Thrombotic microangiopathy and cytomegalovirus in liver transplant recipients: a case-based review.

BACKGROUND

Thrombotic microangiopathy (TMA) is a rare but potentially lethal complication encountered in solid organ and bone marrow transplant recipients, requiring rapid recognition, diagnosis, and initiation of therapy. Several potential causes have been identified in this setting, including viral infections and medications.

METHODS

We report a case of TMA in a liver transplant recipient with active cytomegalovirus (CMV) gastritis. A 41-year-old female presented 3 months after liver transplantation with a 5-week history of nausea, vomiting, anorexia, and diarrhea. CMV serology was donor seropositive and recipient seronegative (D+/R-). The immunosuppressive regimen consisted of tacrolimus, mycophenolate mofetil, and prednisone. Evaluation revealed CMV viremia with a high viral load and intravenous ganciclovir was started. A decline in hemoglobin and platelets with an increase in lactate dehydrogenase (LDH) warranted hematologic evaluation, which revealed findings consistent with microangiopathic hemolytic anemia. Ganciclovir and tacrolimus were discontinued. Intravenous immunoglobulin was administered and daily plasmapheresis was initiated. As the patient's blood counts and LDH started to improve, ganciclovir was cautiously reinstituted. The patient's gastrointestinal symptoms gradually resolved and her blood counts continued to improve with prolonged plasmapheresis (a total of 23 plasmapheresis sessions). Tacrolimus and possibly CMV infection were suspected to be the cause for her TMA, and cyclosporine was substituted.

CONCLUSIONS

TMA is an important entity in the differential diagnosis of acute hemolytic anemia in liver transplant recipients. Many cases seem to be medication-induced. However, in treatment-resistant or relapsing cases, a possibility of concomitant CMV infection should be considered.