MYCOPHENOLATE-MOFETIL VERSUS AZATHIOPRINE IMMUNOSUPPRESSIVE REGIMENS AFTER LUNG TRANSPLANTATION - PRELIMINARY EXPERIENCE

Background: Mycophenolate mofetil reduces episodes of biopsy-proven ac ute cellular rejection or treatment failure in the first year after ki dney transplantation; however, limited data exist regarding the effica cy after lung transplantation. Methods: In a 2-center, nonrandomized c oncurrent cohort study (level III evidence), we analyzed the incidence of biopsy-proven acute cellular rejection (International Society for Heart and Lung Transplantation grade greater than or equal to A2) and decrement in pulmonary function during the first 12 months after succe ssful lung transplantation. All patients received induction immunosupp ression with antithymocyte globulin (less than or equal to 5 days' dur ation), cyclosporine and prednisone, in addition to either mycophenola te mofetil (2.0 g/d) [n = 11] or azathioprine (1 to 2 mg/kg per day) [ n = 11]. Results: During the first 12 months after lung transplantatio n the mycophenolate mofetil group experienced significantly fewer epis odes of acute cellular rejection than the azathioprine group (0.26 +/- 0.34 vs 0.72 +/- 0.43 episodes/100 patient-days [mean +/- SD], p < 0. 01; 95% CI for the difference = 0.126 to 0.813). The change in forced expiratory volume -1 second [Delta FEV1] (liters) between the 3rd and 12th months after lung transplantation was analyzed for the two treatm ent groups. For this interval, Delta FEV1 for the mycophenolate mofeti l group was +0.158 +/- 0.497 L vs -0.281 +/- 0.406 L for the azathiopr ine group (p < 0.05; 95% CI for difference = +0.0356 to 0.843). During the first year, there was 1 death in each group attributed to bronchi olitis obliterans syndrome with concurrent pneumonia. There were no di fferences in incidence of cytomegalovirus or bacterial infections betw een the treatment groups; however, a higher prevalence of aspergillus sp airway colonization in bronchoalveolar lavage fluid was observed fo r the mycophenolate mofetil group (p <.05). The prevalence of bronchio litis obliterans syndrome at 12 months was 36% for the azathioprine gr oup vs 18% for the mycophenolate mofetil group (p = NS). Conclusions: Our preliminary experience with mycophenolate mofetil after lung trans plantation suggests a decreased incidence of biopsy-proven acute cellu lar rejection. Furthermore, less decline in FEV1 after 12 months may s uggest a reduced incidence or delayed onset for development of bronchi olitis obliterans syndrome. Prospective randomized trials with low bet a error (level I evidence) should be performed to assess the efficacy of mycophenolate mofetil vis-a-vis acute allograft rejection and bronc hiolitis obliterans syndrome.