Access to direct-acting antivirals for the treatment of hepatitis C in a country with limited resources. / Evaluación del acceso a antivirales para el tratamiento de la hepatitis C en un país con recursos limitados.

AIMS: To estimate the number of patients that have access to treatment of hepatitis C with direct-acting antivirals in Argentina and evaluate the factors associated with the lack of access. MATERIALS AND METHODS: A cross-sectional cohort study was conducted that included all the consecutive prescriptions of direct-acting antivirals issued at health centers that participated in the ECHOTM telemedicine project directed by the Hospital Italiano de Buenos Aires, within the time frame of January 2016 and February 2017. RESULTS: A total of 143 treatment prescriptions were included and overall access was 70% (95% CI 62-77%). The only independent factor associated with a lack of treatment access was coverage by a public healthcare system (OR 4.98 [95% CI 2.05- 12.09]). CONCLUSION: Patients with hepatitis C that were covered by a public healthcare system had a 4 times higher chance of not having access to treatment with direct-acting antivirals than patients covered by other healthcare systems (private insurance or the social welfare system).

Historical epidemiology of hepatitis C virus (HCV) in select countries - volume 2.

Chronic hepatitis C virus (HCV) infection is a leading cause of liver related morbidity and mortality. In many countries, there is a lack of comprehensive epidemiological data that are crucial in implementing disease control measures as new treatment options become available. Published literature, unpublished data and expert consensus were used to determine key parameters, including prevalence, viremia, genotype and the number of patients diagnosed and treated. In this study of 15 countries, viremic prevalence ranged from 0.13% in the Netherlands to 2.91% in Russia. The largest viremic populations were in India (8 666 000 cases) and Russia (4 162 000 cases). In most countries, males had a higher rate of infections, likely due to higher rates of injection drug use (IDU). Estimates characterizing the infected population are critical to focus screening and treatment efforts as new therapeutic options become available.

Strategies to manage hepatitis C virus (HCV) infection disease burden - volume 2.

The hepatitis C virus (HCV) epidemic was forecasted through 2030 for 15 countries, and the relative impact of two scenarios was considered: (i) increased treatment efficacy while holding the treated population constant and (ii) increased treatment efficacy and increased annual treated population. Increasing levels of diagnosis and treatment, in combination with improved treatment efficacy, were critical for achieving substantial reductions in disease burden. In most countries, the annual treated population had to increase several fold to achieve the largest reductions in HCV-related morbidity and mortality. This suggests that increased capacity for screening and treatment will be critical in many countries. Birth cohort screening is a helpful tool for maximizing resources. In most of the studied countries, the majority of patients were born between 1945 and 1985.

The present and future disease burden of hepatitis C virus (HCV) infections with today's treatment paradigm - volume 2.

Morbidity and mortality attributable to chronic hepatitis C virus (HCV) infection are increasing in many countries as the infected population ages. Models were developed for 15 countries to quantify and characterize the viremic population, as well as estimate the number of new infections and HCV related deaths from 2013 to 2030. Expert consensus was used to determine current treatment levels and outcomes in each country. In most countries, viremic prevalence has already peaked. In every country studied, prevalence begins to decline before 2030, when current treatment levels were held constant. In contrast, cases of advanced liver disease and liver related deaths will continue to increase through 2030 in most countries. The current treatment paradigm is inadequate if large reductions in HCV related morbidity and mortality are to be achieved.

Relapse rates in chronic hepatitis B naïve patients after discontinuation of antiviral therapy with entecavir.

Registration studies show entecavir (ETV) to be effective and safe in NUC-naïve patients with chronic hepatitis B, but relapse rates after treatment discontinuation have not been well established. Relapse rates and predictors of relapse were evaluated in naïve HBeAg-positive and HBeAg-negative patients treated with ETV. Treatment duration was defined according to international guidelines. Virological relapse was defined as reappearance in serum of hepatitis B virus (HBV) DNA to >2000 IU/mL after discontinuation of treatment. A hundred and sixty-nine consecutive patients were treated for a median 181 weeks. 61% were HBeAg positive, 23% had cirrhosis, and mean HBV DNA level was 6.88 ± 1.74 log10 IU/mL. Ninety-two per cent became HBV DNA negative; 71% of HBeAg+ve patients became HBeAg negative and 68% anti-HBe positive; 14% became HBsAg negative and 13% anti-HBs positive. At the end of the study, 36 patients discontinued treatment: one due to breakthrough associated with resistant variants and 35 (20%) due to sustained virological response; 33 of these patients developed HBeAg seroconversion and 18 HBsAg seroconversion. Median off-treatment time was 69 weeks. Nine patients (26%), all HBeAg positive at baseline, developed virological relapse after a median 48 weeks off-treatment, 3 of them showed HBeAg reversion and 4 lost anti-HBe. No patient with HBsAg seroconversion relapsed. HBeAg clearance after week 48 of treatment was associated with an increase risk of relapse. After ETV discontinuation, HBsAg seroconversion was maintained in 100% of the patients, HBeAg seroconversion maintained in 90%, and virological relapse rate was 24%.

Use of liver grafts from anti-hepatitis B core-positive donors: a multicenter study in Argentina.

