Transcript: Hepatitis B Case Study: Lab Interpretation for New Grad NPs

​Liz Rohr:
Hepatitis B it can be super confusing, whether it's the knowing which lab to order, how to interpret them. And then, the alphabet soup that seems to appear when you look in your order set in your EHR. I'm going to be talking all about that today. So if you're new here, I'm Liz Rohr from Real World NP and you're watching NP Practice Made Simple, the weekly videos to help save you time, frustration, and help you learn faster, so you can take the best care of your patients. So, there's a whole bunch that I could say about hepatitis B, it's a really big topic. I'm focusing on the evaluation specifically related to elevated LFTs, which I talked about in this video, I'm going to link to it in the top right corner, if you want to watch that. If you haven't watched it already to go back and do that. Or watch it just when you're done here.
 

But also there's a cheat sheet down below this video that you can print out, keep at your desk to help you with interpretation. And some further resources, if you're interested in learning a little bit more. Like I said, there's a lot to say, so if you want to hear more from me, definitely leave a comment below and I'll talk a little bit more about the different scenarios of testing, and management, and all that kind of stuff.
 

Another note though is that the Lab Interpretation Crash Course for New Nurse Practitioners is opening up this month. Registration opens on January 24th, so put it on your calendar. If you want to get on the waitlist, go over to realworldnp.com/labs. And I'll send you a reminder with the link to sign up and all that information. If you're in a lab interpretation journey, definitely I'd love for you to join us. So, definitely go over to that link at realworldnp.com/labs. But without further ado, I'm going to be sharing a case study with you. And I'm going to share my screen with you.
 

All right so, jumping into the hepatitis B case study. So, this is Nisha she's 62, she's a new patient to the clinic, and this is not her real name or her photo. Although, a lovely photo. She moved here from Singapore. She's establishing care with a new PCP. She doesn't have any concerns, she just needs some refills today. Her past medical history includes hypertension, anemia, and hypothyroidism. She doesn't smoke, use alcohol or drugs, and she has no current sexual partners. So, past surgical history includes appendectomy, and she doesn't know anything about her family history. She's taking amlodipine 5 mg daily and levothyroxine 50 mcg daily. So, her blood pressure is 124/72, which is great, well controlled. Heart rate of 68 and oxygen respirate and BMI are all normal.
 

So, plan. So, I'm going to be focusing today on hepatitis B, really zooming in on this particular workup as it relates to elevated LFTs. But I'll touch on the other components of her holistic care at the end. And one other note is that there is quite a lot to say about hepatitis B, but I'm really going to be focusing on just this one particular part. So, I'm going to check her labs today, CBC, a CMP to check for signs of anemia and her kidney function, liver function, and then her TSH, because she has hypothyroidism is taking levothyroxine. And I put in parentheses HIV and hepatitis B screening because I really should have done that at the time, and I did not. And I'm going to be making a video about screening guidelines, and I'll talk a little bit more about that. But she did qualify for both of those things, and I did not order it at the first past visit.
 

So, results. So, here are her lab results. Her CBC was normal, awesome. So, she actually didn't have anemia anymore. Basic metabolic panel was normal. The TSH was normal. But here's her LFTs, the portion of the complete metabolic panel. So, albumin is normal. Alkaline phosphatase, bilirubin, and total protein are also normal. But the ALT and the AST are slightly elevated. So, the normal range is about 10 to 40 and hers is for both of them. And then, her ALT is 74, and her AST is 62.
 

So, some really important background before we jump in. I think it's really important to understand what's going on, so that you can kind of just more quickly move through the labs because you understand them versus kind of that rote memorization that comes with all the letters of the alphabet soup and the numbers. So, hepatitis B is a virus that affects liver cells. About 95% of people exposed to it and have acute infection will cure it on their own. And usually about by six months. And about 5% of those people transition into a chronic hepatitis B.
 

So 70% of acute hepatitis B is actually subclinical. So they're not symptomatic at all. And of the 30% that are symptomatic, and going back to the LFT lecture you're looking for signs of liver dysfunction, so pain, abdominal pain, jaundice, nausea, things like that. So, definitely go back and watch that video if you haven't watched it already. But about only 1% of those people that are symptomatic lead to, what's called, fulminant acute liver failure, which is great, but it still happens. So, it'd be nice to kind of prevent those with a vaccine.
 

