In a child with suspected Reye syndrome, which laboratory finding would be not consistent with the diagnosis?

In a child with suspected Reye syndrome, which laboratory finding would be not consistent with the diagnosis?

• A. Elevated serum AST
• B. Elevated serum ALT
• C. Elevated plasma ammonia
• D. Elevated serum bilirubin

Answer: (D)

In Reye syndrome, the liver injury is primarily hepatocellular and metabolic. Damaged hepatocytes release enzymes like AST and ALT, so those transaminases are elevated. The liver also fails to adequately detoxify ammonia, leading to hyperammonemia, which is a hallmark of the condition and contributes to encephalopathy. Bilirubin elevation, however, is not a prominent feature early in Reye syndrome because there isn’t a primary cholestatic process; bilirubin may remain normal or only rise mildly as the disease progresses. Therefore, elevated bilirubin would not fit the typical lab pattern of Reye syndrome, making it the not-consistent finding.

In Reye syndrome, the liver injury is primarily hepatocellular and metabolic. Damaged hepatocytes release enzymes like AST and ALT, so those transaminases are elevated. The liver also fails to adequately detoxify ammonia, leading to hyperammonemia, which is a hallmark of the condition and contributes to encephalopathy. Bilirubin elevation, however, is not a prominent feature early in Reye syndrome because there isn’t a primary cholestatic process; bilirubin may remain normal or only rise mildly as the disease progresses. Therefore, elevated bilirubin would not fit the typical lab pattern of Reye syndrome, making it the not-consistent finding.