The effect of interferon on the metabolism of LDLs

Kinetics changes in total cholesterol predict HBeAg seroconversion in chronic hepatitis B patients treated with pegylated interferon-alfa

There is no satisfactory standard for predicting HBeAg seroconversion during Pegylated interferon alpha (PegIFNα) treatment. Studies have shown that IFNα therapy in chronic hepatitis C patients could alter serum lipid profiles. However, there have been no studies on lipid changes that predict the outcome of PegIFNα monotherapy in treated-naive chronic hepatitis B (CHB) patients. This retrospective study included 130 treated-naive HBeAg-positive CHB patients receiving PegIFNα monotherapy. The relationship between serum lipid changes and HBeAg seroconversion was analysed. The TC-ALT-HBsAg-HBeAg-Genotype-Age (CASEGA) model was established to predict HBeAg seroconversion after PegIFN-α monotherapy. Among 130 patients, 33 achieved HBeAg seroconversion (SR) and 97 did not achieve HBeAg seroconversion (NR). The decrease in serum total cholesterol (TC) in the NR group was significantly higher than in the SR group at Week 24 (-9.59% vs. -0.31%, p < 0.001). Multivariate logistic regression analysis showed that the change in TC at Week 24 (odds ratio = 1.065, p = 0.009) was an independent predictor of HBeAg seroconversion. The area under the receiver operating characteristic curve for the CASEGA model was 0.883. The model score at the maximum Youden index was 90, and the specificity, sensitivity, positive predictive value and negative predictive value were 0.727, 0.794, 0.546 and 0.895, respectively. The HBeAg seroconversion rate at Week 72 in patients with scores >90 was significantly higher than that in patients with scores <90 (54.55% vs. 10.47%, p < 0.001). This study indicated that the change in the TC level at 24 weeks in CHB patients treated with PegIFNα was associated with HBeAg seroconversion. The CASEGA prediction model based on the TC change rate of 24 weeks has good predictive efficiency for HBeAg seroconversion.

IFN-α-2b induces apoptosis by decreasing cellular cholesterol levels in rat preneoplastic hepatocytes

IFN-α administration to patients has been long discouraged and pushed back by new and apparently better drugs; however the adverse secondary effect, the high costs and the lack of specific action, make these new drugs hard to be used and put IFN-α again in the eye of the researchers. IFN-α-2b was demonstrated to induce apoptosis and modulation of lipid metabolism and the mechanisms are still unknown. Here, we sought to find the link between these features using a model of early stage cancer development. Using in vitro and in vivo approaches, we evaluated apoptosis and lipid metabolism. IFN-α-2b induced changes in hepatic cholesterol mass due to decreased synthesis and increased secretion. Interestingly, the drop in cellular cholesterol levels was necessary for IFN-α-2b to induce apoptosis. Results presented in this paper show the complexity of the action of IFN-α-2b on the early stages of liver cancer development. We show for the first time an interrelationship between cholesterol, apoptosis and IFN-α-2b. This makes clear the need for a reevaluation of IFN-α-2b action in order to develop softer, safer and more bearable derivatives. In this regard, knowing the molecular mechanisms by which IFN-α exerts its cellular actions is of crucial importance, and it is the main condition for therapy success for classical and new malignancies.

IFN-α-2b treatment protects against diet-induced obesity and alleviates non-alcoholic fatty liver disease in mice

IFN-α is used for inflammatory purposes, and obesity and NAFLD are strongly correlated with inflammatory processes. We wondered whether IFN-α-2b can attenuate obesity development and its associated NAFLD in mice fed high fat diet (HFD) for 10 weeks. IFN-α-2b had a robust effect on body weight loss associated with NAFLD amelioration by decreasing hepatic inflammation. IFN-α-2b-treated mice showed increased plasma cholesterol levels together with decreased hepatic cholesterol, both on chow and HF diets. Interestingly, mice on IFN-α-2b treatment secreted smaller VLDL particles highly enriched in cholesterol. Mechanistically, we found that IFN-α-2b antiobesity effects were related to increased fatty acid oxidation; and its effects on cholesterol metabolism were due to both a decrease in the master cholesterogenic transcription factor SREBP-2 and in the rate limiting enzyme in cholesterol synthesis, HMGCR. To our knowledge, this is the first report showing the effects of IFN-α-2b on the prevention of the development of HFD-induced body weight gain and dyslipidemia through a mechanism that involves fatty acid oxidation and cholesterol decrease. These studies comprise necessary steps for understanding the amelioration of obesity and NAFLD. Results shed some light into the mechanism of action of natural cytokines, and their effects on ameliorating obesity and its related diseases.

Immunometabolic Effect of Cholesterol in Hepatitis C Infection: Implications in Clinical Management and Antiviral Therapy

Hepatitis C virus (HCV) is a lipid-enveloped virion particle that causes infection to the liver, and as part of its life cycle, it disrupts the host lipid metabolic machinery, particularly the cholesterol synthesis pathway. The innate immune response generated by liver resident immune cells is responsible for successful viral eradication. Unfortunately, most patients fail to eliminate HCV and progress to chronic infection. Chronic infection is associated with hepatic fat accumulation and inflammation that triggers fibrosis, cirrhosis, and eventually hepatocellular carcinoma. Despite that the current direct-acting antiviral agents have increased the cure rate of HCV infection, viral genotype and the host genetic background influence both the immune response and lipid metabolism. In this context, recent evidence has shown that cholesterol and its derivatives such as oxysterols might modulate and potentialize the hepatic innate immune response generated against HCV. The impairment of the HCV life cycle modulated by serum cholesterol could be relevant for the clinical management of HCV-infected patients before and after treatment. Alongside, cholesterol levels are modulated either by genetic variations in IL28B, ApoE, and LDLR or by dietary components. Indeed, some nutrients such as unsaturated fatty acids have demonstrated to be effective against HCV replication. Thus, cholesterol modifications may be considered as a new adjuvant strategy for HCV infection therapy by providing a biochemical tool that guides treatment decisions, an improved treatment response and favoring viral clearance. Herein, the mechanisms by which cholesterol contributes to the immune response against HCV infection and how genetic and environmental factors may affect this role are reviewed.

