Which LD isoenzyme pattern is most associated with liver and skeletal muscle tissues?

Which LD isoenzyme pattern is most associated with liver and skeletal muscle tissues?

• A. LD-1 and LD-2
• B. LD-3
• C. LD-4 and LD-5
• D. LD-2 and LD-3

Answer: (C)

LDH isoenzymes come in five forms, built from different proportions of heart-type (H) and muscle-type (M) subunits. The pattern with more M subunits—LD-4 and LD-5—is characteristic of tissues like liver and skeletal muscle. That’s why seeing LD-4 and LD-5 as the predominant pattern points to liver and skeletal muscle involvement. Patterns with LD-1 and LD-2 are more associated with heart and red cells, while LD-3 has its own distribution, so they don’t fit as specifically for liver and muscle.

LDH isoenzymes come in five forms, built from different proportions of heart-type (H) and muscle-type (M) subunits. The pattern with more M subunits—LD-4 and LD-5—is characteristic of tissues like liver and skeletal muscle. That’s why seeing LD-4 and LD-5 as the predominant pattern points to liver and skeletal muscle involvement. Patterns with LD-1 and LD-2 are more associated with heart and red cells, while LD-3 has its own distribution, so they don’t fit as specifically for liver and muscle.