Shou‐Dong Lee

Sequences of 234 complete genomes and 631 hepatitis B surface antigen genes were used to assess the worldwide diversity of hepatitis B virus (HBV). Apart from the described two subgenotypes each for A and F, also B, C, and D divided into four subgenotypes each in the analysis of complete genomes supported by significant bootstrap values. The subgenotypes of B and C differed in their geographical distribution, with B1 dominating in Japan, B2 in China and Vietnam, B3 confined to Indonesia, and B4 confined to Vietnam, all strains specifying subtype ayw1. Subgenotype C1 was common in Japan, Korea, and China; C2 in China, South-East Asia, and Bangladesh, and C3 in the Oceania comprising strains specifying adrq-, and C4 specifying ayw3 is encountered in Aborigines from Australia. This pattern of defined geographical distribution was less evident for D1-D4, where the subgenotypes were widely spread in Europe, Africa, and Asia, possibly due to their divergence having occurred a longer time ago than for genotypes B and C, with D4 being the first split and still the dominating subgenotype of D in the Oceania. The genetic diversity of HBV and the geographical distribution of its subgenotypes provide a tool to reconstruct the evolutionary history of HBV and may help to complement genetic data in the understanding of the evolution and past migrations of man.

We detected des-gamma-carboxy prothrombin, an abnormal prothrombin, in the serum of 69 of 76 patients (91 per cent) with biopsy-confirmed hepatocellular carcinoma (the mean level of the abnormal prothrombin was 900 ng per milliliter). In contrast, levels of the abnormal prothrombin were low in patients with chronic active hepatitis (mean, 10 ng per milliliter) or metastatic carcinoma involving the liver (mean, 42 ng per milliliter), and undetectable in normal subjects. In five patients treated with vitamin K there was no reduction in abnormal prothrombin, indicating that its presence was not due to vitamin K deficiency. Surgical resection of tumors in two patients and chemotherapy in one patient markedly reduced abnormal-prothrombin concentrations, which later increased with recurrence of disease. Serum alpha-fetoprotein levels correlated poorly with abnormal-prothrombin levels. Together, the assay for abnormal prothrombin and the alpha-fetoprotein assay identified 64 of 76 patients with hepatoma (84 per cent). Abnormal prothrombin may be useful in the laboratory diagnosis of primary hepatocellular carcinoma.

Antituberculosis drug-induced hepatitis is one of the most prevalent drug-induced liver injuries. Isoniazid is the major drug incriminated in this hepatotoxicity. Isoniazid is mainly metabolized to hepatotoxic intermediates by N-acetyltransferase (NAT). However, the association of polymorphic NAT acetylator status and antituberculosis drug-induced hepatitis is debatable. To determine whether acetylator status is a risk factor for antituberculosis drug-induced hepatitis, we genotyped NAT2 in 224 incident tuberculosis patients who received antituberculosis treatment. Antituberculosis drug-induced hepatitis was diagnosed based on a positive isoniazid rechallenge test and exclusion of viral hepatitis. Acetylator status was determined by genotyping NAT2 in patients using a polymerase chain reaction with restriction fragment length polymorphism. Univariate analysis and logistic regression analysis were used to evaluate the risk factors of isoniazid-induced hepatitis. Thirty-three patients (14.7%) were diagnosed with antituberculosis drug-induced hepatitis. Slow acetylators had a higher risk of hepatotoxicity than rapid acetylators (26.4% vs. 11.1%, P =.013). Among patients with hepatotoxicity, slow acetylators had significantly higher serum aminotransferase levels than rapid acetylators. Logistic regression showed that slow-acetylator status (odds ratio [OR], 3.66; 95% CI, 1.58-8.49; P =.003) and age (OR, 1.09; 95% CI, 1.04-1.14; P <.001) were the only 2 independent risk factors for antituberculosis drug-induced hepatitis. In conclusion, slow-acetylator status of NAT2 is a significant susceptibility risk factor for antituberculosis drug-induced hepatitis. Additionally, slow acetylators are prone to develop more severe hepatotoxicity than rapid acetylators. Regular monitoring of serum aminotransferase levels is mandatory in patients receiving antituberculosis treatment, especially in slow acetylators.

Bacterial infection may adversely affect the hemostasis of patients with gastroesophageal variceal bleeding (GEVB). Antibiotic prophylaxis can prevent bacterial infection in such patients, but its role in preventing rebleeding is unclear. Over a 25-month period, patients with acute GEVB but without evidence of bacterial infection were randomized to receive prophylactic antibiotics (ofloxacin 200 mg i.v. q12h for 2 days followed by oral ofloxacin 200 mg q12h for 5 days) or receive antibiotics only when infection became evident (on-demand group). Endoscopic therapy for the GEVB was performed immediately after infection work-up and randomization. Fifty-nine patients in the prophylactic group and 61 patients in the on-demand group were analyzed. Clinical and endoscopic characteristics of the gastroesophageal varices, time to endoscopic treatment, and period of follow-up were not different between the two groups. Antibiotic prophylaxis decreased infections (2/59 vs. 16/61; P <.002). The actuarial probability of rebleeding was higher in patients without prophylactic antibiotics (P =.0029). The difference of rebleeding was mostly due to early rebleeding within 7 days (4/12 vs. 21/27, P =.0221). The relative hazard of rebleeding within 7 days was 5.078 (95% CI: 1.854-13.908, P <.0001). The multivariate Cox regression indicated bacterial infection (relative hazard: 3.85, 95% CI: 1.85-13.90) and association with hepatocellular carcinoma (relative hazard: 2.46, 95% CI: 1.30-4.63) as independent factors predictive of rebleeding. Blood transfusion for rebleeding was also reduced in the prophylactic group (1.40 +/- 0.89 vs. 2.81 +/- 2.29 units, P <.05). There was no difference in survival between the two groups. In conclusion, antibiotic prophylaxis can prevent infection and rebleeding as well as decrease the amount of blood transfused for patients with acute GEVB following endoscopic treatment.