Rapid Changes in Serum Lipid Profiles during Combination Therapy with Daclatasvir and Asunaprevir in Patients Infected with Hepatitis C Virus Genotype 1b

Background/Aims

Changes in lipid profiles in patients infected with hepatitis C virus (HCV) during direct-acting antiviral therapy have been reported in recent years. However, the clinical aspects of disturbed lipid metabolism in chronic HCV infection have not been fully elucidated.

Methods

Dynamic changes in serum total, low-density lipoprotein (LDL), and high-density lipoprotein (HDL) cholesterol and apolipoprotein levels in patients infected with HCV genotype 1b were examined during combination therapy with daclatasvir (DCV) and asunaprevir (ASV).

Results

Total, LDL−, and HDL-cholesterol levels increased rapidly and persistently after week 4. Apolipoprotein (apo) A-I, apo B, apo C-II, and apo C-III levels were significantly higher at week 4 than at week 0. In contrast, apo A-II and apo E levels were significantly lower. The differences in LDL− and HDL-cholesterol levels were positively correlated with those of apo B and apo A-I, respectively. Interestingly, in patients with non-sustained virological response, these cholesterol levels decreased rapidly after viral breakthrough or viral relapse. Furthermore, similar changes were observed for apo A-I, apo B and apo C-III levels.

Conclusions

Clearance of HCV using combination therapy with DCV and ASV results in rapid changes in serum lipid profiles, suggesting an influence of HCV infection on disturbed lipid metabolism.

Interferon Control of the Sterol Metabolic Network: Bidirectional Molecular Circuitry-Mediating Host Protection

The sterol metabolic network is emerging center stage in inflammation and immunity. Historically, observational clinical studies show that hypocholesterolemia is a common side effect of interferon (IFN) treatment. More recently, comprehensive systems-wide investigations of the macrophage IFN response reveal a direct molecular link between cholesterol metabolism and infection. Upon infection, flux through the sterol metabolic network is acutely moderated by the IFN response at multiple regulatory levels. The precise mechanisms by which IFN regulates the mevalonate-sterol pathway—the spine of the network—are beginning to be unraveled. In this review, we discuss our current understanding of the multifactorial mechanisms by which IFN regulates the sterol pathway. We also consider bidirectional communications resulting in sterol metabolism regulation of immunity. Finally, we deliberate on how this fundamental interaction functions as an integral element of host protective responses to infection and harmful inflammation.

Increased Immune Activation and Exhaustion in HIV-infected Youth

BACKGROUND

Immune activation and exhaustion drive several comorbidities and disease progression in HIV-infected adults; however, they are not well studied in HIV-infected youth. Thus, this study sought to examine levels of immune activation and exhaustion in this population, investigate associated HIV- and non-HIV-related variables and compare results with a matched healthy control group.

METHODS

HIV-infected youth 8-25 years of age on stable antiretroviral therapy with an HIV-1 RNA level <1000 copies/mL were enrolled, along with matched healthy controls. We measured T-cell and monocyte immune activation and exhaustion markers in cryopreserved peripheral blood mononuclear cell and plasma samples.

RESULTS

A total of 136 subjects (80 HIV+: 66% male; 91% black) were enrolled. Markers of CD4+ and CD8+ T-cell activation were higher in the HIV-infected group versus controls [mean % CD4+CD38+HLA-DR+ and CD8+CD38+HLA-DR+ = 2.2 versus 1.5 (P=0.002) and 4.9 versus 2.2 (P<0.0001), respectively], as were exhausted CD4+ and CD8+ T-cells [mean % CD4+CD38+HLA-DR+PD-1+ and CD8+CD38+HLA-DR+PD-1+ = 1.0 versus 0.5 (P<0.0001) and 1.6 versus 0.7 (P<0.0001), respectively]. There were no differences in proportions of inflammatory or patrolling monocytes between groups (P>0.05); however, soluble CD14 was higher in HIV-infected compared with controls (1.6 versus 1.4 µg/mL; P=0.01). Current CD4 count, low-density lipoprotein cholesterol and age were the variables most associated with CD4+ and CD8+ T-cell activation.

CONCLUSIONS

CD4+ and CD8+ T-cell immune activation and exhaustion are higher in HIV-infected youth compared with matched controls, while monocyte subpopulations are not altered despite a high soluble CD14 level. The clinical significance of the increased immune activation and exhaustion should be further explored.

Relationship among IL-6, LDL cholesterol and lipid peroxidation

Previous studies evidenced a significant reduction in serum cholesterol levels during an episode of acute inflammation. The aim of the present study was to verify the hypothesis of a regulatory role of cytokines through an in vitro model that simulates a situation of vascular inflammation and high levels of LDL or lipoperoxides. Human microvascular endothelial cells-1 were used in all experiments. The cells were exposed for 24 h to increasing doses of LDL, oxidized lipoprotein, and 8-isoprostane (in the absence or presence of SQ29.548, a TXA2 receptor antagonist). Moreover, LDL receptor and oxidized lipoprotein receptor expression analyzed after endothelial cells' incubation with increasing doses of interleukin-6. The ELISA test and quantitative real-time PCR were performed. Endothelial cells showed a significant increase in interleukin-6 medium levels associated with LDL, oxidized LDL and with the degree of oxidation (absence or presence of SQ29.548), while 8-isoprostane did not. Treatment of human microvascular endothelial cells-1 for 24 h with increasing doses of interleukin-6 significantly enhanced LDL receptor and oxidized lipoprotein receptor-1 mRNA expression. Our data suggest the presence of a compensatory mechanism. The induction of a significant increase of IL-6 does not seem to be caused by the presence of the biological activity of 8-isoprostane.

