2250 An Unusual Case of Elevated AFP in a Patient With Chronic Hepatitis B

Abstract

INTRODUCTION: Alpha-fetoprotein (AFP) is commonly used as a screening tool for hepatocellular carcinoma (HCC) among at-risk populations. It is, however, not specific for HCC detection. In addition, the assays can generate false-positive and false-negative AFP results. This case illustrated the dilemma and uncertainties of the AFP results. CASE DESCRIPTION/METHODS: The patient is a 50-year-old Chinese female with stable HBeAg negative chronic hepatitis B and was antiviral treatment naïve. She was first noted to have an asymptomatic elevation of AFP to 1,156ng/ml when she had her tests performed in a new clinic. Initial abdominal MRI did not reveal focal hepatic lesion. The patient was extremely depressed and anxious about the AFP result. She had a suicide attempt and was briefly hospitalized. One month later, she was evaluated at our Liver Center and her AFP remained high at 1,028ng/ml (Roche Assay). MRI of the abdomen and pelvic reported only a 6mm hepatic hemangioma. Other causes of elevated AFP such as embryonic cancers and pregnancy were ruled out. Interestingly, her same day blood sample yielded a normal AFP value of 3ng/ml by the Wako Assay performed in Quest Diagnostic. Over the course of 36 months, her abdominal imaging remained unremarkable and ALT levels were stable. At each follow-up visit, AFP was concurrently tested by both Roche and Wako assay platforms. The discrepant results between the 2 assays persisted after complete HBV DNA suppression by antiviral therapy (Figure 1). With time, the patient gained back confidence with her health and returned to work even though the AFP dilemma continued. We further evaluated her stored samples by 3 other assay platforms (Abbott, Beckman, and Siemens) and they again yielded discordant results (Table 1). Assay interference was systematically evaluated by various local and national laboratories. Presence of heterophilic antibodies most likely explained the elevated AFP values but they could not be confirmed definitively in this case. DISCUSSION: There are a number of lessons to learn from this unusual case of elevated AFP. While diagnostic assays are valuable for medical practice, they have limitations. It is important to understand the potential false- positive and false-negative values of a given test. In this case, it has been very informative to apply multiple assay platforms to unmask the discordant results. That was tremendously helpful to lessen the patient’s anxiety and to prevent unnecessary medical evaluations and procedures.