ABSTRACT
Therapy of acute rejection episodes involves augmenting immune suppression. The first episode is usually treated with intravenous methylprednisolone, 1 g/day for 3 days. Mild episodes may be treated with oral prednisone, typically starting with 100 mg and decreasing by 10 mg/day until the previous maintenance dose is reached. A follow-up transbronchial biopsy should be performed 2 -6 weeks after completion of therapy. This is crucial, since persistent or recurrent rejection was detected in 63% of recipients who were deemed to have responded to previous therapy on the basis of clinical evaluation alone. The second episode is also usually treated with intravenous corticosteroids. Treat ment of subsequent episodes varies from center to center and includes polyclonal horse antihuman lymphocyte globulin (ATGAM) or murine OKT3 monoclonal antibody, plas mapheresis, photopheresis, and total lymphoid irradiation. In addition to such augmen tation, tacrolimus may be substituted for cyclosporine and methotrexate for azathioprine. Regional immune suppression with an aerosol of cyclosporine has also proved effective. Refractory rejection occurs in only 10-15% of recipients, but successful management is crucial, since afflicted recipients appear to be at the highest risk for contracting chronic rejection or losing the allograft to persistent rejection, which is not uncommonly fatal. Prophylaxis for CMV should be given during treatment of subsequent episodes of acute rejection, particularly for recipients who receive cytolytic therapy and are at risk for a primary infection or those who have already manifested CMV disease. Antibacterial pro phylaxis should also be considered for those recipients being treated for recurrent rejection who have had bacterial pneumonia in the allograft and are colonized with potential patho gens such as P. aeruginosa and Staphylococcus aureus.