Inflammatory Cytokines and Antipsychotic-Induced Weight Gain: Review and Clinical Implications

Antipsychotic medications (APs), particularly second-generation APs, are associated with significant weight gain in schizophrenia patients. Recent evidence suggests that the immune system may contribute to antipsychotic-induced weight gain (AIWG) via AP-mediated alterations of cytokine levels. Antipsychotics with a high propensity for weight gain, such as clozapine and olanzapine, influence the expression of immune genes, and induce changes in serum cytokine levels to ultimately down-regulate neuroinflammation. Since inflammatory cytokines are normally involved in anorexigenic responses, reduced inflammation has been independently shown to mediate changes in feeding behaviours and other metabolic parameters, resulting in obesity. Genetic variation in pro-inflammatory cytokines is also associated with both general obesity and weight change during AP treatment, and thus, may be implicated in the pharmacogenetics of AIWG. At this time, preliminary data support a cytokine-mediated model of AIWG which may have clinical utility in developing more effective metabolic monitoring guidelines and prevention measures. However, further research is still needed to clearly elucidate the validity of this immune model. This article reviews the evidence implicating inflammatory cytokines in AIWG and its potential clinical relevance.

Infection homeostasis: implications for therapeutic and immune programming of metabolism in controlling infection

Homeostasis underpins at a systems level the regulatory control of immunity and metabolism. While physiologically these systems are often viewed as independent, there is increasing evidence showing a tight coupling between immune and metabolic functions. Critically upon infection, the homeostatic regulation for both immune and metabolic pathways is altered yet these changes are often investigated in isolation. Here, we summarise our current understanding of these processes in the context of a clinically relevant pathogen, cytomegalovirus. We synthesise from the literature an integrative view of a coupled immune-metabolic infection process, centred on sugar and lipid metabolism. We put forward the notion that understanding immune control of key metabolic enzymatic steps in infection will promote the future development of novel therapeutic modalities based on metabolic modifiers that either enhance protection or inhibit infection.

Impact of IL28B genetic variation on HCV-induced liver fibrosis, inflammation, and steatosis: a meta-analysis

BACKGROUND & AIMS

IL28B polymorphisms were shown to be strongly associated with the response to interferon therapy in chronic hepatitis C (CHC) and spontaneous viral clearance. However, little is known about how these polymorphisms affect the natural course of the disease. Thus, we conducted the present meta-analysis to assess the impact of IL28B polymorphisms on disease progression.

METHODS

A literature search was conducted using MEDLINE, EMBASE, and the Cochrane Library. Integrated odds ratios (OR) were calculated with a fixed-effects or random-effects model based on heterogeneity analyses.

RESULTS

We identified 28 studies that included 10,024 patients. The pooled results indicated that the rs12979860 genotype CC was significantly associated (vs. genotype CT/TT; OR, 1.122; 95%CI, 1.003-1.254; P = 0.044), and that the rs8099917 genotype TT tended to be (vs. genotype TG/GG; OR, 1.126; 95%CI, 0.988-1.284; P = 0.076) associated, with an increased possibility of severe fibrosis. Both rs12979860 CC (vs. CT/TT; OR, 1.288; 95%CI, 1.050-1.581; P = 0.015) and rs8099917 TT (vs. TG/GG; OR, 1.324; 95%CI, 1.110-1.579; P = 0.002) were significantly associated with a higher possibility of severe inflammation activity. Rs8099917 TT was also significantly associated with a lower possibility of severe steatosis (vs. TG/GG; OR, 0.580; 95%CI, 0.351-0.959; P = 0.034), whereas rs12979860 CC was not associated with hepatic steatosis (vs. CT/TT; OR, 1.062; 95%CI, 0.415-2.717; P = 0.901).

CONCLUSIONS

IL28B polymorphisms appeared to modify the natural course of disease in patients with CHC. Disease progression seems to be promoted in patients with the rs12979860 CC and rs8099917 TT genotypes.

Association of low-density lipoprotein receptor genotypes with hepatitis C viral load

Several data suggest that low-density lipoprotein receptor (LDLR) is a co-receptor for hepatitis C virus (HCV). Soluble LDLR can inhibit HCV infectivity; greater plasma low-density lipoprotein levels are associated with treatment success; LDLR genotypes have a synergistic impact on the likelihood of achieving SVR with Peg-IFN plus RBV, as well as on viral kinetics after starting treatment. The objective of this study was to assess the impact of genetic polymorphisms in genes related to cholesterol synthesis and transport pathways on pre-treatment plasma HCV viral load (VL). A total of 442 patients infected with HCV and treatment naive were prospectively recruited. One hundred forty-four SNPs located in 40 genes from the cholesterol synthesis/transport and IL28B were genotyped and analyzed for genetic association with pre-treatment plasma HCV VL. SNPs rs1433099 and rs2569540 of LDLR showed association with plasma HCV VL (P=4 × 10(-4) and P=2 × 10(-3)) in patients infected with genotypes 1 and 4. A haplotype including the last three exons of LDLR showed association with the cutoff level of 600 000 IU ml(-1) VL for genotypes 1 and 4 (OR=0.27; P=8 × 10(-6)), as well as a quantitative VL (mean±s.d.: 6.19±0.9 vs CC+CG 5.58±1.1 logIU ml(-1), P=8 × 10(-5)). LDLR genotypes are a major genetic factor influencing HCV VL in patients infected with genotypes 1 and 4.

