Clinicopathological Analysis of Immunologically High-Risk Kidney Transplantation Using High-Dose Intravenous...

High-dose intravenous immunoglobulin (H-IVIg) has been used as a desensitization therapy for donor-specific anti-HLA antibody (DSA)-positive kidney transplant recipients in Japan since 2019. This study reports the clinical and pathological outcomes of patients who received H-IVIg at Sapporo City General Hospital.

This study included 7 patients who underwent kidney transplantation at our hospital and received H-IVIg as pretransplant desensitization therapy. At our institution, H-IVIg is indicated for patients with a history of sensitization, such as prior blood transfusion, pregnancy, or organ transplantation, and who tested positive in a flow cytometry crossmatch (FCXM) before transplantation. The recipients (mean age: 55.2 ± 11 years) included one male and six females. The donors (mean age: 62.8 ± 8.8 years) included five males and two females. All were living donor transplants, with four cases involving spousal donation. We assessed the immunological status before and after desensitization and retrospectively analyzed kidney function, anti-donor antibody status, and pathological findings.

Before desensitization, 6 patients were FCXM-T positive, and all were FCXM-B positive. After desensitization, 3 patients converted to FCXM-T negative; however, all remained FCXM-B positive. The Luminex single antigen test was positive in 4 patients before desensitization; one converted to negative, while one initially negative patient became positive. Consequently, 4 patients remained DSA positive at transplantation. Three patients experienced acute rejection within 1 month: one had antibody-mediated rejection (ABMR), and two had T-cell-mediated rejection. All patients responded to antirejection therapy, preserving their graft function. At 36 months of follow-up, all the patients survived with functional grafts. Pathological findings revealed early rejection in 3 patients, who later developed chronic ABMR. The remaining 4 patients did not experience rejection episodes.

The H-IVIg regimen facilitates kidney transplantation in immunologically high-risk recipients. However, the risk of early postoperative rejection and the potential development of chronic ABMR necessitate careful posttransplant monitoring.