Smaragdi Marinaki

Immunohistochemical evaluation of podocalyxin expression in glomerulopathies associated with nephrotic syndrome

It is now well established that morphological change of podocytes is closely correlated to the development of proteinuria. The aim of this study was to investigate the role of podocalyxin, a major podocyte protein, in the pathogenesis of glomerulopathies primarily associated with the nephrotic syndrome. Immunohistochemical expression of podocalyxin has been evaluated in 51 renal samples, including healthy controls, patients with podocytopathies (minimal change disease [MCD], focal segmental glomerulosclerosis [FSGS]) and membranous glomerulopathy (MG). A computerized image analysis program has been used. Statistical analysis was performed using analysis of variance and Bonferroni tests. Immunohistochemical expression of podocalyxin has been observed within the podocytes of healthy controls. In MCD, podocalyxin expression was globally reduced despite the normal appearance of the glomeruli. In FSGS, podocalyxin loss was observed in both the segmental sclerotic and the nonsclerotic areas being significantly more prominent in the former. Reduction of podocalyxin in MG was demonstrated for the first time immunohistochemically. The percentage of the stained area was statistical significantly higher in the controls than in each pathologic group. However, among pathologic groups (FSGS, MCD, MG), there was no statistically significant difference. This is one of the few studies investigating podocalyxin immunohistochemical expression in glomerulopathies associated with nephrotic syndrome. The observed reduction in podocalyxin expression suggests that it constitutes a target molecule in nephrotic syndrome pathogenesis regardless of the underlying cause.

Renal outcomes in patients with AL amyloidosis: Prognostic factors, renal response and the impact of therapy

A staging system for patients with renal AL amyloidosis, based on eGFR (<50 ml/min/1.73 m2) and proteinuria (≥5 g/day) at diagnosis, as well as criteria for renal progression (≥25% eGFR reduction) and response (≥30% reduction of proteinuria without renal progression) were recently proposed. We validated these criteria in a cohort of 125 patients with renal AL amyloidosis, mostly treated with bortezomib or lenalidomide. We confirmed the prognostic value of the renal staging system but also identified the limitations of renal progression criteria which are based only on eGFR reduction. We identified the ratio of 24h proteinuria to eGFR as a sensitive marker of renal risk which also accounts for changes in both proteinuria and eGFR: 24h proteinuria/eGFR ratio <30 (in mg/ml/min/1.73 m2) was associated with a 2‐year progression to dialysis rate of 0% compared to 9% for a ratio of 31‐99 and 35% for a ratio ≥100 (P < .001). In landmark analysis, patients who achieved a reduction of this ratio by at least 25% or ≤100 (if initially >100) at 3 months had a 2‐year progression to dialysis of 0% vs 24% for patients who either did not reduce to or still had a ratio >100 (P = .001); similar results were obtained by applying the same criteria at 6 months; thus, the evaluation of treatment effect on renal function may be identified early. Furthermore, primary bortezomib‐based therapy was more effective than lenalidomide‐based therapy, in terms of renal outcomes, especially in patients at intermediate renal risk, but without affecting overall survival.

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-Hodgkins 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.

Membranoproliferative glomerulonephritis in the setting of multicentric angiofollicular lymph node hyperplasia (Castleman's disease) complicated by Evan's syndrome.

Systemic Castlemans disease is a lymphoproliferative disorder with various clinical presentations and incompletely understood aetiology. The authors report on a rare case of the plasma cell variant of Castlemans disease associated with autoimmune haemolytic anaemia and autoimmune thrombocytopenia (Evans syndrome) and complicated by mixed nephrotic–nephritic syndrome and acute renal failure due to an underlying glomerulopathy with microscopic and immunofluorescence findings suggestive of membranoproliferative glomerulonephritis (MPGN) type I. Immunocomplexed glomerulonephritis is rare in Castlemans disease, while, to the best of our knowledge, constellation of all these autoimmune phenomena is reported for the first time suggesting that apart from the putative role of VEGF and IL-6 in the pathogenesis of the disease, a more generalised immunological disturbance occurs, probably through autoantibodies induced by active polyclonal B cells raised from Castlemans disease tumour.

