Benign monoclonal gammopathy turning to AL amyloidosis after kidney transplantation.

The fate of preexisting benign monoclonal gammopathy after organ transplantation is largely unknown. We report the case of a 47-year-old male kidney graft recipient with a pretransplantation IgG kappa monoclonal gammopathy who developed, 10 years after transplantation, de novo augloid light chain (AL) amyloidosis involving skin and kidney graft. The potential role of heavy immunosuppressive treatment in the development of this complication is discussed. The possible occurrence of AL amyloidosis should be kept in mind when a patient with benign monoclonal gammopathy is evaluated for organ transplantation, as well as when a transplanted patient with pre-existing monoclonal gammopathy develops new onset of proteinuria.