Occurrence of gammopathies and lymphoproliferative disorders in liver transplant recipients randomized to tacrolimus (FK506)- or cyclosporine-based immunosuppression

Lymphoproliferative disorders (LPDs) are a serious side effect of immunosuppression after liver transplantation, and the introduction on the market of a new immunosuppressive drug has been associated with an increased risk of these disorders, To compare the effect of cyclosporine A (CSA) and FK506 in a clinical setting, the incidence of monoclonal or oligoclonal gammopathies known to often precede the appearance of LPDs was evaluated, A total of 88 adult patients was analyzed, 46 were prospectively randomized to CSA and 42 to FK506 for immunosuppression. None of these patients had gammopathy before transplantation. All the patients were tested for immunoglobulin abnormalities five to nine times during a period of 1 year and then two to four times per year thereafter from December 1990 until March 1997, The same incidence of serum immunoglobulin (Ig) abnormalities was observed in both groups (13%) with a mean delay of appearance of 11.1 +/- 5.9 versus 7.6 +/- 3.6 months for CSA and FK506, respectively (P > .05). In each group, the gammopathies were transient in 3 patients and persisted in 2, The class of Ig involved was IgG, and a monoclonal component was documented in 2 patients treated with CSA and in 3 patients with FK506, One patient treated with FK506 developed an LPD localized to the lymph nodes 8 months after the occurrence of serum protein abnormalities, The lymphoproliferative lesions subsequently disappeared with the reduction of immunosuppression. In this study, an immunosuppressive regimen of FK506 has not shown an increased incidence of lymphoproliferation compared with CSA in adult liver transplant patients. Copyright (C) 1998 by the American Association for the Study of Liver Diseases.