Chylomicronemia from GPIHBP1 autoantibodies.

Some cases of chylomicronemia are caused by autoantibodies against glycosylphosphatidylinositol-anchored HDL binding protein 1 (GPIHBP1), an endothelial cell protein that shuttles LPL to the capillary lumen. GPIHBP1 autoantibodies prevent binding and transport of LPL by GPIHBP1, thereby disrupting the lipolytic processing of triglyceride-rich lipoproteins. Here, we review the "GPIHBP1 autoantibody syndrome" and summarize clinical and laboratory findings in 22 patients. All patients had GPIHBP1 autoantibodies and chylomicronemia, but we did not find a correlation between triglyceride levels and autoantibody levels. Many of the patients had a history of pancreatitis, and most had clinical and/or serological evidence of autoimmune disease. IgA autoantibodies were present in all patients, and IgG4 autoantibodies were present in 19 of 22 patients. Patients with GPIHBP1 autoantibodies had low plasma LPL levels, consistent with impaired delivery of LPL into capillaries. Plasma levels of GPIHBP1, measured with a monoclonal antibody-based ELISA, were very low in 17 patients, reflecting the inability of the ELISA to detect GPIHBP1 in the presence of autoantibodies (immunoassay interference). However, GPIHBP1 levels were very high in five patients, indicating little capacity of their autoantibodies to interfere with the ELISA. Recently, several GPIHBP1 autoantibody syndrome patients were treated successfully with rituximab, resulting in the disappearance of GPIHBP1 autoantibodies and normalization of both plasma triglyceride and LPL levels. The GPIHBP1 autoantibody syndrome should be considered in any patient with newly acquired and unexplained chylomicronemia.

Therapeutic approaches in hypertriglyceridemia-induced acute pancreatitis: A literature review of available therapies and case series.

Hypertriglyceridemia-induced acute pancreatitis (HGAP) is the third most common etiology of acute pancreatitis. HGAP can be attributed to genetic disturbances in triglyceride metabolism or multiple secondary causes. Here, we presented three cases for HGAP and explored different therapeutic approaches for treating HGAP. A case series of three patients who presented with HGAP and underwent different therapeutic approaches was conducted. The first patient was a 37-year-old male who presented with nonsevere HGAP; he was treated with conservative therapy with insulin and heparin infusion, which resulted in clinical and laboratory improvement. The second patient was a 64-year-old male with human immunodeficiency virus on multiple highly active antiretroviral therapy. He presented with severe HGAP and multiorgan failure. After initiation of therapeutic plasma exchange, his HGAP resolved. The third patient was a 28-year-old male who presented with recurrent episodes of HGAP; his conservative therapy failed and was eventually escalated to therapeutic plasma exchange (TPE). HGAP can be attributed to genetic disturbances of lipid or secondary etiologies. A nonsevere form of HGAP can be managed with conventional therapy including insulin and heparin; however, severe HGAP may require TPE.

Pro-inflammatory chemokines CCL2, chemerin, IP-10 and RANTES in human serum during an oral lipid tolerance test.

BACKGROUND: There is a strong coincidence of obesity and a chronic state of modest inflammation. Secretion of pro-inflammatory cytokines from adipocytes and immune cells represents a key mechanism in this process and is affected by fatty acids. MATERIAL AND METHODS: A study cohort of 100 overnight fasted healthy volunteers underwent an oral lipid tolerance test (OLTT) by ingestion of 160ml of a protein- and sugar-free lipid emulsion of defined composition. Venal blood was drawn at 0h (fasting) and at 2, 4, and 6h after lipid ingestion. Subjects were characterized by anthropometric and standard laboratory parameters. Serum concentrations of CCL2, IP-10, chemerin, and RANTES were measured by enzyme-linked immunosorbent assay (ELISA). Murine 3T3-L1 adipocytes were stimulated with free fatty acids (FA) and with sex steroids and concentrations of CCL2 and chemerin in cell culture supernatants were measured by ELISA. RESULTS: A significant reduction of circulating CCL2, IP-10, and chemerin concentrations was observed as a consequence of triglyceride ingestion whereas RANTES levels were increased. CCL2 serum concentrations were positively correlated with resistin and visfatin levels and with LDL/HDL ratio and negatively with adiponectin. There were significant differences in chemerin and RANTES serum concentrations in female and male subjects. CCL2 secretion from 3T3-L1 adipocytes was inhibited by treatment with linoleic (LA) and oleic acid (OA) whereas chemerin secretion was induced. Chemerin release from 3T3-L1 adipocytes was inhibited by testosterone. CONCLUSIONS: Oral lipid loading is linked to reduced circulating pro-inflammatory chemokines CCL2, IP-10, and chemerin and to increased RANTES levels, suggesting that dietary lipids affect immune function.

