A spike of alpha-2 macroglobulin (A2) is most characteristic of which condition?

• A. Nephrotic syndrome
• B. Acute hepatitis
• C. Iron-deficiency anemia
• D. Chronic liver disease

Answer: (A)

In nephrotic syndrome, massive loss of albumin in the urine lowers plasma oncotic pressure, and the liver compensates by increasing the production of several plasma proteins. Alpha-2 macroglobulin is a large protease inhibitor made by the liver, and its serum level rises as part of this hepatic response, often producing a noticeable spike in the alpha-2 globulin region on serum protein electrophoresis. This pattern is more characteristic of nephrotic syndrome than of acute hepatitis (where multiple acute-phase proteins may rise but not show a prominent alpha-2 macroglobulin spike), iron-deficiency anemia (no such specific shift), or chronic liver disease (overall protein synthesis tends to fall).