Tocilizumab for treatment of chronic active antibody‐mediated rejection in kidney transplant recipients

Background The optimal treatment for chronic active antibody‐mediated rejection (ca‐AMR) remains unclear. Tocilizumab (TCZ), a monoclonal antibody against IL‐6, has been proposed as a therapeutic option. We reported our experience treating ca‐AMR with TCZ either as the first line option or as a rescue therapy. Methods We studied 11 adult kidney transplant recipients with biopsy‐proven ca‐AMR and preserved kidney function (eGFR 57 ± 18) who were treated with TCZ (8 mg/kg IV monthly). All biopsies were prompted by abnormal surveillance biomarker testing with DSA and/or dd‐cfDNA. Clinical monitoring included dd‐cfDNA and DSA testing every 3 months during the treatment with TCZ. Results In this cohort, ca‐AMR was diagnosed at a median of 90 months (range 14–224) post‐transplant, and 4 of 11 patients had DSA negative ca‐AMR. Patients received a minimum of 3 months of TCZ, with 6 patients receiving at least 12 months of TCZ. Dd‐cfDNA was elevated in all patients, with a median 2.24% at the start of TCZ treatment. After 6 months of TCZ treatment, 8/11 patients had dd‐ cfDNA