HLA antigen in Chinese patients with hepatocellular carcinomas.

One hundred and fourteen Chinese patients with hepatocellular carcinomas (HCC) were studied for alpha-fetoprotein (AFP), hepatitis B surface antigen (HBsAg), anti-HBsAg, and HLA markers. Younger patients with HCC (less than 60 yr old) were more significantly associated with elevated serum AFP (P less than 0.0001) and serum HBsAg (P less than 0.0001) than were older (greater than or equal to 60 yr old) patients. A strong correlation existed between serum AFP and HBsAg among the patients (P less than 0.0001). Of 27 AFP-negative patients, 15 (55.6%) had HLA-B15 compared to 53 of 238 (22.3%) healthy controls (corrected P less than 0.003, relative risk = 4.4). The frequency of HLA-B15 was even higher in the AFP-negative plus HBsAg-negative subgroup (61%). AFP-negative patients also had a significant lack of blood group A.

Human hepatitis B virus mutants: significance of molecular changes.

Human hepatitis B virus, the leading pathogen for hepatitis B, is a compact DNA virus with viral genes that largely overlap. An increasing number of mutations have emerged following human interventions such as vaccination and anti-viral therapy. While vaccine escape mutants are characterized by mutations on the antigenic hepatitis B surface antigen, those carrying mutations in other viral proteins are either resistant to anti-viral therapy or implicated in acute liver diseases. Molecular identification of these various mutants should shed new lights on the underlying mechanism of hepatitis B virus viral escape and resistance and provide helpful information on their effective eradication.

Detection of hepatitis B surface antigen mutants and their integration in human hepatocellular carcinoma.

Vaccine escape hepatitis B virus surface antigen (HBsAg) mutants are capable of independent replication and have been implicated in acute hepatitis. We now report the detection of these mutants with changes at various positions of the antigenic 'a' determinant in human hepatocellular carcinoma (HCC). Southern blot analysis indicated that the HBsAg mutant with the Glycine to Arginine change at position 145 was integrated in HCC, whereas those with a Threonine at position 133 instead of a Methionine were identified in the serum of aggressive HCC. Further studies on HBsAg mutants in HCC should provide new insights on their involvement in the hepatocarcinogenesis.

Two-dimensional echocardiographic abnormalities of right atrial metastatic tumors in hepatoma.

We describe two patients suffering from hepatoma who presented with right atrial metastatic tumors as a result of invasion of the inferior vena cava and extension into the right atrium. Two-dimensional echocardiographic studies detected the right atrial tumor during life in both patients and the invasion of the inferior vena cava in one patient.

Hepatitis B virus variants with lamivudine-related mutations in the DNA polymerase and the 'a' epitope of the surface antigen are sensitive to ganciclovir.

Lamivudine is a new antiviral agent effective against hepatitis B viral (HBV) infections but can result in virus-drug resistance associated with mutations in the conserved 'YM552DD' motif of the HBV DNA polymerase. Due to their overlapping coding regions in the HBV genome, mutations in the DNA polymerase may result in substitutions in the hepatitis B surface antigen (HBsAg), albeit outside the antigenic 'a' epitope. Here we report the identification of a novel type of lamivudine-related mutations located in both the polymerase (YM552DD-->Y1552DD) and the 'a' epitope of HBsAg (Gly130-->Asp130). The same virus carried a HBsAg Gly145-->Arg145 mutation prior to therapy. Both the wild type HBV and lamivudine-related mutants with the Gly145-->Arg145 HBsAg mutation were suppressed following ganciclovir treatment, indicating a beneficial additive effect of both drugs against different forms of HBV mutants.

Maternal-child hepatitis B virus transmission in Singapore.

