Clinical anatomy of hepatic vessels by computed tomography angiography: A minireview

The liver has a complex vascular anatomy with a unique dual blood supply. Clinical conditions of the liver vary widely and include disorders originating in the vascular and biliary systems as well as the parenchyma. In most vascular disorders, the effects on the liver are generally subclinical because of its abundant blood supply. However, early diagnosis of such vascular diseases can significantly reduce patient morbidity and mortality. Because imaging findings of vascular disease are not always readily apparent, diagnosis can be difficult. Computed tomography angiography is an excellent imaging modality for visualizing the vascular anatomy of patients for treatment planning. In this review article, we focus on the vascular anatomy of the liver and the imaging findings in some acute hepatic vascular diseases.

Liver immunity, autoimmunity, and inborn errors of immunity

The liver is the front line organ of the immune system. The liver contains the largest collection of phagocytic cells in the body that detect both pathogens that enter through the gut and endogenously produced antigens. This is possible by the highly developed differentiation capacity of the liver immune system between self-antigens or non-self-antigens, such as food antigens or pathogens. As an immune active organ, the liver functions as a gatekeeping barrier from the outside world, and it can create a rapid and strong immune response, under unfavorable conditions. However, the liver's assumed immune status is anti-inflammatory or immuno-tolerant. Dynamic interactions between the numerous populations of immune cells in the liver are key for maintaining the delicate balance between immune screening and immune tolerance. The anatomical structure of the liver can facilitate the preparation of lymphocytes, modulate the immune response against hepatotropic pathogens, and contribute to some of its unique immunological properties, particularly its capacity to induce antigen-specific tolerance. Since liver sinusoidal endothelial cell is fenestrated and lacks a basement membrane, circulating lymphocytes can closely contact with antigens, displayed by endothelial cells, Kupffer cells, and dendritic cells while passing through the sinusoids. Loss of immune tolerance, leading to an autoaggressive immune response in the liver, if not controlled, can lead to the induction of autoimmune or autoinflammatory diseases. This review mentions the unique features of liver immunity, and dysregulated immune responses in patients with autoimmune liver diseases who have a close association with inborn errors of immunity have also been the emphases.

Retrospective Evaluation of Hepatitis C Awareness in Turkey Through Two Decades

BACKGROUND/AIMS

Chronic hepatitis C (CHC) is the only viral infection that can be treated with oral antiviral agents. However, CHC awareness is a major barrier to the World Health Organization's target of eliminating hepatitis C virus (HCV) by 2030. Here, CHC awareness trends were analyzed in Hacettepe University Hospital, Turkey, between January 2000 and December 2017.

MATERIALS AND METHODS

Central laboratory data were retrospectively analyzed for HCV test results (anti-HCV, HCV RNA, HCV genotype). After combining 548,141 anti-HCV test results, 395,103 cases were analyzed. The following two parameters were defined for CHC awareness: (1) the presence of HCV RNA results for anti-HCV positives and (2) the presence of a genotype result for HCV RNA positives.

RESULTS

Anti-HCV positives were older than negatives (mean age-years ± SD, 59.4 ± 19.0 vs. 44.0 ± 18.9), and the positivity rate was higher in women than in men (1.4% vs. 1.0%). Anti-HCV positivity decreased from 3.1% to 0.6% from 2000 to 2015 and subsequently stabilized. The overall percentage of RNA testing among anti-HCV positives was 53.1% (range, 20%-70%), which stabilized at approximately 50% after 2010. The genotyping rate for RNA positives varied between 40% and 70%. The main genotype identified was genotype 1 (85.7%).

CONCLUSION

In an ideal CHC awareness state, all anti-HCV positives should undergo RNA testing, and genotyping should be performed when RNA tests are positive. However, even in our referral center, the combined rate of RNA and genotype testing was only approximately 50% during the last 10 years.

Liver immunology and herbal treatment

Beyond the metabolic functions, the liver recently has been defined as an organ of immune system (IS), which have central regulatory role for innate and adaptive immunity. The liver keeps a delicate balance between hepatic screening of pathogenic antigens and immune tolerance to self-antigens. Herbal treatments with immunological effects have potential to alter this hepatic immune balance towards either therapeutic side or diseases side by inducing liver injury via hepatotoxicity or initiation of autoimmune diseases. Most commonly known herbal treatments, which have therapeutic effect on liver and IS, have proven via in vitro, in vivo, and/or clinical studies were summarized in this review.

A key problem and challenge for hepatology: Obesity-related metabolic liver diseases

With the arrival of the new millennium, gastroenterologists have been faced with the problem of metabolic liver diseases associated with obesity. The active role of the liver in metabolism and inflammation make it a key organ in the war against the rapidly-spreading world-wide epidemic of obesity. Many lives and much money could be saved if the work of hepatologists led to the development of effective diagnostic and therapeutic strategies against this growing leader of cirrhosis.