Increased levels of invariant natural killer T lymphocytes worsen metabolic abnormalities and atherosclerosis in obese mice.

Obesity is a chronic inflammatory state characterized by infiltration of adipose tissue by immune cell populations, including T lymphocytes. Natural killer T (NKT) cells, a specialized lymphocyte subset recognizing lipid antigens, can be pro- or anti-inflammatory. Their role in adipose inflammation continues to be inconclusive and contradictory. In obesity, the infiltration of tissues by invariant NKT (iNKT) cells is decreased. We therefore hypothesized that an excess iNKT cell complement might improve metabolic abnormalities in obesity. Vα14 transgenic (Vα14tg) mice, with increased iNKT cell numbers, on a LDL receptor-deficient (Ldlr(-/-)) background and control Ldlr(-/-) mice were placed on an obesogenic diet for 16 weeks. Vα14tg.Ldlr(-/-) mice gained 25% more weight and had increased adiposity than littermate controls. Transgenic mice also developed greater dyslipidemia, hyperinsulinemia, insulin resistance, and hepatic triglyceride accumulation. Increased macrophage Mac2 immunostaining and proinflammatory macrophage gene expression suggested worsened adipose inflammation. Concurrently, these mice had increased atherosclerotic lesion area and aortic inflammation. Thus, increasing the complement of iNKT cells surprisingly exacerbated the metabolic, inflammatory, and atherosclerotic features of obesity. These findings suggest that the reduction of iNKT cells normally observed in obesity may represent a physiological attempt to compensate for this inflammatory condition.

Adipocyte fatty acid binding protein: a novel adipokine involved in the pathogenesis of metabolic and vascular disease?

Adipocyte fatty acid binding protein (AFABP, also known as aP2 and FABP4) has recently been introduced as a novel fat-derived circulating protein. AFABP serum concentrations are positively correlated with markers of the metabolic syndrome and vascular disease in various cross-sectional and interventional studies. Furthermore, a small set of prospective studies indicates that high AFABP serum levels at baseline predict the risk for metabolic and vascular morbidity and mortality. Studies in Afabp (also known as Fabp4) knockout mice and AFABP inhibitor-treated animals suggest that total AFABP promotes insulin resistance, hypertriacylglycerolaemia and atherosclerosis by ligand/ligand delivery, as well as ligand-independent mechanisms. In contrast, the pathophysiological significance of circulating AFABP and the mechanisms leading to its release remain to be established. The current review summarises recent findings on the regulation and potential role of AFABP in metabolic and vascular disease.

Association between obesity, hypertriglyceridemia and low hepatitis B viral load.

OBJECTIVE: This study aimed to investigate the metabolic risk factors of high hepatitis B viral load. DESIGN: Large-scale, community-based cross-sectional study. SUBJECTS: A total of 3587 hepatitis B virus (HBV)-infected participants without liver cirrhosis at study entry were investigated. High HBV viral load was defined as a serum level 10(4) copies per ml for hepatitis B e antigen (HBeAg) seronegatives or 10(8) copies per ml for HBeAg seropositives. RESULTS: Among HBeAg seropositives (n=545), high HBV viral load was reversely associated with extreme obesity (odds ratio (OR), 0.30; 95% confidence interval (CI), 0.13-0.68; P=0.004) or central obesity (OR, 0.53; 95% CI, 0.34-0.82; P=0.004) after adjustment for gender, hypertriglyceridemia, hyperuricemia and history of hypertension. High HBV viral load remained significantly inversely associated with extreme obesity (OR, 0.17; 95% CI, 0.05-0.63; P=0.008) and central obesity (OR, 0.44; 95% CI, 0.25-0.78; P=0.005) in male HBeAg-seropositive participants in stratification analyses by gender. Among HBeAg seronegatives (n=3042), however, high HBV viral load was inversely associated with hypertriglyceridemia (OR, 0.74; 95% CI, 0.61-0.89, P=0.002) after adjustment for age, gender, high serum alanine aminotransferase level, and extreme obesity or central obesity. High HBV viral load was still inversely associated with hypertriglyceridemia in both female (OR, 0.70; 95% CI, 0.50-0.97; P=0.041) and male (OR, 0.75; 95% CI, 0.60-0.94; P=0.011) HBeAg-seronegative participants. CONCLUSION: Extreme obesity and central obesity were associated with a low prevalence of high HBV viral load in HBeAg seropositives, especially in men; while hypertriglyceridemia was associated with a low prevalence of high viral load in HBeAg seronegatives in both women and men.

