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标题: HBV杂志回顾 2011年7月 [打印本页]

作者: StephenW 时间: 2011-7-14 09:39 标题: HBV杂志回顾 2011年7月

本帖最后由 StephenW 于 2011-7-14 09:49 编辑

http://www.hbvadvocate.org/news/HBJ8.7.htm

HBV Journal Review
July 1, 2011, Vol 8, no 7
by Christine M. Kukka

Undetectable  Viral Load  Reduces Liver Cancer Risk  by 72%
People who are infected with the  hepatitis B virus (HBV), but who have undetectable viral load (HBV DNA) in  their bloodstream are 72% less likely to develop liver cancer, according to a  report published in the June edition of the journal Infectious Disease Special Edition.
The finding underscores the importance of  treating people to keep their viral load undetectable or as low as possible,  according to Taiwanese and U.S. researchers who collaborated on the study.
The team studied what factors contributed to  liver cancer, including viral load, the hepatitis B “e” antigen (HBeAg)–which  usually indicates high viral load, and the hepatitis B surface antigen  (HBsAg)–which indicates the presence of an HBV infection.
They monitored viral load and presence of the  “e” and surface antigens in 1,285 patients with HBV DNA levels exceeding 10,000  copies/mL between 1991 and 2007. During the 16-year study period, 111 patients  (8.64%) developed liver cancer. Researchers found that patients with undetectable  viral load were 72% less likely to develop cancer than those with detectable  HBV DNA.
In contrast, the risk for developing cancer was  similar among those with undetectable HBV DNA no matter if they cleared HBeAg  or HBsAg.
“Distinguishing  between individuals with or without HBsAg seroclearance did not significantly  affect the rates of (liver cancer) among those with undetectable HBV DNA  levels, with 1.6% of the latter group and 1.9% of the former group developing  cancer,” they reported.
Researchers said the study underscores the  importance of treating patients with antivirals to suppress viral load in order  to prevent liver disease and cancer.

Some Dietary Supplements Cause Liver  Damage
According to a review of published studies that  examined the impact of dietary supplements on the liver, many supplements such  as Herbalife® and Hydroxycut products can cause liver damage,  especially in people with pre-existing liver infections such as hepatitis B.
Researchers, reporting in the journal Liver International, conducted a review of studies on dietary  supplements and liver health published between 1990 and 2010.
They found that, “Significant liver injury was  reported after intake of Herbalife’s
and Hydroxycut products, tea  extracts from Camellia sinensis, products containing usnic acid and high  contents of vitamin A, anabolic steroids and others.”
No uniform pattern of liver damage was  identified, and liver damage ranged from asymptomatic elevations of liver  enzymes, which indicate liver cell damage or death, to liver failure and death.
“Exact estimates on how frequent adverse …  reactions occur as a result of dietary supplements cannot be provided,” they  noted. However, liver injury from these supplements, which appear to mimic  other liver diseases, is being increasingly documented.
Researchers promoted tighter government  regulation of dietary supplements, and increased awareness among consumers and  health care providers.

Some People Have a Genetic  Susceptibility to Cirrhosis
Researchers, writing in the June issue of Hepatology, report that some people may be genetically predisposed to developing  cirrhosis. About 5% of patients with cirrhosis have no cause, such as viral  hepatitis, fatty liver disease, or alcoholism, for their severe liver scarring.
Now researchers are suggesting that some people  are genetically predisposed to cirrhosis, and that their liver cells become  cirrhotic because they lack the enzymes and capacity to regenerate properly.
Data from epidemiological studies of people who  have cirrhosis with no apparent cause show that when compared to European  Americans, this type of cirrhosis is 3.1-fold higher in Hispanic Americans and  3.9-fold lower in African Americans.
This genetic predisposition to cirrhosis may be  the reason why some people with  hepatitis B advance to cirrhosis so quickly, while others do not experience  severe liver damage at all.

Low HBsAg Levels Associated with  HBeAg Seroconversion during Interferon Treatment
Researchers followed 399 HBV-infected patients,  all positive for HBeAg, treated with pegylated interferon (180 μg/week) alone  or with lamivudine (100 mg/day) for 48 weeks to see which patients responded to  the treatment.
According to the report published in the  journal Hepatology International, the patients with lower levels of HBsAg (around  5,000 IU/mL) tended to clear HBeAg and develop “e” antibodies at higher rates  than those whose HBsAg levels were higher, around 50,000 IU/mL.
HBeAg seroconversion rates six months after  treatment stopped were significantly higher in patients with HBsAg less than  1,500 IU/mL at weeks 12 and 24 (56.7 and 54.4% respectively) compared to  patients with HBsAg levels between 1,500 to 20,000 IU/mL (32.3 and 26.1%  respectively).

