Publications

GOALS AND BACKGROUND

Besides United States population born between 1945 and 1965, screening for hepatitis C virus (HCV) is not recommended for the general US population. However, HCV may be more prevalent in certain subgroups and screening may be warranted. The goal of this study was to examine the proportion of HCV in a large sample of community Asian American patients presenting for non-liver-related complaints.

STUDY

We conducted a cross-sectional study of 1246 patients tested for hepatitis C virus antibodies (anti-HCV) referred to 2 gastroenterology clinics for non-liver-related gastrointestinal reasons between January 2001 and February 2011. We determined HCV status and patient history via electronic medical record review.

RESULTS

Of the 1246 study patients tested for anti-HCV, the majority were Asian (81.4%) and 29 Asian patients (2.9%) had positive anti-HCV. HCV proportion in the remaining 232 non-Asians (non-Hispanic whites and Hispanics) was 1.7%. Asians with positive anti-HCV were more likely to have had blood transfusions (31.0% vs. 6.6%, P<0.0001) or acupuncture (10.3% vs. 1.5%, P<0.0001). Of the 976 Asian patients with hepatitis B surface antigen testing, 38 (3.9%) also had detectable hepatitis B surface antigen.

CONCLUSIONS

Among patients seen at community gastroenterology clinics for non-liver-related reasons, HCV proportion was 1.7% for non-Asians and 2.9% for Asians. Screening for HCV should be offered to high-risk patients presenting to gastroenterology clinics with unrelated gastrointestinal complaints.

Lymphotoxin (LT) is a member of the tumour necrosis factor (TNF) superfamily that was originally thought to be functionally redundant to TNF, but these proteins were later found to have independent roles in driving lymphoid organogenesis. More recently, LT-mediated signalling has been shown to actively contribute to effector immune responses. LT regulates dendritic cell and CD4(+) T cell homeostasis in the steady state and determines the functions of these cells during pathogenic challenges. The LT receptor pathway is essential for controlling pathogens and even contributes to the regulation of the intestinal microbiota, with recent data suggesting that LT-induced changes in the microbiota promote metabolic disease. In this Review, we discuss these newly defined roles for LT, with a particular focus on how the LT receptor pathway regulates innate and adaptive immune responses to microorganisms.

Inflammation accompanies obesity and its comorbidities-type 2 diabetes, non-alcoholic fatty liver disease and atherosclerosis, among others-and may contribute to their pathogenesis. Yet the cellular machinery that links nutrient sensing to inflammation remains incompletely characterized. The protein deacetylase sirtuin-1 (SirT1) is activated by energy depletion and plays a critical role in the mammalian response to fasting. More recently it has been implicated in the repression of inflammation. SirT1 mRNA and protein expression are suppressed in obese rodent and human white adipose tissue, while experimental reduction of SirT1 in adipocytes and macrophages causes low-grade inflammation that mimics that observed in obesity. Thus suppression of SirT1 during overnutrition may be critical to the development of obesity-associated inflammation. This effect is attributable to multiple actions of SirT1, including direct deacetylation of NFκB and chromatin remodeling at inflammatory gene promoters. In this work, we report that SirT1 is also suppressed by diet-induced obesity in macrophages, which are key contributors to the ontogeny of metabolic inflammation. Thus, SirT1 may be a common mechanism by which cells sense nutrient status and modulate inflammatory signaling networks in accordance with organismal energy availability.