What can cause increases in serum Alkaline Phosphatase (ALP) concentration?

What can cause increases in serum Alkaline Phosphatase (ALP) concentration?

• A. Decreased hepatic clearance due to kidney disease.
• B. ALP is unaffected by corticosteroids.
• C. Increased production induced by corticosteroids and bone growth.
• D. ALP increases only with liver disease.

Answer: (C)

Serum alkaline phosphatase rises when production by ALP-producing tissues increases, especially in bone. Bone-forming cells (osteoblasts) make more ALP during periods of rapid bone growth, remodeling, or healing. Corticosteroids can stimulate osteoblast activity, boosting ALP production in bone. So the combination of increased bone growth and corticosteroid exposure leads to higher ALP levels. This explains why ALP can rise in growing individuals and with corticosteroid use, independent of liver disease or changes in clearance. The other ideas don’t fit as well: kidney disease isn’t a primary driver of ALP via hepatic clearance, and saying corticosteroids don’t affect ALP contradicts what happens at the tissue level. ALP can be elevated in liver disease as well, but the best-reasoned mechanism for the stated scenario is increased production in bone from growth and corticosteroids.

Serum alkaline phosphatase rises when production by ALP-producing tissues increases, especially in bone. Bone-forming cells (osteoblasts) make more ALP during periods of rapid bone growth, remodeling, or healing. Corticosteroids can stimulate osteoblast activity, boosting ALP production in bone. So the combination of increased bone growth and corticosteroid exposure leads to higher ALP levels.

This explains why ALP can rise in growing individuals and with corticosteroid use, independent of liver disease or changes in clearance. The other ideas don’t fit as well: kidney disease isn’t a primary driver of ALP via hepatic clearance, and saying corticosteroids don’t affect ALP contradicts what happens at the tissue level. ALP can be elevated in liver disease as well, but the best-reasoned mechanism for the stated scenario is increased production in bone from growth and corticosteroids.