Association of IFNL3 rs12979860 and rs8099917 with biochemical predictors of interferon responsiveness in chronic hepatitis C virus infection

BACKGROUND & AIMS

Genetic variations near the interferon lambda 3 gene (IFNL3, IL28B) are the most powerful predictors for sustained virologic response (SVR) in patients with chronic hepatitis C virus (HCV) infection, compared to other biochemical or histological baseline parameters. We evaluated whether the interplay of both IFNL3 polymorphisms rs12979860 and rs8099917 together with non-genetic clinical factors contributes to the predictive role of these genetic variants.

METHODS

The cohort comprised 1,402 patients of European descent with chronic HCV type 1 infection. 1,298 patients received interferon-based antiviral therapy, and 719 (55%) achieved SVR. The IFNL3 polymorphisms were genotyped by polymerase chain reaction and melting curve analysis.

RESULTS

A significant correlation was found between the IFNL3 polymorphisms and biochemical as well as virologic predictors of treatment outcome such as ALT, GGT, cholesterol, and HCV RNA levels. In multivariate regression analysis, IFLN3 SNPs, HCV RNA levels, and the GGT/ALT ratio were independent predictors of SVR. Dependent on the GGT/ALT ratio and on the HCV RNA concentration, significant variations in the likelihood for achieving SVR were observed in both, carriers of the responder as well as non-responder alleles.

CONCLUSIONS

Our data support a clear association between IFNL3 genotypes and baseline parameters known to impact interferon responsiveness. Improved treatment outcome prediction was achieved when these predictors were considered in combination with the IFNL3 genotype.

Effects of IL28B rs12979860 CC genotype on metabolic profile and sustained virologic response in patients with genotype 1 chronic hepatitis C

BACKGROUND & AIMS

Patients with genotype 1 chronic hepatitis C (G1 CHC) frequently develop steatosis and insulin resistance (IR), caused by metabolic and viral factors. These accelerate the progression of liver disease and reduce the response to therapy. A sustained virologic response (SVR) to therapy in patients with G1 CHC is associated strongly with polymorphisms near the interleukin-28B (IL28B) gene, but the interaction between IL28B genotype and IR, and their combined effects on SVR, have not been defined. We tested the association between the IL28B rs12979860 single-nucleotide polymorphism and metabolic features, including IR, and evaluated their effects on SVR.

METHODS

We performed genotype analysis of IL28B rs12979860 for 434 white G1 CHC patients who underwent consecutive biopsy analysis at 3 tertiary centers. Metabolic profile analyses included assessments of lipid levels and IR by the homeostasis model assessment.

RESULTS

Patients with the CC polymorphism in IL28B had higher levels of total and low-density lipoprotein cholesterol, lower levels of triglycerides, and a lower prevalence of IR and moderate-severe steatosis (P < .05) than patients without this genotype. By multiple logistic regression analysis, body mass index (odds ratio [OR], 1.223; P < .001), level of triglycerides (OR, 1.007; P = .006), the CC polymorphism in IL28B (OR, 0.378; P = .001), and levels of HCV RNA greater than 850,000 IU/mL (OR, 1.803; P = .01) were associated with IR. The CC polymorphism in IL28B (OR, 8.350; P < .001) and IR (OR, 0.432; P = .005), but not steatosis (OR, 0.582; P = 0.25), was associated with an SVR.

CONCLUSIONS

In white patients with G1 CHC, the IL28B rs12979860 CC genotype is associated with reduced IR. IL28B rs12979860 genotype and IR by the homeostasis model assessment strongly affect the outcome of antiviral therapy.

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.

The interleukin 28B rs12979860 C/T polymorphism and serum cholesterol as predictors of fibrosis progression in patients with chronic hepatitis C and persistently normal transaminases

The interleukin 28B (IL-28B) rs12979860 C/T polymorphism is a predictor of spontaneous and treatment-induced hepatitis C virus (HCV) clearance. The C/C genotype is associated with higher serum cholesterol, predictor of a favorable outcome in chronic hepatitis C. Whether IL-28B polymorphism and serum cholesterol play a role in modulating the history of mild hepatitis C is unknown. To clarify this issue, 93 untreated patients infected with HCV with normal or near-normal transaminases and an initial Ishak staging score ≤1 were investigated retrospectively in the longitudinal study (median histological follow-up of 10 years). An additional confirmatory cohort of 143 patients with chronic HCV infection and abnormal levels of transaminases was evaluated in the cross-sectional study. In the longitudinal study, at the end of follow-up, Ishak staging scores progressed more frequently among carriers of a T/* allele who had a baseline serum cholesterol ≤175 mg/dl than in remaining patients: 6/36 (change ≤0), 15/45 (change 1-2), 6/12 (change ≥3), improvement chi-square P < 0.02, OR 3.1, 95% C.I. 1.3-7.7. In the cross-sectional study, the frequency of patients carrying the T/T genotype or serum cholesterol values ≤175 mg/dl increased starting from those with a staging score ≤2 (36/76, 47.4%), to those with a staging score of 3-4 (26/41, 63.4%) and to those with a staging score of 5-6 (20/26, 76.9%, P < 0.01 for linear trend). In conclusion, the interaction between IL-28B rs12979860 T/T genotype and low serum cholesterol concentration is an independent predictor of a worse disease course among patients infected with HCV with normal or near-normal transaminases.

