Flow cytometric analysis of bronchoalveolar lavage and venous blood lymphocyte phenotype for the diagnosis of acute graft rejection in lung transplant patients : The Lung Transplant Group, Ospedale Maggiore di Milano

OBJECTIVE: To investigate modifications of phenotype in bronchoalveolar lavage (BAL) and venous blood lymphocytes as markers of acute organ rejection in lung transplant patients. STUDY DESIGN: Five consecutive patients receiving successful single lung transplants between March 1991 and April 1992 were followed for two years; serial bronchoscopies with BAL and transbronchial biopsies (TBBs) were performed. BAL and venous blood lymphocyte cytofluorimetry was performed at every procedure, and an index, (blood T4/T8)/(BAL T4/T8), was computed. RESULTS: The index was always > or = 3 in the two patients who did not have graft rejection and always < 3 in the two patients who had repeated episodes of acute rejection (even when no rejection was apparent). The index was frequently < 3 when cytomegalovirus infection was diagnosed. CONCLUSIONS: Since BAL is far less invasive and carries lower risks than TBB, the index might be considered, if our results are confirmed, for screening patients at high risk of acute rejection. TBB could be used as a confirmatory tool for patients who have an index < 3.