And then, one other background thing to say is that, just going back to immunology, when viruses come into our body they have surface proteins that are called the antigens. And so, our body forms antibodies in response to that. And so, the hepatitis B virus has antigens on its surface. And then, once it gets inside the hepatocytes, the liver cells themself, there's an intracellular antigen as well called the core antigen. And that's important because that's one of the tests that we're going to be looking at. And then, antibodies are formed in response to both the surface antigen and the core antigen. And so, that's why there's so many different tests here because we're talking about surface and core when we're talking about the blood tests. And we can't measure core antigen, again, because it's inside the liver cells. And so, the only way we can look and see if there's an infected liver cell inside of its core is by looking at the antibodies that come in response to it, which is really important.
 

So, some key labs for hepatitis B, I mean really the most labs that you're going to do. I'm going to introduce them on this slide because it's kind of a lot, again, it's like an alphabet soup for a reason, it's kind of a lot. So, I'll introduce it here and then I'll walk you through kind of the ways to think about it. So, hepatitis B, I'm going to present it in a very specific way, because this is actually the order that it will become positive in your body. So surface antigen, again, if you have a virus with a protein on its surface, that's an antigen. That's going to be detectable first because our body doesn't automatically make an antibody. It takes a little bit of time. So, the surface antigen comes first and that's usually abbreviated as Hep B sAG.
 

And again, unfortunately, what it comes down to is with your lab is that it may be a little bit different, but if you understand what you're looking for you can kind of talk with your laboratory technician to kind of figure out which is the right one to order.
 

Hepatitis B core antibody. Remember, like I said, the core antigen you can't detect because it's inside of the cells. And so, the first thing you're going to look for is the core antibody. Something that your body is making in response to an actual infection within your cells. And that's usually written as an anti-HBc's, anything that's anti dash something is an antibody. So anti-HBc, there's going to be different endings, HBc, HBs, and HBe, which stick with me for a second, but surface antigen, core antibody. And then, the next thing is your surface antibody. There's some other ones that kind of come up. This is a little bit out of order, but the Hep B surface antibody is what your body makes in response to that surface antigen that's on the virus.
HBV DNA, I put this later in the list because it's not one of the first tests that you're going to order, but it comes into the algorithm. But really what that is, is looking at the actual number of virus particles that you have. So, it's going to be reported as like tens, hundreds, thousands, millions, and that's really important for management. I'm really talking about the evaluation in this video. I'm not going to be talking about management, but if you're interested in that, I'm happy to make another one specifically to kind of talk about that. Most of the management's going to be with GI, but there are some cases where you can monitor and kind of keep them in-house, but there's a little bit more involved that I want to make its own video about it.
 

So, I have this in parentheses here, Hep B e antigen and e antibody. This I don't want to confuse you, just the brief note that I'm going to make before I get into that is that it's a test that you would order if somebody had Hep B confirmed which, again, I'll get into. And that really just points to whether or not it's actively replicating or not. The antigen, again, similar. And I'll talk you through the natural course of the virus, but typically you'll have the antigen become positive, and then your body can cure it on its own with the antibody. And that will kind of help you figure out where we are in the illness. So just stick with me for a second.
 

So, the natural course of Hep B, and the reason I'm spending so much time in this kind of foundational information is because once you understand this the labs are going to be so much faster. So, the natural course of Hep B, you're exposed to the virus. So, the first available blood test that's going to change is the detection of the antigen on those cells... on the virus, rather. You'll also have the HBV DNA detectable around the same time. And this happens about four weeks on average after exposure. And these patients are not symptomatic. They just are exposed, and those things are forming, and all that. I'm really only focusing on the scenario for this particular patient. But if you were worried about a post-exposure that's kind of a different scenario.
 

But anyway, FYI, it becomes positive about a month after, on average, of getting exposed to it. So, the next stage is that they can become symptomatic, although 70% of them will never become symptomatic. So the 30% that they would be symptomatic, you would be able to see these other labs, which is nice because once they get symptomatic, you can kind of be sure that the labs that you need to order to figure things out are going to be there.
 

So, the next thing that comes positive, again because the antibodies don't get formed right away whereas the antigens are immediately detectable, is this core antibody. Again, because it's inside the cells, we can't detect that antigen, but we can get the core antibody and kind of to complicate things a little bit further there's total, and then there's the different kinds. Going back to immunology again, if you have your IgM, that's the first available. So, you're kind of like, "Where are we in this illness?" You're thinking about an IgM versus like the total or the IgG, which forms a little bit later. And so, this becomes positive around 8 to 12 weeks approximately, don't really memorize this. And actually in the cheat sheet down below this video is going to have this particular slide you can print out and just kind of reference as well because, I don't know, I think visually it helps me feel a little bit better about it.
 