A study of maternal-infant transmission of hepatitis B virus (HBV) was conducted in Singapore between June 1980 and June 1982. HBsAg carrier rate was highest among Chinese (6.2%) followed by Malay (2.3%) and Indian (0.6%) mothers. The presence of HBeAg in maternal sera correlated well with high titre HBsAg (p = 7.34 X 10(-5)). Overall HBV transmission occurred in 27/56 (48.2%) infants from carrier mothers. The majority of the transmission was perinatal. There was a very strong correlation between transmission and HBeAg status of the mother (p = 1.85 X 10(-9); odds ratio = 68.44) and to a lesser extent with high titre HBsAg (p = 0.002; odds ratio = 6.38). A strong negative correlation was seen between transmission and anti-HBeAg (p = 8.19 X 10(-7); odds ratio = 0.04). At one year 19 (70.4%) infants were still HBsAg positive while seven (25.9%) lost the antigenemia and acquired anti-HBsAg and one developed HBsAg after one year. It could be calculated that perinatal HBV transmission contributed about 18% to the total pool of HBsAg positive infants of one year of age.

Comparison of various assays for detection of AFP in differentiating patients with primary hepatocellular carcinoma from controls.

Four assays for the detection of alphafetoprotein (AFP) in the diagnosis of primary hepatocellular carcinoma (HCC) were evaluated. The frequency of AFP detection was compared in 89 HCC patients and in 71 patients with chronic active hepatitis/cirrhosis. Of the four assays, immunodiffusion, counterimmunoelectrophoresis (CIE), supplement CIE, and radioimmunoassay, the best for differentiating patients with HCC from those with chronic active hepatitis and cirrhosis was CIE.

Long-term survival following treatment of hepatocellular carcinoma in Singapore: evaluation of Wellferon in the prophylaxis of high-risk pre-cancerous conditions.

The present paper reviews several studies performed between 1977 and 1986 in Singapore on the 10-year survival outcome of treatment for stage I and II hepatocellular carcinoma (HCC). Of 801 HCC patients evaluated, only 2 survivors (0.3%) remained in complete remission for 13 and 14 years, respectively. One had received four weekly cycles of prednisolone, Adriamycin, vincristine and 5-fluorouracil for an inoperable HCC with a 10-cm diameter, and the other had received localised synchronised hepatic irradiation and Adriamycin. As follow-up, the use of localised hepatic irradiation consisting of 131I-labeled (30 mCi) iodised oil in lipiodol infused via the hepatic artery appeared to benefit patients with small residual tumours but did not affect larger tumours measuring 2 cm in diameter. Prophylactic, intermittent long-term administration of lymphoblastoid interferon-alpha (Wellferon) was carried out in pre-cancerous, high-risk hepatitis B surface antigen (HBsAg)-positive patients with cirrhosis, in immediate male relatives of liver cancer patients, and in persons who had undergone hepatic resection. In the untreated group, 10/162 (6%) cirrhotics, 3/18 (17%) male family members, and 6/10 (60%) post-resection cases developed single or multiple HCCs within 1 year of screening done at 3-month intervals on the basis of alpha-fetoprotein (AFP) levels and real-time hepatic ultrasonography. In contrast, none of the Wellferon-treated group consisting of 518 cirrhotic patients, 82 male relatives of HCC patients and 20 post-resection cases developed HCC. Two HBsAg-positive individuals who had not been treated with interferon (IFN) developed hepatic nodules which that showed dysplasia, AFP elevation and chromosomal changes. These studies demonstrate the poor results of late diagnosis and show that early intervention and prophylaxis with Wellferon can reduce the incidence of HCC in high-risk persons. In addition, transhepatic chemoembolisation and liver resection are suitable methods for treating small HCCs (single or multiple) that are detected by screening. However, some of these early-detected HCCs remain highly malignant. Prophylactic treatment of pre-cancerous conditions appears to be a better option as a long-term programme for HCC.

Primary hepatocellular carcinoma. Present state of the disease and prospects for the future.

