Eculizumab for ATCR-associated de novo thrombotic microangiopathy in a Chinese kidney transplant recipient with type 2 diabetes: a case report.

OBJECTIVE: This study aimed to explore the efficacy of eculizumab in the treatment of newly developed thrombotic microangiopathy (TMA) associated with acute T-cell-mediated rejection (ATCR) in patients with type 2 diabetes after kidney transplantation. METHODS: New-onset thrombotic microangiopathy (TMA) after kidney transplantation is a relatively rare but serious complication that is clinically challenging to manage and requires timely intervention to prevent graft dysfunction or early graft loss. Currently, there is no consensus in clinical practice regarding the diagnosis, optimal treatment strategies, or preventive measures for post-transplant new-onset TMA. This article provides a retrospective analysis of the first case in China successfully treated with eculizumab for de novo TMA occurring in the context of acute T-cell-mediated rejection (ATCR), type 2 diabetes, and post-transplant immunosuppression. PATIENT: The patient was a 59-year-old male who underwent cadaveric donor kidney transplantation on July 31, 2024. The surgery was successful, and postoperative recovery was good. He was followed up in the outpatient department every week. On September 15, 2024, the patient experienced acute pain and swelling in the right lower abdomen, and his 24-h urine output decreased to 1,200 mL. After admission, biopsy of the transplanted kidney was performed, and severe thrombotic microangiopathy (TMA) was diagnosed. After pathological diagnosis, eculizumab was administered for 3 months (900 mg/time in the first four weeks, once a week; 1,200 mg/time from the fifth week to the 12th week, once a week). RESULTS: After eculizumab treatment, the patient's clinical symptoms improved significantly. Laboratory indicators, such as platelet count, lactate dehydrogenase (LDH), and serum creatinine (SCr) gradually returned to normal. During the 9-month follow-up after the last dose, the SCr level remained stable at 180 μmol/L, with no recurrence of thrombotic microangiopathy (TMA) and no signs of proteinuria were observed. CONCLUSION: Eculizumab is effective in treating new-onset ATCR-related TMA in patients with type 2 diabetes after kidney transplantation, and treatment should be initiated immediately after diagnosis.