Selective hepatic insulin resistance, VLDL overproduction, and hypertriglyceridemia.

Insulin plays a central role in regulating energy metabolism, including hepatic transport of very low-density lipoprotein (VLDL)-associated triglyceride. Hepatic hypersecretion of VLDL and consequent hypertriglyceridemia leads to lower circulating high-density lipoprotein levels and generation of small dense low-density lipoproteins characteristic of the dyslipidemia commonly observed in metabolic syndrome and type 2 diabetes mellitus. Physiological fluctuations of insulin modulate VLDL secretion, and insulin inhibition of VLDL secretion upon feeding may be the first pathway to become resistant in obesity that leads to VLDL hypersecretion. This review summarizes the role of insulin-related signaling pathways that determine hepatic VLDL production. Disruption in signaling pathways that reduce generation of the second messenger phosphatidylinositide (3,4,5) triphosphate downstream of activated phosphatidylinositide 3-kinase underlies the development of VLDL hypersecretion. As insulin resistance progresses, a number of pathways are altered that further augment VLDL hypersecretion, including hepatic inflammatory pathways. Insulin plays a complex role in regulating glucose metabolism, and it is not surprising that the role of insulin in VLDL and lipid metabolism will prove equally complex.

Krill oil versus fish oil in modulation of inflammation and lipid metabolism in mice transgenic for TNF-α.

PURPOSE: Biological effects of marine oils, fish oil (FO) and krill oil (KO), are mostly attributed to the high content of n-3 polyunsaturated fatty acids (n-3 PUFAs), predominantly eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). The study was aimed to investigate the influence of FO and KO on lipid homeostasis and inflammation in an animal model of persistent low-grade exposure to human tumor necrosis factor α (hTNF-α) and to evaluate whether these effects depend on the structural forms of EPA and DHA [triacylglycerols (TAG) vs. phospholipids]. METHODS: Male C57BL/6 hTNF-α mice were fed for 6 weeks a high-fat control diet (24.50 % total fats, w/w) or high-fat diets containing either FO or KO at similar doses of n-3 PUFAs (EPA: 5.23 vs. 5.39 wt%, DHA: 2.82 vs. 2.36 wt% of total fatty acids). RESULTS: We found that KO, containing bioactive n-3 PUFAs in the form of phospholipids, was capable of modulating lipid metabolism by lowering plasma levels of TAG and cholesterol and stimulating the mitochondrial and peroxisomal fatty acid ß-oxidation, as well as improving the overall carnitine turnover. Though the administration of FO was not as effective as KO in the lowering of plasma TAG, FO significantly improved the levels of all cholesterol classes in plasma. Except from the increase in the levels of IL-17 in FO-fed mice and a trend to decrease in MCP-1 levels in KO-fed animals, the levels of pro-inflammatory cytokines were not substantially different between treatment groups. CONCLUSION: Our findings demonstrate that FO and KO are comparable dietary sources of n-3 PUFAs. However, when quantitatively similar doses of n-3 PUFAs are administered, KO seems to have a greater potential to promote lipid catabolism. The effect of dietary oils on the levels of inflammatory markers in hTNF-α transgenic mice fed a high-fat diet needs further investigations.

CD11c/CD18 expression is upregulated on blood monocytes during hypertriglyceridemia and enhances adhesion to vascular cell adhesion molecule-1.

