C1 inhibitor mitigates peritoneal injury in zymosan-induced peritonitis.

Peritonitis, due to a fungal or bacterial infection, leads to injury of the peritoneal lining and thereby forms a hazard for the long-term success of peritoneal dialysis (PD) and remains a lethal complication in patients with PD. This study investigated whether C1 inhibitor (C1-INH) could protect against the progression of peritoneal injuries with five daily administrations of zymosan after mechanical scraping of the rat peritoneum to mimic fungal peritonitis. Severe peritoneal injuries were seen in this model, accompanied by fibrinogen/fibrin exudation and peritoneal deposition of complement activation products such as activated C3 and C5b-9. However, intraperitoneal injection of C1-INH decreased peritoneal depositions of activated C3 and C5b-9, ameliorated peritoneal thickening, reduced the influx of inflammatory cells, and prevented the production of peritoneal fibrous layers with both one and two doses of C1-INH each day. Our results suggest that C1-INH might be useful to protect against peritoneal injuries after causes of peritonitis such as fungal infection. This clinically available agent may thus help extend the duration of PD.NEW & NOTEWORTHY Peritoneal injuries associated with peritonitis comprise an important issue to prevent long-term peritoneal dialysis (PD) therapy. Here, we showed that C1 inhibitor (C1-INH), as an anticomplement agent, protected against peritoneal injuries in a peritonitis animal model related to fungal infection. Therefore, C1-INH might be useful to protect against peritoneal injuries after peritonitis due to fungal infection. This clinically available agent may thus help extend the duration of PD.

Anti-C5a complementary peptide mitigates zymosan-induced severe peritonitis with fibrotic encapsulation in rats pretreated with methylglyoxal.

In a previous study of fungal peritoneal injury in peritoneal dialysis patients, complement (C)-dependent pathological changes were developed in zymosan (Zy)-induced peritonitis by peritoneal scraping. However, the injuries were limited to the parietal peritoneum and did not show any fibrous encapsulation of the visceral peritoneum, which differs from human encapsular peritoneal sclerosis (EPS). We investigated peritoneal injury in a rat model of Zy-induced peritonitis pretreated with methylglyoxal (MGO) instead of scraping (Zy/MGO peritonitis) to clarify the role of C in the process of fibrous encapsulation of the visceral peritoneum. Therapeutic effects of an anti-C5a complementary peptide, AcPepA, on peritonitis were also studied. In Zy/MGO peritonitis, peritoneal thickness, fibrin exudation, accumulation of inflammatory cells, and deposition of C3b and C5b-9 with loss of membrane C regulators were increased along the peritoneum until day 5. On day 14, fibrous encapsulation of the visceral peritoneum was observed, resembling human EPS. Peritoneal injuries and fibrous changes were significantly improved with AcPepA treatment, even when AcPepA was administered following injection of Zy in Zy/MGO peritonitis. The data show that C5a might play a role in the development of encapsulation-like changes in the visceral peritoneum in Zy/MGO peritonitis. AcPepA might have therapeutic effects in fungal infection-induced peritoneal injury by preventing subsequent development of peritoneal encapsulation.

Liraglutide relieves cardiac dilated function than DPP-4 inhibitors.

INTRODUCTION: Diabetes mellitus is a progressive disease with cardiovascular complications. This study evaluated the effects of liraglutide, a glucagon-like peptide-1 analogue and the dipeptidyl peptidase 4 inhibitors sitagliptin and linagliptin on cardiac function in type 2 diabetes patients with renal impairment. MATERIALS AND METHODS: A total of 139 patients who were referred because of suboptimal glycaemic control were randomly assigned to liraglutide 0.9 mg/d (n = 45), sitagliptin 50 mg/d, (n = 49) or linagliptin 5 mg/d (n = 45) at enrolment and were evaluated. Blood glucose, glycosylated haemoglobin and serum creatinine were assayed every 3 months for 48 months. Echocardiography was performed every 12 months for 48 months. RESULTS: Compared with baseline, fasting glucose, postprandial glucose, and systolic and diastolic pressure, but not estimated glomerular filtration rate, significantly decreased in all three groups. Albuminuria decreased from 24 to 48 months with liraglutide, but only from 24 to 30 months with sitagliptin and linagliptin. Diastolic function, assessed by E/e' or left atrial dimension improved only with liraglutide. CONCLUSIONS: Liraglutide was effective for glucose and blood pressure control, reduced albuminuria and improved diastolic function. Diastolic function was not improved by sitagliptin and linagliptin.

