ABSTRACT
Acute cellular rejection (ACR) is a common complication occurring in 30% to 90% of patients during the first year following transplantation (1-12). Indeed, ACR occurs with much greater frequency in lung allografts when compared to all other solid organ transplants. Why lung allografts are more susceptible to ACR is not entirely clear, although it is speculated that lung tissue is more immunogenic. Furthermore, it is likely that nonalloimmune injury to the graft via inhalation of toxic substances or infectious agents may expose targets and or upregulate the immune system to attack. Although most cases of ACR are readily treatable with transient augmented immunosuppression, the long-term implication of ACR may be extremely important. In numerous studies, ACR has been identified as the major risk factor for bronchiolitis obliterans syndrome (BOS), the clinical hallmark of chronic allograft dysfunction and the leading cause of long-term morbidity and mortality after the first year following lung transplantation (1,13-18).
PART VIII: LUNG ALLOGRAFT REJECTION
