For decades, the human being leukocyte antigen (HLA) complex has been considered the primary target of antibody-mediated rejection (AMR), and treatment strategies have mainly focused on anti-HLA antibodies. transplant in 2007. The donor and the recipient were blood group compatible with a 5 ABDRDQ-HLA-antigen mismatch. Pre-transplant panel reactivity antibody and direct microcytotoxicity cross-match were bad. For baseline immunosuppression, the patient received basiliximab, tacrolimus, enteric-coated mycophenolate sodium, and steroids. Postopera-tive program and follow up were uneventful. Seven years after transplantation, the patient was hospitalized with worsening graft function and low calcineurin inhibitor Celecoxib levels (Table 1), reflecting occasional non-compliance with immunosuppressants. Antibody screening showed anti-HLA sensitization, with donor-specific antibodies (DSAs) against B58 and DQ9, and high titers of anti-AT1R antibodies (>50 U/L). Interestingly, both anti-HLA DSAs were unable to fix C1q, suggesting that anti-AT1R antibodies played a toxic part, in this specific setting. Histopathologic exam confirmed AMR. The patient received an initial multimodality treatment based on a combination of steroids, plasma exchange, and intravenous immunoglobulins. Then, bortezomib (Velcade?, Takeda, Osaka, Japan) was given at 1.3 mg/m2 of body surface area, on days 1, 4, 8, and 11, to directly inhibit antibody production th-rough plasma cell Celecoxib depletion.2 Following anti-rejection treatment, anti-HLA DSA and anti-AT1R antibodies promptly disappeared, and SCr stably decreased. One year later on, the patient is doing fine, with stable graft function, no proteinuria, and undetectable DSA and anti-AT1R antibodies (Table 1). Table 1 Clinical Guidelines before, during, and after Bortezomib Administration Despite medical improvements and novel immunosuppressive regimens, long-term kidney allograft survival has not significantly improved during last decades, since we are now dropping organs mainly due to AMR.3 Recently, in ER81 addition to anti-HLA antibodies, fresh antibodies have been discovered in transplant recipients experiencing rejection, supporting the hypothesis that anti-HLA antibodies may not be the only effectors of alloimmune humoral response. Among them, anti-AT1R antibodies seem to be particularly significant. AT1R is the main receptor for angiotensin II. Anti-AT1R antibodies can mimic angiotensin II and result in multiple autoreactive and alloreactive reactions, eventually leading to cell damage, apoptosis, and hypertension due to allosteric activation of AT1R.4 Anti-AT1R antibodies can act independently or synergistically with other effectors of the rejection pathway.5 Our patient experienced AMR seven years after transplantation due to noncompliance. An association between anti-HLA and anti-AT1R antibodies offers been already explained in under-immunosuppressed kidney transplant recipients. 5 anti-AT1R antibodies have been also recognized after episodes of allosensitization, 6 becoming consistently associated with rejection and poor graft and Celecoxib patient survivals.7 However, screening for non-anti-HLA antibodies is not routinely performed, such that their actual prevalence and incidence in the transplant human population are basically unfamiliar.7 What may cause the introduction of anti-AT1R antibodies after transplantation continues to be under investigation. Many factors have already been suggested: 1) hereditary polymorphisms impacting the framework of AT1R extra-cellular domains; 2) hereditary polymorphisms altering the geometric form of the receptor; 3) antigenic publicity secondary to loss of life perturbations; and 4) cell harm due to alloimmune response, which modifies In1R expression in to the graft exposing concealed epitopes previously.5 Meanwhile, several therapeutic options have already been suggested to take care of early-onset anti-HLA AMR. Some mixture strategies show good results for a while, although no apparent advantage of one specific program has been showed, and long-term email address details are sub-optimal. Knowledge with late-onset non-anti-HLA AMR is more small even.8 Celecoxib Inhibition of B-cells and antibody production by administration of anti-CD20 monoclonal antibodies (e.g., rituximab) or proteasome inhibitors (e.g., bortezomib) may represent a appealing option together with apheretic techniques and intravenous immunoglobulins.9 Optimal treatment of late-onset acute AMR is still a matter of issue. Reports on anti-AT1R AMR are anecdotal: some authors support the part of apheresis combined with intravenous normal human being immunoglobulins, rituximab, and high-dose AT1R-blockers.10 This journal has already published a first successful experience with bortezomib.1 Our experience with a multimodality treatment, including bortezomib, confirms its efficiency in stably clearing not only anti-HLA but also anti-AT1R antibodies, halting renal function deterioration even in the longer term. Further investigations are warranted to better address the part of proteasome inhibition in the establishing.