Primary hepatocellular cancer is a common and virulent malignancy found all over the world. New insights into this disease are being provided by evaluation of the impact of epidemiologic data (hepatitis viral exposure, race, sex, HLA typing, and environmental factors). An enhanced appreciation of the biochemical modulators of hepatocellular cancer metabolism is now also possible. The limited success of current therapies is far from satisfactory, but prospects for the future seem more varied and promising than ever before.

Treatment of primary liver cancer in Singapore. A review of 3200 cases seen between January 1, 1977, and July 31, 1987.

Between January 1977 and July 1987, 3200 patients with hepatocellular carcinoma (HCC) were studied in Singapore. HCC formed 90% of primary liver cancers seen in Singapore and is the second most common fatal malignancy seen in men in the country. Extensive clinical and basic research has defined certain treatment strategies. Of importance is the prompt detection of early nodular tumours, which can be resected. Resection, 'targetting' with anticancer drugs and, in selected cases, synchronised direct hepatic irradiation with adriamycin, used as a radiosensitiser, have been promising treatment methods. Biological modifiers, such as interferons and interleukins, offer potential for the future. Preliminary pilot studies suggest that interferons may prevent the development of HCC, but more studies are required. Similarly, selective localisation of anticancer agents with radio-isotopical agents opens opportunities for treatment.

Hepatitis B infection in households of acute cases.

Seroepidemiological studies conducted in 369 household contacts of 80 acute cases of hepatitis B in Singapore showed that asymptomatic chronic carriers of hepatitis B surface antigen (HBs Ag) are the main source of acute hepatitis B infection. The HBs Ag prevalence rate in asymptomatic household members was 20% compared with a 6% prevalence for the general population. The majority of the household carriers (60%) were highly infectious with positive hepatitis e antigen (HBe Ag). The overall prevalence of HBV infection (with at least one HBV marker) of the household contacts was 40.7%. Spouses and parents of acute cases had a significantly higher prevalence of HBV infection than other members of the families. HBV prevalence rate showed no association with the household size. Factors associated with the risk of transmission of HBV infection included sharing of various personal and household articles, such as toothbrush, towel, handkerchief, clothing, razor, comb, bed and bedding. Sleeping in the same bedroom, eating together at meals, and sharing of eating and drinking utensils were not associated with an increased risk of transmission of infection. Follow-up studies six months later showed that 30% of the acute cases became chronic HBs Ag carriers (with 46% HBe Ag positive), thus providing an additional source of infection in the families, while 8% of the susceptible household members acquired asymptomatic HBV infection. Health education on the prevention of HBV transmission in the homes of acute cases should be based on sound epidemiological information. Household contacts of acute cases of hepatitis B should be routinely screened and the susceptible vaccinated against the disease as soon as possible.

The prevalence of hepatitis B virus markers in dental personnel in Singapore.

A seroepidemiological survey of the prevalence of hepatitis B virus (HBV) markers was conducted in a group of 693 dental personnel in Singapore where HBV infection is endemic. The overall prevalence of HBsAg (4.5%) and anti-HBc (29%) was no higher than that in the general population. However, dentists had a significantly higher HBsAg prevalence (11.4%) compared with that in the general population (4.2%) (P less than 0.01) and of other categories of dental personnel (3.1%) (P less than 0.001). Similarly, the anti-HBc prevalence of the dentists (45.6%) was significantly higher than that of the general population (29.7%) (P less than 0.01) and of other categories of dental personnel (25.7%) (P less than 0.0001). It appears that dentists in the endemic area have a definite occupational risk of acquiring HBV infection.

Intra-familial evidence of horizontal transmission of hepatitis B virus surface antigen mutant G145R.