Genotype rs8099917 near the IL28B gene and amino acid substitution at position 70 in the core region of the hepatitis C virus are determinants of serum apolipoprotein B-100 concentration in chronic hepatitis C

The life cycle of the hepatitis C virus (HCV) is closely related to host lipoprotein metabolism. Serum levels of lipid are associated with the response to pegylated interferon plus ribavirin (PEG-IFN/RBV) therapy, while single nucleotide polymorphisms (SNPs) around the human interleukin 28B (IL28B) gene locus and amino acid substitutions in the core region of the HCV have been reported to affect the efficacy of PEG-IFN/RBV therapy in chronic hepatitis with HCV genotype 1b infection. The aim of this study was to elucidate the relationship between serum lipid and factors that are able to predict the efficacy of PEG-IFN/RB therapy, with specific focus on apolipoprotein B-100 (apoB-100) in 148 subjects with chronic HCV G1b infection. Our results demonstrated that both the aa 70 substitution in the core region of the HCV and the rs8099917 SNP located proximal to the IL28B were independent factors in determining serum apoB-100 and low-density lipoprotein (LDL) cholesterol levels. A significant association was noted between higher levels of apoB-100 (P = 1.1 × 10(-3)) and LDL cholesterol (P = 0.02) and the subjects having Arg70. A significant association was also observed between subjects carrying the rs8099917 TT responder genotype and higher levels of apoB-100 (P = 6.4 × 10(-3)) and LDL cholesterol (P = 4.2 × 10(-3)). Our results suggest that apoB-100 and LDL cholesterol are markers of impaired cellular lipoprotein pathways and/or host endogenous interferon response to HCV in chronic HCV infection. In particular, serum apoB-100 concentration might be an informative marker for judging changes in HCV-associated intracellular lipoprotein metabolism in patients carrying the rs8099917 responder genotype.

Beneficial IL28B genotype associated with lower frequency of hepatic steatosis in patients with chronic hepatitis C

BACKGROUND & AIMS

IL28B polymorphisms have been associated with both treatment induced and spontaneous clearance of hepatitis C virus (HCV). We previously found that LDL cholesterol levels were higher in chronic hepatitis C (CHC) patients with the CC genotype at the rs12979860 polymorphism, located proximal to the IL28 gene. Here we analyzed the association of steatosis with IL28B genotype in treatment naïve patients with CHC.

METHODS

Two independent cohorts of 145 genotype 1 infected patients from an antifibrotic study and 180 genotype 1 patients from Duke were analyzed for the presence and severity of steatosis in relation to the rs12979860 polymorphism at the IL28B locus. TaqMan assay based genotyping classified three groups CC, CT, and TT.

RESULTS

CC genotype was associated with a lower prevalence of steatosis. In the antifibrotic study, steatosis was found in 47.6% (50/105) of IL28B non-CC vs. 22.5% (9/40; p=0.008) in CC patients. Similarly, steatosis was found in 67.4% (89/132) of non-CC patients compared to only 39.6% (19/48; p=0.001) of CC patients in the Duke cohort.

CONCLUSIONS

IL28B CC genotype is associated with less pronounced disturbances of lipid metabolism, as reflected both in serum lipoprotein levels and hepatic steatosis, in HCV infection.

Interferon-lambda genotype and low serum low-density lipoprotein cholesterol levels in patients with chronic hepatitis C infection

Recently, genetic polymorphisms occurring in the interferon (IFN)-lambda gene region were associated with response to IFN-based treatment of hepatitis C infection. Both infection with the hepatitis C virus and IFN therapy are associated with decreased serum cholesterol and high cholesterol has been associated with increased likelihood to respond to IFN. We sought to determine if the IFN-lambda gene variant was also associated with serum lipid levels in chronic hepatitis C patients. We compared genotypes of the rs12979860 polymorphism, located proximal to the IL28 gene, with serum lipid and apolipoprotein levels in 746 subjects with chronic hepatitis C virus infection, not currently undergoing treatment, using multivariable analysis of variance. Levels of total cholesterol (P = 6.0 x 10(-4)), apolipoprotein B (P = 1.3 x 10(-6)) and low-density lipoprotein (LDL) cholesterol (P = 8.9 x 10(-10)) were significantly higher in subjects carrying the rs12979860 CC responder genotype compared with those with the CT or TT genotype. Levels of triglycerides (P = 0.03), apolipoprotein A-I (P = 0.06), and apolipoprotein E (P = 0.01) were slightly lower in the rs12979860 CC genotype group, whereas levels of high-density lipoprotein cholesterol (P = 0.78) and apolipoprotein C-III (P = 0.74) did not vary by rs12979860 genotype.

CONCLUSION

Our results suggest that low levels of LDL cholesterol in chronic hepatitis C patients may be a marker of host endogenous IFN response to hepatitis C and that subjects with the rs12979860 CC responder genotype may have a lower endogenous IFN response to the virus.

Preoperative total serum cholesterol as a prognostic factor for survival in patients with resectable non-small-cell lung cancer

BACKGROUND

Coexisting hypocholesterolemia in cancer has been known for a very long time but its relationship to cancer is still controversial. Hypocholesterolemia has been reported in patients with lung cancer, although its association with survival has not been explored.

OBJECTIVES

The purpose of the study was to determine whether preoperative total serum cholesterol is a prognostic factor for survival after lung cancer resection.

METHODS

The retrospective study comprised 198 patients (162 men, 36 women) operated upon for resectable non-small-cell lung cancer (clinical stages I-IIIB) between January 1992 and April 1994. Total serum cholesterol concentration was determined preoperatively in each patient. The effects of sex, age, stage, histological type and preoperative total serum cholesterol concentration on survival were tested in univariate and multivariate analysis.

RESULTS

Preoperative total serum cholesterol was a significant prognostic factor in both univariate and multivariate analysis. The median value for total serum cholesterol was 5.3 mmol/l and patients below that cut-off had significantly shorter overall survival times than patients in the high cholesterol group (5-year survival 41% vs. 56%, P < 0.05). In a multivariate Cox proportional-hazard regression model, only stage and preoperative total serum cholesterol were found to be of significance for survival (relative risk 0.84 for each mmol/l increase in concentration, CI 0.71-1.00, P < 0.05).

CONCLUSIONS

Our results suggest that preoperative total serum cholesterol may be an important prognostic factor for overall survival after lung cancer resection. It may prove to be a valuable tool in the follow-up of patients with lung cancer and in detection of high-risk cases.

