A 45 days old infant shows development of icterus and two days' later symptoms and signs of acute liver failure appeared. Child was found to be +ve for HbsAg. The mother was also HbsAg carrier. The mother's hepatitis B serological profile is likely to be:

1. A

   HbAg and Ab +ve

2. B

   HbsAg and anti Hbe Ab +-ve

3. C

   HbsAg +ve only

4. D

   Mother infected with mutant HBV

Appeared in: AIIMS Nagpur NO- 2020

Explanation

• The infant's rapid progression to acute liver failure is a hallmark of fulminant hepatitis, a rare but severe outcome of perinatal HBV transmission.
• Fulminant hepatitis in infants is strongly associated with infection by specific HBV variants, known as precore or core promoter mutants.
• These mutant strains are often unable to produce HBeAg. The lack of HBeAg exposure in utero is thought to prevent the development of immune tolerance in the infant.
• Consequently, the infant's immune system mounts a massive, uncontrolled attack on infected liver cells post-birth, leading to widespread necrosis and liver failure.

Why Other Options Were Wrong

• Option A: This option states the mother is positive for both Hepatitis B surface antigen (HBsAg) and its corresponding antibody (anti-HBs). This is serologically contradictory and impossible, as the antibody would neutralize the antigen.
• Option B: This profile (HBsAg positive, anti-HBe positive) is common in inactive chronic carriers or those with HBeAg-negative chronic hepatitis. While the mother with a mutant strain would have this profile, this option only describes the serological state without identifying the underlying cause of the infant's severe disease. 'Mother infected with mutant HBV' is a more specific and explanatory answer.
• Option C: This is an incomplete serological profile. While the mother is HBsAg positive, this information alone is insufficient to explain the severe clinical course in her infant. It doesn't provide any detail about the virus's replicative status or potential for virulence.

Related Visual

Clinical Relevance

• Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Perinatal transmission of Hepatitis B and the clinical significance of mutant HBV strains as background academic context rather than a clinical decision trigger.
• This case highlights the critical importance of universal screening for HBsAg in all pregnant women to identify those at risk of transmitting HBV to their infants.
• For infants born to HBsAg-positive mothers, timely administration of Hepatitis B immune globulin (HBIG) and the first dose of the hepatitis B vaccine within 12 hours of birth is a crucial nursing responsibility to prevent transmission.
• Nurses must be vigilant in monitoring infants of HBsAg-positive mothers for signs of liver dysfunction, such as jaundice (icterus), poor feeding, and lethargy, as this could indicate immunoprophylaxis failure and fulminant hepatitis.

How to Approach the Question

• First, analyze the clinical scenario presented in the question stem. Identify the patient (45-day-old infant) and the key clinical findings (icterus, acute liver failure).
• Note the relevant history: the infant is HBsAg positive, and the mother is an HBsAg carrier. This establishes perinatal transmission.
• Focus on the most unusual and severe aspect of the case: acute liver failure. A typical perinatal infection leads to a chronic carrier state, not fulminant hepatitis.
• Evaluate the options in the context of what could cause such a severe outcome. The question is asking for the most likely explanation for this severity.
• Eliminate option A as serologically impossible. Eliminate option C as incomplete.
• Compare options B and D. While a mother with a mutant strain would be anti-HBe positive (Option B), Option D (infection with a mutant HBV) provides the direct cause for the virulence and severe disease in the infant, making it the most specific and correct answer.

Concept Tested & Keywords

• Concept Tested: Perinatal transmission of Hepatitis B and the clinical significance of mutant HBV strains.
• Stem keywords: 45 days old infant, icterus, acute liver failure, HbsAg, mother HbsAg carrier
• Lead-in keywords: likely to be
• Clinical cues: The development of acute liver failure in a very young infant is the key clinical cue, pointing towards a highly virulent or aggressive form of infection rather than a typical chronic carrier state.

Question ID

QsqmwkWBmicU8jkuw5Ljna

Copy ID

Reference Book

E6 Nelson Textbook of Pediatrics(2024) — Volume 2 p. 247-249

E6 Medicine Harrison 22e Part 2 p. 550-552