Erythropoietin Reduces Auto- and Alloantibodies by Inhibiting T Follicular Helper Cell Differentiation.

BACKGROUND: Although high-affinity IgG auto- and alloantibodies are important drivers of kidney inflammation that can result in ESKD, therapeutic approaches that effectively reduce such pathogenic antibodies remain elusive. Erythropoietin (EPO) has immunomodulatory functions, but its effects on antibody production are unknown. METHODS: We assessed the effect and underlying mechanisms of EPO/EPO receptor (EPOR) signaling on primary and secondary, T cell-dependent and T-independent antibody formation using in vitro culture systems, murine models of organ transplantation and lupus nephritis, and mice conditionally deficient for the EPOR expressed on T cells or B cells. RESULTS: In wild-type mice, recombinant EPO inhibited primary, T cell-dependent humoral immunity to model antigens and strong, polyclonal stimuli, but did not alter T-independent humoral immune responses. EPO also significantly impaired secondary humoral immunity in a potent allogeneic organ transplant model system. The effects required T cell, but not B cell, expression of the EPOR and resulted in diminished frequencies of germinal center (GC) B cells and T follicular helper cells (TFH). In vitro and in vivo experiments showed that EPO directly prevented TFH differentiation and function via a STAT5-dependent mechanism that reduces CD4+ T cell expression of Bcl6. In lupus models, EPO reduced TFH, GC B cells, and autoantibody production, and abrogated autoimmune glomerulonephritis, demonstrating clinical relevance. In vitro studies verified that EPO prevents differentiation of human TFH cells. CONCLUSIONS: Our findings newly demonstrate that EPO inhibits TFH-dependent antibody formation, an observation with potential implications for treating antibody-mediated diseases, including those of the kidney.

Bone, inflammation and the bone marrow niche in chronic kidney disease: what do we know?

Recent improvements in our understanding of physiology have altered the way in which bone is perceived: no longer is it considered as simply the repository of divalent ions, but rather as a sophisticated endocrine organ with potential extraskeletal effects. Indeed, a number of pathologic conditions involving bone in different ways can now be reconsidered from a bone-centred perspective. For example, in metabolic bone diseases like osteoporosis (OP) and renal osteodystrophy (ROD), the association with a worse cardiovascular outcome can be tentatively explained by the possible derangements of three recently discovered bone hormones (osteocalcin, fibroblast growth factor 23 and sclerostin) and a bone-specific enzyme (alkaline phosphatase). Further, in recent years the close link between bone and inflammation has been better appreciated and a wide range of chronic inflammatory states (from rheumatoid arthritis to ageing) are being explored to discover the biochemical changes that ultimately lead to bone loss and OP. Also, it has been acknowledged that the concept of the bone-vascular axis may explain, for example, the relationship between bone metabolism and vessel wall diseases like atherosclerosis and arteriosclerosis, with potential involvement of a number of cytokines and metabolic pathways. A very important discovery in bone physiology is the bone marrow (BM) niche, the functional unit where stem cells interact, exchanging signals that impact on their fate as bone-forming cells or immune-competent haematopoietic elements. This new element of bone physiology has been recognized to be dysfunctional in diabetes (so-called diabetic mobilopathy), with possible clinical implications. In our opinion, ROD, the metabolic bone disease of renal patients, will in the future probably be identified as a cause of BM niche dysfunction. An integrated view of bone, which includes the BM niche, now seems necessary in order to understand the complex clinical entity of chronic kidney disease-mineral and bone disorders and its cardiovascular burden. Bone is thus becoming a recurrently considered paradigm for different inter-organ communications that needs to be considered in patients with complex diseases.

[Thrombophilic study in dialysis patients].

Chronic kidney disease is a complex phenotype that results from the association of underlying kidney disease and environmental and genetic factors. In addition to the traditional risk factors, genetic factors are involved in the etiology of renal disease, including single nucleotide polymorphisms which could account for the increased mortality from cardiovascular disease of our hemodialysis patients. The genes that influence the development and rate of progression of kidney disease deserve to be better defined. We have evaluated the alterations of thrombophilia genes in hemodialysis patients and in blood donors and we have compared the results obtained. The objective of the present study is to identify biomarkers of morbidity and mortality, which allow us to identify patients with chronic kidney disease at high risk, thanks to which it is possible to implement accurate therapeutic strategies and preventive strategies that have the objective of intensifying controls in these patients.

Efficacy of Supra-HFR in Removing FGF23 and Cytokines: A Single Session Analysis.