Roles of infection, inflammation, and the immune system in cholesterol gallstone formation

Cholesterol gallstone formation is a complex process mediated by genetic and environmental factors. Until recently, the role of the immune system in the pathogenesis of cholesterol gallstones was not considered a valid topic of research interest. This review collates and interprets an extensive body of basic literature, some of which is not customarily considered to be related to cholelithogenesis, describing the multiple facets of the immune system that appear to be involved in cholesterol cholelithogenesis. A thorough understanding of the immune interactions with biliary lipids and cholecystocytes should modify current views of the pathogenesis of cholesterol gallstones, promote further research on the pathways involved, and lead to novel diagnostic tools, treatments, and preventive measures.

Secretory phospholipase A2 of group IIA: Is it an offensive or a defensive player during atherosclerosis and other inflammatory diseases?

Since its discovery in the serum of patients with severe inflammation and in rheumatoid arthritic fluids, the secretory phospholipase A2 of group IIA (sPLA2-IIA) has been chiefly considered as a proinflammatory enzyme, the result of which has been very intense interest in selective inhibitors of sPLA2-IIA in the hope of developing new and efficient therapies for inflammatory diseases. The recent discovery of the antibacterial properties of sPLA2-IIA, however, has raised the question of whether the upregulation of sPLA2-IIA during inflammation is to be considered uniformly negative and the hindrance of sPLA2-IIA in every instance beneficial. The aim of this review is for this reason, along with the results of various investigations which argue for the proinflammatory and proatherogenic effects of an upregulation of sPLA2-IIA, also to array data alongside which point to a protective function of sPLA2-IIA during inflammation. Thus, it could be shown that sPLA2-IIA, apart from the bactericidal effects, possesses also antithrombotic properties and indeed plays a possible role in the resolution of inflammation and the accelerated clearance of oxidatively modified lipoproteins during inflammation via the liver and adrenals. Based on these multipotent properties the knowledge of the function of sPLA2-IIA during inflammation is a fundamental prerequisite for the development and establishment of new therapeutic strategies to prevent and treat severe inflammatory diseases up to and including sepsis.

Hepatic injury, liver monitoring and the beta-interferons for multiple sclerosis

This review explores the salient issues surrounding liver injury and liver monitoring associated with beta-interferon (IFNB) treatment for multiple sclerosis (MS). Post-marketing studies have found a higher proportion of IFNB-treated MS patients with elevated aminotransferases than reported in the pivotal clinical trials. Although the risk of severe liver injury appears small, the true incidence is unknown. Post-marketing studies have shown that the greatest period of risk for the development of liver test abnormalities appears to be in the first year of IFNB treatment. The risk also increases with the more frequently administered, higher-dosage IFNBs. Males are more likely than females to develop elevated aminotransferases (> upper normal limit), although females appear at a greater risk of severe liver injury. Of the commonly used biochemical liver tests, alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (AP) and bilirubin appear the most useful for routine monitoring of IFNB treatment. Whilst many other factors can affect liver test results, including obesity, alcohol, concomitant medications, co-morbidities and theoretically even MS itself, regular liver testing both prior and during IFNB therapy might help minimise Type A or dose/frequency dependent aminotransferase elevations. However, testing will probably not prevent the Type B idiosyncratic reactions which can result in severe hepatic injury; hence patients need to be aware, and to report hepatic side effects promptly.

Effects of infection and inflammation on lipid and lipoprotein metabolism: mechanisms and consequences to the host

Infection and inflammation induce the acute-phase response (APR), leading to multiple alterations in lipid and lipoprotein metabolism. Plasma triglyceride levels increase from increased VLDL secretion as a result of adipose tissue lipolysis, increased de novo hepatic fatty acid synthesis, and suppression of fatty acid oxidation. With more severe infection, VLDL clearance decreases secondary to decreased lipoprotein lipase and apolipoprotein E in VLDL. In rodents, hypercholesterolemia occurs attributable to increased hepatic cholesterol synthesis and decreased LDL clearance, conversion of cholesterol to bile acids, and secretion of cholesterol into the bile. Marked alterations in proteins important in HDL metabolism lead to decreased reverse cholesterol transport and increased cholesterol delivery to immune cells. Oxidation of LDL and VLDL increases, whereas HDL becomes a proinflammatory molecule. Lipoproteins become enriched in ceramide, glucosylceramide, and sphingomyelin, enhancing uptake by macrophages. Thus, many of the changes in lipoproteins are proatherogenic. The molecular mechanisms underlying the decrease in many of the proteins during the APR involve coordinated decreases in several nuclear hormone receptors, including peroxisome proliferator-activated receptor, liver X receptor, farnesoid X receptor, and retinoid X receptor. APR-induced alterations initially protect the host from the harmful effects of bacteria, viruses, and parasites. However, if prolonged, these changes in the structure and function of lipoproteins will contribute to atherogenesis.

Lipid transfer inhibitor protein defines the participation of high density lipoprotein subfractions in lipid transfer reactions mediated by cholesterol ester transfer protein (CETP)

Cholesterol ester transfer protein (CETP) moves triglyceride (TG) and cholesteryl ester (CE) between lipoproteins. CETP has no apparent preference for high (HDL) or low (LDL) density lipoprotein as lipid donor to very low density lipoprotein (VLDL), and the preference for HDL observed in plasma is due to suppression of LDL transfers by lipid transfer inhibitor protein (LTIP). Given the heterogeneity of HDL, and a demonstrated ability of HDL subfractions to bind LTIP, we examined whether LTIP might also control CETP-facilitated lipid flux among HDL subfractions. CETP-mediated CE transfers from [3H]CE VLDL to various lipoproteins, combined on an equal phospholipid basis, ranged 2-fold and followed the order: HDL3 > LDL > HDL2. LTIP inhibited VLDL to HDL2 transfer at one-half the rate of VLDL to LDL. In contrast, VLDL to HDL3 transfer was stimulated, resulting in a CETP preference for HDL3 that was 3-fold greater than that for LDL or HDL2. Long-term mass transfer experiments confirmed these findings and further established that the previously observed stimulation of CETP activity on HDL by LTIP is due solely to its stimulation of transfer activity on HDL3. TG enrichment of HDL2, which occurs during the HDL cycle, inhibited CETP activity by approximately 2-fold and LTIP activity was blocked almost completely. This suggests that LTIP keeps lipid transfer activity on HDL2 low and constant regardless of its TG enrichment status. Overall, these results show that LTIP tailors CETP-mediated remodeling of HDL3 and HDL2 particles in subclass-specific ways, strongly implicating LTIP as a regulator of HDL metabolism.

