Varocha Mahachai

Peginterferon alpha-2a (40 kDa): an advance in the treatment of hepatitis B e antigen-positive chronic hepatitis B

Current therapies for chronic hepatitis B (CHB) have a number of limitations, and better treatment options are needed. Peginterferon α‐2a (40 kDa) is superior to conventional interferon α‐2a in the treatment of chronic hepatitis C. This is the first report on peginterferon α‐2a (40 kDa) in the treatment of CHB. In this phase II study, 194 patients with CHB not previously treated with conventional interferon‐α were randomized to receive weekly subcutaneous doses of peginterferon α‐2a (40 kDa) 90, 180 or 270 μg, or conventional interferon α‐2a 4.5 MIU three times weekly. Twenty‐four weeks of therapy were followed by 24 weeks of treatment‐free follow‐up. All subjects were assessed for loss of hepatitis B e antigen (HBeAg), presence of hepatitis B antibody (anti‐HBe), suppression of hepatitis B virus (HBV) DNA, and normalization of serum alanine transaminase (ALT) after follow‐up.

Asia-Pacific consensus guidelines on gastric cancer prevention

Background and Aim:  Gastric cancer is a major health burden in the Asia–Pacific region but consensus on prevention strategies has been lacking. We aimed to critically evaluate strategies for preventing gastric cancer.

Helicobacter pylori in North and South America before Columbus

We present a molecular epidemiologic study, based on an analysis of vacA, cagA and cag right end junction genotypes from 1042 Helicobacter pylori isolates, suggesting that H. pylori was present in the New World before Columbus. Eight Native Colombian and Alaskan strains possessed novel vacA and/or cagA gene structures and were more closely related to East Asian than to non‐Asian H. pylori. Some Native Alaskan strains appear to have originated in Central Asia and to have arrived after strains found in South America suggesting that H. pylori crossed the Bering Strait from Asia to the New World at different times.

Molecular Epidemiology and Outcome of Helicobacter pylori Infection in Thailand: a Cultural Cross Roads

Background.  Thailand is at the cultural cross roads between East and South Asia. It has been suggested that this is also the region where the predominant Helicobacter pylori (H. pylori) genotype changes from East Asian to South Asian.

Result of endoscopic biliary drainage in hilar cholangiocarcinoma.

Patients with hilar obstruction usually require bilateral biliary drainage. The prognosis of patients who fail bilateral biliary drainage after contrast injection into both intrahepatic ducts is poor due to a high infection rate in the undrained segments. The incidence of post–endoscopic retrograde cholangiopancreatography cholangitis in those with successful bilateral biliary drainage was less, but still significant. Incomplete subsegmental intrahepatic duct drainage is suggested to be responsible for post–biliary drainage cholangitis in cases of advanced hilar tumors. This study was undertaken to determine the incidence of post–endoscopic retrograde cholangiopancreatography cholangitis, jaundice resolution, and stent clogging in different types of malignant biliary obstruction after biliary drainage. From our endoscopic retrograde cholangiopancreatography database, there were 63 patients who underwent endoscopic biliary drainage between September 2000 and November 2001, for malignant biliary obstruction. Sixty-one endoscopic retrograde cholangiopancreatographies had biliary drainage performed (2 patients who failed biliary drainage were excluded). We divided our patients into 3 groups: Group 1 = Bismuth I, Group 2 = Bismuth II, and Group 3 = Bismuth III and IV. All but 2 Group 1 patients had successful biliary endoprosthesis (plastic [n = 13], metallic [n = 12], failed [n = 2]) placement into an extrahepatic duct. All patients from Group 2 (n = 10) and 20 patients from Group 3 (n = 26) had successful bilateral biliary drainage. Unilateral biliary drainage was performed in 6 patients from Group 3, each with a plastic endoprosthesis. The incidence of post–biliary drainage cholangitis (new onset of fever >38.5°C with leukocytosis), jaundice resolution (normal bilirubin level), and the duration of endoprosthesis patency were compared among the 3 groups. The incidences of post–endoscopic retrograde cholangiopancreatography cholangitis, jaundice resolution, and the duration of endoprosthesis patency were: Group 1 (4%, 96%, and 87.2 days, respectively), Group 2 (10%, 100%, and 69.1 days, respectively) and Group 3 (57.7%, 73.1%, and 41.3 days, respectively). Of those patients who did not undergo surgery, patients from Group 3 required endoprosthesis exchange sooner than others. The outcome of biliary drainage in patients with advanced hilar tumors (Bismuth III or IV) was poorer than hilar tumor at earlier stages (Bismuth I or II).

Rationale in diagnosis and screening of atrophic gastritis with stomach-specific plasma biomarkers

Abstract Background and aims. Atrophic gastritis (AG) results most often from Helicobacter pylori (H. pylori) infection. AG is the most important single risk condition for gastric cancer that often leads to an acid-free or hypochlorhydric stomach. In the present paper, we suggest a rationale for noninvasive screening of AG with stomach-specific biomarkers. Methods. The paper summarizes a set of data on application of the biomarkers and describes how the test results could be interpreted in practice. Results. In AG of the gastric corpus and fundus, the plasma levels of pepsinogen I and/or the pepsinogen I/pepsinogen II ratio are always low. The fasting level of gastrin-17 is high in AG limited to the corpus and fundus, but low or non-elevated if the AG occurs in both antrum and corpus. A low fasting level of G-17 is a sign of antral AG or indicates high intragastric acidity. Differentiation between antral AG and high intragastric acidity can be done by assaying the plasma G-17 before and after protein stimulation, or before and after administration of the proton pump inhibitors (PPI). Amidated G-17 will rise if the antral mucosa is normal in structure. H. pylori antibodies are a reliable indicator of helicobacter infection, even in patients with AG and hypochlorhydria. Conclusions. Stomach-specific biomarkers provide information about the stomach health and about the function of stomach mucosa and are a noninvasive tool for diagnosis and screening of AG and acid-free stomach.