Liver transplantation success is limited by the availability of donors. To overcome this limitation, anti-core-positive donors are increasingly being accepted, but underutilization of this resource still occurs. We performed the current study to determine the prevalence of anti-core-positive donors in our region and to describe the management of these donors and their recipients. Between January 2005 and July 2011, the national transplant database included 2,262 registered liver donors among whom 106 (4.7%) were anti-core-positive including 59 (56%) discarded and 47 (44%) implanted organs. A median of 14.5 offers (range 4-60) were rejected before harvesting and implanting the accepted grafts. The only difference between the implanted and the discarded grafts was found for the alanine aminotransferase level, which was higher among the discarded ones (50 ± 59 UI/L vs 25 ± 16, P < .05). Among 40 recipients included in the study, 5 (12.5%) did not receive any prophylaxis; 18 (45%) a nucleos(t)ide analog 11 (25.5%), heptitis B immunoglobulin and nucleos(t)ide analogs and 6 (15%) pretransplant hepatitis B vaccination. Over a mean follow-up of 871 ± 585 days, 4 de novo hepatitis B cases were identified at 545, 720, 748, and 1,080 days posttransplantation. None of these patients had received any prophylaxis. In all cases entecavir successfully controlled viral replication. We believe that better utilization of these donors and careful management of their recipients represent safe strategies to expand the liver donor pool in Argentina.

Chronic hepatitis B: current epidemiology in the Americas and implications for management.

Hepatitis B virus (HBV) remains a serious health threat in many parts of the world. Although its prevalence is lower in the Americas than in Asia, Africa and the Middle East, it is responsible for significant morbidity and mortality in North, Central and South America. There is a nonuniform pattern of distribution throughout this region, with HBV prevalence related to geographical, social and cultural factors that predispose certain individuals to infection. This report details the incidence, modes of viral transmission of hepatitis B in the Americas and clinical course of disease in different regions of the Americas. Additionally, the implications for management focusing on issues predominant in high-risk populations are presented.

Vascular nitric oxide production during the development of two experimental models of portal hypertension.

BACKGROUND/AIMS: The aim of this study was to determine the relative roles of constitutive NOS (NOS3) and inducible NOS (NOS2) isoforms during the development of two models of portal hypertension in rats. METHODS: Vascular reactivity of aortic rings for norepinephrine was performed in control, sham-operated, portal-vein-stenosed and secondary biliary cirrhotic rats 1, 4, 7, 14 and 28 days after surgery. NOS activity and nitrate plasma levels were also measured. RESULTS: An impaired response to norepinephrine observed in sham-operated, portal-vein-stenosed and cirrhotic rats at days 1 and 4 compared with controls was reversed after L-NNA and aminoguanidine. Portal hypertensive rats remained hyporeactive at days 7, 14 and 28 compared with sham-operated rats. At days 7 and 14 in portal-vein-stenosed rats, vascular hyporeactivity was reversed by L-NNA and W7. At days 14 and 28 in cirrhotic rats, vascular hyporeactivity was reversed by L-NNA and W7. Nitrate levels increased at day 1 in the 3 groups, and increased at days 14 and 28 in portal hypertensive rats. Total NOS-activity increased in cirrhotic rats at day 28, in portal-vein-stenosed rats at day 14, and in sham-operated rats at day 1 compared to controls. NOS2 activity increased only in sham-operated rats at day 1. CONCLUSIONS: This study shows that for two models of portal hypertension, increased NO production in the first days is related to NOS2 induction secondary to surgery. On the other hand, when portal hypertension has fully developed, the NOS3 isoform appears to play the major role.

Endothelial calcium-calmodulin dependent nitric oxide synthase in the in vitro vascular hyporeactivity of portal hypertensive rats.

BACKGROUND/AIMS: Increased nitric oxide production has been implicated in impaired vascular responsiveness to vasoconstrictors in portal hypertension. However, there is no firm evidence concerning the involved nitric oxide synthase isoform. The present study investigated the possible contribution of one nitric oxide synthase isoform, the endothelial constitutive Ca2+-calmodulin dependent, in the overproduction of nitric oxide in portal hypertension. METHODS: Vascular responses to norepinephrine and acetylcholine were evaluated in isolated thoracic aortic rings from normal and portal vein stenosed rats. RESULTS: An impaired concentration-dependent contraction to norepinephrine was observed in intact rings from portal hypertensive rats compared to controls. The hyporeactivity to norepinephrine was reversed after endothelium denudation, the inhibition of nitric oxide synthase with L-NOARG or the inhibition of calmodulin with W-7, but not after pre-incubation with indomethacin. Stimulation of intact rings with norepinephrine after the inhibition of calmodulin with calmidazolium was followed by a decreased vascular response in vessels from normal rats but not in those from portal hypertensive rats. Stimulation of intact rings with norepinephrine in a Ca2+-free medium was followed by a decreased vascular response in vessels from both portal hypertensive and normal rats. No difference in vasoconstrictive responses was observed between the two groups after calmidazolium or in a Ca2+-free medium. Relaxation induced by acetylcholine in norepinephrine-precontracted rings was more marked in rings from portal hypertensive rats than in controls. No differences in the vasodilator responses were observed after relaxations had been inhibited by the removal of the endothelium, pre-incubation with L-NOARG, indomethacin, W-7 or calmidazolium and in a Ca2+-free medium. CONCLUSIONS: This study demonstrates the involvement of the endothelial constitutive Ca2+-calmodulin dependent nitric oxide synthase isoform in the overproduction of nitric oxide in portal hypertension.