Cytokines in coagulation and thrombosis: a preclinical and clinical review

The cytokine network is a complex and dynamic system, involved in numerous biological responses in the human body. This review of the current literature describes the role of cytokines and their interaction with the coagulation system, specifically in the maintenance of the thrombo-hemorrhagic balance in vivo in human subjects and in animals. In general, cytokines are thrombogenic, but they are amenable to therapeutic manipulations and hence are a potentially attractive tool in the clinician's armamentarium. Studies of the effects of cytokines in vivo are difficult because cytokines act in a very finite microenvironment and, although their actions are significant, they are transient. Most of the available clinical data related to interactions between cytokines and the coagulation system focuses on the role of tumor necrosis factor-alpha and interleukin-1 in septicemia and septic shock. However, several other cytokines and related proteins, such as platelet activating factor and plasminogen activator inhibitor, are also known to influence coagulation and thrombosis. These factors interact closely with cytokines, and have been included in this review for a better understanding of their interactions with traditional cytokines. Studies that utilize cell culture systems do not accurately model the in vivo status of this complex system and, hence, this review has excluded such studies. The role of the cytokine network in coronary artery disease, angiogenesis, or neoplasia has been addressed elsewhere by other workers and is not discussed here. By emphasizing important in vivo interactions, the intention of this review is to serve as an impetus to further translational research, both clinical and in the laboratory.

Effects of interferon-beta on plasma lipid and lipoprotein composition and post-heparin lipase activities in patients with chronic hepatitis C

BACKGROUND

Interferon therapy has been shown to induce lipid abnormalities.

AIM

We assessed the effects of interferon-beta on the lipoprotein profile and post-heparin lipase activities in 26 normolipaemic patients with chronic hepatitis C.

METHODS

Interferon-beta was administered subcutaneously at doses of 6 x 106 U (units) three times a week, over 6 months, and lipoproteins and post-heparin lipases were measured at baseline and at the end of therapy.

RESULTS

Plasma triglycerides increased by 21% due to preferential enrichment in those contained in the very low density lipoprotein (VLDL) and low density lipoprotein (LDL) fractions. The concentration of cholesterol decreased slightly in the high density lipoprotein (HDL) subfractions. Lipoprotein lipase, but not hepatic lipase activity decreased by a 36%, and this change showed a significant negative correlation with changes in plasma triglycerides. Five patients (19.5%) responded to interferon-beta therapy. The lipoprotein profile was no different between responders and non-responders to therapy.

CONCLUSIONS

Interferon-beta treatment in normolipaemic patients with chronic hepatitis C induced moderate disturbances in plasma lipoproteins, associated with inhibition of lipoprotein lipase activity.

Interferon beta1a therapy changes lipoprotein metabolism in patients with multiple sclerosis

To assess whether interferon beta1a (IFNbeta1a) therapy affects plasma lipoprotein metabolism, twelve patients with relapsing-remitting multiple sclerosis (MS) were studied during a two-year follow-up period. High density lipoprotein (HDL2) cholesterol and the HDL2/HDL3 ratio were increased at year 2 and lipoprotein (a) was transitorily increased at year 1, in comparison to baseline levels. Apolipoprotein A-I was lower and apolipoprotein E higher at year 1, only in a subgroup of patients who experienced relapses and/or progressed during therapy. These findings suggest that IFNbeta1a treatment is associated with changes in the lipoprotein metabolism. Alterations in this metabolism could be related to the immunomodulatory actions of the drug and the disease activity in multiple sclerosis patients.

Differential roles of extracellular signal-regulated kinase-1/2 and p38(MAPK) in interleukin-1beta- and tumor necrosis factor-alpha-induced low density lipoprotein receptor expression in HepG2 cells

The inflammatory cytokines interleukin-1beta (IL-1beta) and tumor necrosis factor-alpha (TNF), elevated in inflammatory, malignant, and infectious diseases, induce low density lipoprotein (LDL) receptor transcription in HepG2 cells, and such an induction can account for hypocholesterolemia associated with these states. However, the signaling mechanisms of cytokine-mediated LDL receptor induction are largely unexplored. In the present studies, we examined the potential involvement of different mitogen-activated protein kinase (MAPK) pathways. Northern analysis demonstrated that IL-1beta or TNF significantly increased LDL receptor transcript in HepG2 cells, whereas expression of another tightly regulated sterol-responsive squalene synthase gene was unaffected. IL-1beta treatment resulted in transient activation of three MAPK cascades, namely p46/54(JNK), p38(MAPK), and ERK-1/2, with maximal activation of 20-, 25-, and 3-fold, respectively, occurring 15-30 min after cytokine addition. PD98059, a specific inhibitor of MAPK kinase activity, inhibited IL-1beta-induced LDL receptor expression. In contrast, SB202190, a specific inhibitor of p38(MAPK), enhanced IL-1beta-induced LDL receptor expression, with a concomitant increase in ERK-1/2 activity. Similarly, TNF induced LDL receptor expression also required ERK-1/2 activation. Finally, sterols repressed IL-1beta induced receptor expression, without affecting ERK-1/2 activation. These results show that IL-1beta- or TNF-induced LDL receptor expression requires ERK-1/2 activation, that the p38(MAPK) pathway negatively regulates LDL receptor expression, and that sterols inhibit induction at a point downstream of ERK-1/2 in HepG2 cells.

