B Cell Depletion: Rituximab in Glomerular Disease and Transplantation

B cells play a central role in the pathogenesis of many autoimmune diseases. Selective targeting can be achieved with the use of the monoclonal antibody rituximab. In addition to being a drug for non-Hodgkin's lymphoma, rituximab is also an FDA-approved treatment for refractory rheumatoid arthritis and, since recently, ANCA vasculitis. It has shown efficacy in many autoimmune diseases. This review will discuss current evidence and the rationale of the use of rituximab in glomerular diseases, including randomized controlled trials. The focus will be on the use of rituximab in idiopathic membranous nephropathy, systemic lupus erythematosus and ANCA-associated vasculitis. The emerging role of rituximab in renal transplantation, where it seems to be important for the desensitization protocols for highly sensitized patients as well as for the preconditioning of ABO-incompatible recipients and the treatment of antibody-mediated rejection, will also be addressed

Pathogenesis and management of acute kidney injury in patients with nephrotic syndrome due to primary glomerulopathies

Acute kidney injury in the context of nephrotic syndrome is a serious and alarming clinical problem. Largely, acute kidney injury is a relatively frequent complication among patients with comorbidities while it has been independently associated with an increased risk of adverse outcomes, including death and chronic kidney disease. Nephrotic syndrome, without hematuria or with minimal hematuria, includes a list of certain glomerulopathies; minimal change disease, focal segmental glomerulosclerosis and membranous nephropathy. In the light of primary nephrotic syndrome, pathophysiology of acute kidney injury is differentiated by the nature of the primary disease and the severity of the nephrotic state. This review aims to explore the clinical circumstances and pathogenetic mechanisms of acute kidney injury in patients with nephrotic syndrome due to primary glomerulopathies, focusing on newer perceptions regarding the pathogenesis and management of this complicated condition, for the prompt recognition and timely initiation of appropriate treatment in order to restore renal function to its baseline level. Prompt recognition of the precise cause of acute kidney injury is crucial for renal recovery. Clinical characteristics, laboratory and serological findings along with histopathological findings, if required, will reveal the implicated pathway leading to individualized approach and management. © 2019 by the authors. Licensee MDPI, Basel, Switzerland

Understanding the complement-mediated glomerular diseases: focus on membranoproliferative glomerulonephritis and C3 glomerulopathies

An enhanced understanding of the role of complement in the pathogenesis of membranoproliferative glomerulonephritis has led to reclassification of the latter into immunoglobulin-mediated and non-immunoglobulin-mediated disease. The new classification schema resulted in improved diagnostic clinical algorithms, while it brought into light again the diseases, which are characterized by the presence of glomerular deposits, composed predominantly by C3, in the absence of significant amounts of immunoglobulins in renal biopsy, namely, C3 glomerulopathies (dense deposit disease and C3 glomerulonephritis). Despite the lack of randomized controlled trials following the advances in the understanding of the pathogenetic pathways involved in membranoproliferative glomerulonephritis, it is important that the new mechanistic approach has opened new roads for the exploration and discovery of targeted therapies. © 2016 APMIS. Published by John Wiley & Sons Lt

The clinical course of IgA nephropathy after kidney transplantation and its management

Immunoglobulin (Ig) A nephropathy is one of the most common primary glomerulonephritides worldwide causing end stage renal disease in up to 20–40% of affected patients, nearly two decades post diagnosis. Kidney transplantation is the treatment of choice for patients with renal failure, secondary to glomerular diseases. However, IgA nephropathy has a strong tendency to recur in the graft, and although initially thought to be a benign condition, several reports of graft loss, due to recurrent IgA nephropathy, there have been over the last three decades. Overall graft survival has been significantly improved in kidney transplantation, as a result of reduced incidence of acute rejection, as more potent and more specific immunosuppressive agents are now available in clinical practice. Thus, the rates of IgA nephropathy and other glomerulonephritides recurrence are expected to increase, since graft survival has been improved. However, the reported incidence of IgA nephropathy recurrence in the graft varies substantially across centers, as a consequence of different levels of interest, diverse biopsy policies and differing durations of follow up, of the published studies. Notably, recurrence rates of patients receiving graft biopsies by clinical indication only, ranges from 13% to 50% with graft loss being between 1.3% and 16%. The aim of this review is to underline important pathogenetic insights of IgA nephropathy, describe the clinical course of the disease after kidney transplantation, with emphasis on the incidence of recurrence and the associated risk factors, and finally provide all available options for its management in transplant recipients. © 2017 Elsevier Inc

