An elevated ALP with normal bilirubin is most consistent with which factors?

An elevated ALP with normal bilirubin is most consistent with which factors?

• A. Liver cholestasis
• B. Kidney disease
• C. Bone growth or turnover; age (children or pregnancy) or bone disease
• D. Muscle injury

Answer: (C)

Alkaline phosphatase comes from several tissues, mainly bone and liver. When ALP is elevated but bilirubin is normal, the rise is most consistent with bone activity rather than liver disease. This situation fits scenarios of active bone growth or turnover—such as in children, pregnancy, or certain bone disorders where osteoblasts are highly active. In liver cholestasis, you’d expect ALP to rise alongside bilirubin and often with a rise in GGT, signaling a hepatobiliary source. Kidney disease isn’t a typical driver of a prominent ALP elevation, and muscle injury tends to elevate enzymes like CK and AST rather than ALP.

Alkaline phosphatase comes from several tissues, mainly bone and liver. When ALP is elevated but bilirubin is normal, the rise is most consistent with bone activity rather than liver disease. This situation fits scenarios of active bone growth or turnover—such as in children, pregnancy, or certain bone disorders where osteoblasts are highly active. In liver cholestasis, you’d expect ALP to rise alongside bilirubin and often with a rise in GGT, signaling a hepatobiliary source. Kidney disease isn’t a typical driver of a prominent ALP elevation, and muscle injury tends to elevate enzymes like CK and AST rather than ALP.