Orthotopic heart transplant rejection in association with immunomodulatory therapy for AL amyloidosis: A case series and review of the literature.

Although end-organ damage caused by AL amyloidosis historically portends a poor prognosis, advances in therapy in combination with solid organ transplantation can lead to significant improvements in survival. Immunomodulatory agents (IMiDs), such as lenalidomide and pomalidomide, are an effective class of drugs in the treatment of AL amyloidosis. However, there is growing concern that these agents may precipitate acute transplant rejection via upregulation of interleukin-2 and inhibition of immune tolerance. This case series describes three patients who underwent orthotopic heart transplantation for AL amyloidosis and later had progression of their underlying plasma cell dyscrasia, leading to treatment with IMiD therapy. Two patients subsequently developed acute allograft rejection, including the first reported case of pomalidomide-associated allograft rejection. The third patient tolerated long-term therapy without signs of rejection: the first reported case of IMiD tolerability after heart transplant. These cases, together with a review of the literature, demonstrate variable outcomes and elucidate the potential risk of organ rejection associated with the use of IMiDs. When treatment with IMiDs is necessary, close surveillance and modification of immunosuppression may mitigate risks of rejection and complications.