Antiviral Treatment Markedly  Improves Survival after Liver Cancer Surgery
Chinese researchers compared survival rates  among 136 liver cancer patients treated with antivirals to those who received  no treatment, after all had liver tumors surgically removed.
All of the liver cancers resulted from HBV  infection and patients were followed for five years after surgery. Forty-two  received antiviral treatment and 94 (the control group) received no treatment  after cancerous tumors were removed from their livers.
According to the report published in the June  issue of Archives of Surgery, antiviral treatment markedly improved  survival. The  1-, 3-, and 5-year survival rates in the treated group were 88.1%, 79.1%, and  71.2% respectively; compared to the control group’s survival rates of 76.5%,  47.5%, and 43.5% respectively.
The 1-, 3-, and 5-year disease-free survival  rates in the treatment group were 66.5%, 51.4%, and 51.4% respectively, and in  the control group they were 48.9%, 33.8%, and 33.8%.
The researchers recommend that all patients  receive antiviral treatment following surgical removal of liver tumors.

Blood Tests May Accurately Identify  When Treatment Is Needed –Bypassing Biopsies
Doctors continue to search for a noninvasive  blood test that gives a true picture of the health of a patient’s liver so they  can know if treatment is needed. While testing alanine aminotransferase (ALT)  levels is universally used and usually indicates when severe liver damage is  present (elevated ALTs indicate damaged or dying liver cells) doctors know some  patients with normal ALT levels also have liver damage and require treatment.
Short of an invasive liver biopsy, doctors want  a simple way to determine the health of the liver so they know if treatment is  necessary.
Recently, researchers applied a wide range of  liver tests to 227 viral hepatitis-infected patients with normal or moderately  elevated ALT levels to see which test, or which combination of tests, provided  the most accurate snapshot of liver health. Fifty-three of the patients were  known to have serious liver inflammation, which was previously identified by a  liver biopsy.
Writing in the journal Liver International, researchers described testing the patients’  ALT and aspartate aminotransferase (AST) levels, platelet count, γ-glutamyl  transpeptidase, alkaline phosphatase, hyaluronic acid, haptoglobin,  apolipoprotein A1 and procollagen III N-terminal peptide levels to assess liver  health.
They found that elevated AST and apolipoprotein  A1 levels accurately identified liver inflammation or fibrosis in patients,  even when the patients’ ALT levels were normal.
These two blood tests, when used together, can  potentially identify patients who are experiencing liver damage and require  treatment, even when their ALT levels are normal. If proven to be accurate when  tested on a larger number of patients, the two tests can help determine when  treatment is needed and avoid costly and invasive liver biopsies.
In an unrelated article published in the Journal of Viral Hepatitis, British researchers report that the Enhanced  Liver Fibrosis (ELF) test also appears to accurately identify liver fibrosis  and damage in patients with hepatitis C, even when ALT levels are normal. The  ELF test measures three things to identify the presence of fibrosis–hyaluronic  acid, amino-terminal propeptide of type III collagen, and tissue inhibitor of  matrix metaloproteinase 1.
They used the test in 347 patients, who also  had liver biopsies, to determine its accuracy. ELF was able to predict severe  fibrosis in 81% of the patients, which means those biopsies could have been avoided.

Researchers Recommend  Biopsy and Treatment When ALT Slightly                   Elevated
Researchers, writing in the June issue of Liver International, recommend liver biopsies for all hepatitis B  patients who test negative for HBeAg and have ALT levels that are 1.5-times  higher than normal.
Currently, treatment and a liver biopsy are  often recommended when ALT levels are twice normal. Normal ALT levels for women  are 19 IU/L and 30 IU/L for men.
The researchers followed three groups of 499  hepatitis B patients with detectable viral load over a three-year period and  administered liver biopsies to them.
· Group  1 had 181 patients with normal ALT levels.
· Group  2 had 200 patients with ALT levels between normal and twice normal.
· Group  3 had 118 patients with ALT levels that were twice normal or higher.
As expected, patients with highly elevated ALT  levels were found to have liver inflammation and fibrosis.
However, in Group 1 among those with positive  HBeAg status, 29 (52.7%) had liver damage and five (9.1%) had fibrosis. Among  those in Group 1 who were HBeAg-negative, 66 (23.1%) had liver damage and 31  (10.8%) had fibrosis.
In Group 2 with positive HBeAg status, 14  (15.7%) had moderate-to-severe liver damage and 19 (21.2%) had fibrosis. Among  those in Group 2 with negative HBeAg, 34 (30.6%) had moderate-to-severe liver  damage and 38 (34.2%) had fibrosis.
Additionally, liver damage and fibrosis were  significantly greater in patients age 30 and older.
“We recommend liver biopsy in HBeAg-negative  (hepatitis B patients) over 30 years of age regardless of ALT level and  starting treatment at when ALT is 1.5-times normal instead of twice normal,”  they wrote.

