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ghlester wrote: > We have been working up Abbott AxSYM Troponin I assay for introduction into > routine service. Presently we do Vitros total CK with AxSYM CK-MB mass in > selected cases by special request. We have been doing TnI on these CK-MBs > in parallel. Findings reinforce the paper in Feb 99 Clinical Chemistry but > we came across this case which has puzzeled us. Does anyone have any > experience to throw light on the situation? > > A 93 year old lady admitted via A&E (ER for colleagues in US) with history > of "fall, collapsed, low temperatue ?cause". > > Admission: CK 1372 iu/L (Ref Range < 135) > CK-MB 131 ug/L ( < 7.0 ) > TnI 0.2 ug/L > > 9 hours later: CK 794 > CK-MB 68.4 > TnI 0.2 > Trop T 0.02 ug/L ( < 0.10 ) > Non-specific ECG changes were noted. > > 35 hours later: CK 428 > CK-MB 22.9 > TnI 0.1 > > Do the AxSYM CK-MB or TnI assay suffer HMMA effects? Results of CK > isoenzymes by electrophoresis are awaited. > > Thanks > > Geoff Lester > Chemical Pathology Department > Frenchay Hospital > BRISTOL UK. > [log in to unmask] For what it is worth, there was a 2 week long exchange of postings on MEDLAB-L regarding the problems of heterophile antibodies and cardiac markers, especially on the AxSym. In case you don't routinely read that list, I am quoting the letters below. Were it just the immunoassay parameters (CKMB, TnI) which were elevated, I could assume that you were dealing with a heterophile antibody. I recall seeing a report of heterophile interference in a patient with elevated rheumatoid factor. But the elevated total CK on the Vitros confuses the issue, particularly since we are dealiing with an elderly female, with typically low muscle mass, and the %RI (ratio of CKMB to tCK) is in the 5-10% range which is well above the levels I would associate with skeletal muscle. Do you have any further information? Hope the attached may be useful. maurice green, phd clinical chemist stanford hospital palo alto, ca [log in to unmask]