RESUMO
The aim of this study was to evaluate the incidence of postoperative lymphocytotoxic antibodies (LA) formation and to assess their potential utility in immunologic monitoring after lung transplantation. We determined prospectively the percentage LA against a reference panel reactive antibody in a complement-dependent microlymphocytotoxicity test in 137 sequential serum samples obtained from 14 consecutive lung transplant recipients who survived over the first postoperative year. Four patients developed high titers of LA (greater than 10% panel reactive antibody reactivity in at least 3 consecutive samples) by 2 to 24 months after surgery. Antibodies were mostly immunoglobulin M isotype, without any specificity against the donor's human leukocyte antigen and were correlated with the development of bronchiolitis obliterans syndrome (p=.01) and with chronic bronchial infectious colonization (p=.03). In conclusion, a polyclonal immunoglobulin M antibody production can be detected in serum samples from lung transplant recipients and seems to be involved in the progression of chronic rejection process. These preliminary results incline to carry on the cytotoxicity screening of a panel of lymphocytes to better understand the significance of such reactivity.