclerotic CVD, such as myocardial and stroke, is much more prevalent than classical autoimmune conditions such as rheumatoid arthritis, psoriasis, and systemic lupus erythematosus, these types of pathology have many similarities, raising the possibility that therapies against autoimmune disease can have beneficial effects on CVD. Substantial clinical and experimental data support the potential for immunomodulatory approaches to combating both autoimmune and cardiovascular diseases, including classical immunosuppressants, anticytokine therapy, the targeting of T and B cells and their responses, and vaccination. In this review, we discuss experimental and clinical studies that have used immunomodulatory approaches to mitigate autoimmune reactions and examine their potential to prevent and treat atherosclerotic CVD.

Regulation of HDL genes: transcriptional, posttranscriptional, and posttranslational

HDL regulation is exerted at multiple levels including regulation at the level of transcription initiation by transcription factors and signal transduction cascades; regulation at the posttranscriptional level by microRNAs and other noncoding RNAs which bind to the coding or noncoding regions of HDL genes regulating mRNA stability and translation; as well as regulation at the posttranslational level by protein modifications, intracellular trafficking, and degradation. The above mechanisms have drastic effects on several HDL-mediated processes including HDL biogenesis, remodeling, cholesterol efflux and uptake, as well as atheroprotective functions on the cells of the arterial wall. The emphasis is on mechanisms that operate in physiologically relevant tissues such as the liver (which accounts for 80% of the total HDL-C levels in the plasma), the macrophages, the adrenals, and the endothelium. Transcription factors that have a significant impact on HDL regulation such as hormone nuclear receptors and hepatocyte nuclear factors are extensively discussed both in terms of gene promoter recognition and regulation but also in terms of their impact on plasma HDL levels as was revealed by knockout studies. Understanding the different modes of regulation of this complex lipoprotein may provide useful insights for the development of novel HDL-raising therapies that could be used to fight against atherosclerosis which is the underlying cause of coronary heart disease.

Visceral leishmaniasis is associated with marked changes in serum lipid profile

BACKGROUND

Infection is often accompanied by lipid profile alterations. The aim of this study was to evaluate the lipid profile changes in patients with visceral leishmaniasis (VL).

MATERIALS AND METHODS

We included 15 patients [10 men, aged 50 (24-82) years old] with VL and 15 age- and sex-matched controls. The parameters estimated at diagnosis and 4 months after VL resolution were total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), triglycerides (TGs), low-density lipoprotein cholesterol (LDL-C), apolipoproteins (apo) A-Ι, B, E, C-II, C-III, lipoprotein (a) [Lp(a)], activities of lipoprotein-associated phospholipase A2 (Lp-PLA2), HDL-Lp-PLA2, PON1 (paraoxonase 1) and cholesterol ester transfer protein (CETP), cytokines (interleukins 1β and 6 and tumour necrosis factor α), as well as LDL subfraction profile.

RESULTS

Patients with VL at diagnosis had lower levels of TC, LDL-C, apoΒ and Lp(a), and higher TG and apoE concentrations compared with 4 months after VL resolution. The activities of Lp-PLA2, HDL-Lp-PLA2 and ΡΟΝ1 were reduced at diagnosis compared with post-treatment values. VL patients had decreased levels of both large and sdLDL-C at diagnosis; no effect on mean LDL particle size was observed. Patients with VL at diagnosis had decreased HDL-C and apoA-I concentrations; these increased 4 months after VL resolution, but remained lower compared with controls. The activities of HDL-Lp-PLA2 and PON1 remained lower in patients after VL resolution compared with controls.

CONCLUSIONS

Patients with VL exhibit increased TG levels and decreased cholesterol subclasses at diagnosis. HDL-C, apoA-I and associated enzymes remain lower 4 months after VL resolution compared with controls.

Global consequences of liver ischemia/reperfusion injury

Liver ischemia/reperfusion injury has been extensively studied during the last decades and has been implicated in the pathophysiology of many clinical entities following hepatic surgery and transplantation. Apart from its pivotal role in the pathogenesis of the organ's post reperfusion injury, it has also been proposed as an underlying mechanism responsible for the dysfunction and injury of other organs as well. It seems that liver ischemia and reperfusion represent an event with “global” consequences that influence the function of many remote organs including the lung, kidney, intestine, pancreas, adrenals, and myocardium among others. The molecular and clinical manifestation of these remote organs injury may lead to the multiple organ dysfunction syndrome, frequently encountered in these patients. Remote organ injury seems to be in part the result of the oxidative burst and the inflammatory response following reperfusion. The present paper aims to review the existing literature regarding the proposed mechanisms of remote organ injury after liver ischemia and reperfusion.