So, about two to five months after they're exposed, they can become symptomatic. And then they can also have that IgM form. And the IgM actually goes away after a while because it's at first pass kind of like acute symptoms. So, if you have an IgM positive then, it's pretty consistent that it's this early on thing which, again, this will all kind of come back together in just a moment.
 

So, the next phase is about six months after exposure, or about 15 weeks after they get their symptoms, if they do they're going to clear it on their own. And what's going to happen is that that surface antigen, that first lab that you're going to have, and the HBV DNA are going to go away. And what's going to happen instead is that you're going to have the Hep B surface antibody, not the core antibody, the surface antibody that's going to take over, and the antigen is going to go away. And this, again, typically happens about six months after exposure. So, if you persistently have this about after six months, it's going to be chronic. And, again, that's about 5% of people.
 

So, the next stage is if you have chronic Hep B. So, if it hasn't cured itself, what's going to be left over is that you're going to still have surface antigen. You're going to still have core antibody because the core antibody never goes away that's there for life. The IgM goes away, but the total IgG stays for life, but you'll still have either a Hep B surface antigen and/or HPV DNA. And the caveat I have here down at the bottom, and which is why it's included in the handout if you want to print that out, is that it's kind of a lot of information, first of all, but that if you're kind of walking into this situation of like, "I don't know where we are in this illness," if somebody has Hep B, if you order the IgM, typically, that will have gone away by about six to nine-ish months. And so, if you have an IgM there of your core IgM, then you're going to be in an acute infection. So, again, this is a lot of information. It'll all come together when I walk you through it in just a sec.
 

So, let's go back to Nisha. So again, her CBC, BMP, TSH were all normal. And here are her labs. Her ALT, and her AST are just slightly elevated. And so, definitely go back and watch that slightly elevated LFT lecture that I posted a couple weeks back, because that will really kind of help clue you into what we're talking about here, because this is really just zooming in on one particular aspect of that elevated LFT workup. This is not comprehensive for LFT evaluation. This is just talking about, does this person have Hep B or not?
 

So, again, your question here is, is this Hep B and then, where in the illness is she? Is this acute? Is this in the middle? Or is this towards the end? Or is it chronic?
 

So, specifically for this scenario of somebody with elevated LFTs, again go back and watch that video if you haven't already, do they have a Hep B infection? That's your kind question. There's a couple of different ways you can order Hep B labs, whether it's for screening or if you have somebody who's acutely symptomatic that's a little bit different. But in terms of this particular scenario of slightly elevated LFTs that are generally asymptomatic, this is the approach you're going to take. So your number one question, again, do they have a Hep B infection or is this because of something else? So, the three labs are going to order, again, going back. Again, kind of being repetitive on purpose, Hep B surface antigen, that first one that's available in an infection you're going to check that.
 

Number two, you're going to check the anti-HBc, which is the core antibody. And you can check either the total or the IgM. And I don't think that there's a great way to do this either way. There aren't necessarily recommendations that I found. You can just start with the total. Again, if you're worried about somebody with acute liver symptoms, you would probably order the IgM. However, if this is kind of someone who's asymptomatic, slightly elevated LFTs just order the core antibody total because you don't even know if this person is Hep B yet, because you're going to have to order more labs than just these three.
 

So, anti-HBs, which is the surface antibody, again, that appears once the antigen goes away. And once they've cleared the infection, you're going to want to test that too because we're just kind of dropping you into the middle of evaluating this patient's illness. Where are we? You're just trying to get your bearings. So, if they have signs of infection, which I'm going to talk about and this is actually in the handout, if you haven't downloaded it already, what's kind of the positive marks, but just stick with me for a second.
 

This is the second pass of labs, if they have signs of an infection. HPV DNA, again, you're going to measure the quantity that you have, which is important for management. You're going to jump into this, if you have this available at your lab, if you don't, then you can kind of skip this and send them to G. But Hep Be antigen and anti-HBe, which is the antibody to that e antigen really speaks to if something is rapidly replicating. So, that is very expected, if it's an acute infection. But if it's a chronic infection and you still have that rapidly replicating antigen in there that's a little bit more concerning in those patients. Again, that influences who needs treatment versus who needs monitoring.
 

The other thing you want to think about, if you haven't ordered it already, is that anti-HBc IgM, which is the core antibody IgM, the first pass of an acute infection to the core antigen, to the core antibody. And then, just this is going a little bit more into heavy management, which I'm not getting super into this video, is about how is ordering a Hep C antibody and ordering an HIV antibody because those co-infections kind of are really influential in the Hep B management.
 

