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Background. Antibody-mediated rejection (ABMR) following kidney transplantation is associated with poor allograft survival. Conventional treatment based on plasmapheresis (PPH) and the administration of intravenous immunoglobulins (IVIG) is not satisfactory. Two compounds, more specifically targeting B cells and plasma cells, may help to improve the prognosis: rituximab, a B-cell-depleting monoclonal antibody, and bortezomib, a proteasome inhibitor causing apoptosis of plasma cells. Methods. Starting in February 2009, we treated 10 consecutive patients with ABMR according to current Banff criteria with one cycle of bortezomib [1.3 mg/m2 intravenously (i.v.), Day 1, 4, 8, 11]. This group was compared to a historical control group of patients (n = 9) treated with a fixed single dose of rituximab (500 mg i.v.). All patients received PPH (6×) and IVIG (30 g). Patients with acute ABMR additionally received methylprednisolone (3 × 500 mg i.v.). Results. Patient survival in both groups was 100%. At 18 months after treatment, graft survival was 6/10 in the bortezomib group as compared to 1/9 functioning grafts in the rituximab group (P = 0.071). Renal function was superior in patients treated with bortezomib as compared to rituximab-treated patients (serum creatinine at 9 months: 2.5 ± 0.6 versus 5.1 ± 2.1 mg/dL, P = 0.008). Proteinuria was not different between both groups (9 months: 1.3 ± 1.0 versus 1.6 ± 1.6 g/day, P = n.s.). Conclusions. Treatment of ABMR with bortezomib in addition to standard therapy was partially effective, whereas treatment with a fixed dose of rituximab in addition to standard therapy with PPH and IVIG did not result in sufficient long-term graft survival. In the future, new strategies including the combination of both substances and the application of higher doses must be discussed. [ABSTRACT FROM PUBLISHER]

Antineutrophil cytoplasmic antibodies-associated vasculitis (AAV) is a well-described cause of multiple organ involvement including rapidly progressive pauci-immune crescentic glomerulonephritis. Kidney transplantation (KTx) is considered the treatment of choice in patients with end-stage renal disease (ESRD) due to AAV. Patient and graft survival in AAV after KTx is favourable and comparable with other non-diabetic causes of ESRD. While relapse of AAV is high in dialysis patients (up to 50%), it decreases after KTx (8.6–22.2%). Yet, relapse may occur at any time after KTx and transplant involvement has been documented in at least 25 cases. Therapeutic guidelines for the management of AAV after KTx do not exist and clinical management is a controversial discussion. We present two unusual cases of young males with smouldering AAV who recently underwent KTx at our hospital. Case 1 experienced repeated relapses after KTx and was finally successfully treated with rituximab. Case 2 received rituximab pre-emptively before living kidney donation and remained free of flairs. Prompted by theses two cases, we reviewed the literature focusing on the right point of time for transplantation, risk assessment, role of antineutrophil cytoplasmic antibodies, clinical presentation of flairs and immunosuppression in smouldering Wegener's granulomatosis (WG) and in relapse, including individualized treatment with rituximab. [ABSTRACT FROM PUBLISHER]

The article presents a study of a 42-year-old man diagnosed with peripheral oedema after being conducted with deceased-donor kidney transplantation. His abdominal examination indicated a loud systolic-diastolic murmur, in which the authors suspected him for acute renal allograft. He was performed with magnetic resonance imaging and magnetic resonance angiography. It mentions that both examination indicated arteriovenous malformation (AVM).

Background. Autosomal recessive polycystic kidney disease (ARPKD) [MIM 263200] belongs to a group of congenital hepatorenal fibrocystic syndromes and is caused by mutations in the PKHD1 gene encoding the multidomain protein fibrocystin/polyductin (FPC). The serine-threonine kinase mammalian target of rapamycin (mTOR) is one of the most important gate-keepers integrating numerous signals related to cell proliferation and growth. Whereas the direct activation of mTOR has been shown recently in autosomal-dominant PKD, no data are available on the role of mTOR signalling in proliferation and progression of ARPKD. Methods. Formalin-fixed and paraffin-embedded kidney specimens obtained during nephrectomy from children with ARPKD (n = 12) were used for immunohistochemical investigation of FPC expression (monoclonal antibody (mAb) 18, mAb 5a), proliferative activity (Ki-67) and activation of the mTOR pathway. Kidney specimens from children (n = 4) who died from causes not associated with kidney disease served as controls. For the detection of AKT, mTOR and S6K antibodies specifically recognizing the activated (phosphorylated) isoforms of these proteins were used. In all patients mutation analysis of the PKHD1 gene was performed. Results. In 10 out of 12 patients, we could confirm the diagnosis by the identification of PKHD1 mutations. The tubular cyst epithelium of all kidney specimens stained strongly positive with the FPC-specific monoclonal antibody (mAb) 18 but only very faint signals were obtained with mAb 5a. In contrast, healthy kidneys showed rather weak signals with both FPC-specific mAbs, indicating dysregulated expression of FPC in our patients. Phosphorylated AKT as well as activated mTOR and its down-stream effector S6K were strongly expressed in cystic epithelia of all kidney specimens but not in control tissues. No association between the activation of this pathway and the proliferative activity (Ki-67 expression) was observed. Conclusions. Our results point to a central role of AKT/mTOR signalling in ARPKD and justify further investigations to evaluate the therapeutic potential of mTOR inhibitors in ARPKD patients. [ABSTRACT FROM AUTHOR]

Antibody mediated rejection (AMR) is becoming an increasing challenge in renal allotransplantation. AMR is usually associated with profound allograft dysfunction and inferior allograft survival. In the era of refined crossmatch-techniques and improved solid-phase assays, hyperacute rejections in presensitized patients are less common. Majority of AMRs occur due to de novo production of donor specific antibodies. AMR appears to stand for a spectrum of histologic changes paralled with immunohistochemical positivity for C4d along peritubular capillaries. Removal of antibodies with plasmapheresis or immunoadsorption in combination with neutralizing and immunomodulatory intravenous immunoglobulin are therapy standards in majority of transplant centers worldwide. The addition of anti-CD20 (rituximab) with the aim to reduce the number of B-cells may offer advantage in some cases. Apart from donor specific HLA-antibodies, non-HLA antibodies reacting to arterial antigens have been speculated to be responsible for rejections in some patients. More precise definition of antigen targets for non-HLA antibodies is emerging. The analysis of the subtle mechanistic and diagnostic differences among rejection subtypes will help to identify patients at particular risk and improve outcome of AMR. [ABSTRACT FROM AUTHOR]