Vascular endothelial growth factor receptor-3 is a novel target to improve net ultrafiltration in methylglyoxal-induced peritoneal injury.

Appropriate fluid balance is important for good clinical outcomes and survival in patients on peritoneal dialysis. We recently reported that lymphangiogenesis associated with fibrosis developed in the peritoneal cavity via the transforming growth factor-ß1-vascular endothelial growth factor-C (VEGF-C) pathway. We investigated whether VEGF receptor-3 (VEGFR-3), the receptor for VEGF-C and -D, might be a new target to improve net ultrafiltration by using adenovirus-expressing soluble VEGFR-3 (Adeno-sVEGFR-3) in rodent models of peritoneal injury induced by methylglyoxal (MGO). We demonstrated that lymphangiogenesis developed in these MGO models, especially in the diaphragm, indicating that lymphangiogenesis is a common feature in the peritoneal cavity with inflammation and fibrosis. In MGO models, VEGF-D was significantly increased in the diaphragm; however, VEGF-C was not significantly upregulated. Adeno-sVEGFR-3, which was detected on day 50 after administration via tail vein injections, successfully suppressed lymphangiogenesis in the diaphragm and parietal peritoneum in mouse MGO models without significant effects on fibrosis, inflammation, or neoangiogenesis. Drained volume in the peritoneal equilibration test using a 7.5% icodextrin peritoneal dialysis solution (the 7.5% icodextrin peritoneal equilibration test) was improved by Adeno-sVEGFR-3 on day 22 (P<0.05) and day 50 after reduction of inflammation (P<0.01), indicating that the 7.5% icodextrin peritoneal equilibration test identifies changes in lymphangiogenesis. The solute transport rate was not affected by suppression of lymphangiogenesis. In human peritoneal dialysis patients, the dialysate to plasma ratio of creatinine positively correlated with the dialysate VEGF-D concentration (P<0.001). VEGF-D mRNA was significantly higher in the peritoneal membranes of patients with ultrafiltration failure, indicating that VEGF-D is involved in the development of lymphangiogenesis in peritoneal dialysis patients. These results indicate that VEGFR-3 is a new target to improve net ultrafiltration by suppressing lymphatic absorption and that the 7.5% icodextrin peritoneal equilibration test is useful for estimation of lymphatic absorption.

Light Chain Deposition Disease Recurrence in Renal Allograft after Long-Term Remission.

Light chain deposition disease (LCDD) is a rare manifestation of monoclonal gammopathy, which can lead to renal failure. We previously reported a detailed recurrence process in a case of LCDD after renal transplantation. To the best of our knowledge, no report has described the long-term clinical course and renal pathology findings of recurrent LCDD in patients after renal transplantation. In this case report, we describe the long-term clinical presentation and changes in renal pathology of the same patient after early LCDD relapse in a renal allograft. A 54-year-old woman with recurrent immunoglobulin A λ-type LCDD in an allograft was admitted 1 year post-transplant for bortezomib and dexamethasone therapy. At 2 years post-transplantation, a graft biopsy performed after complete remission was achieved, showing some glomeruli with residual nodular lesions similar to the pre-treatment renal biopsy findings. However, the enlarged subendothelial space disappeared. She remained in complete remission serologically for 6 years. Subsequently, the ratio of serum κ/λ-free light chains decreased gradually. She underwent a transplant biopsy approximately 12 years after renal transplantation due to increased proteinuria and decreased renal function. Compared with the previous graft biopsy, almost all glomeruli showed advanced nodule formation and subendothelial expansion. Because the LCDD case relapsed after long-term remission following renal transplantation, protocol biopsy monitoring might be necessary.

