Tokavanich N, Sinphurmsukskul S, Kongruttanachok N, et al. - Researchers investigated if there exists an association between circulating growth differentiation factor-15 (GDF-15) and acute cellular cardiac allograft rejection (ACR), and they intended to assess a longitudinal trend of GDF-15 following heart transplantation. Whether GDF-15 holds a prognostic value in predicting a composite outcome of severe primary graft dysfunction (PGD) and 30 day mortality following transplantation, was also inquired. Experts matched 60 post-transplant serum samples to the corresponding endomyocardial biopsies. They found a markedly increased level of circulating GDF-15 in patients with end-stage heart failure, and a fall in circulating GDF-15 level was evident post-heart transplantation. A significant link with post-transplant PGD and mortality was shown by GDF-15. Since no link was found between ACR and GDF-15, routine use of GDF-15 as a biomarker to identify ACR is thus not supported. However, the likely potential utility of GDF-15 for ascertaining heart transplant recipients at high risk for adverse post-transplant outcomes, was suggested. By assessing GDF-15 levels in recipient serum, risk stratification can be obtained for severe PGD including death during postoperative period. This novel biomarker may be beneficial for timely interventions against severe PGD and adverse results during the first 4 weeks post-transplantation.