Excellent long term patient and renal allograft survival after ABO-incompatible kidney transplantation: Experience of one center

AIM To investigate the long-term results of ABO-incompatible (ABOi) kidney transplantation in a single center in Greece. METHODS Thirty consecutive ABOi kidney transplantations were performed from June 2005 to December 2013. All patients received rituximab one month prior to transplantation. Immunoadsorption therapy was performed for the removal of anti-A/B IgG antibodies until the titer was ≤ 1:16. Additional apheresis sessions were performed post-operatively. Intravenous immunoglobulin and oral immunosuppression consisting of tacrolimus (TAC) in combination with either everolimus or mycophenolate acid was administered. We compared the long term results of our ABOi group to those of a matched group of 30 ABO compatible (ABOc) living kidney recipients with similar baseline characteristics. The ABOc recipients received an immunosuppressive regimen consisting of TAC and mycophenolate acid. All patients in both groups received induction therapy with Basiliximab or Daclizumab, whereas corticosteroids were instituted on the day of surgery. During the follow-up period, indication biopsies were performed and interpreted by an experienced nephropathologist. The parameters we analyzed included the following: Donor/recipient age, gender, blood type, human leukocyte antigen mismatches, panel reactive antibodies, primary cause of renal failure, mean time on dialysis, immunosuppressive regimen, patient survival, graft outcome, incidence of rejections, surgical and infectious complications. RESULTS The mean follow-up period was 6 years (range 1 to 9 years). A mean of 5.0 ± 3.0 (range 0-14) pre-transplant immunoadsorptions were required in order to reach the target titer. Patient survival in ABOi group in comparison to ABOc group at 1, 3, 5 and 8 years did not differ significantly (100% vs 100%, 96% vs 100%, 92% vs 100% and 92% vs 100%, P = ns). Additionally, graft survival was similar in the two groups at the same time points (100% vs 100%, 96% vs 96%, 92% vs 96% and 81% vs 92%, P = ns). The mean serum creatinine and the estimated glomerular filtration rate by the modification of diet in renal disease formula at 1, 3, 5 and 8 years did not differ significantly between ABOi and ABOc group. None of the patients in the ABOi group developed acute or chronic antibody-mediated rejection evidenced by histological signs. Four patients (13.3%) in the ABOi group and 3 (10%) in the ABOc group experienced acute cellular rejection, which was treated successfully in all cases. Bacterial and viral infections were also similar between the two groups. CONCLUSION ABOi kidney transplantation is a safe and effective alternative that enables kidney transplantation in countries with unacceptably long deceased-donor waiting lists.

Depletion of B Lymphocytes in Idiopathic Membranous Glomerulopathy: Results from Patients with Extended Follow-Up

Aims: To assess the long-term therapeutic benefit of temporary depletion of B lymphocytes in patients with idiopathic membranous glomerulopathy (MGN) and search for potential predictors of response. Patients and Methods: The patients included had been diagnosed with biopsy-proven MGN in the absence of secondary causes. Estimated glomerular filtration rate should be above 30 ml/min/1.73 m2 and 24-hour proteinuria 3 g/day or more. Patients who had been treated with cyclosporine or cytotoxic agents the year prior to study entry were excluded. Depletion of B cells was achieved with rituximab, which was administered intravenously for 4 consecutive weeks. Partial remission was defined as a >50% decrease in proteinuria with absolute proteinuria <3 g/day, while complete remission was defined as a >50% decrease in proteinuria and an absolute protein excretion <0.3 g/day. Results: Twelve patients were studied (4 females/8 males) with a mean age of 51.3 years. No major adverse effects were observed. During a median follow-up time of 48 months, 11/12 (91.6%) patients achieved remission [7/12 (58.3%) complete remission and 4/12 (33.3%) partial remission], while 1 patient did not respond to therapy. Twelve months after therapy, 68.8% (p = 0.003) of cases had achieved partial and 28.4% complete remission. Measurements of lymphocyte subpopulations did not reveal any changes except for the B cell depletion. B cell infiltrates captured per mm3 of renal tissue in the diagnostic biopsy did not correlate with subsequent response. Conclusion: Depletion of B cells in idiopathic MGN was well tolerated and resulted in significant and long-lasting response rates in a series of 12 patients.