Hepatitis C in hemodialysis patients

Despite reduction of hepatitis C prevalence after recognition of the virus and testing of blood products, hemodialysis (HD) patients still comprise a high risk group. The natural history of hepatitis C virus (HCV) infection in dialysis is not fully understood while the clinical outcome differs from that of the general population. HD patients show a milder liver disease with lower aminotransferase and viral levels depicted by milder histological features on liver biopsy. Furthermore, the "silent" clinical course is consistent with a slower disease progression and a lower frequency of cirrhosis and hepatocellular carcinoma. Potential explanations for the "beneficial" impact of uremia and hemodialysis on chronic HCV infection are impaired immunosurveillance leading to a less aggressive host response to the virus and intradialytic release of "hepatoprotective" cytokines such as interferon (IFN)-α and hepatocyte growth factor. However, chronic hepatitis C is associated with a higher liver disease related cardiovascular and allcause mortality of HD patients. Therapy is indicated in selected patients groups including younger patients with low comorbidity burden and especially renal transplant candidates, preferably after performance of a liver biopsy. According to current recommendations, choice of treatment is IFN or pegylated interferon with a reported sustained viral response at 30%-40% and a withdrawal rate ranging from 17% to 30%. New data regarding combination therapy with low doses of ribavirin which provide higher standard variable rates and good safety results, offer another therapeutic option. The new protease inhibitors may be the future for HCV infected HD patients, though data are still lacking. © 2015 Baishideng Publishing Group Inc

Hepatitis B in renal transplant patients

Hepatitis B virus (HBV) poses a significant challenge for both dialysis patients and kidney transplant recipients despite its decreasing rates, especially in developed countries. The best preventive method is vaccination. Patients with chronic renal disease should ideally be vaccinated prior to dialysis, otherwise, reinforced vaccination practices and close antibody titer monitoring should be applied while on dialysis. HBV infected dialysis patients who are renal transplant candidates must be thoroughly examined by HBV-DNA, and liver enzyme testing and by liver biopsy. When needed, one must consider treating patients with tenofovir or entecavir rather than lamivudine. Depending on the cirrhosis stage, dialysis patients are eligible transplant recipients for either a combined kidney-liver procedure in the case of decompensated cirrhosis or a lone kidney transplantation since even compensated cirrhosis after sustained viral responders is no longer considered an absolute contraindication. Nucleoside analogues have led to improved transplantation outcomes with both long-term patient and graft survival rates nearing those of HBsAg(-) recipients. Moreover, in the cases of immunized HBsAg(-) potential recipients with concurrent prophylaxis, we are enabled today to safely use renal grafts from both HBsAg(+) and HBsAg(-)/anti- HBc(+) donors. In so doing, we avoid unnecessary organ discarding. Universal prophylaxis with entecavir is recommended in HBV kidney recipients and should start perioperatively. One of the most important issues in HBV(+) kidney transplantation is the duration of antiviral prophylaxis. In the absence of robust data, it seems that prophylactic treatment may be discontinued in selected stable, low-risk recipients during maintenance immunosuppression and should be reintroduced when the immune status is altered. All immunosuppressive agents in kidney transplantation can be used in HBV(+) recipients. Immunosuppression is intimately associated with increased viral replication; thus it is important to minimize the total immunosuppression burden long term. © The Author(s) 2017

Arterial Stiffness in Patients With Renal Transplantation; Associations With Co-morbid Conditions, Evolution, and Prognostic Importance for Cardiovascular and Renal Outcomes

Patients with chronic kidney disease (CKD), particularly those with end-stage renal disease (ESRD), are at increased risk of cardiovascular events and mortality. The spectrum of arterial remodeling in CKD and ESRD includes atheromatosis of middle-sized conduit arteries and, most importantly, the process of arteriosclerosis, characterized by increased arterial stiffness of aorta and the large arteries. Longitudinal studies showed that arterial stiffness and abnormal wave reflections are independent cardiovascular risk factors in several populations, including patients with CKD and ESRD. Kidney transplantation is the treatment of choice for patients with ESRD, associated with improved survival and better quality of life in relation to hemodialysis or peritoneal dialysis. However, cardiovascular mortality in transplanted patients remains much higher than that in general population, a finding that is at least partly attributed to adverse lesions in the vascular tree of these patients, generated during the progression of CKD, which do not fully reverse after renal transplantation. This article attempts to provide an overview of the field of arterial stiffness in renal transplantation, discussing in detail available studies on the degree and the associations of arterial stiffness with other co-morbidities in renal transplant recipients, the prognostic significance of arterial stiffness for cardiovascular events, renal events and mortality in these individuals, as well as studies examining the changes in arterial stiffness following renal transplantation. © Copyright © 2019 Korogiannou, Xagas, Marinaki, Sarafidis and Boletis

A case report of hypocomplementemic urticarial vasculitis presenting with membranoproliferative glomerulonephritis

Background: Hypocomplementemic urticarial vasculitis syndrome is an infrequent condition characterized by ocular, renal, gastrointestinal and pulmonary involvement with low serum complement levels and autoantibodies. Renal manifestations vary from microscopic hematuria to nephrotic syndrome and acute kidney injury. Accordingly differing histologic patterns have been reported. Case presentation: We present the case of a 65 years old woman with a history of chronic uveitis who presented with arthralgias, urticarial rush, nephrotic syndrome, glomerular hematuria and low serum complement. Kidney biopsy revealed an immune-complex membranoproliferative glomerulonephritis. The patient received induction therapy with steroids, cyclophosphamide and hydroxychloroquine followed by rapid clinical improvement and remission of proteinuria. Maintenance treatment consisted of rituximab pulses. Conclusions: The majority of hypocomplementemic urticarial vasculitis syndrome cases is idiopathic, although an association to drugs, infections or other autoimmune disorders has been recorded. Given the rarity and heterogeneity of the disease, no standard treatment is established. © 2020 The Author(s)