Pathophysiology
Clinical meaning
Lipase and amylase are pancreatic enzymes released into the serum when acinar cells are damaged, making them the primary biochemical markers for acute pancreatitis. Understanding their characteristics, diagnostic performance, and clinical contexts is essential for the NP. Lipase is produced almost exclusively by the pancreas (with minor amounts from gastric, pharyngeal, and lingual sources). It hydrolyzes triglycerides into fatty acids and glycerol. In acute pancreatitis, lipase rises within 4-8 hours, peaks at 24-48 hours, and remains elevated for 8-14 days due to its slower renal clearance and longer half-life. Lipase is the PREFERRED diagnostic marker for acute pancreatitis because of its superior sensitivity (85-100%), superior specificity for pancreatic origin, and longer window of detection compared to amylase. Amylase is produced by both the pancreas (P-amylase isoenzyme) and the salivary glands (S-amylase isoenzyme). Serum amylase rises within 6-12 hours of acute pancreatitis onset, peaks at 48 hours, and returns to normal within 3-5 days. Its utility is limited by lower specificity (non-pancreatic sources include salivary glands, fallopian tubes, lungs, and small intestine) and shorter elevation window. Conditions causing elevated amylase without...