Fatty-acid-binding protein as a plasma marker for the estimation of myocardial infarct size in humans.
BACKGROUND
There are substantial amounts of cytoplasmic heart-type fatty-acid-binding protein (FABP) (15 kDa) in myocardial tissue. The rapid release of FABP into plasma during ischaemia indicates the possibility of using this protein as a biochemical marker for ischaemic myocardial injury.


OBJECTIVE
To study the completeness of the release of FABP from damaged tissue in patients with acute myocardial infarction (AMI) and the suitability of serial plasma FABP concentrations for estimation of myocardial infarct size.


METHODS
Immunochemically assayed FABP and enzymatically assayed creatine kinase isoenzyme MB (CK-MB) and alpha-hydroxybutyrate dehydrogenase (HBDH) were determined serially in plasma samples from 49 patients with AMI who had been treated with thrombolytic agents within six hours after the onset of AMI. Previously validated circulatory models and a value of 2.6 h-1 for the fractional clearance rate of FABP from plasma were used to calculate cumulative protein release into plasma.


RESULTS
Release of FABP was completed earlier (24-36 h) after AMI than that of CK-MB (50-70 h) and that of HBDH (> 70 h). However, infarct size estimated from the cumulative release of the proteins and expressed as gram equivalents of healthy myocardium per litre of plasma yielded a comparable value of 4-6 for both FABP and the two enzymes.


CONCLUSIONS
The data indicate that FABP released from the heart after AMI is quantitatively recovered in plasma and that FABP is a useful biochemical plasma marker for the estimation of myocardial infarct size in humans.
Glatz
J F
JF
Department of Physiology, University of Limburg, Maastricht, The Netherlands.
Kleine
A H
AH
van Nieuwenhoven
F A
FA
Hermens
W T
WT
van Dieijen-Visser
M P
MP
van der Vusse
G J
GJ
D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D002352:Carrier Proteins / Q000032:analysis / Q000097:blood*; D003402:Creatine Kinase / Q000097:blood; D000071438:Fatty Acid-Binding Protein 7; D050556:Fatty Acid-Binding Proteins; D005227:Fatty Acids / Q000097:blood*; D005260:Female; D006801:Humans; D006884:Hydroxybutyrate Dehydrogenase / Q000097:blood; D007527:Isoenzymes; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood / Q000473:pathology*; D009206:Myocardium / Q000737:chemistry; D009363:Neoplasm Proteins; D012016:Reference Values; D025521:Tumor Suppressor Proteins
D015415:Biomarkers; D002352:Carrier Proteins; C107608:FABP7 protein, human; D000071438:Fatty Acid-Binding Protein 7; D050556:Fatty Acid-Binding Proteins; D005227:Fatty Acids; D007527:Isoenzymes; D009363:Neoplasm Proteins; D025521:Tumor Suppressor Proteins; D006884:Hydroxybutyrate Dehydrogenase; D003402:Creatine Kinase