Which best explains “Flipping effect”?

Which best explains “Flipping effect”?
a) LDH 1 > LDH 2
b) LDH2 > LDH1
c) LDH 2 > LDH 3
d) LDH 3 > LDH 2
Correct Answer - A
Answer: A - LDH 1 > LDH 2
Lactate dehydrogenase, tetrameric enzyme with 4 subunits,
4 Subunits with 2 isoforms - H isoform (Heart) & M isoform
(Muscle)
Heart & RBCs - LDH-1 (4H);
Reticuloendothelial system - LDH-2 (3H1M)
Lungs - LDH-3 (2H2M)
Kidneys, placenta, & pancreas - LDH-4 (1H3M)
Liver & striated muscle - LDH-5 (4M)
Uses:
LDH levels are more in RBC
Helpful in assessment of Hemolysis / Tissue breakdown
Flipping effect:
Usually LDH 2 in predominant in serum & LDH 1 is predominant in
heart
Higher levels of LDH 1 than LDH 2 (Flipped pattern) is suggestive of
myocardial infarction
Damaged cardiac tissues release LDH 1 into bloodstream.