Fig. 2

The clinical course of case 2. We present the clinical course of one HTLV-1-positive recipient (case 2) who underwent renal transplantation from an HTLV-1-negative donor at our hospital (Table 3, Fig. 2A and B). In September 2018, a 75-year-old female case with nephrosclerosis underwent a living kidney transplant from her husband, who had an HLA mismatch and blood type incompatibility. Immunosuppressive therapy to prevent kidney transplantation was administered using FK. Regarding FK trough concentration in PB just prior to develop ATL, the blood levels of FK in the renal transplant recipient (case 2) were 5.7 ng/mL (FK 2.5 mg per day). FK withdrawal was performed from 2.5 mg per day to 1.5 mg per day. In December 2021, the patient showed high levels of LDH and sIL-2R, and systemic lymphadenopathy in the left cervical, mediastinal, and abdominal LNs on CT. Bone marrow examination revealed 25% large abnormal cells. Abnormal lymphocytes in the bone marrow showed an unusual phenotype of CyCD3 + CD3-4 + 8 + 30 + 25- on FCM. Furthermore, Southern blot analysis showed the monoclonal proliferation of ATL cells (Fig. 2A). Thus, the patient was diagnosed with an acute-type ATL. Consequently, the patient developed ATL 3 years and 3 months after the renal transplantation. The patient showed poor PS, ADL, and organ impairment (Fig. 2B). Regarding the treatment for ATL after renal transplantation, the patient was treated with tapering of FK and PSL therapy. However, the patient presented with MOF. Unfortunately, the patient died at day 5 after ATL diagnosis. A BM findings, FCM findings, Southern blot analysis and radiological findings (Case 2). B Clinical course of ATL development after renal transplantation (HTLV-1 carrier → Acute-type ATL) (Case 2)