Immune system differences in men with hypo- or hypercholesterolemia

Substantial epidemiologic evidence indicates that relative hypocholesterolemia in apparently healthy individuals is associated with increased subsequent mortality from cancer and other nonatherosclerotic causes of death. To test a hypothesis potentially underlying these unexplained associations, we evaluated whether individuals with hypo- and hypercholesterolemia differ in various enumerative and functional indices of the immune system. Nineteen healthy adult men with a mean age of 46 years and a mean total cholesterol concentration of 151 mg/dl constituted a low cholesterol group and were compared with 39 men of a similar age whose total cholesterol averaged 261 mg/dl. Relative to the high cholesterol group, hypocholesterolemic men had significantly fewer circulating lymphocytes, fewer total T cells, and fewer CD8+ cells (P's < 0.05). Trends toward fewer CD4+ cells and less IL-2 release in response to PHA were also noted in the low, compared to the high, cholesterol group. The low and high cholesterol groups did not differ in number of B lymphocytes, level of PHA-induced proliferation, number of natural killer (NK) cells, or degree of NK cytotoxicity. These data provide preliminary evidence of immune system differences in healthy individuals with hypo- and hypercholesterolemia.

Serum cholesterol levels in patients with cancer. Relationship with nutritional status

Epidemiological surveys indicate an inverse relationship between cancer occurrence and serum cholesterol. Low serum cholesterol might be either a risk factor for cancer or the effect of factors associated with cancer itself, such as biological properties of malignant cells, tumor mass, and poor nutritional status. We have measured serum cholesterol in 975 selected patients admitted to our hospital; 496 (272 males, 224 females) had solid tumors and 479 (253 males, 226 females) had non-neoplastic diseases. Serum cholesterol was positively correlated with body mass index, serum albumin, hemoglobin, and cholinesterase in both cancer and non-cancer subjects. Cholesterol was significantly lower in cancer patients than in age- and sex-matched non-cancer subjects. After adjustment for nutritional variables (analysis of covariance), the difference in cholesterol level between cancer and non-cancer subjects lost statistical significance in all but patients with tumors of the upper gastrointestinal tract. No difference was found in adjusted mean serum cholesterol between cancer patients subdivided according to the extension of the tumor was defined by the TNM system. In patients with solid tumors, serum cholesterol seems to be more related to the nutritional status than the presence and extension of cancer.

Signal transduction in atherosclerosis: second messengers and regulation of cellular cholesterol trafficking

The data summarized in this review demonstrate that the regulation of intracellular cholesterol trafficking is mediated not only by extracellular lipoprotein concentrations and transcriptional responses to alterations in intracellular free cholesterol content. Rather, the modulation of cholesterol trafficking is also regulated by the products synthesized following activation of signal transduction pathways originating at the cell surface. Furthermore, we have identified those cell-derived factors which utilize these signal transduction pathways to elicit alterations in cholesterol trafficking, and demonstrated the importance of the generation of second messengers, most notably eicosanoids, and cyclic AMP in promoting a modulatory influence on specific pro-atherogenic effects of mitogens.

Clinical toxicity of the interferons

Since their initial description in 1957, the interferons (IFNs) have been increasingly used to treat a wide array of diseases. Acute adverse effects, i.e. 'flu-like' syndromes, hypo- or hypertension, tachycardia, headache, myalgias and gastrointestinal disorders, occur within the first hour or day after starting treatment. They are seldom treatment-limiting and are easily manageable. Sub-acute and chronic effects develop after several days, usually within 2 and 4 weeks of therapy. The most typical is neurological toxicity, including fatigue/asthenia, and behavioural and cognitive changes. Such symptoms may seriously impair quality of life and result in treatment discontinuation. Seizures have seldom been described. Other infrequent central nervous system adverse effects include vertigo, cramp and oculomotor nerve paralysis. Distal paraesthesias and peripheral neuropathy have been reported. IFN-associated autoimmunity is quite rare but a matter of concern. Biological or clinical manifestations usually require several months to become apparent. Autoantibodies have been shown to develop in most patients but have been inconsistently associated with clinical symptoms of systemic lupus erythematosus, rheumatoid-like arthritis and thyroiditis. Both hypo- and hyperthyroidism have been described but are usually reversible. Other infrequent autoimmune reactions include diabetes, pemphigus and worsening of multiple sclerosis. Although several patients present with a pre-existing autoimmune disorder, no predisposing factor has been clearly established. While hypotension and tachycardia are the most frequent acute cardiovascular complications, a few additional cases of cardiac arrhythmias and myocardial ischaemia have been reported after a short course or several weeks of treatment. These latter complications do not appear to be dose-dependent or age-related. Isolated cases of congestive heart failure have also been described. Mild proteinuria has been observed in 15 to 25% of patients, but acute renal toxicity is uncommon. A transient rise in serum aminotransferase levels is frequently noted during the first stage of therapy, especially in patients receiving the highest dosages. Direct hepatotoxicity is extremely rare. Autoimmune hepatitis, which is ill-diagnosed as chronic viral hepatitis, and de novo induction of autoimmune hepatitis, account for the majority of liver diseases. Haematotoxicity is relatively common but mild to moderate, and develops gradually during the first weeks of treatment. Neutropenia is the most common haematological toxicity, but is usually not dose-limiting and resolves rapidly upon drug discontinuation. Myelosuppression, autoimmune and immune allergic haemolytic anaemias and thrombocytopenias have seldom been described. Cutaneous adverse effects comprised nonspecific erythema and hair loss and, less frequently, vasculitis, local ulcerations at the site of injection and exacerbation of psoriasis.(ABSTRACT TRUNCATED AT 250 WORDS)