OBJECTIVE: Atherosclerosis is associated with monocyte adhesion to the arterial wall that involves integrin activation and emigration across inflamed endothelium. Involvement of ß(2)-integrin CD11c/CD18 in atherogenesis was recently shown in dyslipidemic mice, which motivates our study of its inflammatory function during hypertriglyceridemia in humans. METHODS AND RESULTS: Flow cytometry of blood from healthy subjects fed a standardized high-fat meal revealed that at 3.5 hours postprandial, monocyte CD11c surface expression was elevated, and the extent of upregulation correlated with blood triglycerides. Monocytes from postprandial blood exhibited an increased light scatter profile, which correlated with elevated CD11c expression and uptake of lipid particles. Purified monocytes internalized triglyceride-rich lipoproteins isolated from postprandial blood through low-density lipoprotein-receptor-related protein-1, and this also elicited CD11c upregulation. Laboratory-on-a-chip analysis of whole blood showed that monocyte arrest on a vascular cell adhesion molecule-1 (VCAM-1) substrate under shear flow was elevated at 3.5 hours and correlated with blood triglyceride and CD11c expression. At 7 hours postprandial, blood triglycerides decreased and monocyte CD11c expression and arrest on VCAM-1 returned to fasting levels. CONCLUSIONS: During hypertriglyceridemia, monocytes internalize lipids, upregulate CD11c, and increase adhesion to VCAM-1. These data suggest that analysis of monocyte inflammation may provide an additional framework for evaluating individual susceptibility to cardiovascular disease.

Lymphocyte count was significantly associated with hyper-LDL cholesterolemia independently of high-sensitivity C-reactive protein in apparently healthy Japanese.

The aim of this study was to investigate the association between leukocyte subtype counts and hyper-LDL cholesterolemia, hypertriglyceridemia, and hypo-HDL cholesterolemia. Logistic regressions using hyper-LDL cholesterolemia, hypertriglyceridemia, and hypo-HDL cholesterolemia as a dependent variable and total leukocyte, basophil, eosinophil, neutrophil, lymphocyte, and monocyte counts as an independent variable were calculated adjusting for age, body mass index (BMI), high-sensitivity C-reactive protein (hs-CRP), smoking, drinking, and physical activity in apparently healthy Japanese men (1,803) and women (1,150). The odds ratio (OR) of hyper-LDL cholesterolemia for total leukocyte, eosinophil, and lymphocyte counts, the OR of hypertriglyceridemia for total leukocyte, eosinophil, neutrophil, and lymphocyte counts, and the OR of hypo-HDL cholesterolemia for total leukocyte, neutrophil, and lymphocyte counts were significant in men, and the OR of hyper-LDL cholesterolemia, for lymphocyte count, and the OR of hypo-HDL cholesterolemia for eosinophil count were significant in women. Lymphocyte count was significantly associated with hyper-LDL cholesterolemia independently of hs-CRP in apparently healthy Japanese.

Insulin resistance in critical illness.

PURPOSE OF REVIEW: The purpose of this review is to describe current concepts on inflammation, immunity and insulin resistance. Metabolic and immune systems are closely involved in inflammation and significantly contribute to the pathology seen in the pediatric intensive care unit. The ability of insulin to decrease hepatic glucose production, suppress adipose tissue lipolytic rate, stimulate skeletal muscle glucose uptake, suppress protein breakdown and increase protein synthesis is critical to maintain metabolic function. Hence, a better understanding of these regulatory mechanisms and the alterations leading to dysfunction will set the basis for a better metabolic and immune support of critically ill patients. RECENT FINDINGS: Inflammation can be elicited by infection (sepsis) through pathogen associated molecular patterns (PAMPs) or through danger associated molecular patterns (DAMPs) as a response to an insult (systemic inflammatory response syndrome; SIRS) in the absence of infection. Mitochondrial DAMPs and PAMPs share the same pattern recognition receptors. These receptors act also as nutrient sensors, and in the presence of fatty acids will induce an inflammatory cascade that affects insulin signaling with development of insulin resistance. Lipotoxicity is emerging as a significant contributor to the development of insulin resistance. SUMMARY: Insulin resistance is an adaptive mechanism that prioritizes utilization of energy for immune response in the presence of infection or injury. A better understanding of the complex interactions between metabolism, inflammation and immunity in critically ill children will lead to appropriate metabolic and immune support of these patients.

