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For the past decades, complement activation and complement-mediated destruction of allograft cells were considered to play a central role in anti-HLA antibody-mediated rejection (AMR) of kidney transplants. However, also complement-independent mechanisms are relevant in the downstream immune activation induced by donorspecific antibodies, such as Fc-gamma receptor (FcγR)-mediated direct cellular activation. This article reviews the literature regarding FcγR involvement in AMR, and the potential contribution of FcγR gene polymorphisms to the risk for antibody mediated rejection of kidney transplants. There is large heterogeneity between the studies, both in the definition of the clinical phenotypes and in the technical aspects. The study populations were generally quite small, except for two larger study cohorts, which obviates drawing firm conclusions regarding the associations between AMR and specific FcγR polymorphisms. Although FcγR are central in the pathophysiology of AMR, it remains difficult to identify genetic risk factors for AMR in the recipient's genome, independent of clinical risk factors, independent of the donor-recipient genetic mismatch, and in the presence of powerful immunosuppressive agents. There is a need for larger, multi-center studies with standardised methods and endpoints to identify potentially relevant FcγR gene polymorphisms that represent an increased risk for AMR after kidney transplantation. [ABSTRACT FROM AUTHOR]

A review of the article "Urinary proteomics to diagnose chronic antibody-mediated rejection in pediatric kidney transplantation" by N. Kanzelmeyer is presented.

Presents a letter to the editor about cyclosporine vascular toxicity.

An author index for the November 2013 issue of the periodical "Transplant International" is presented.

Small blood pressure (BP) elevations may occur post kidney donation. This prospective study determined 24-h ambulatory BP (ABP) and other cardiovascular risk factor changes in 51 living donors over 12 months postdonation. Donors also provided 24-h urine collections for monitoring protein and creatinine clearance, 75 g oral glucose tolerance tests (OGTT), and fasting lipids. Nondipping was defined as night-day systolic (SBP) ratio ≥0.9. Baseline and 12-month pre to postdonation comparisons were made both for dippers and nondippers. Of 51 donors, 35 were dippers and 16 nondippers. In these two groups, predonation 24-h SBP were 115.2 ± 8 and 115.6 ± 10 mmHg; serum creatinine (SCr) 69.3 ± 12 and 71.1 ± 13 μmol/l; and 24-h urine protein 0.12 ± 0.05 and 0.09 ± 0.03 g (all P = NS) while at 12 months, 24-h SBP were 111.4 ± 11 and 114.3 ± 8 mmHg ( P = 0.384), SCr 97.9 ± 16 and 97.7 ± 21 μmol/l ( P = 0.810); and 24-h urine protein 0.139 ± 0.09 and 0.111 ± 0.07 g/d ( P = 0.360) respectively. The 24-h SBP was significantly lower in the dippers at 12 months as compared with predonation ( P = 0.036). OGTT and lipid profiles remained normal in both groups. Predonation nocturnal nondipping does not carry adverse postdonation consequences over 12 months. [ABSTRACT FROM AUTHOR]

Liver transplant recipients are at increasingly high risk for suffering from impaired renal function and probable need of renal replacement therapy. Extended criteria organs and transplantation of patients with higher model for end-stage liver disease scores further increase this problem. Acute and chronic nephrotoxicity are the trade-off in immunosuppression with potent calcineurin inhibitors (CNIs). As a good renal function is associated with better graft and patient survival, CNI minimization protocols have been developed. Current strategies to overcome CNI toxicity include reduction or withdrawal of CNIs concurrently with switching over to mammalian target of rapamycin inhibitor or mycophenolate mofetil (MMF)-based regimens. This strategy caused an improvement in renal function in a significant number of liver transplantation patients according to several studies. However, total CNI avoidance seems to result in higher rejection rates. To prevent chronic renal dysfunction in patients prone to or with acute renal failure, CNI delay – with induction therapy for bridging – followed by low-dose CNI in combination with MMF are proven strategies without risking higher rejection rates. An individualized, tailor-made immunosuppressive regime, with a special focus on renal function is recommended. This review gave an overview on CNI minimization protocols in liver transplantation also focusing on recently analyzed studies. [ABSTRACT FROM AUTHOR]

An author index for the September 2, 2007 issue of "Transplant International" is presented.

Two forms of post-transplant thrombotic microangiopathy (TMA) may be recognized: recurrent TMA and de novo TMA. Recurrent TMA may occur in patients who developed a nondiarrhoeal form of haemolytic uraemic syndrome (HUS) being particularly frequent in patients with autosomal recessive or dominant HUS. The recurrence is almost the rule in patients with mutation in complement factor H gene. Most patients eventually lose the graft. Treatment with plasma infusions or plasmapheresis is often disappointing, but few cases may be rescued. Intravenous immunoglobulins and rituximab have also been successful in anedoctic cases. De novo TMA is rarer. A number of factors including viral infection may be responsible of de novo TMA, but in most cases TMA is triggered by calcineurin inhibitors or mTOR inhibitors. The clinical presentation of de novo TMA may be variable with some patients showing clinical and laboratory features of HUS while others showing only a progressive renal failure. The prognosis is less severe than with recurrent TMA. Complete withdrawal of the offending drug may lead to improvement in many cases. The addition of plasma exchange may result in graft salvage in about 80% of cases. [ABSTRACT FROM AUTHOR]

