心臓臓器移植におけるAMR治療の実態とrituximab（遺伝子組換え）使用に関する全国使用実態調査の結果

抄録

【Objective】 To survey the details of treatment with rituximab for antibody-mediated rejection (AMR) after heart transplantation.

【Methods】 A retrospective study was conducted to survey outcomes in patients who underwent heart transplantation in Japan from August 2001 through December 2016 and were treated with rituximab for post-transplant AMR. A questionnaire was sent to medical institutions that have used rituximab for such treatment, and information on AMR treatment rituximab dosage, efficacy, and safety was collected.

【Results】 Three medical institutions reported a total of 4 patients (2 male and 2 female), 5 to 45 years of age at transplantation: 3 patients with dilated cardiomyopathy and 1 with a single ventricle. All had a history of blood transfusion. Records showed acute AMR in 3 cases, chronic AMR in 1 case, and T cell-mediated rejection (TCMR) as a comorbidity in 3 cases. All 4 patients tested positive for donor-specific antibodies (DSA). Two patients experienced 2nd AMRs each: 1 acute AMR and 1 suspected AMR. Rituximab was administered to both patients for the first rejection and to one patient for suspected AMR. Doses ranged from 368 mg/m² to 383 mg/m². All patients recovered from rejection and experienced successful engraftment of the transplanted organ. AMR treatments, including rituximab, were well tolerated. However, 1 of the 4 patients developed acute renal failure, pulmonary mycosis, and gastrointestinal bleeding, and eventually died from herpes zoster with a functioning graft.

【Conclusion】 Treatment containing rituximab is considered effective for AMR, but careful monitoring is required to prevent or reduce the development of infections.