The effect of bezafibrate and omega-3 fatty acids on lymphocyte cytokine release and systemic inflammation in patients with isolated hypertriglyceridemia.

PURPOSE: The aim of this study was to compare the effects of fibrates and omega-3 fatty acids on lymphocyte secretory function and systemic inflammation in patients with isolated hypertriglyceridemia. METHODS: The study included 107 patients with isolated hypertriglyceridemia who received bezafibrate (200 mg twice daily), omega-3 fatty acids (1 g twice daily) or placebo for 12 weeks. The lipid profile, fasting and 2-h post-glucose load plasma glucose levels, homeostasis model assessment index (HOMA), plasma high-sensitivity C-reactive protein (hsCRP) levels and lymphocyte release of interleukin-2, interferon-γ and tumor necrosis factor-α were assessed at baseline, on the day of randomization, and after 4 and 12 weeks of treatment. RESULTS: Both bezafibrate and omega-3 fatty acids reduced plasma triglyceride levels. Bezafibrate additionally decreased total and low-density lipoprotein-cholesterol levels and the HOMA and insignificantly decreased post-glucose load plasma glucose, as well as increased high-density lipoprotein-cholesterol. Bezafibrate treatment was associated with a reduction in lymphocyte release of interleukin-2, interferon-γ and tumor necrosis factor-α, which was accompanied by a reduction in plasma hsCRP levels. Omega-3 fatty acid did not significantly reduce lymphocyte cytokine release and plasma hsCRP. The anti-inflammatory effects of both drugs did not correlate with their action on plasma lipids, but in the case of the former the effect was related to the improvement in insulin sensitivity. CONCLUSION: Our results indicate that bezafibrate is superior to omega-3 fatty acid in inhibiting systemic inflammation and lymphocyte secretory function.

Anti-lipoprotein lipase antibodies in patients with hypertriglyceridemia without associated autoimmune disease.

BACKGROUND: Anti-lipoprotein lipase antibodies have been described in rare cases of patients with hypertriglyceridemia. However, no systematic study evaluating these antibodies in patients with this lipid abnormality has been undertaken. OBJECTIVES: To analyze the correlation of anti-lipoprotein lipase (anti-LPL) antibodies with other laboratory findings in patients with hypertriglyceridemia but no autoimmune disease. METHODS: We evaluated 44 hypertriglyceridemic patients without autoimmune disease. Clinical and laboratory evaluations included analyses of comorbidities, fasting lipid profile and anti-LPL antibodies. RESULTS: Mean patient age was 55 +/- 10 years; 46% of the patients were female and 64% were Caucasian. The mean disease duration was 94.4 months and mean body mass index 28.7 +/- 3.6 kg/m2; 34.0% were diabetic, 25.0% were obese, 72.7% had systemic arterial hypertension, 75% were sedentary, 15.9% were smokers, 56.8% had a family history of dyslipidemia, 45.5% had a family history of coronary insufficiency, 20.5% had acute myocardial infarction, 9.0% had undergone revascularization and 11.0% angioplasty, 79.5% were being treated with statins and 43.2% were taking fibrates. Median triglyceride levels were 254 mg/dl (range 100-3781 mg/dl), and total cholesterol level was 233 t 111 mg/dl. High-density lipoprotein was 42.6 +/- 15.4 mg/dl, low-density lipoprotein 110.7 +/- 42.4 mg/dl and very low-density lipoprotein 48 +/- 15 mg/dl. Anti-LPL antibodies were identified in 2 patients (4.5%), both of whom had a family history of dyslipidemia, coronary insufficiency and acute myocardial infarction; one had undergone myocardial revascularization and percutaneous transluminal coronary angioplasty, and both were using fibrates and had normal triglyceride levels. CONCLUSIONS: Our findings demonstrate a correlation between the immune response and dyslipoproteinemia in hypertriglyceridemic patients, suggesting that autoimmune disease contributes to the dyslipidemia process.

Diurnal Rhythmicity Programs of Microbiota and Transcriptional Oscillation of Circadian Regulator, NFIL3.

