Recurrent treatment of refractory acute cellular rejection with alemtuzumab after lung transplantation.

We present an exceptional case of a lung transplant recipient successfully treated by multiple courses of alemtuzumab for refractory acute cellular rejection (ACR). The patient experienced multiple episodes of ACR following the transplantation procedure. Alemtuzumab was initiated as a third-line rejection treatment and was repeated 6 times. Each treatment course resulted in complete recovery of the pulmonary function and depletion of T- and B-lymphocytes and natural killer cells (NK cells). The onset of rejection was consistently preceded by the recovery of NK cells, while T- and B-lymphocytes remained depleted. This suggests a rejection process mediated by NK cells. This case contributes to recent research findings suggesting that NK cells play a significant role in ACR in lung transplant recipients and stresses the importance to further investigate the role of NK cells in rejection. Furthermore, it demonstrates that ACR following lung transplantation can be repeatedly managed by treatment with alemtuzumab.