BACKGROUND/AIM: Supra hemodiafiltration with reinfusion of the endogenous ultrafiltrate (Supra-HFR) is a dialysis technique used to improve uremic toxin removal in the range of the middle molecular weight molecules. Supra-HFR does not require the preparation and online infusion of high-purity dialysis water because it allows the production of an endogenous ultrafiltrate that undergoes detoxification through an adsorbing resin. PATIENTS AND METHODS: We investigated the ability of Supra-HFR to remove fibroblast growth factor 23 (FGF23), interleukin 6 (IL-6), tumor necrosis factor alpha (TNF-alpha), interleukin 8 (IL-8), and transforming growth factor alpha (TGF-alpha) after a single session dialysis in nine patients affected by end stage renal disease (ESRD). The same patients underwent a single session of online hemodiafiltration (OL-HDF) to evaluate possible differences in FGF23 and IL-6 levels. RESULTS: A significant reduction in FGF23 was observed with both Supra-HFR (p=0.001) and OL-HDF. As for TNF-alpha and TGF-alpha, which were measured using Supra-HFR only, their percentage values were significantly lower at the end of dialysis than at the start (p=0.0028 and p=0.03, respectively). This did not change with post-dialysis rebound. Supra-HFR was found to have no effect on IL-6 and IL-8. Interestingly, the removal rate for FGF23 and IL-6 was similar to that observed with OL-HDF. CONCLUSION: Supra-HFR was not superior to OL-HDF, with suboptimal convective volume in the removal of the molecules tested, especially FGF23, which is considered a large middle molecular weight uremic toxin.

[Intoxications in nephrology: clinical cases and local experience in Sciacca Hospital].

Intoxications are a common problem all over the world and cause acid-base balance disturbances, dysionias or acute renal failure; they can develop rapidly leading to severe cellular dysfunction and death. Intoxications and drug overdoses often require the intervention of Nephrologists, for the correction of acidosis, the administration of selective inhibitory enzymes and also hemodialysis treatment. Extracorporeal therapies have been used to remove toxins for over fifty years and have acquired an increasing role, thanks to the use of new treatment modalities in intoxicated patients. In our clinical practice in the Covid period we have found an increase in clinical cases of intoxication with psychiatric drugs, including benzodiazepines, clozapine, lithium, quetiapine and cocaine.

Detoxification of bilirubin and bile acids with intermittent coupled plasmafiltration and adsorption in liver failure (HERCOLE study).

BACKGROUND: CPFA is an extracorporeal treatment used in severe sepsis to remove circulating proinflammatory cytokines. Limited evidence exists on the effectiveness of bilirubin adsorption by the hydrophobic styrenic resin, the distinctive part of CPFA. The aim of this study is to validate CPFA effectiveness in liver detoxification. METHODS: In this prospective observational study, we enrolled patients with acute or acute-on-chronic liver failure (serum total bilirubin > 20 mg/dL or MELD Score > 20) hospitalized from June 2013 to November 2017. CPFA was performed using the Lynda (Bellco/MedTronic, Mirandola, Italy) or the Amplya (Bellco/MedTronic, Mirandola, Italy) machines. Anticoagulation was provided with unfractionated heparin or citrate. Bilirubin and bile acids reduction ratios per session (RRs) were the main parameters for hepatic detoxification. RESULTS: Twelve patients with acute (n = 3) or acute-on-chronic (n = 9) liver failure were enrolled. Alcohol was the main cause of liver disease. Thirty-one CPFA treatments of 6 h each were performed, 19 with heparin and 12 with citrate. RRs was 28.8% (range 2.2-40.5) for total bilirubin, 32.7% (range 8.3-48.9) for direct bilirubin, 29.5% (range 6.5-65.4) for indirect bilirubin and 28.9% (16.7- 59.7) for bile acids. One patient received liver transplantation and 8/9 were alive at 1 year of follow-up. Three patients (25%) died: 2 during hospitalization and 1 for a cardiac event at 4 months of follow up with restored liver function. CONCLUSIONS: CPFA resulted to be effective in liver detoxification. Thus, it may be considered as a "bridge technique" both to the liver transplant and to the recovery of the basal liver function.

[Non erythropoietic effects of Erythropoietin].

Over the past two decades it has emerged that, in addition to erythropoietic activity, erythropoietin (EPO) has numerous other functions, including neuro-protective, anti-apoptotic, antioxidant, angiogenetic and immunomodulatory ones. EPO interacts with two different forms of its receptor (EPOR): a homodimer receptor, responsible for the erythropoietic effects, and a heterodimer receptor, responsible for the non-erythropoietic effects. The effects on the heterodimer receptor are responsible for EPO-induced prolongation of organ transplant survival in mice and humans. The development of new molecules that selectively target the heterodimer EPOR is allowing to test the effect of long-term treatments, without the possible complications related to the increased hematocrit.

Pneumococcal Polysaccharide Vaccine Ameliorates Murine Lupus.

