# A nurse is assessing a 35-year-old patient who presents to the emergency department with a 2-week history of fatigue, nausea, and abdominal discomfort, reports recent unprotected sexual contact, and has no history of hepatitis vaccination. Which assessment finding would be most indicative of acute hepatitis B infection?

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## 문제

A nurse is assessing a 35-year-old patient who presents to the emergency department with a 2-week history of fatigue, nausea, and abdominal discomfort, reports recent unprotected sexual contact, and has no history of hepatitis vaccination. Which assessment finding would be most indicative of acute hepatitis B infection?

A 35-year-old patient presents to the emergency department with a 2-week history of fatigue, nausea, and abdominal discomfort. The patient reports recent unprotected sexual contact and has no history of hepatitis vaccination.

## 보기

1. Elevated serum alanine aminotransferase (ALT) levels with presence of hepatitis B surface antigen (HBsAg) **✔ 정답**
2. Presence of hepatitis B surface antibody (anti-HBs) with normal liver enzymes
3. Elevated bilirubin levels with presence of hepatitis B core antibody IgG (anti-HBc IgG) only
4. Normal ALT levels with presence of hepatitis B e antigen (HBeAg) only

**정답: 1**

## 해설

Elevated ALT levels with presence of HBsAg best indicate acute hepatitis B infection, as ALT reflects liver inflammation and HBsAg indicates active viral replication. Other options show immunity, past infection, or lack of liver damage, which are not specific to acute infection.

## 심화 해설

Understanding the Clinical Scenario

A 35-year-old patient presents with a 2-week history of fatigue, nausea, and abdominal discomfort, which are classic prodromal symptoms of acute hepatitis. The risk factor of recent unprotected sexual contact and lack of hepatitis B vaccination strongly elevates the suspicion for an acute hepatitis B virus (HBV) infection. The diagnostic goal is to identify serologic markers that confirm an active, acute infection.

Why Option 1 is Correct

The combination of an elevated serum alanine aminotransferase (ALT) level and the presence of hepatitis B surface antigen (HBsAg) is the hallmark of acute hepatitis B infection. HBsAg is a protein on the surface of the virus and is the first serologic marker to appear, detectable within 1 to 10 weeks after exposure. Its presence indicates active viral replication and ongoing infection. The elevation in ALT, a liver enzyme released into the bloodstream when hepatocytes are injured, provides the biochemical evidence of the hepatic inflammation and parenchymal injury that characterize the condition. As noted in the provided rationale, acute HBV infection is clinically characterized by hepatic inflammation and parenchymal injury [1]. This pairing of a positive viral antigen with evidence of liver cell damage is the most direct and specific indicator of an acute infection.

Analysis of Incorrect Options

- **Option 2:** The presence of hepatitis B surface antibody (anti-HBs) with normal liver enzymes indicates immunity, not an active infection. Anti-HBs is the antibody that neutralizes the virus and provides long-term protection. It appears after the resolution of an infection or following successful vaccination. Since this patient has no vaccination history and is symptomatic, this finding would suggest a past, resolved infection, not the current acute episode.

- **Option 3:** An elevated bilirubin level with hepatitis B core antibody IgG (anti-HBc IgG) only is a complex picture. Anti-HBc IgG signifies past or chronic infection. During the "window period" of an acute infection, when HBsAg has disappeared but anti-HBs has not yet appeared, anti-HBc IgM would be the key marker, not IgG alone. The presence of anti-HBc IgG without HBsAg or anti-HBs is an atypical profile that requires further evaluation but does not serve as the primary indicator of a new, acute infection.

- **Option 4:** Normal ALT levels with the presence of hepatitis B e antigen (HBeAg) only is inconsistent with acute hepatitis. HBeAg is a marker of high viral replication and infectivity, but it is found in conjunction with HBsAg. Its presence without HBsAg is not a standard diagnostic pattern. More importantly, normal ALT levels would contradict the clinical presentation of symptomatic acute hepatitis, which, by definition, involves hepatic inflammation and injury [1].

Connecting to the Rationale and Clinical Practice

The provided rationale emphasizes that acute HBV infection is a systemic process marked by hepatic inflammation [1]. This directly supports why an elevated ALT is a non-negotiable part of the diagnosis. The virus's impact is not limited to the liver; it can cause systemic effects, including bone marrow suppression, which is a critical clinical consideration. The case report discusses how HBV can reduce peripheral blood cell counts via suppressing bone marrow hematopoiesis, leading to severe complications like agranulocytosis [1]. This underscores the importance of a thorough assessment beyond liver enzymes. For the NCLEX-RN, understanding this link is vital. When you see a positive HBsAg and elevated ALT, your nursing assessment must expand to monitor for signs of systemic complications, including bleeding, infection risk from neutropenia, and changes in mental status from hepatic encephalopathy. The diagnosis of acute hepatitis B is not just about the liver; it is about recognizing a systemic viral infection that requires comprehensive patient monitoring and education on transmission prevention.

References (research sources)

- [1]A case report of agranulocytosis caused by acute hepatitis B virus infection.Case reportLiang Q, Tang K, Jiao W, Yuan Y, Lu X, Wang H. (2026) · DOI: 10.1097/md.0000000000047479

## 임상 시나리오

Clinical Interpretation of Acute Hepatitis B Serology

When evaluating a patient with suspected acute hepatitis B, the most direct diagnostic approach is to correlate serologic markers with biochemical evidence of liver injury. The hallmark of acute infection is the detection of hepatitis B surface antigen (HBsAg) in serum, which appears 1–10 weeks after exposure and precedes symptom onset. This must be paired with an elevated alanine aminotransferase (ALT) level, confirming hepatocyte damage. A typical ALT elevation in acute viral hepatitis exceeds 10 times the upper limit of normal, often peaking above 1000 IU/L.

During the window period (after HBsAg clears but before anti-HBs appears), IgM anti-HBc may be the only detectable marker. Anti-HBs alone with normal ALT indicates resolved infection or vaccination. Isolated anti-HBc IgG suggests past exposure. HBeAg is a marker of high viral replication and infectivity but is not used alone for initial diagnosis. In high-risk patients with prodromal symptoms, prompt serologic testing guides isolation precautions and consideration of antiviral therapy if severe or prolonged.

Nursing priorities include monitoring for complications such as fulminant hepatitis, coagulopathy, and encephalopathy, while providing supportive care and education on transmission prevention.

## 핵심 개념

- **HBsAg** — Hepatitis B surface antigen; a viral protein detectable early in acute infection, indicating active viral replication.
- **ALT** — Alanine aminotransferase; a liver enzyme elevated in serum due to hepatocyte injury, indicating hepatic inflammation.
- **anti-HBs** — Hepatitis B surface antibody; its presence typically indicates resolved infection or immunity from vaccination.
- **anti-HBc IgG** — Hepatitis B core antibody IgG; a marker of past or chronic infection, not solely diagnostic for the acute phase.
- **HBeAg** — Hepatitis B e antigen; a marker of high viral replication and infectivity, often present in acute and some chronic infections.

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