实验室检查乙型肝炎病毒感染

StephenW

Laboratory tests for Hepatitis B infection

May 14, 2016 the sangai express 38 0 0


Different laboratory tests can diagnose hepatitis B virus (HBV) infection and monitor people with chronic hepatitis B. Hepatitis B is first diagnosed using a blood test that looks for certain antigens (fragments of HBV) and antibodies (produced by the immune system in response to HBV). Initial blood tests to diagnose HBV infection look for one antigen, HBsAg (hepatitis B surface antigen), and two antibodies, anti-HBs (antibodies to the HBV surface antigen) and anti-HBc (antibodies to HBV core antigen).
Actually, two types of anti-HBc antibodies are produced: immunoglobulin M (IgM) antibodies and immunoglobulin G (IgG) antibodies. IgM antibodies are produced early in the course of infection. IgG antibodies are produced later in the course of infection and replace IgM antibodies.
Depending on the results of the above tests, additional diagnostic tests may be necessary. Somebody who has never been infected with HBV or has been vaccinated against the virus does not require any additional testing. Someone who was recently infected with HBV and has acute hepatitis B may want to get another blood test after six months have passed to make sure that the necessary immune response has occurred. People with chronic HBV infection require additional testing to learn more about their hepatitis B.
Additional tests
HBeAg and anti-HBe: HBeAg is the hepatitis B envelope antigen, and anti-HBe are the antibodies produced against this antigen. If HBeAg is detectable in a blood sample, this means that the virus is still active in the liver (and can be transmitted to others). If HBeAg is negative and anti-Hbe is positive, this generally means that the virus is inactive. However, in some people with chronic hepatitis – specially those who have been infected with HBV for many years – may have what is known as a “precore” or “core variant” mutated form of HBV. This can cause HBeAg to be negative and anti-HBe to be positive, even though the virus is still active in the liver.
HBV viral load: This test measures the actual amount of HBV in a blood sample, which helps determine whether HBV is reproducing in the liver. In a person with detectable HBeAg, an HBV viral load greater than 20,000 international units per millilitre (IU/mL) of blood indicates that the virus is active and has the greatest potential to cause damage to the liver. Similarly, in a person with an active HBeAg-negative chronic hepatitis B, an HBV viral load of greater than 2,000 IU/mL indicates that the virus is active and has potential to cause damage to the liver. Measurement of HBV viral load is of help in monitoring of treatment response.
Liver Function Tests: One of the most important liver enzymes to look for is alanine aminotransferase (ALT), sometimes called SGPT on lab reports. An elevated ALT level indicates that the liver is not functioning properly and that there is a risk of permanent liver damage. During acute hepatitis B infection, ALT levels can be temporarily elevated, but this rarely leads to long-term liver problems. In chronic hepatitis B, ALT levels can be either periodically or consistently increased, indicating a higher risk of long-term liver damage.
HBV genotype: HBV genotypes and subgenotypes have been associated with differences in clinical and virological characteristics, indicating that they may play a role in the virus-host relationship. The HBV genotype appears to influence not only the natural history of HBV related liver disease but also the response to HBV treatment. HBV genotype also determine the treatment regime and duration of treatment.
Imaging: HBV infection is a known cause of liver cancer. Magnetic resonance imaging (MRI) and “triple-phase” computed tomography (CT or CAT) scans are becoming more common, less painful tests to look for changes in the liver, most notably liver cancer.
Some experts suggest that MRI and triple-phase CT scans are the best way to look for tumours in people who have cirrhosis of the liver.
Ultrasound: Like MRI and CT scans, ultrasound can be used to look for liver cancer tumours. Some experts suggest that ultrasound is an effective screening tool in people who do not have cirrhosis of the liver.
Fibroscan: Fibroscan, also called transient elastography, is a technique used to assess liver stiffness (measured in kPa correlated to fibrosis) without invasive investigation. The result shows the condition of the liver and allows physicians to diagnose and monitor disease evolution in conjunction with treatment and other factors. It helps to anticipate various complications, as well as assess and monitor the damage caused by complications such as cirrhosis.
Liver biopsy: Sometimes a liver biopsy may be needed to look for evidence of cirrhosis and liver cancer.
(The writer is Junior Microbiologist, BABINA Diagnostics, Imphal)