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.

Hepatitis B and C in Kidney Transplantation

The prevalence of chronic hepatitis B and C virus infection has declined among the dialysis population during the past decades. However, it still comprises a major health problem with high morbidity and mortality. Renal transplantation is the optimal treatment for patients with end‐stage renal disease and hepatitis B or C, although it is associated to lower patient and allograft survival compared to seronegative kidney recipients. Novel therapeutic strategies with the use of new antiviral agents, especially direct‐acting antiviral agents in hepatitis C, have significantly changed the natural history of both hepatitis B and C not only in the general population but also in renal‐ transplant recipients. We believe that future research should focus on the impact of new antiviral medications in this specific subset of patients.

IgA nephropathy in Greece: data from the registry of the Hellenic Society of Nephrology

Abstract Background Natural history, predisposing factors to an unfavourable outcome and the effect of various therapeutic regimens were evaluated in a cohort of 457 patients with immunoglobulin A nephropathy (IgAN) and follow-up of at least 12 months. Methods Patients with normal renal function and proteinuria <1 g/24 h as well as those with serum creatinine (SCr) >2.5 mg/dL and/or severe glomerulosclerosis received no treatment. Patients with normal or impaired renal function and proteinuria >1 g/24 h for >6 months received daily oral prednisolone or a 3-day course of intravenous (IV) methylprednisolone followed by oral prednisolone per os every other day or a combination of prednisolone and azathioprine. The clinical outcome was estimated using the primary endpoints of end-stage renal disease and/or doubling of baseline SCr. Results The overall 10-year renal survival was 90.8%, while end-stage renal disease and doubling of baseline SCr developed in 9.2% and 14.7% of patients, respectively. Risk factors related to the primary endpoints were elevated baseline SCr, arterial hypertension, persistent proteinuria >0.5 g/24 h and severity of tubulointerstial fibrosis. There was no difference in the clinical outcome of patients treated by the two regimens of corticosteroids; nevertheless, remission of proteinuria was more frequent in patients who received IV methylprednisolone (P = 0.000). The combination of prednisolone with azathioprine was not superior to IV methylprednisolone followed by oral prednisolone. Side effects related to immunossuppressive drugs were observed in 12.8% of patients. Conclusion The clinical outcome of patients with IgAN was related to the severity of clinical and histological involvement. The addition of azathioprine to a corticosteroid-based regimen for IgAN does not improve renal outcome.

Cardiovascular morbidity of severe resistant hypertension among treated uncontrolled hypertensives: a 4-year follow-up study

Data regarding the prognosis of resistant hypertension (RHTN) with respect to its severity is limited. We investigated the cardiovascular risk of severe RHTN in a prospective observational study. A cohort of 1700 hypertensive patient with treated uncontrolled HTN was followed for a mean period of 3.6 ± 1.8 years. At baseline, standard clinical and laboratory workup was performed, including testing for secondary causes of RHT where applicable. Three groups were identified depending on presence of RHTN (office-based uncontrolled HTN under at least three drugs including a diuretic) and levels of office systolic blood pressure (BP): 1187 patients (70%) without RHTN, 313 (18%) with not-severe RHTN (systolic BP < 160 mmHg) and 200 (12%) with severe RHTN (systolic BP ≥ 160 mmHg). Endpoint of interest was cardiovascular morbidity set as the composite of coronary heart disease and stroke. During follow-up, incidence rates of cardiovascular events per 1000 person-years were 7.1 cases in the non-RHTN group, 12.4 cases in the not-severe RHTN group and 18 cases in the severe RHTN group. Unadjusted analysis showed that compared to uncontrolled patients without RHTN, patients with not-severe RHTN exhibited a similar risk but patients with severe RHTN had a significantly higher risk, by 2.5 times (CI: 1.28–4.73, p = 0.007). Even after multivariate adjustment for established risk factors including BP levels and isolated systolic HTN, severe RHTN remained as an independent predictor of the cardiovascular outcome (OR: 2.30, CI: 1.00–5.29, p = 0.05). In conclusion, among treated yet uncontrolled hypertensive patients, severe RHTN exhibits a significantly higher cardiovascular risk indicating the need for prompt management.