Myeloperoxidase and carbonyl proteins: promising markers for non-invasive monitoring of graft rejection after heart transplantation.
BACKGROUND
After heart transplantation (HTx), endomyocardial biopsy (EMB) is currently the standard method to diagnose acute graft rejection. A non-invasive marker of rejection would be desirable as an alternative or to permit more selective use of the costly and invasive EMB.


METHODS
In this retrospective study, outcomes of routinely taken EMBs were used to select 28 patients after HTx EMB Grade 0R (8 patients), 1R (9 patients) or 2R (11 patients). For these patients, myeloperoxidase (MPO) and carbonyl proteins (CP) in serum were measured using enzyme-linked immunoassay (ELISA).


RESULTS
MPO and CP levels in post-HTx patients with Grade 2R rejection were significantly (MPO: p < 0.01; CP: p < 0.001) elevated at the time of rejection compared with levels 1 month earlier. MPO and CP levels predicted Grade 2R rejection and the best cut-off point was 237.5 μg/l for MPO and 222.5 pmol/mg for CP, respectively. Clinically most important was the marked increase (doubling of basic values within 1 month) of MPO and CP levels in cases of Grade 2R rejection in post-HTx patients.


CONCLUSIONS
MPO and CP seem to be appropriate parameters to monitor rejection events non-invasively and to minimize the application of EMBs after HTx.
Koestenbauer
Sonja
S
Department of Surgery, Division of Transplantation Surgery, Medical University of Graz, Graz, Austria. sonja.koestenbauer@medunigraz.at
Stiegler
Philipp
P
Stadlbauer
Vanessa
V
Mayrhauser
Ursula
U
Leber
Bettina
B
Schweiger
Martin
M
Wasler
Andrae
A
Prenner
Günther
G
Sereinigg
Michael
M
Zelzer
Sieglinde
S
Stojakovic
Tatjana
T
Scarpatetti
Michael
M
Griesbacher
Antonia
A
Greilberger
Joachim
J
Tscheliessnigg
Karlheinz
K
D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D001706:Biopsy / Q000379:methods; D002097:C-Reactive Protein / Q000032:analysis*; D005260:Female; D006084:Graft Rejection / Q000097:blood / Q000175:diagnosis* / Q000201:enzymology; D016027:Heart Transplantation; D006801:Humans; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000473:pathology; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D010446:Peptide Fragments / Q000097:blood*; D009195:Peroxidase / Q000097:blood*; D011237:Predictive Value of Tests; D050050:Protein Carbonylation; D012189:Retrospective Studies
D015415:Biomarkers; D010446:Peptide Fragments; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain; D002097:C-Reactive Protein; D009195:Peroxidase