Tags: Sh.Nilica Devi

StephenW

实验室检查乙型肝炎病毒感染

5月14日，2016年sangai表达38 0 0


不同的实验室试验可以诊断乙型肝炎病毒（HBV）感染和监测慢性乙型肝炎乙型肝炎的人使用血液检查看起来对某些抗原（乙型肝炎病毒的片段）和抗体（通过免疫系统响应于所产生的第一个诊断HBV）。初始血液测试来诊断HBV感染外表为一种抗原，乙肝表面抗原（乙型肝炎表面抗原），和两种抗体，抗HBs（抗体与HBV表面抗原）和抗-HBc（抗体HBV核心抗原）。
实际上，产生两种类型的抗-HBc抗体：免疫球蛋白M（IgM抗体）的抗体和免疫球蛋白G（IgG）的抗体。 IgM抗体在感染过程早期产生的。 IgG抗体稍后在感染过程中产生的，并更换IgM抗体。
根据上述试验的结果，额外的诊断测试可能是必要的。谁从未感染HBV或已接种病毒的人不需要任何额外的测试。有人谁最近被感染HBV并有急性乙肝可能希望得到另一个验血后，半年过去了，以确保发生必要的免疫反应。慢性HBV感染者需要额外的测试，以了解他们的乙型肝炎
附加测试
HBeAg和抗-HBe：e抗原是乙型肝炎包膜抗原和抗-HBe是针对该抗原产生的抗体。如果e抗原是血液样品中检测到，这意味着该病毒仍然活跃在肝脏（和可以传送给其他）。如果e抗原是阴性和抗HBe是肯定的，这通常意味着该病毒是不活动的。然而，在一些人的慢性肝炎 - 特别是那些谁曾感染过乙肝病毒多年 - 可能有什么是被称为“前C区”或“核心变种”乙肝病毒变异形式。这可能会导致的HBeAg为阴性和抗HBe为阳性，即使该病毒仍然在肝脏活性。
乙肝病毒载量：该试验测量血液样品，这有助于确定HBV是否在肝再生中的HBV的实际量。在具有可检测的HBeAg一个人，一个HBV病毒负荷的血液每毫升大于20,000国际单位（IU /毫升），表示该病毒是活性，并具有最大的潜力以致使所述肝脏损害。同样，在用活性HBeAg阴性慢性乙型肝炎的人，大于2000国际单位/毫升的HBV病毒负荷表明病毒是活性，并具有潜在的引起对肝脏的损伤。 HBV病毒负荷的测量是在治疗反应监测帮助。
肝功能检查：其中最重要的肝酶找的是谷丙转氨酶（ALT），有时也被称为对实验报告SGPT。一个ALT升高水平表明肝脏不正常，并且有永久性肝脏损伤的风险。在急性乙型肝炎感染，ALT水平可以暂时升高，但这种情况极少导致长期肝问题。在慢性乙型肝炎，ALT水平可以是周期性地或持续增加，这表明了长期的肝损伤的风险较高。
HBV基因型：HBV基因型和亚型已在临床和病毒学特性的差异相关，这表明它们可能在病毒 - 宿主关系发挥作用。该HBV基因型似乎影响不仅HBV相关性肝脏疾病的自然史也给乙肝治疗的反应。 HBV基因型也确定治疗方案和治疗的持续时间。
影像学检查：乙肝病毒感染是肝癌的病因不明。磁共振成像（MRI）和“三阶段”计算机断层扫描（CT或CAT）扫描正在变得越来越普遍，痛苦少测试，以寻找在肝脏，最值得注意的是肝癌的变化。
一些专家建议，MRI和三期CT扫描，以寻找在谁拥有肝硬化人肿瘤的最佳方式。
超声：像MRI和CT扫描，超声波可用于寻找肝癌肿瘤。一些专家认为，超声波是在没有肝硬化的人谁一种有效的筛选工具。
Fibroscan的：Fibroscan的，也被称为瞬时弹性，是用于评估肝脏硬度的技术，而不侵入调查（以kPa测量相关的纤维化）。结果表明肝脏的状态，并允许医生诊断和监测与治疗和其他因素结合疾病演变。它有助于预见各种并发症，以及评估和监测所引起的并发症如肝硬化的损害。
肝活检：有时肝活检可能需要寻找肝硬化和肝癌的证据。
（作者是小型微生物学家，巴比纳诊断，英帕尔）

标签：Sh.Nilica德维