Aim of review. We review published evidence on the torque teno virus (TT virus, TTV), which was discovered in the late of the 20th century.

Key points. TTV is frequently confirmed in patients with hepatitises of viral origin or no definite viral aetiology, as well as in healthy people. Particular biochemical and histological changes in hepatic tissue and bile duct epithelium are reported for TTV monoinfection, which suggest viral replication in hepatocytes. At the same time, no cytopathic effects inherent in pathogenic hepatotropic viruses were revealed in hybridisation assays with TTV-infected cells. Novel data incited novel opinions on the TTV interaction with human. Earlier views of hepatotropic TTV gradually changed with newer evidence on its dispersion and coinfection with other viruses, including known hepatitis agents. Polytropism of TTV disproves its exclusive attribution to hepatitis viruses. High prevalence of the virus in human population argues in favour of its non-pathogenic persistence in the human viriome. TTV DNA content in blood is proposed as an endogenous immune status marker to observe prior to organ transplantation.

Conclusion. High TTV dispersion in human population suggests its persistence in the human viriome. Seldom observed damaging effect of TTV on hepatic cells and bile duct epitheliocytes may indirectly suggest its opportunistic pathogenic properties.

Bulevirtide is a novel antiviral agent approved for suppression of chronic hepatitis D but requiring further research into optimising the treatment scheme.

Aim. Comparative assessment of bulevirtide monotherapy versus combined treatment with bulevirtide and pegylat-ed interferon (PEG-IFN) using published trial data.

Key points. MYR201 and MYR203 trials expose a higher frequency of HBsAg and HDV RNA extinction, as well as more effective HDV suppression for combined bulevirtide/PEG-IFN therapy compared to bulevirtide monotherapy.

Conclusion. Combined bulevirtide/PEG-IFN therapy has particular advantages over bulevirtide monotherapy in patients with chronic hepatitis D. Further research is required to optimise bulevirtide dosage and duration of therapy. 

Previous viral hepatitis B increases the risk of cirrhosis in various chronic liver diseases.

Aim. Assessment of association between previous hepatitis B and the severity of liver fibrosis in patients with nonalcoholic fatty liver disease (NAFLD).

Materials and methods. A single-centre cross-sectional trial included 110 HBsAg- and anti-HCV-negative patients with confirmed NAFLD (median (IQR) age 60 (53-66) years). Obesity, type 2 diabetes and dyslipidemia were in 78 (70.9%), 64 (58.2%) and 77 (70%) individuals, respectively. To confirm previous and occult hepatitis B virus (HBV) infection, blood of all participants was examined for anti-HBc (IgG) and HBV DNA. Liver biopsy was performed in 35 patients (31.8%), other patients had transient elastography with steatometry and/or a serum FibroMax™ assay (FibroTest+SteatoTest+NashTest).

Results. In 85 patients, liver fibrosis was scored F0-F2 with METAVIR, 25 persons had severe fibrosis (F4 in 23, F3 in 2). Patients with severe fibrosis were significantly older than persons with F0-F2 and had more frequent type 2 diabetes. Anti-HBc was detected in 10 of 25 (40%) patients with F3-F4 and in 7 of 85 (8.2%) persons with F0-F2 (p <0.001). None of anti-HBc-positive individuals had HBV DNA in blood. Presence of anti-HBc was the major factor directly associated with severe liver fibrosis (OR 7.339; 95% CI 2.189-24.604; p = 0.001).

Conclusion. Anti-HBc-positive patients with NAFLD have a much higher risk of severe liver fibrosis compared to patients without previous viral hepatitis B.

Aim. Analysis of the experience of managing patients with liver cirrhosis (LC) at the Regional Clinical Hospital No. 2 of the Ministry of Health of Krasnodar Krai.

Materials and methods. In this retrospective study, we assessed data on routine outpatient monitoring of 832 patients with LC and oesophageal varices by the outpatient and inpatient services of the Regional Clinical Hospital No. 2 during 2009-2019.

