Is Mycophenolate Mofetil Better Than Azathioprine in Organ Transplantation?

McNeil and coworkers have to be congratulated for their important paper just published in Transplantation (1) showing no differences in the incidence of bronchiolitis obliterans in de novo lung transplant recipients randomized to mycophenolate mofetil (MMF) or azathioprine (AZA) in combination with induction therapy, cyclosporine, and corticosteroids. In the paper, they stated that “These results are at variance with the results of the studies in other solid organ transplant scenarios. The use of MMF in kidney transplantation has been associated with a clear benefit in terms of reducing acute rejection rates, while in heart transplantation a reduction in the manifestation of so called chronic rejection was seen in MMF-treated patients. Not all of these studies, however, have been prospective, randomized, controlled trials analyzed according to intention to treat.” This beautifully depicts the current scenario and again stresses the importance of their study. It is important, however, that the authors acknowledge a study published in the Lancet (2), which is indeed prospective, randomized, and, according to intention-to-treat analysis, shows a similar incidence of acute rejections episodes in 334 recipients of cadaver-kidney transplants over six-month treatment with MMF or AZA along with cyclosporine microemulsion and steroids (Phase A) and over 15 more months without steroids (Phase B). This paper, which actually was the first to show no differences between AZA and MMF in organ transplantation, is absolutely in line with McNeil's findings and supports their conclusions. Piero Ruggenenti Giuseppe Remuzzi Department of Medicine and Transplantation Azienda Ospedaliera Ospedali Riuniti and Mario Negri Institute for Pharmacological Research Bergamo, Italy