In the diagnosis of ACS, we have definite bio markers for acute MI . Further, ECG has a good spcecificity for STEMI . While ,clinical and ECG features of ischemia are not perfect. A bio marker for ischemia is the ultimate dream of cardiologists and emergency room physicians. . In this context , the IMA -ischemia modifed albumin has come with great expectation .
Ischemia modifies what ?
Normal albumin moleule has a metal binding site (Copper ) .There are few free binding sites available .During ischemia this metal binding capacity reduces . A cobalt containing reagent when added to ischemic blood finds binding sites scarce , and hence excess free cobalt will color the sample and a posiitve test for ischemia is diagnosed.
*Normal human albumin may contain 2% of ischmia modifed albumin which is expected to increase up to 6% during ischemia
IMA raises not only during ischemia it can also raise during oxidative stress
- Chronic kidney disease
- liver disease,
It can also be elevated following
- Routine coronary angiogram
- DC shock
Increased lactic acid for example in sepsis may reduce the IMA level and can miss an episode of true ischemia
IMA can be a useful tool to identify ischemia early .But lacks senstiivty . New improved immunoassays may be more sensitive and specific