So, kind of going back to this really overwhelming slide, I just want to highlight again, just to reinforce what we're looking at is number one, we're looking at the Hep B surface antigen, Hep B core antibody, and then the Hep B surface antibody. And then, when we're getting it to the other things, once you've kind of determined if they're on that path of a chronic infection versus not, then you can kind of order those next fancier tests.
 

So, again, recapping one more time. So, Hep B surface antigen, core antibody and surface antibody. And so, if you have antigen positive, core antibody or core antigen positive that's signs of infection. So, you're going to do that second pass, which I already kind of mentioned. If, for example though, if you only have a positive surface antibody, but there's no antigen and there's no core antibody, then those patients are just immune from having a vaccine. So, you can just stop your work up there. However, if you have signs of active infection for all intents and purposes right now, I think depending on where you are in your practice, I recommended as a new nurse practitioner that you do these initial labs, and then you have them see GI because the management and determining who stays in primary care with monitoring versus who needs treatment is a little bit more nuanced, especially for the scope of this presentation.
 

If you're interested in learning more, there are definitely patients that I feel more comfortable with monitoring in-house. But there's just a couple more elements you need to be mindful of. If you're interested in learning more about that, definitely I'm happy to make kind of longer Hep B specific management type of video. If you're interested in that, definitely let me know, leave a comment below.
 

And then just a recap, if somebody has positive DNA and the antigen, those patients are actively replicating, whether they're acute versus chronic. And in any of these situations before, if you're hesitating with referring to GI or not, you can definitely consult with your supervisor, and they can kind of let you know what they recommend for monitoring going forward.
 

So, again, I'm going to give you the opportunity to pause if you'd like, if you want to kind of work through these labs, when I'm going to go through her labs and kind of my recommendation. So, you can hit pause if you want. So I've got her lab results here. Hep B surface antigen is positive. Again, the alphabet soup, I apologize. It's anti-HBc, which is the core antibody. So, anti meaning antibody, and then the C meaning the core. So, core antibody total is positive. On this first pass, I ordered the IgM which, again, plus or minus you could do. Anti-hepatitis B core IgM, which is the first pass of an acute infection is negative. And then, the last one is the surface antibody, which is the anti HBs or the Hep B sAB. So, sorry that's so confusing, but those are the options. And again, this is all on the cheat sheet, so you don't have to memorize these right now. And that's negative.
 

And so, depending if you've paused or not welcome back. So, again, for checking the first pass labs for this patient, again, we're walking into her labs with an elevated LFT of, "Hey, is this from Hep B or is it from something else?" And these are labs that you would do.
 

And so, number two, we have the second pass labs because this is consistent with a chronic hepatitis B because of the antigen being positive, the core being positive and the IgM is negative. And so, if the IgM is positive it would be more of an acute infection. And the fact that the surface antibody isn't there yet, it means that it hasn't quite reached that point of clearing on its own. And, again, if the IgM is already gone, then it's probably going to be a hanging on persistent infection compared to the acute ones that still could clear on their own in the next six months. So, again, that's the HBV DNA, HBe antigen, and e antibody, and then Hep C and HIV to make sure they don't have a co-infection.
 

And then kind of wrapping up with Nisha. So, she's 62, so we're concerned here about a chronic hepatitis B. And so, I'm going to refer her to GI because, again, I'm not really talking about the management in this video. I'm happy to do that, if you're interested in talking about it a little bit more. And another thing to think about, maybe I'll get into this more in the management video. But there are cases where you can kind of continue to monitor in-house and recheck these at a certain interval. But, again, I want to keep this short and sweet, so we'll leave it at that for right now.
 

Hypertension, thyroid, going back to the beginning, those are all well controlled, which is awesome. So, returning to clinic, I really leave that up to the patient. Do you want to come back in three months? Do you want to come back in six months? I'd feel comfortable with about six months. I mean, depending on the Hep B, making sure that she's kind of still getting connected with GI, and hasn't been lost to follow-up. And then, coming back for a physical exam because we haven't really talked about screening tests, vaccines, or other preventative measures because you really have to manage your time. In 15 minutes it's kind of a hard thing to address all of those things. So, again, it's kind of depending on your scheduling, and the clinic, and what her comfort level is, but I definitely want to have her come back for a full physical. We can talk a little bit more about stuff.
 

Did you like this video? If so, hit like, and subscribe. And share with your NP friends, so together we can reach as many new grads as possible to help make their transition to practice a little bit easier. And, like I said, if you want to join us for the Lab Interpretation Crash Course this month go over to realworldnp.com/labs. I'll send you all the details as they come about, and you'll also get in the loop for those fast action bonuses that are coming along with the early registration. And I hope to talk to you soon. Thank you so much again for watching. Hang in there and I'll see you soon.