Thrombotic Microangiopathy (TMA) in a Heart Transplant Patient: A Complex Clinical-Pathologic Dilemma

Drug-induced thrombotic microangiopathy is a rare cause of microangiopathic hemolytic anemia. Tacrolimus is a commonly used immunosuppressive agent postorgan transplant. Due to life-threatening complications associated with microangiopathic hemolytic anemia, it is essential to have a high clinical suspicion for this drug-induced microangiopathy. Here, we present a case of suspected drug-induced thrombotic microangiopathy secondary to long-term tacrolimus use. Although it is difficult to entirely exclude alternative causes of TMA when presented with this rare pathology, clinicians must remain vigilant of this association with tacrolimus use when there is a high suspicion for TMA. To date, few case reports have highlighted this association with chronic calcineurin use. Our case highlights the need for further research into this association.