Diagnostic role of serum glypican-3 in differentiating hepatocellular carcinoma from non-malignant chronic liver disease and other liver cancers

Background and Aims:  The role of glypican‐3 (GPC3), a novel serum marker, in differentiating hepatocellular carcinoma (HCC) from non‐malignant chronic liver disease and other malignant space‐occupying lesions in the liver is largely unknown. The aims of this study were to evaluate its diagnostic role and clinical correlations in patients with HCC.

Role of Deletion Located between the Intermediate and Middle Regions of the Helicobacter pylori vacA Gene in Cases of Gastroduodenal Diseases

ABSTRACT The vacuolating cytotoxin gene of Helicobacter pylori, vacA, induces cytoplasmic vacuolation in gastric epithelial cells. Recently, the vacA intermediate (i) region, which is located between the signal (s) and middle (m) regions, was identified as a third polymorphic determinant of vacA activity. In vacA, there are approximately 81-bp deletions between the vacA i and m regions (denoted the d region). The aim was to clarify the roles of the vacA d region in relation to H. pylori-related diseases and histopathological gastric mucosal changes. We assessed the vacA signal s-, m-, i-, and d-region genotypes and cagA status in H. pylori isolates recovered from Western countries (n = 266) and East Asian countries (n = 244) by PCR. In East Asian countries, there were no relationships between the vacA genotypes and the clinical outcomes and histopathological changes. In Western countries, strains with the vacA s1, m1, i1, or d1 (no deletion) genotype significantly increased the risk for the development of gastric cancer compared with the risk from strains with the s2, m2, i2, or d2 genotype (adjusted odd ratios, 3.17 [95% confidence interval {CI}, 1.07 to 9.45] for s1, 10.65 [95% CI, 3.36 to 31.35] for m1, 8.57 [95% CI, 2.85 to 25.81] for i1, and 8.04 [95% CI, 2.67 to 24.16] for d1). The highly virulent vacA genotypes significantly enhanced neutrophil infiltration and gastric atrophy in univariant analysis, whereas only the vacA d-region genotype was significantly associated with neutrophil infiltration and gastric atrophy in both the antrum and the corpus by multiple linear regression analysis. The presence of the vacA d1 genotype in H. pylori strains could be an improved predictor of histological inflammation and the potential for atrophy compared with the presence of the vacA s-, m-, and i-region genotypes in Western countries.

Hepatitis B: overview of the burden of disease in the Asia‐Pacific region

Abstract: Hepatitis B virus (HBV) infection and its liver‐related complications are a substantial health concern in the Asia‐Pacific region. Over the last two decades, public health interventions and the implementation of universal vaccination programs have substantially reduced the incidence of HBV infections in many countries in this region. However, large proportions of individuals remain chronically infected and subject to an increased risk for serious sequelae, including cirrhosis, decompensated liver disease, and hepatocellular carcinoma. The management of HBV infection varies throughout the Asia‐Pacific region, with each country confronting different issues related to prevention, screening, and treatment. These issues include the availability of diagnostic testing and treatment, the cost of diagnosis and treatment, the availability of trained medical professionals and medical facilities, and disease awareness among primary care physicians and the public. This article reviews the epidemiology of HBV infection in the Asia‐Pacific region, explains factors influencing hepatitis B prevalence and prevention, and discusses barriers to prevention and treatment of chronic hepatitis B and its liver‐related complications.

Role of Helicobacter pylori cagA EPIYA motif and vacA genotypes for the development of gastrointestinal diseases in Southeast Asian countries: a meta-analysis.

BackgroundInfection with cagA-positive, cagA EPIYA motif ABD type, and vacA s1, m1, and i1 genotype strains of Helicobacter pylori is associated with an exacerbated inflammatory response and increased risk of gastroduodenal diseases. However, it is unclear whether the prevalence and virulence factor genotypes found in Southeast Asia are similar to those in Western countries. Here, we examined the cagA status and prevalence of cagA EPIYA motifs and vacA genotypes among H. pylori strains found in Southeast Asia and examined their association with gastroduodenal disease.MethodsTo determine the cagA status, cagA EPIYA motifs, and vacA genotypes of H. pylori, we conducted meta-analyses of 13 previous reports for 1,281 H. pylori strains detected from several Southeast Asian countries.ResultsThe respective frequencies of cagA-positive and vacA s1, m1, and i1 genotypes among examined subjects were 93% (1,056/1,133), 98% (1,010/1,033), 58% (581/1,009), and 96% (248/259), respectively. Stratification showed significant variation in the frequencies of cagA status and vacA genotypes among countries and the individual races residing within each respective country. The frequency of the vacA m-region genotype in patients infected with East Asian-type strains differed significantly between the northern and southern areas of Vietnam (p < 0.001). Infection with vacA m1 type or cagA-positive strains was associated with an increased risk of peptic ulcer disease (odds ratio: 1.46, 95%CI: 1.01-2.12, p = 0.046 and 2.83, 1.50-5.34, p = 0.001, respectively) in the examined Southeast Asian populations.ConclusionsBoth Western- and East Asian-type strains of H. pylori are found in Southeast Asia and are predominantly cagA-positive and vacA s1 type. In Southeast Asia, patients infected with vacA m1 type or cagA-positive strains have an increased risk of peptic ulcer disease. Thus, testing for this genotype and the presence of cagA may have clinical usefulness.