Lamivudine-Resistant Patients Fare Slightly Better When Treated with Interferon Than Adefovir
Researchers treated HBeAg-positive patients,  who had developed resistance to the antiviral lamivudine (Epivir-HBV) with  either pegylated interferon (Pegasys) or adefovir (Hepsera) to see which drug  worked best.
Adefovir, an antiviral like lamivudine,  prevents the virus from replicating by disrupting its reproductive  capabilities. Interferon boosts the immune system to fight the infection.  Antivirals are used over an indefinite period, while interferon injections can  span six to 12 months.
The researchers, reporting in the June 2011  issue of the journal Alimentary  Pharmacology and Therapeutics,  reported that the 55 patients treated with interferon had a higher HBeAg  seroconversion rate (loss of HBeAg and development of “e” antibodies) of 14.6%  compared to a 3.8% seroconversion rate among 80 adefovir-treated patients.
At week 72, interferon-treated patients who had  a steep decline in HBsAg during the first 24 weeks of treatment had the highest  rate of HBeAg seroconversion compared to patients who did not have such a  decline (25.5% versus 7.7%.)
However, after 72 weeks of continuous adefovir  treatment, 22.5% of patients achieved undetectable HBV DNA (viral load)  compared with 10.6% in interferon-treated patients.
Overall, the response to interferon treatment  remained disappointing, researchers noted, with a response rate of only 14.6%.  However, monitoring HBsAg levels during the early weeks of treatment can help  to predict who will ultimately respond to interferon.

Tenofovir Effective When  Entecavir Fails in an Immune-Compromised Patient
Doctors, writing in the June issue of the  journal Infection, described successfully treating a hepatitis B  patient who had failed to respond to treatment with the antiviral entecavir  (Baraclude.)
What puzzled doctors was that even though the  patient had a weakened immune system, he had not developed any drug resistance  to the antiviral entecavir. Yet, the antiviral was ineffective in lowering his  high viral load (HBV DNA).
Doctors next treated him with tenofovir  (Viread), an antiviral that is known for its potency and its low rate of drug resistance.  Within weeks, the patient achieved undetectable viral load
“This case highlights the difficulty in  choosing an optimal therapy in such specific conditions and supports the  concept of tailoring therapy (including combination regimens) on the basis of  the particular conditions of each individual patient,” they wrote.

Researchers Urge CDC to Screen More  Adults for Hepatitis B
Current U.S. Centers for Disease Control and Prevention and Public Health Service guidelines recommend that doctors screen adults  for hepatitis B only if they are from high-risk groups (including immigrants  from high prevalence areas, injecting drug users, or men who have sex with men)  that have HBV infection rates exceeding 2%.
However, an article published in the July issue  of the journal of Clinical  Infectious Diseases argues it  is cost-effective to screen nearly all adults, even those from lower-risk  populations.
Researchers factored the costs of screening and  then treating a 35-year-old man in a region with low HBV infection rate to  assess if screening would be cost effective. They evaluated the cost of not  screening the patient compared with the cost of screening, followed by  treatment.
Researchers determined that even if the  prevalence of hepatitis B was as low as 0.3%, it would still be cost-effective  to screen and treat adults, and avoid more costly treatment when the disease  has progressed, and therefore the current screening policy, “should be  reconsidered” to include a larger population.

Screening Immigrants for HBV Would  Save Lives  and Money
Current Canadian health policy does not  recommend screening immigrants for hepatitis B. Chronic hepatitis B infection  among immigrants to North America ranges from 2% to 15%. Forty percent of those  with chronic HBV infection will develop advanced liver disease.
Researchers assessed the cost effectiveness of  a variety of strategies to determine if not screening is economically  advisable.
They studied the cost effectiveness of not  screening, screening and then treating (instead of waiting for advanced liver  disease to develop), and screening, treating, and then vaccinating uninfected  family members of immigrants age 20 to 65.
They measured predicted HBV-related deaths,  cost of treatment, quality-adjusted life years, and cost effectiveness.
“Our results show that screening all immigrants  will prevent 59 HBV-related deaths per 10,000 persons screened over the  lifetime of the (group),” researchers wrote in the journal Liver International. Screening produced an increase in quality of  life and a cost savings (in avoided medical costs) of $1,665 per person when  compared with no screening.
The “screen, treat, and vaccinate” approach  initially costs the government an additional $81 per person, but it also  increases length and quality of life among those infected with HBV, and it  saves $3,648 per person, compared with the screen and treat approach.
“We show that a selective hepatitis B screening  program targeted at all immigrants in Canada is likely to be moderately  cost-effective,” they added. “Identification of silent chronic hepatitis B  infection with the offer of treatment when appropriate can extend the lives of  immigrants at reasonable cost.”

作者: hbv_warrior 时间: 2011-7-14 16:22

本帖最后由 hbv_warrior 于 2011-7-14 16:32 编辑

先来第一段：病毒载量是肝癌发生的很大因素，在11年的时间跨度中，病毒载量检测不到（文中的标准是小与10的4次方）的病人较能够检测到的病人相比得肝癌的几率小72个百分点。在检测不到病毒载量的人群中，e抗原和表面抗原的消除与否对肝癌发生率影响不大。《本人总结：降低病毒载量才是王道》

作者: lzwp 时间: 2011-7-14 21:08

看起来DNA转阴才是乙肝治疗的重中之重。

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