Few studies used paired kidneys for comparison between tacrolimus and cyclosporine in renal transplantation. Most of the published data used whole blood trough levels for drug monitoring. However, the use of limited sampling strategy and abbreviated formula to estimate the 12-h area under concentration-time curve (AUC0-12) allowed better prediction of drug exposure. Sixty-six first cadaveric renal transplant recipients receiving paired kidneys were randomized to receive either tacrolimus-based (n = 33) or cyclosporine microemulsion (Neoral)-based therapies (n = 33). Abbreviated AUC0-12 was used for drug monitoring and dose titration. Mean follow-up duration was 2.8 ± 2 years. The patient and graft survival were comparable. Fewer incidence of acute rejection was observed in tacrolimus group (15% vs. 27.3%) though the difference was not significant (P = 0.23). The absolute value and the rate of decline of creatinine clearance were both significantly better in tacrolimus-treated patients. Prevalence of hypertension, post-transplant diabetes mellitus, infection, and malignancy were similar in both groups. Prevalence of hypercholesterolemia (11/33 vs. 4/33) and gum hypertrophy (6/33 vs. 1/33) was more common in cyclosporine-treated patients (P = 0.04 in both parameters). This was the first prospective, randomized study with paired kidney analysis showing the renal function was significantly better in tacrolimus-treated patients than in cyclosporine-treated patients. [ABSTRACT FROM AUTHOR]

Presents an author index of the December 2005 issue of the journal "Transplant International."

Chronic allograft nephropathy (CAN) is the leading cause of graft loss following kidney transplantation. One factor contributing to CAN is chronic alloimmune injury. However, the involvement of alloantigen-dependent and -independent factors in CAN is unclear. The pathomechanism of CAN has been extensively studied by utilizing the Fischer-to-Lewis (F344-to-LEW) rat model. Transplant capillaropathy (circumferential multiplication of the peritubular capillary basement membrane) and transplant glomerulopathy (reduplication of the glomerular basement membrane) have recently been validated clinicopathologically as ultrastructural indicators of chronic alloimmune injury. To investigate the presence of these markers, F344-to-LEW kidneys were examined by electron and light microscopy 32, 40 and 52 weeks after implantation. F344 rats with or without 30-min ischemia of the left kidney following right nephrectomy served as controls. All transplanted rats displayed marked proteinuria. On electron microscopy, transplant capillaropathy, transplant glomerulopathy, and T-cell cytotoxicity (indicator of ongoing cellular rejection) were absent. On light microscopy, the arteries were devoid of intimal fibrosis. Focal-segmental glomerulopathy resembling hyperfiltration injury was encountered, with mild interstitial infiltration, fibrosis, and tubular atrophy. The proteinuria and kidney pathology were more severe in transplanted than in ischemic or uninephrectomized rats. Because chronic-active rejection could not be detected between weeks 32 and 52, we propose that the alloantigen-dependent initial graft injury subsides, but induces the late events: glomerular hyperfiltration, proteinuria, and glomerulosclerosis. Accordingly, the model– in the late phase– is suitable to investigate alloantigen-independent factors of CAN and lacks markers of alloantigen-dependent processes. [ABSTRACT FROM AUTHOR]

After renal transplantation, different immunological and non-immunological factors lead to long-term allograft deterioration. Acute rejection episodes are one risk factor for chronic renal allograft dysfunction (CRAD). Following the current Banff classification the histological grade in acute rejection episodes is of limited prognostic value, therefore, additional morphological surrogate markers would be helpful. We investigated the biopsies of 91 patients with early acute rejection episodes for the immunohistochemical expression of key molecules (perforin, granzyme B, TIA-1, CD40) in the T cell-mediated rejection process. Staining results were correlated to long-term allograft outcome. Patients with greater than 2% of granzyme B or greater than 25% of CD40-positive cells in the interstitial infiltrate showed significantly shorter allograft survival. Patients with a CD40-positive vascular rejection or greater than 2% of granzyme B-positive cells in the interstitial infiltrate were significantly correlated with an earlier onset of CRAD. Our findings provide potential morphological surrogate markers in biopsies with early acute rejection episodes after renal transplantation. These could become part of combined clinical and histological algorithms, allowing patient-specific risk estimation and customized therapy options to be made. [ABSTRACT FROM AUTHOR]

Polyomavirus (PV) nephropathy is a rare cause of graft dysfunction, but it may accompany acute rejection (AR), resulting in complications with respect to its diagnosis and treatment. To examine the validity of tubulitis and inflammatory phenotype in the diagnosis of concurrent AR, we reviewed the renal histology of ten biopsy samples from nine patients with PV nephropathy, and the immunohistochemistry from eight samples. Tubulitis was present in seven patients and was associated with AR in six. The degrees of tubulitis and interstitial inflammation were higher in biopsy samples with AR than in those without, but the degree of tubulitis was not related to the degree of interstitial inflammation. Virally infected cells were rare in the samples with no, or mild, tubulitis, but did not increase with the degree of interstitial inflammation. Immuno-phenotyping of inflammatory cells did not show any T-cell dominance in AR: T cells were dominant over B cells in three of six samples with AR and both samples without AR. Although the degrees of tubulitis and interstitial inflammation were higher in the AR subjects, the presence of tubulitis or inflammatory phenotype was not helpful in the diagnosis of concurrent AR. Further studies will be required to find a better marker for coexisting AR in patients with PV nephropathy and to establish strategies for treatment. [ABSTRACT FROM AUTHOR]