Current guidelines encourage administering pneumococcal vaccine Prevnar-13 to patients with lupus, but whether such vaccinations affect disease severity is unclear. To address this issue, we treated 3-month-old MRL-lpr mice, that spontaneously develop a lupus-like syndrome, with Prevnar-13 or vehicle control. After 3 months, we quantified circulating anti-Pneumococcal polysaccharide capsule (PPS) antibodies and signs of disease severity, including albuminuria, renal histology and skin severity score. We also compared immunophenotypes and function of T and B cells from treated and untreated animals. Prevnar-13 elicited the formation of anti-pneumococcal IgM and IgG. Prevnar-13 treated animals showed reduced albuminuria, renal histological lesions, and milder dermatitis compared to vehicle-treated controls. Mitigated disease severity was associated with reduced and increased T follicular helper cells (TFH) and T follicular regulatory cells (TFR), respectively, in Prevnar-treated animals. T cells from Prevnar-13 vaccinated mice showed differential cytokine production after aCD3/aCD28 stimulation, with significantly decreased IL-17 and IL-4, and increased IL-10 production compared to non-vaccinated mice. In conclusion, pneumococcal vaccination elicits anti-pneumococcal antibody response and ameliorates disease severity in MRL-lpr mice, which associates with fewer TFH and increased TFR. Together, the data support use of Prevnar vaccination in individuals with SLE.

Erythropoietin inhibits SGK1-dependent TH17 induction and TH17-dependent kidney disease.

IL-17-producing CD4+ cells (TH17) are pathogenically linked to autoimmunity including to autoimmune kidney disease. Erythropoietin's (EPO) newly recognized immunoregulatory functions and its predominant intra-renal source suggested that EPO physiologically regulates TH17 differentiation, thereby serving as a barrier to the development of autoimmune kidney disease. Using in vitro studies of human and murine cells and in vivo models, we show that EPO ligation of its receptor (EPO-R) on CD4+ T cells directly inhibits TH17 generation and promotes trans-differentiation of TH17 into IL-17-FOXP3+CD4+ T cells. Mechanistically, EPO/EPO-R ligation abrogates upregulation of SGK1 gene expression and blocks p38 activity to prevent SGK1 phosphorylation, thereby inhibiting RORC-mediated transcription of IL-17 and IL-23 receptor genes. In a murine model of TH17-dependent aristolochic acid (ArA)-induced, interstitial kidney disease associated with reduced renal EPO production, we demonstrate that transgenic EPO overexpression or recombinant EPO (rEPO) administration limits TH17 formation and clinical/histological disease expression. EPO/EPO-R ligations on CD4+ T cells abrogate, while absence of T cell-expressed EPO-R augments, TH17 induction and clinical/histological expression of pristane-induced glomerulonephritis (associated with decreased intrarenal EPO). rEPO prevents spontaneous glomerulonephritis and TH17 generation in MRL-lpr mice. Together, our findings indicate that EPO physiologically and therapeutically modulate TH17 cells to limit expression of TH17-associated autoimmune kidney disease.

Association Between Lifestyle and Systemic Arterial Hypertension in Young Adults: A National, Survey-Based, Cross-Sectional Study.

INTRODUCTION: The prevalence of systemic arterial hypertension in young adults is increasing worldwide in association with modifiable risk factors. AIM: To assess the prevalence of high blood pressure (BP) in young adults participating to a screening campaign during the World Hypertension Day (17/05/2014), and to determine the possible association with lifestyle factors. METHODS: 493 individuals aged 18-35 years were selected in 13 Italian cities. All participants underwent BP measurement together with the administration of a questionnaire exploring: medical and drug history; traditional cardiovascular risk factors and diseases; dietary pattern; salt intake; sleep habits; mood disorders. RESULTS: High BP (≥140/90 mmHg) was found in 54 individuals, with a prevalence of 11% and awareness of 28%. Those with high BP values were more frequently men, reported a higher BMI and a greater use of corticosteroids and non-steroidal anti-inflammatory drugs, and had a lower anxiety score. Concerning dietary habits, they were more likely to eat cheese/cold cuts ≥3 times/week, to have their meals out ≥1/day and to eat in fast foods ≥1/week. In the multiple logistic regression analysis, male sex [OR 3.19, 95% CI (1.33-7.63)], BMI [OR 1.14 95% CI (1.04-1.25)], eating in fast foods [OR 3.10 95% CI (1.21-7.95)], and anxiety [OR 0.85 95% CI (0.75-0.97)], were independently associated with high BP. CONCLUSIONS: High BP values were found in 11 % young adults. Male sex, adiposity and alimentary habits were the main determinants of high BP values, indicating that young men are a suitable target for healthy lifestyle interventions.