[Biomarker for diagnosis of rejection after heart transplantation]

Heart transplantation is an established therapeutic modality in patients with end-stage heart failure. In the 1st year after transplantation acute cellular rejection is still important. The diagnosis of acute cellular rejection is based on the histological evaluation of endomyocardial biopsy (EMB) specimens. EMB is an invasive procedure with a definite risk and poor tolerance in some patients. Imaging methods like echocardiography and magnetic resonance imaging as well as intracardiac ECG have been used for noninvasive diagnosis of acute cellular rejection. In addition, a large number of circulating biomarkers have been evaluated for noninvasive diagnosis of rejection. B-type natriuretic peptide, troponin and inflammatory markers are the most important biomarkers in this field. Although these parameters are useful, none of them has the potential to replace EMB as the gold standard for diagnosis of rejection. In the near future microarray technology might get important for diagnosis of acute cellular rejection. Using microarray technique gene expression profiles can be detected, which are associated with an increased risk for rejection. Ongoing studies will demonstrate, whether microarrays can at least reduce the number of EMBs.