Diagnosis of Hepatitis B Virus Infection (HBV) and Interpretation of HBV Serology

00:01 As I've told you, what our focus would be here with Hepatitides of viral type will be diagnosis.

00:08 Let’s begin.

00:11 Now we will move on to hepatitis B. As you can notice on this slide, the X axis represents the time after the exposure to the virus, while the Y axis depicts the titer of the antigens and the antibodies that occur in response to infection. The first antigen to rise in hepatitis B infection is the hepatitis B surface antigen (HBsAg). This usually appears one month after exposure to the virus, sometimes even before the development of symptoms. HBV DNA can usually be detected during the same period as you can see on the graph.

00:46 The hepatitis B e antigen (HBeAg) will most likely be positive in patients suffering from acute hepatitis B.

00:54 When positive, this indicates greater risk of transmissibility of the virus. Anti-HBe represents the antibody against the hepatitis B e antigen and, when it appears, it is an indicator of low infectivity.

01:09 Another important antigen is the hepatitis core antigen (HBcAg). This is not depicted on the graph, because this antigen is not detected in the blood of patients with hepatitis B.

01:21 What we can detect though is the antibody against this antigen, called anti-HBc (IgM or IgG). The IgM antibody against the core antigen usually appears with the onset of symptoms.

01:35 While the IgM antibody levels fall, the IgG antibody is indefinitely positive in individuals with past hepatitis B infection.

01:45 The antibody against the surface antigen (anti-HBs) appears weeks after the disappearance of the surface antigen. The period between the disappearance of the surface antigen and the appearance of the antibody against the surface antigen is called ’’the window period’’. During this period, only the antibodies against the core antigen can be found in the blood.

02:12 Interpretation of your table here.

02:14 This is once again for your hepatitis B specifically.

02:18 That’s your topic for the entire table.

02:20 and on the top are the different types of components of Hepatitis B depending on what's going on in your patient.

02:27 Let's begin with the interpretation at the far end of the table, And your focus would be acute infection or perhaps, reactivation.

02:37 So which one of these markers are you going to find? Early, acute.

02:42 Hepatitis B surface antigen I told you, shows up quite early in the symptomatic period.

02:47 Anti-HBS, no. Negative. That shows up later on.

02:51 In order for this table to make perfect sense, I recommend that you take a look back at the graph that we've just discussed.

02:58 So that you have a visualization, As to the journey or the time course of hepatitis B.

03:03 And you also have a table in which it speaks to And then listen to me, so that we can all reinforce this information And at some point in time, I'll come back to you, very quickly.

03:15 We have anti-hepatitis B core IgM.

03:19 IgM is the first immunoglobulin to show up thus, positive and acute.

03:25 And we have hepatitis B-E antigen this DNA if all possible, you'll find this very early early early.

03:31 This represents acute.

03:33 Understood? Let's go on to prior infection with immunity.

03:40 If you're thinking about prior infection, what kind of immunoglobulin should you be jumping to Good. IgG.

03:48 You will notice here that Anti-HBc IgG is possible.

03:52 That’s where your focus should be in, prior infection. Why why why? Anytime there is prior infection, the type of immunoglobulin that all you then are going to have chronically, will be IgG.

04:02 Obviously anti-HBs would be positive.

04:05 HBE may or may not be found but your focus here should be on IgG.

04:10 What about vaccination with immunity? Well, with immunity and vaccination, we still might find anti-HBs way down the line.

04:18 That that represents vaccination.

04:21 Let's do chronic HBV, this is a carrier patient; carrier.

04:29 So, what is the patient now carrying? It will be HBs as you can expect.

04:36 What kind of immunoglobulin It would be IgG.

04:41 Hepatitis B and carrier you will notice, you have anti-HBe Here the viral account for HBV DNA will less than 20,000 but not as high as you find in an acute, it is still present, why? Your patient is state of chronic carrier state.

05:03 Next, we have e Anti-positive chronic hepatitis B In this thing here is dangerous, dangerous.

05:09 You find a couple things here.

05:11 Your focus should be once again IgG, hepatitis B surface antigen same on which you found earlier with chronic carriers.

05:18 Here there is going to be e Antigen present but this is difficult.

05:21 For the patient and for you because you have a great number of HBV DNA.

05:28 Active? Extremely. Chronic? Yes.

05:34 e Antigen not good in terms of whether or not the patient is able to pass it on to, his or her partner.

05:41 And finally, we have e Antigen negative, chronic Hepatitis B, anything that you find here, is the fact that you have anti HBVe At this point is e Antigen negative.

05:54 In terms of viral count it will still be greater than 20,000.

05:59 Interpretation is where your focus will be at first, then you take a look at the various markers, we interpet as such, and then go back and take a look at the graph so that you will be able to understand the timeline.