Long-term peritoneal dialysate exposure modulates expression of membrane complement regulators in human peritoneal mesothelial cells.

The membrane complement regulators (CRegs) CD46, CD55, and CD59 are highly expressed on human peritoneal mesothelial cells. However, how mesothelial CRegs change according to the peritoneal dialysis (PD) history of patients has remained unclear. We therefore examined longitudinal changes in CRegs in primary cultured mesothelial cells from PD patients (human peritoneal mesothelial cells; HPMCs) and examined which components of PD fluid (PDF) affect CRegs in vitro. We measured levels of soluble C5b-9 in overnight-dwelling PDF in PD patients and also evaluated changes in CRegs expression on HPMCs collected from PDF using flow cytometry and polymerase chain reaction at a 1-year interval of PD therapy. We also evaluated changes in CReg expressions with stimulation by each component of PDF (glucose, lactic acid and pH) using the Met5A human mesothelial cell line. Levels of sC5b-9 in PDF decreased significantly during 1 year, while expressions of CD46 and CD59 proteins and mRNAs increased significantly in HPMCs during 1 year. Analyzing Met-5A cells, we observed that expressions of the three CRegs were increased by glucose and lactic acid in a concentration-dependent manner, but conversely that expressions of CRegs were decreased by lower pH stimulation. History of PD might influence expression of CRegs by HPMCs through properties of PDF such as glucose, lactic acid, and pH. These results suggest that mesothelial cells may alter expression of CRegs for the purpose of protecting the peritoneum and the presence of PDF might affect peritoneal homeostasis associated with the complement system.

Quality of Life and Emotional Distress in Peritoneal Dialysis and Hemodialysis Patients.

Cardiovascular disease-associated morbidity and mortality are reportedly higher in hemodialysis (HD) patients compared with peritoneal dialysis (PD) patients. However, few studies have estimated changes in state of depression and cognitive impairment in patients undergoing HD and PD. The present study evaluated the impact of HD or PD on patients' quality of life (QoL), cognitive impairment, and depression status over 2 years. This 24-month observational, prospective study included 45 HD and 30 PD patients. Patients were assessed before and every 12 months after starting dialysis for 24 months. Measurements included QoL (36-Item Short-Form Health Survey [SF-36]), cognitive impairment (Mini-Mental State Examination [MMSE]), depressive state (Center for Epidemiologic Studies Depression Scale [CES-D]), grip strength, and 24-h urine volume (UV). Physical and social component scores of the SF-36 significantly improved in PD patients at 24 months compared with those observed at baseline (42.8 vs. 39.4; P < 0.05 and 46.4 vs. 37.3; P < 0.05, respectively); however, scores remained unchanged in HD patients. MMSE scores were significantly decreased at 12 and 24 months in HD patients (29.0 vs. 26.0, 25.0; P < 0.05), but remained unchanged in PD patients. Moreover, CES-D scores significantly worsened at 24 months in HD patients (12.8 vs. 16.5), but remained unchanged in PD. Preservation of UV and grip strength was associated with SF-36, CES-D, and MMSE scores. Our findings indicate that PD is associated with higher QoL and recovery from cognitive failure compared with HD.

Impact of glucagon like peptide-1 receptor agonist and sodium glucose cotransporter 2 inhibitors on type 2 diabetes patients with renal impairment.

