Hepatitis C: Clinical sciences

Hepatitis C virus, or HCV for short, is a bloodborne viral infection that’s typically transmitted through contaminated blood, or sexual contact. Once inside the body, hepatitis C virus circulates through the blood, eventually reaching the liver, where it infects hepatocytes. Acute hepatitis C infections are usually asymptomatic, but if the virus sticks around long enough in the body, acute infection can progress to chronic infection, which can lead to the development of cirrhosis, and even hepatocellular carcinoma.

Now, if you suspect hepatitis C infection, first perform an ABCDE assessment to determine if your patient is unstable or stable.

If unstable, your patient may present with alarming signs and symptoms, such as altered mental status, asterixis, upper GI hemorrhage, and ascites. In this case, immediately stabilize their airway, breathing, and circulation. Next, obtain IV access and put your patient on continuous vital sign monitoring, including blood pressure, heart rate, and pulse oximetry.

Here’s a clinical pearl to keep in mind! These findings can be seen in individuals with fulminant hepatitis, often referred to as acute liver failure, which is most often caused by viral hepatitis or acetaminophen overdose. Lab findings suggestive of fulminant hepatitis include elevated transaminases like AST and ALT, as well as elevated PT/INR and serum bilirubin. It’s important to recognize these patients on time, and once stable, refer them to a liver transplant center for further management!

Ok, let’s go back to the ABCDE assessment and take a look at stable individuals.

If the patient is instead stable, obtain a focused history and physical examination. History typically reveals symptoms such as fatigue, anorexia, low-grade fever, as well as nausea and vomiting. Additionally, your patient might report right upper quadrant abdominal pain and difficulty sleeping.

Finally, history might be positive for IV substance use, needlestick injury, sexual intercourse without protection, or receiving a non-sterile tattoo.

On the other hand, physical exam typically reveals jaundice and abdominal tenderness, while sometimes you might notice inflammatory skin changes, like psoriasis or urticaria, as well as signs consistent with thrombocytopenia, such as petechiae.

Your next step is to order labs, such as CMP, PT/INR, and PTT, which may reveal either elevated or normal AST and ALT, bilirubin, PT/INR, and PTT. These lab findings, in combination with your patient’s signs and symptoms, should lead you to suspect hepatitis C infection. Keep in mind that many patients with HCV are asymptomatic, so they may come to clinical attention on routine lab evaluation.

Let’s look at patients with positive HCV antibody tests.

Once you suspect hepatitis C infection, you should order an HCV antibody test to determine whether or not your patient has HCV antibodies. If the HCV antibody test is positive, obtain an HCV RNA test to assess the viral load, or in other words, how much of the HCV is in the patient’s blood. As a side note, many labs will reflexively send the HCV RNA test if the HCV antibody is positive. So, if the HCV RNA test does not detect viral load, assess for risk factors, such as a history of HCV exposure in the last 6 months or history of immunocompromised status.

Now, here’s a clinical pearl to keep in mind! Patients that are HCV antibody positive with undetectable HCV RNA levels may have three possible clinical scenarios. Firstly, they might have been infected but cleared the infection spontaneously. Secondly, they may have had an HCV infection that was already treated with antiviral medication. And thirdly, the patient’s antibody test may be a false positive; in this case, if your suspicion is high based on clinical presentation, you should repeat HCV antibody test and order HCV RNA test within 6 months to rule out or confirm the diagnosis.

So back to assessing risk factors, no known exposure to the virus and no history of immunocompromised state mean that you should consider alternative diagnoses. However, if your patient reports HCV exposure or is immunocompromised, then you should repeat the HCV RNA test 6 months after the initial testing. If the HCV RNA test does not detect viral load after 6 months, you should consider alternative diagnoses. On the other hand, if the HCV RNA test detects viral load, you can confirm the diagnosis of acute or chronic hepatitis C.