OBJECTIVES: To provide intra-familial evidence on the horizontal transmission of hepatitis B virus surface antigen (HBsAg) mutant G145R. METHODS: Serum samples from family members of 10 vaccinated infants who carried this G145R mutant were collected. The presence of the mutant was analysed by polymerase chain reaction (PCR) and sequencing. RESULTS: The G145R mutant was identified in family members of three of the 10 infants. In family 1, the mutant found initially in child 1 was identified in another child and the father. In families 2 and 3, the G145R mutant detected previously in child 1 was detected in the father. Additional mutations in HBsAg were identified in at least two members in family 1 and 2, suggesting horizontal transmission of the mutant among them. The G145R mutant was found in samples with high levels of neutralizing antibody against HBV (anti-HBs). In addition, liver damage was seen in one G145R carrier infant. CONCLUSIONS: The G145R mutant could be transmitted horizontally among family members, and this could occur in the presence of high levels of anti-HBs. Improvement of detection system for the G145R and other HBsAg mutant will be needed for their effective control.

Evaluation of a low dose of hepatitis B vaccine given within a childhood immunisation programme in Singapore.

The feasibility of introducing low dose (5 micrograms) hepatitis B (HB) virus vaccination at birth and again 1 and 2 months later as part of an existing primary immunisation programme of childhood, was assessed in 662 healthy newborn Singapore children. The vaccine (B-Hepavac, Menck, Sharp and Dohme) was given to three neonatal groups: those born to HB surface antigen (sAg)-negative mothers, HBsAg-positive/HBeAg-positive mothers and HBsAg-positive/HBeAg-negative mothers. A dose of 5 micrograms was compared in a randomised study with the more usual 10 micrograms dose given at the same intervals. Neonates born to HBsAg-positive/HBeAg-positive mothers were also given hepatitis B immunoglobulin (HBIg) at birth. The 5 microgram dose of vaccine was as immunogenic as the 10 microgram dose in all three groups of children studied. At 1 year, anti-HBsAg seroconversion among infants of antigen-negative mothers was 95.8% for the 5 microgram dose and 91.9% for the 10 microgram dose. Suppression of anti-HBsAg formation was not seen even when maternal anti-HBsAg was present or HBIg given. Among infants born to HBsAg-positive/HBeAg-positive mothers, passive plus active immunisation was 100% protective at doses of 5 micrograms and 10 micrograms vaccine in the newborns who were HBsAg-negative at 24 h. Seroconversion after both the 5 and 10 microgram doses of vaccine was reduced, however, to 88% in each group of infants who were already HBsAg-positive at 24 h of age. Overall, passive plus active immunisation as well as HB vaccine alone (5 micrograms dose), given within the existing but expanded primary immunisation programme of childhood, was effective in preventing infection and the chronic carrier state in newborns exposed to risk of HB virus infection during infancy.

Medullary infarction--was it depo-provera?

PIP: A possible relation between parenteral Depo-Provera and the subsequent development of medullary infarction in a heavy smoker is reported. The patient, a 40-year old Chinese woman had smoked 30 cigarettes daily for many years. She received injections of 150 mg Depo-Provera in April and July 1979. 2 days after the 2nd injection she was admitted to the hospital for vomiting and vertigo of 2 days duration. Clinical examination showed a 12th nerve palsy with the tongue deviated to the right but no other neurological abnormalities. She was treated symptomatically with intravenous fluids and stemetil and improved. On the 5th day her vertigo and vomiting progressed and she developed more lower brain stem signs. The same day she had a grand mal fit and went into a coma. She died on the 7th hospital day. A partial autopsy limited to the skull revealed minimal atherosclerosis of the vertebral artery but no thrombosis or occlusion. Cut sections after perfusion revealed an area of softening associated with some hemorrhage involving the whole length of the right half of the medulla oblongata dorsal to the olivary nucleus. Histological examination revealed an infarct undergoing liquefaction necrosis. The possibility of a causative relationship is suggested by the development of tinnitis about 12 hours after injection of Depo-Provera.^ieng

Hepatitis E in Singapore--a seroprevalence study.