Changes in lipid levels with inflammation and therapy in RA: a maturing paradigm

Dyslipidaemia is commonly observed in patients with active rheumatoid arthritis (RA), with lower total cholesterol levels as well as lower levels of high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) reported in these patients than in individuals without RA. This pattern is mirrored in sepsis and other inflammatory states, suggesting systemic inflammation has the general effect of lowering circulating lipid levels. In line with such observations, suppressing inflammation with DMARDs, biologic therapies and small-molecule Janus kinase inhibitors seems to elevate levels of lipid fractions in RA, albeit in a variable manner dependent presumably upon the mechanism of action of the different agents. In addition, limited epidemiological data in patients with RA suggest increased cardiovascular disease (CVD) risk at relatively low cholesterol levels, a pattern contrasting with that observed in the population without RA. Our understanding of the potential mechanisms behind these inflammation-associated lipid changes remains suboptimal and requires further study. In clinical terms, however, use of the total cholesterol to HDL-C ratio as the lipid component of CVD risk scoring in patients with RA would seem appropriate given that these lipid parameters generally change in parallel with inflammation and suppression of inflammation. Whether alternative lipid or lipoprotein measures (or simple markers of inflammation) could improve stratification of CVD risk in RA beyond the established risk factors requires future investigation.

The association of high-density lipoprotein cholesterol with cancer incidence in type II diabetes: a case of reverse causality?

BACKGROUND

Low high-density lipoprotein cholesterol (HDL-C) and type II diabetes are associated with an increased risk for cancer. Patients with type II diabetes typically have low HDL-C; however, the association between HDL-C and cancer has not been examined in this population.

METHODS

A total of 11,140 patients with type II diabetes were followed for a median of 5 years. Cox proportional hazard models were used to assess the association between baseline HDL-C and risk of cancer incidence and cancer death, with adjustments made for potential confounders. To explore the possibility of reverse causation, analyses were repeated for the cancers occurring in the first and second halves of follow-up.

RESULTS

Six hundred and ninety-nine patients developed cancer, with 48% occurring within the first half of follow-up. For every 0.4 mmol/L lower baseline HDL-C, there was a 16% higher risk of cancer [HR 1.16; 95% confidence interval (CI), 1.06-1.28; P = 0.0008] and cancer death (HR 1.16; 95% CI, 1.01-1.32; P = 0.03). After adjustment for confounding, the higher risk remained significant for cancer (adjusted HR 1.10; 95% CI, 1.00-1.22; P = 0.05) but not for cancer death (adjusted HR 1.08; 95% CI, 0.93-1.25; P = 0.31). The association was driven by cancers occurring within the first half of follow-up (adjusted HR 1.22; 95% CI, 1.05-1.41; P = 0.008) as no significant association was found between HDL-C and cancer in the second half of follow-up.

CONCLUSIONS

Low HDL-C is associated with cancer risk in patients with type II diabetes. However, this association may be explained by confounding and reverse causation.

IMPACT

HDL-C is not a risk factor for cancer in type II diabetes.

Update on adrenal insufficiency in patients with liver cirrhosis

Liver cirrhosis is a major cause of mortality worldwide, often with severe sepsis as the terminal event. Over the last two decades, several studies have reported that in septic patients the adrenal glands respond inappropriately to stimulation, and that the treatment with corticosteroids decreases mortality in such patients. Both cirrhosis and septic shock share many hemodynamic abnormalities such as hyperdynamic circulatory failure, decreased peripheral vascular resistance, increased cardiac output, hypo-responsiveness to vasopressors, increased levels of proinflammatory cytokines [interleukine(IL)-1, IL-6, tumor necrosis factor-alpha] and it has, consequently, been reported that adrenal insufficiency (AI) is common in critically ill cirrhotic patients. AI may also be present in patients with stable cirrhosis without sepsis and in those undergoing liver transplantation. The term hepato-adrenal syndrome defines AI in patients with advanced liver disease with sepsis and/or other complications, and it suggests that it could be a feature of liver disease per se, with a different pathogenesis from that of septic shock. Relative AI is the term given to inadequate cortisol response to stress. More recently, another term is used, namely "critical illness related corticosteroid insufficiency" to define "an inadequate cellular corticosteroid activity for the severity of the patient's illness". The mechanisms of AI in liver cirrhosis are not completely understood, although decreased levels of high-density lipoprotein cholesterol and high levels of proinflammatory cytokines and circulatory endotoxin have been suggested. The prevalence of AI in cirrhotic patients varies widely according to the stage of the liver disease (compensated or decompensated, with or without sepsis), the diagnostic criteria defining AI and the methodology used. The effects of corticosteroid therapy on cirrhotic patients with septic shock and AI are controversial. This review aims to summarize the existing published information regarding AI in patients with liver cirrhosis.