Circadian rhythms are a very exquisite mechanism to influence on transcriptional levels and physiological activities of various molecules that affect cell metabolic pathways. Long-term alteration of circadian rhythms increases the risk of cardiovascular diseases, hypertension, hypertriglyceridemia, and metabolic syndrome. A drastic change in dietary patterns can affect synchronizing the circadian clock within the metabolic system. Therefore, the interaction between the host and the bacterial community colonizing the mammalian gastrointestinal tract has a great impact on the circadian clock in diurnal programs. Here, we propose that the microbiota regulates body composition through the transcriptional oscillation of circadian regulators. The transcriptional regulator, NFIL3 (also called E4BP4) is a good example. Compositional change of the commensal bacteria influences the rhythmic expression of NFIL3 in the epithelium, which subsequently controls obesity and insulin resistance. Therefore, control of circadian regulators would be a promising therapeutic target for metabolic diseases.

Effects of Daily Raspberry Consumption on Immune-Metabolic Health in Subjects at Risk of Metabolic Syndrome: A Randomized Controlled Trial.

Consumption of red raspberries has been reported to exert acute beneficial effects on postprandial glycemia, insulinemia, triglyceridemia, and cytokine levels in metabolically disturbed subjects. In a two-arm parallel-group, randomized, controlled trial, 59 subjects with overweight or abdominal obesity and with slight hyperinsulinemia or hypertriglyceridemia were randomized to consume 280 g/day of frozen raspberries or to maintain their usual diet for 8 weeks. Primary analyses measured metabolic differences between the groups. Secondary analyses performed with omics tools in the intervention group assessed blood gene expression and plasma metabolomic changes following the raspberry supplementation. The intervention did not significantly affect plasma insulin, glucose, inflammatory marker concentrations, nor blood pressure. Following the supplementation, 43 genes were differentially expressed, and several functional pathways were enriched, a major portion of which were involved in the regulation of cytotoxicity, immune cell trafficking, protein signal transduction, and interleukin production. In addition, 10 serum metabolites were found significantly altered, among which ß-alanine, trimethylamine N-oxide, and bioactive lipids. Although the supplementation had no meaningful metabolic effects, these results highlight the impact of a diet rich in raspberry on the immune function and phospholipid metabolism, thus providing novel insights into potential immune-metabolic pathways influenced by regular raspberry consumption.

Leukocyte activation by triglyceride-rich lipoproteins.

OBJECTIVE: Postprandial lipemia has been linked to atherosclerosis and inflammation. Because leukocyte activation is obligatory for atherogenesis, leukocyte activation by triglyceride-rich lipoproteins (TRLs) was investigated. METHODS AND RESULTS: The expression of CD11b and CD66b after incubation with glucose and native and artificial TRLs (NTRL and ATRL) in vivo and in vitro was evaluated by flowcytometry. Oral fat loading tests showed an increased expression of CD11b on monocytes and neutrophils and CD66b on neutrophils. In 11 volunteers, postprandial leukocytes became enriched with meal-derived fatty acids ([1-(13)C]16:0) suggesting uptake of exogenous fat. ApoB binding on leukocytes measured by flowcytometry in 65 subjects was highest on neutrophils and monocytes suggesting adherence of apoB-containing lipoproteins. Physiological concentrations of TRLs showed 62% increased neutrophil CD11b and a dose-dependent increased monocyte CD11b up to 84% in vitro. Incubations with lipid emulsions in the hypertriglyceridemic range showed a 5-fold increased monocyte CD11b expression, which was higher than the positive control (fMLP), and a dose-dependent 2- to 3-fold increased neutrophil CD11b and CD66b. The oxidative scavenger DMTU decreased the neutrophil CD66b expression by 36%. CONCLUSIONS: Acute hypertriglyceridemia is a leukocyte activator most likely by direct interaction between TRLs and leukocytes and uptake of fatty acids. TG-mediated leukocyte activation is an alternative proinflammatory and proatherogenic mechanism of hypertriglyceridemia in part associated to the generation of oxidative stress.

Extreme hypertriglyceridemia: Genetic diversity, pancreatitis, pregnancy, and prevalence.