The seroprevalence of anti-HEV IgG was determined in a hospital-based population in a general medical unit. Patients who were otherwise well but admitted for acute, non-hepatological conditions represent the "healthy" general population, and those admitted primarily with liver disorders were studied. The seroprevalence of anti-HEV IgG was found to be 10.5% in the "healthy" population and 14.7% amongst those with liver diseases. The lack of travel history and past history of jaundice suggests presence of local cases and subclinical manifestation in some of the infected patients. There is an association between seroprevalence of hepatitis A and E, suggesting common predisposing factors for both infections. Anti-HAV IgG has a higher seroprevalence. Retesting of anti-HEV IgG in those who were initially positive found persistence of antibodies beyond twelve months. Both anti-HAV IgG and anti-HEV IgG were found more commonly in the older age groups.

Oncology--the past, the present and the future.

Oncology is the science which deals with the study of malignant diseases. Cancer itself is a complex subject which demands the dedication of laboratory scientists and clinicians to work closely together to achieve greater understanding of the problems of malignancy. Simplified education programmes on cancer risk factors and avoidable lifestyles may help to reduce the incidence of certain environment induced malignancies. In Singapore, active cancer research programmes are in existence in the epidemiology and biostatistical analysis of cancers locally and research studies on liver, nasopharyngeal and choriocarcinoma. However, with the increasing mortality from cancer over the years, more integration and cooperation is required among the clinicians, laboratory scientists and the field staff working in different parts of the country, so that eventually the risk from developing certain cancers can be reduced and the overall management of such cancers can be further improved.

Problems and strategies in the prevention of viral hepatitis in the Asian Pacific Region.

Viral hepatitis is endemic in the Asian Pacific Region, and seasonal outbreaks of these acute infections diseases occur regularly and annually. In this region, which extends from zones of temperate climate to tropical rain belt, vast distances, insufficient medical and laboratory services, and differences in the distribution of vaccines are further accentuated by local socio-economic factors. Prevention and control of these viral infections is one of the most important health issues because of their linkages with high mortality and morbidity due to their infections and to liver cancer, which is a foremost cancer in the region. Viral hepatitis A, B, delta region and Non A Non B are now present in the region. Strategies to prevent and control the spread of these diseases require the support of national authorities and the guidance of the World Health Organisation. Such strategies include public health education programmes on modes of transmission and their prevention, the use of suitable vaccines in susceptible populations, and the building up of local scientific know-how for regional collaboration and information on the dissemination of serious outbreaks.

Primary liver cancer--the potential for prevention and elimination.

Primary liver cancer (PLC) is one of the top ten cancers in the world, and a leading cause of cancer mortality in Singapore and the Asia Pacific region. Chronic hepatitis B infection accounts for at least 80% of primary hepatocellular cancer. Other chemical carcinogens, such as aflatoxins, have been identified in foodstuffs and have also been found in the urine of normal human subjects. Aflatoxin and other chemical carcinogens, e.g. alcohol, cigarettes, also pose serious risks of hepatocarcinogenesis. Identification of small tumours (not necessarily early) may allow for earlier treatment to be instituted. Capsular lesions in general have a better prognosis than infiltrating cancers. In Singapore, if hepatitis B virus can be eliminated by the year 2000, at least 65% of hepatitis B related deaths can be saved. This would involve large scale hepatitis B immunisation to prevent the carrier state and the use of antiviral drugs earlier to eliminate hepatitis B infections.

Prevention of primary liver cancer.

Primary Hepatocellular Carcinoma (HCC) is the most common form of liver cancer and is now one of the leading causes of cancer in the world. Chronic Hepatitis B carriage is now recognised to contribute to at least 80% of the liver cancers seen today. Hepatic toxins (such as Aflatoxin) are responsible for a smaller proportion of HCC and may have an additional synergistic effect in Aflatoxin-endemic areas where HCC occurs early. Prevention and control programmes require control of Aflatoxins and hepatic carcinogen contamination of human food material (from direct or indirect sources), and the control and prevention of Hepatitis B transmission to prevent the carrier state. Opportunities to treat the chronic carrier state may be possible in the future, since there have been considerable advances in genetic engineering and molecular biology in the last few years.