Successful multidisciplinary treatment of refractory cytomegalovirus infection after living donor liver transplantation using mixed lymphocyte reactions: report of a case.

A 52-year-old Japanese male underwent ABO-incompatible living donor liver transplantation for acute-on-chronic hepatitis B infection. Fifty-one months later, he became feverish and a cytomegalovirus (CMV) infection was diagnosed. A dramatically high CMV pp65 antigen (C10/C11) load (2,412) was measured, which did not respond to ganciclovir and immune globulin treatment, and increased further to 5,353. The next treatment strategy was the reduction of immunosuppressants, but to simply reduce immunosuppressants can lead to graft loss. Therefore, before using this strategy, responses to alloantigens were evaluated using a carboxyfluorescein-diacetate-succimidyl ester-labeled mixed lymphocyte reaction (CFSE-MLR). Only limited CD4(+) and CD8(+) T-cell proliferation was observed, suggesting the patient was hyporesponsive. After reducing tacrolimus levels from 3-4 ng/mL to <1.5-1.8 ng/mL, the fever dropped immediately and C10/C11 disappeared after 2 months. In conclusion, CFSE-MLR could be a useful tool for the treatment of refractory infectious disease after transplantation and, importantly, for checking a patient's immunosuppressive state beyond the perioperative period.