Painful crural ulcerations and proteinuria as complications after several years of therapy with mTOR inhibitors in the renal allograft recipient: a case report.

Abstract Background Proliferation signal inhibitors (mammalian target of rapamycin [mTOR]) are a class of immunosuppressive drugs with a new mechanism of action and safety profile, different form calcineurin inhibitors. However, their use is limited because of an high incidence of adverse reactions, the majority of which occur within the first 6 months after commencing treatment. In this paper, we report a patient with substantial proteinuria and painful crural ulcerations that appeared after a few years of mTOR inhibitor therapy and necessitated their withdrawal. Case Report A 43-year-old man who received a cadaveric kidney was converted to sirolimus from cyclosporine after being diagnosed with adenocarcinoma and carcinoma clarocellulare of his own removed cystic kidney. After 5.5 years of fairly good tolerance of the treatment, proteinuria and painful crural ulcerations appeared. Because of the progressive character of the adverse reactions and no satisfactory results of the applied treatment, mTOR therapy was discontinued. Proteinuria was reduced, pain improved, and the ulcerations healed. Conclusions This case report indicates that adverse reactions may develop as a result of mTOR inhibitor use even after many years of good tolerance of the drug and they may necessitate its withdrawal.