Clinical History:
- A 35-year-old woman has had increasing malaise for the past week. She has noted that her skin has a yellowish color. She has nausea and sometimes vomits up what she has just eaten. Laboratory testing reveals a normal CBC. Serum chemistries shows sodium 141 mmol/L, potssium 4.2 mmol/L, chloride 90 mmol/L, CO2 28 mmol/L, creatinine 0.7 mg/dL, urea nitrogen 13 mg/dL, glucose 70 mg/dL, total protein 5.8 g/dL, albumin 3.3 g/dL, alkaline phosphatase 39 U/L, AST 578 U/L, ALT 613 U/L, total bilirubin 7.2 mg/dL, and direct bilirubin 4.8 mg/dL. Serologic testing showed hepatitis A virus positive, hepatitis B virus negative, and hepatitis C virus negative.
- What form of cellular injury is occuring here?
There is individual cell necrosis, or apoptosis, as a result of viral infection with hepatitis A virus.
- Explain the physical and laboratory findings.
She has icterus as a result of the increased serum bilirubin. The direct and indirect bilirubin are both increased as a result of injury to hepatocytes. The AST and ALT are increased because of necrosis of liver cells. Decreased liver function has decreased the serum albumin. The serologies indicate infection with hepatitis A, which tends to be a more acute infection, typically foodborne, than hepatitis B or C.
- What is the outcome for this illness?
Virtually everyone recovers from hepatitis A. A very few people develop a fulminant hepatitis with extensive necrosis of liver.
- How can you tell if the serology indicates a recent or remote event?
The first antibody response to infection is production of mainly IgM antibodies. In a couple of weeks, mainly IgG antibodies are produced. Thus, acute infections can be determined if mainly IgM antibody is present. In this case, the HAV-IgM (hepatitis A virus IgM component) would be positive. If just HAV-IgG were present, then this would indicate past infection. For more chronic, slowly developing infections like hepatitis B or C, it is unlikely that an IgM component will be found, and just the IgG is measured. In the case of hepatitis C, only the antigen can be detected at present by current laboratory tests.
- What agency needs to be notified of this event?
The state and/or local health department needs to be notified of infections that have a potential public health implication. There is a list of such infections that physicians must report. Since hepatitis A is often foodborne, then an investigation needs to be performed to determine if control measures need to be taken (e.g., if the infection originated in a restaurant).
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