INTRODUCTION: Diabetes mellitus is a progressive disease with cardiovascular complications. We evaluated the impact of a glucagon like peptide-1 (GLP-1) receptor agonist and sodium glucose cotransporter 2 (SGLT-2) inhibitors dapagliflozin and empagliflozin on renal and cardiac function in type 2 diabetes patients with renal impairment. MATERIALS AND METHODS: A total of 156 patients referred with suboptimal glycemic control were assigned to Group G (GLP-1): n = 72 or Group S (SGLT-2 inhibitor)-dapagliflozin (n = 52) or empagliflozin (n = 32). Renal function was assessed every 3 months for 36 months. Cardiovascular parameters were evaluated every 12 months for 36 months. RESULTS: Compared with baseline, HbA1c and systolic blood pressure significantly decreased in both groups (p < 0.05). The estimated glomerular filtration rate decreased, but without significance. Albuminuria decreased significantly in both groups and then subsequently increased after 30 months in Group S. Diastolic cardiac function, assessed by E/e' or left atrial volume index, decreased only in Group G at 36 months. CONCLUSIONS: The GLP-1 receptor agonist and SGLT-2 inhibitors were effective for glycemic and blood pressure control and for maintaining renal function. The GLP-1 receptor agonist improved diastolic function at 36 months.

High Levels of Soluble C5b-9 Complex in Dialysis Fluid May Predict Poor Prognosis in Peritonitis in Peritoneal Dialysis Patients.

BACKGROUND: We searched for indicators to predict the prognosis of infectious peritonitis by measuring levels of complement proteins and activation products in peritoneal dialysis (PD) fluid (PDF) of patients at early stages of peritonitis. We retrospectively analyzed the relationship between the levels of sC5b-9, C3 and C4 in PDF and the subsequent clinical prognosis. METHODS: We measured levels of sC5b-9, C3 and C4 in PDF on days 1, 2 and 5 post-onset of peritonitis in 104 episodes of infectious peritonitis in PD patients from 2008 and retrospectively compared levels with clinical outcomes. Further analysis for the presence of causative microorganisms or to demonstrate bacterial culture negative peritonitis was performed and correlated with change of levels of sC5b-9 in PDF. RESULTS: When PD patients with peritonitis were divided into groups that either failed to recover from peritonitis and were finally withdrawn from PD (group 1; n = 25) or recovered (group 2; n = 79), levels of sC5b-9, C3 and C4 in PDF were significantly higher in group 1 patients compared to those in group 2 on day5. Analysis of microorganisms showed significantly higher sC5b-9 levels in PDF of peritonitis cases caused by culture negative peritonitis in group 1 compared with group 2 when we analyzed for individual microorganisms. Of note, on day5, the sC5b-9 levels in PDF were similarly high in peritonitis caused by fungi or other organisms. CONCLUSION: Our results suggested that levels of complement markers in PDF, especially sC5b-9, have potential as surrogate markers to predict prognosis of PD-related peritonitis.

Expression of membrane complement regulators, CD46, CD55 and CD59, in mesothelial cells of patients on peritoneal dialysis therapy.

We investigated the expression of membrane complement regulators (CRegs), CD46, CD55 and CD59 in human mesothelial cells, and correlated with clinical background and level of complement (C) activation products in peritoneal dialysis (PD) fluids (PDF) to clarify influence of the C activation system in PD patients. Expression of CRegs was assessed on primary cultures of mesothelial cells (HPMC) harvested from PD fluid of 31 PD patients. Because expression of CD55 but not CD46 and CD59 in mesothelial cells was significantly correlated to value of dialysate-to-plasma creatinine concentration ratio (D/P Cre) (p<0.005) as an indicator of peritoneal function, we focused on analysis of CD55 expression of HPMCs in comparison with levels of C activation products in the PDF of the PD patients, and their background factors. When comparing expression of the CRegs between systemic neutrophils and HPMC, no correlation was observed, supporting that change of CRegs' expression in HPMC was independently occurring in the peritoneum. Expression of CD55 protein in HPMC was closely correlated with expression at the mRNA level (p<0.0001) and was inversely correlated with levels of sC5b-9 (p<0.05), but not C3, C4, IL6 and CA125 in the PDF. Complications of diabetes, usage of icodextrin and residual renal function were not correlated with change of CD55 expression in HPMCs. Our data show that the process of PD therapy modifies expression of CD55 on peritoneal mesothelium and triggers local C activation. These findings support efforts to modify PD therapy to limit effects on activation and regulation of the C system.