Hello
There have been a few publications recently on the subject of Troponin T
elevations in polymyositis and other chronic muscle diseases which should
alleviate the confusion:
White, Clin Chem 47 :6 1130-1131 (2001) and
Hammerer-Lercher Clin Chem 47:3 451-458 (2001).
In both of these articles the authors correctly interpret Troponin T
elevations as indicative of minor myocardial damage.
Additionally, biochemical studies have proven that any cTnT isoforms
expressed in regenerating muscle are NOT detected by the commerically
available TnT assay.
Please see Richiutti Clin Chem 44:9 1919-1924 (1998) and the above article
by Hammerer-Lercher.
Cardiac Troponin T elevations, as detected by the commerical TnT assay,
originate from the heart and indicate myocardial necrosis. When these
elevations appear in conjunction with ischemic symptoms, an MI is indicated
according to the ACC/ESC consensus document. Many other chronic conditions
with myocardial involvement can cause elevations of Troponin T. Some of
these are given in Jaffe , Circulation, 102: 1216-1220 (200) To
discriminate between ischemic and chronic mechanisms of injury, serial
measurements of Troponin T are helpful (an increase in TnT over a 4-6 hour
time frame is consistent with an ischemic mechanism of injury). Troponin
elevations should always be interpreted in conjunction with clinical
symptoms.
------ACB discussion List Information--------
This is an open discussion list for the academic and clinical
community working in clinical biochemistry.
Please note, archived messages are public and can be viewed
via the internet. Views expressed are those of the individual and
they are responsible for all message content.
ACB Web Site
http://www.acb.org.uk
List Archives
http://www.jiscmail.ac.uk/lists/ACB-CLIN-CHEM-GEN.html
List Instructions (How to leave etc.)
http://www.jiscmail.ac.uk/
|