BACKGROUND: Triglyceride (TG) concentrations >2000 mg/dL are extremely elevated and increase the risk of pancreatitis. OBJECTIVES: We characterized five cases and two kindreds and ascertained prevalence in a reference laboratory population. METHODS: Plasma lipids and DNA sequences of LPL, GPIHBP1, APOA5, APOC2, and LMF1 were determined in cases and two kindreds. Hypertriglyceridemia prevalence was assessed in 440,240 subjects. RESULTS: Case 1 (female, age 28 years) had TG concentrations >2000 mg/dL and pancreatitis since infancy. She responded to diet and medium-chain triglycerides, but not medications. During two pregnancies, she required plasma exchange for TG control. She was a compound heterozygote for a p.G236Gfs*15 deletion and a p.G215E missense mutation at LPL, as was one sister with hypertriglyceridemia and pancreatitis during pregnancy. Her father was heterozygous for the deletion and had hypertriglyceridemia and recurrent pancreatitis. Other family members had either the missense mutation or the deletion, and had hypertriglyceridemia but no pancreatitis. In kindred 2, three preschool children had severe hypertriglyceridemia and were homozygous for a GPIHBP1 p.T108R missense mutation. Case 5 (male, age 43 years) presented with pancreatitis and TG levels >5000 mg/dL and had heterozygous GPIHBP1 p.G175R and APOC2 intron 2-4G>C mutations. On diet, fenofibrate, fish oil, and atorvastatin, his TG concentration was 2526 mg/dL, but normalized to <100 mg/dL with added pioglitazone. In our population study, 60 subjects (0.014%) of 440,240 had TG concentrations >2000 mg/dL, and 66.7% were diabetic and had elevated insulin levels. CONCLUSIONS: Extreme hypertriglyceridemia is rare (0.014%); and during pregnancy, it may require plasma exchange.

Case Report of Acquired Generalized Lipodystrophy Associated With Common Variable Immunodeficiency.

Context: Acquired generalized lipodystrophy (AGL), a rare disorder characterized by loss of subcutaneous adipose tissue, is estimated to occur in association with autoimmune diseases in ~25% of the cases. Common variable immunodeficiency (CVI) is a condition known for its strong association with autoimmune diseases often occurring with negative autoantibodies. To the best of our knowledge, we describe the first known case of AGL in a patient with CVI. Case Description: A 24-year-old man was referred to our center with hyperglycemia, hypertriglyceridemia, hepatomegaly, and a clear pattern of generalized fat loss. AGL had been diagnosed on the basis of the clinical and laboratory findings. Because of the presence of associated hypogammaglobulinemia, a diagnosis of CVI was subsequently established. Conclusions: We propose that AGL be added to the list of possible diseases associated with CVI and, owing to the similar clinical presentation with type 1 diabetes mellitus, be included in the differential diagnosis of this condition, which is present in 1.5% of patients with CVI.

Anti-sense oligonucleotide therapies for the treatment of hyperlipidaemia.

INTRODUCTION: Anti-sense oligonucleotide (ASO) therapies are a new development in clinical pharmacology offering greater specificity compared to small molecule inhibitors and the ability to target intracellular process' not susceptible to antibody-based therapies. AREAS COVERED: This article reviews the chemical biology of ASOs and related RNA therapeutics. It then reviews the data on their use to treat hyperlipidaemia. Data on mipomersen - an ASO to apolipoprotein B-100(apoB) licensed for treatment of homozygous familial hypercholesterolaemia (FH) is presented. Few effective therapies are available to reduce atehrogenic lipoprotein (a) levels. An ASO therapy to apolipoprotein(a) (ISIS Apo(a)Rx) specifically reduced lipoprotein (a) levels by up to 78%. Treatment options for patients with familial chylomicronaemia syndrome (lipoprotein lipase deficiency; LPLD) or lipodystrophies are highly limited and often inadequate. Volanesorsen, an ASO to apolipoprotein C-3, shows promise in the treatment of LPLD and severe hypertriglyceridaemia as it increases clearance of triglyceride-rich lipoproteins and can normalise triglycerides in these patients. EXPERT OPINION: The uptake of the novel ASO therapies is likely to be limited to selected niche groups or orphan diseases. These will include homozygous FH, severe heterozygous FH for mipomersen; LPLD deficiency and lipodystrophy syndromes for volanesorsen and treatment of patients with high elevated Lp(a) levels.