Results. Endoscopic oesophageal variceal ligation was performed in 832 patients, with total 1149 surgeries and 1 to 8 banding repeats per individual. Transjugular intrahepatic portosystemic shunting (TIPS) was implemented in 2014 and performed 51 times in 5 years, coupled in 20 patients with simultaneous gastric variceal embolisation. Oesophageal variceal ligation preceded TIPS in 34 (66.7 %) patients; 62 patients were included in the liver transplant waiting list. Among 17 liver transplant patients, 6 had oesophageal variceal bleeding in history. Endoscopic ligation was performed in 5, and TIPS — in 3 patients awaiting a transplant. Successful adoption of health telecom technologies in Krasnodar Krai renders high-quality specialised medical aid publically accessible, also in remote regions.

Conclusion. A model is presented for providing high-tech specialised assistance to LC patients, which engages a surgeon, a gastroenterologist, an endoscopist, an X-ray physician, an endovascular surgeon and an infectionist. A resident physician should coordinate the multidisciplinary team at the outpatient stage, and a surgeon — upon the patient's admission in case of surgical LC complications.

The growth hormone/insulin-like growth factor-1 (IGF-1) system is an important humoral mediator of liver function with an inherent potential for assessing liver condition and survival prognosis following liver transplantation (LT).

Aim. Analysis of associations between growth hormone and IGF-1 levels in blood and markers of liver function and post-LT survival in children.

Materials and methods. We examined 143 children with end-stage liver disease (ESLD) aged 3 to 73 (median 8) months after related LT. The growth hormone and IGF-1 concentrations in plasma were evaluated in ELISA assays.

Results. In children with ESLD, concentrations of growth hormone and IGF-1 were significantly higher and lower, respectively, compared to healthy children of the same age (p <0.01). Compared to the level of growth hormone, the level of IGF-1 was related to the diagnosis (r = 0.30, p = 0.004). IGF-1 shows lower concentrations in biliary atresia and other cholestatic liver diseases compared to non-cholestatic aetiologies (4.7 (0.0—23.4) and 42.3 (9.0—55.0) ng/mL, respectively, p = 0.03). The growth hormone level directly correlated with the severity of liver fibrosis (r = 0.47, p = 0.02). It was higher in fibrosis grade 4 (F4) than in F1—F3 (4.7 (2.1—7.2) and 2.1 (1.2—3.3) ng/mL, respectively, p = 0.02). Hormone levels normalised after LT. Unlike IGF-1, the level of growth hormone correlated one month after LT with the 6-months survival rate of recipients (r = 0.36, p = 0.01) being significantly lower in survivors compared to patients who did not survive this period (1.3 (0.5—1.9) and 2.9 (1.6—12.4) ng/mL, respectively, p = 0.02).

Conclusion. Blood levels of growth hormone and IGF-1 were shown to differ significantly between ESLD and healthy children, correlating with fibrosis severity and disease aetiology. The level of growth hormone in the blood of LT recipients associates with a short-term survival rate.

Aim of review. Description of intestinal mucosal barrier permeability disruption causes as morbid factors in gastrointestinal tract (GIT) functional disorders.

General provisions. Intestinal mucosal barrier is composed of several elements: pre-epithelial barrier, a mucosal lining of epithelium; epithelial barrier that leverages tight junctional structures and high regenerative capacity of epithelium; post-epithelial barrier established by immune cells and blood vessels. Gut microbiota profile may also be constituent of the intestinal mucosal barrier. Functional dyspepsia (FD) and irritable bowel syndrome (IBS) leave distinct morphological imprint. For instance, FD patients exhibit variant expression of cell junction proteins (claudin-1, zonula occludens, occludin, E-cadherin, β-catenin and desmoglein-2), and IBS patients — overexpression of claudin-2. Permeability disruption leads to inflammatory changes in intestinal wall resulting in visceral and central sensitisation, as well as intestinal motor dysfunctions causal of IBS and FD.