Castleman's disease accompanied by hypolipidemic cerebral hemorrhage and nephrosclerosis

A 56-year-old Japanese man developed a cerebral hemorrhage and was diagnosed with plasma cell-type multicentric Castleman's disease (MCD) based on the findings of an inguinal lymph node biopsy in addition to clinical findings, including hypergammaglobulinemia, anemia and elevation of the levels of CRP and serum IL-6. Although a renal biopsy showed nephrosclerosis, the levels of serum lipids and apolipoprotein were low. Following the initiation of treatment with anti-interleukin-6 receptor antibodies, the hypergammaglobulinemia, anemia, CRP level and serum lipid profile improved. However, inflammation due to overproduction of IL-6 persisted, and atherosclerotic vascular events occurred as critical complications, even though the serum levels of lipids were very low.

Metabolic syndrome in French HIV-infected patients: prevalence and predictive factors after 3 years of antiretroviral therapy

Treatment of HIV infection with highly active antiretroviral therapy can induce metabolic complications and increase the risk of developing the metabolic syndrome (MS). The purpose of this study was to report the prevalence and the risk factors for MS in HIV-infected patients who started highly active antiretroviral therapy (HAART) after 2000. SYMET is a prospective, multicentric, cohort study evaluating the prevalence of MS in 269 patients who had received continuous HAART for 1 to 4 years up to September 2007. MS was defined according to the American Heart Association (AHA) and the National Heart, Lung, and Blood Institute (NHLBI) 2005 criteria. Cross-sectional assessment included clinical examination and fasting evaluation of metabolic, inflammatory, and oxidative parameters. Data were analyzed with Chi-square, Student, or Wilcoxon tests. Univariate and multivariate logistic regressions were performed to identify predictive factors for MS. The prevalence of MS was 18.2% after a median duration of HAART of 29.8 months. In multivariate analysis, predictive factors of MS were high non-HDL-cholesterol (OR=1.87; p<0.0001), high-sensitivity C-reactive protein levels (hsCRP) (OR=1.56; p=0.01), coinfection with hepatitis C virus (HCV) (OR=5.67; p=0.02), as well as age (OR=1.04; p=0.02) and duration of exposure to protease inhibitors (PI) (OR=1.03; p=0.02) or to abacavir (ABC) (OR=1.03; p=0.02). In this cohort of patients exposed to less than 4 years of HAART, MS prevalence was 18.2%. Older age, high hsCRP, HCV coinfection, and elevated non-HDL-cholesterol were risk factors for the MS. There was also a moderate significant association of increased risk of MS with cumulative PI and ABC exposure.

HDL Mimetic Peptide Administration Improves Left Ventricular Filling and Cardiac output in Lipopolysaccharide-Treated Rats

AIMS: Cardiac dysfunction is a complication of sepsis and contributes to morbidity and mortality. Since raising plasma apolipoprotein (apo) A-I and high density lipoprotein (HDL) concentration reduces sepsis complications, we tested the hypothesis that the apoA-I mimetic peptide 4F confers similar protective effects in rats treated with lipopolysaccharide (LPS). METHODS AND RESULTS: Male Sprague-Dawley (SD) rats were randomized to receive saline vehicle (n=13), LPS (10 mg/kg: n=16) or LPS plus 4F (10 mg/kg each: n=13) by intraperitoneal injection. Plasma cytokine and chemokine levels were significantly elevated 24 hrs after LPS administration. Echocardiographic studies revealed changes in cardiac dimensions that resulted in a reduction in left ventricular end-diastolic volume (LVEDV), stroke volume (SV) and cardiac output (CO) 24 hrs after LPS administration. 4F treatment reduced plasma levels of inflammatory mediators and increased LV filling, resulting in improved cardiac performance. Chromatographic separation of lipoproteins from plasma of vehicle, LPS and LPS+4F rats revealed similar profiles. Further analyses showed that LPS treatment reduced the agarose electrophoretic mobility of isolated HDL fractions. HDL-associated proteins were characterized by SDSPAGE and mass spectrometry. ApoA-I and apoA-IV were reduced while apoE content was increased in LPStreated rats. 4F treatment in vivo attenuated changes in HDL-associated apolipoproteins and increased the electrophoretic mobility of the particle. CONCLUSIONS: The ability of 4F to reduce inflammation and improve cardiac performance in LPS-treated rats may be due to its capacity to neutralize endotoxin and prevent adverse changes in HDL composition and function.