Increased LD1 and LD2 fractions on electrophoresis are associated with which condition?

• A. Nephrotic syndrome
• B. Hemolytic anemia
• C. Pancreatitis
• D. Hepatic damage

Answer: (B)

Lactate dehydrogenase (LDH) has several isoenzymes, and their patterns on electrophoresis reflect where LDH is released from. Red blood cells are rich in the LDH-1 and LDH-2 isoenzymes. When hemolysis occurs, these isoenzymes are released into the serum, elevating the LDH fractions that correspond to LD-1 and LD-2. In that scenario, you see increased activity in the LD-1 and LD-2 bands on electrophoresis, reflecting RBC destruction.

In contrast, liver or skeletal muscle conditions tend to raise other isoenzymes more (for example, LD-5 is more associated with hepatic and muscle involvement). So the specific rise in LD-1 and LD-2 fractions points to hemolytic processes causing red blood cell breakdown.