Conclusion. Disruption of intestinal mucosal barrier may be considered a pathogenetic factor of PD and IBS progression.

Situs inversus is a rare mirror transposition of internal organs relative to the median plane. Liver transplantation in situs inversus is a serious medical challenge imposed by an abnormal arrangement of the recipient's organs.

Aim. Clinical description of a successful cadaveric liver transplantation in an adult patient with situs inversus and portal vein thrombosis.

Key points. A 32 years-old patient with situs inversus, chronic hepatitis B/D-induced liver cirrhosis and portal vein thrombosis had cadaveric liver transplantation, with the transplant reoriented in abdominal cavity 90° clockwise relative to the median plane. End-to-side cavocaval anastomosis was formed between the donor's retrohepatic and the recipient's main inferior vena cava, with successive portal and arterial anastomoses and complete donor liver reperfusion. A biliary reconstruction was performed with an end-to-end biliobiliary anastomosis. The surgery duration comprised 5 h 20 min, intraoperative blood loss — 2000 mL, cold ischemia time — 4 h. The patient was discharged on the 10^th day after surgery in satisfactory condition.

Conclusion. Situs inversus is not a contraindication to liver transplantation.

Aim: Clinical description of an ectopic pancreas (EP) in the duodenal wall.

Key points: Aberrant or ectopic pancreas is a congenital abnormality of pancreatic heterotopy into unrelated organs with no connection to the true pancreas. Asymptomatic EP often leads to its casual diagnosis due to background complications or concomitant gastrointestinal disorders. A 57 years-old patient was urgently admitted to a surgery unit with signs of gastrointestinal bleeding. Esophagogastroduodenoscopy (EGD), colonoscopy, abdominal CT without intravenous contrast failed to diagnose the source of bleeding. Following two months, MRI scanning with contrast revealed an atypical lateral formation on descending duodenum with the lobulous contour and structure corresponding to normal pancreatic tissue, as well as signs of chronic pancreatitis and a solitary cyst in the pancreatic body. EP in duodenal wall was diagnosed as a putative cause of gastric bleeding.

Aim. Current recommendations of the Russian Gastroenterological Association are developed to acquaint medical practitioners with modern diagnostics, treatment and trends in rational drug therapy for gastroesophageal reflux disease (GERD).

General provisions. Incidence rate of GERD in the Russian Federation varies from 11.3 to 23.6%. GERD is diagnosed with medical history and laboratory examination evidence. Esophagogastroduodenoscopy (EGDS) allows detection of reflux esophagitis of various severity and cylindrical epithelial metaplasia of esophagus. The refractory form of disease (lack of conclusive clinical and endoscopic remission during 4-8 weeks of standard-dose PPI therapy), presence of strictures and Barrett's esophagus require EGDS with esophageal biopsy and bioptic histological examination. Patients should be conclusively performed esophageal 24-hour pH-metry or pH-impedance monitoring, high-resolution manometry to thoroughly examine functionality of esophagus, esophagogastric junction and assess disease prognosis and therapy outcomes.

Treatment of GERD should be personalised accounting for clinical manifestations and severity, as well as aimed at symptom improvement, lesion healing in erosive esophagitis, averting complications, Barrett's esophagus progression, dysplasia and esophageal adenocarcinoma.

Proton pump inhibitors (PPIs) are most effective agents in primary (4-8 weeks) and maintenance anti-GERD therapy. Antacids are recommended in monotherapy for occasional nonerosive heartburn and complex anti-GERD settings for fast symptom improvement. Prokinetics can be used in combination with PPIs for their properties to recover normal functionality of esophagus through affecting pathogenetic mechanisms of GERD.

Complicated patients (repeated bleedings, peptic esophageal strictures) are recommended anti-reflux surgery with prior examination of esophageal functionality using pH-impedance and high-resolution manometry.

Conclusion. Current recommendations provide an up-to-date evidential medicial review of GERD and guidelines to advance special medical care and timely preventive measures.