A Case of Atypical Hemolytic Uremic Syndrome Triggered by Acute Pancreatitis in a Patient with a Membrane Cofactor Protein (CD46) Genetic Variant

Atypical hemolytic uremic syndrome (aHUS) is a type of HUS. We herein report a case of aHUS triggered by pancreatitis in a patient with a heterozygous variant of membrane cofactor protein (MCP; P165S), a complement-related gene. Plasma exchange therapy and hemodialysis improved thrombocytopenia and anemia without leading to end-stage kidney disease. This MCP heterozygous variant was insufficient to cause aHUS on its own. Pancreatitis, in addition to a genetic background with a MCP heterozygous variant, led to the manifestation of aHUS. This case supports the "multiple hit theory" that several factors are required for the manifestation of aHUS.

Effects of empagliflozin on progression of chronic kidney disease: a prespecified secondary analysis from the empa-kidney trial

BACKGROUND

Sodium-glucose co-transporter-2 (SGLT2) inhibitors reduce progression of chronic kidney disease and the risk of cardiovascular morbidity and mortality in a wide range of patients. However, their effects on kidney disease progression in some patients with chronic kidney disease are unclear because few clinical kidney outcomes occurred among such patients in the completed trials. In particular, some guidelines stratify their level of recommendation about who should be treated with SGLT2 inhibitors based on diabetes status and albuminuria. We aimed to assess the effects of empagliflozin on progression of chronic kidney disease both overall and among specific types of participants in the EMPA-KIDNEY trial.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA), and included individuals aged 18 years or older with an estimated glomerular filtration rate (eGFR) of 20 to less than 45 mL/min per 1·73 m2, or with an eGFR of 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher. We explored the effects of 10 mg oral empagliflozin once daily versus placebo on the annualised rate of change in estimated glomerular filtration rate (eGFR slope), a tertiary outcome. We studied the acute slope (from randomisation to 2 months) and chronic slope (from 2 months onwards) separately, using shared parameter models to estimate the latter. Analyses were done in all randomly assigned participants by intention to treat. EMPA-KIDNEY is registered at ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and then followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroups of eGFR included 2282 (34·5%) participants with an eGFR of less than 30 mL/min per 1·73 m2, 2928 (44·3%) with an eGFR of 30 to less than 45 mL/min per 1·73 m2, and 1399 (21·2%) with an eGFR 45 mL/min per 1·73 m2 or higher. Prespecified subgroups of uACR included 1328 (20·1%) with a uACR of less than 30 mg/g, 1864 (28·2%) with a uACR of 30 to 300 mg/g, and 3417 (51·7%) with a uACR of more than 300 mg/g. Overall, allocation to empagliflozin caused an acute 2·12 mL/min per 1·73 m2 (95% CI 1·83-2·41) reduction in eGFR, equivalent to a 6% (5-6) dip in the first 2 months. After this, it halved the chronic slope from -2·75 to -1·37 mL/min per 1·73 m2 per year (relative difference 50%, 95% CI 42-58). The absolute and relative benefits of empagliflozin on the magnitude of the chronic slope varied significantly depending on diabetes status and baseline levels of eGFR and uACR. In particular, the absolute difference in chronic slopes was lower in patients with lower baseline uACR, but because this group progressed more slowly than those with higher uACR, this translated to a larger relative difference in chronic slopes in this group (86% [36-136] reduction in the chronic slope among those with baseline uACR <30 mg/g compared with a 29% [19-38] reduction for those with baseline uACR ≥2000 mg/g; ptrend<0·0001).

INTERPRETATION

Empagliflozin slowed the rate of progression of chronic kidney disease among all types of participant in the EMPA-KIDNEY trial, including those with little albuminuria. Albuminuria alone should not be used to determine whether to treat with an SGLT2 inhibitor.

FUNDING

Boehringer Ingelheim and Eli Lilly.

Impact of primary kidney disease on the effects of empagliflozin in patients with chronic kidney disease: secondary analyses of the EMPA-KIDNEY trial

BACKGROUND

The EMPA-KIDNEY trial showed that empagliflozin reduced the risk of the primary composite outcome of kidney disease progression or cardiovascular death in patients with chronic kidney disease mainly through slowing progression. We aimed to assess how effects of empagliflozin might differ by primary kidney disease across its broad population.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA). Patients were eligible if their estimated glomerular filtration rate (eGFR) was 20 to less than 45 mL/min per 1·73 m2, or 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher at screening. They were randomly assigned (1:1) to 10 mg oral empagliflozin once daily or matching placebo. Effects on kidney disease progression (defined as a sustained ≥40% eGFR decline from randomisation, end-stage kidney disease, a sustained eGFR below 10 mL/min per 1·73 m2, or death from kidney failure) were assessed using prespecified Cox models, and eGFR slope analyses used shared parameter models. Subgroup comparisons were performed by including relevant interaction terms in models. EMPA-KIDNEY is registered with ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroupings by primary kidney disease included 2057 (31·1%) participants with diabetic kidney disease, 1669 (25·3%) with glomerular disease, 1445 (21·9%) with hypertensive or renovascular disease, and 1438 (21·8%) with other or unknown causes. Kidney disease progression occurred in 384 (11·6%) of 3304 patients in the empagliflozin group and 504 (15·2%) of 3305 patients in the placebo group (hazard ratio 0·71 [95% CI 0·62-0·81]), with no evidence that the relative effect size varied significantly by primary kidney disease (pheterogeneity=0·62). The between-group difference in chronic eGFR slopes (ie, from 2 months to final follow-up) was 1·37 mL/min per 1·73 m2 per year (95% CI 1·16-1·59), representing a 50% (42-58) reduction in the rate of chronic eGFR decline. This relative effect of empagliflozin on chronic eGFR slope was similar in analyses by different primary kidney diseases, including in explorations by type of glomerular disease and diabetes (p values for heterogeneity all >0·1).

INTERPRETATION

In a broad range of patients with chronic kidney disease at risk of progression, including a wide range of non-diabetic causes of chronic kidney disease, empagliflozin reduced risk of kidney disease progression. Relative effect sizes were broadly similar irrespective of the cause of primary kidney disease, suggesting that SGLT2 inhibitors should be part of a standard of care to minimise risk of kidney failure in chronic kidney disease.

FUNDING

Boehringer Ingelheim, Eli Lilly, and UK Medical Research Council.

The uric acid-urea distribution volume ratio is a potential marker of hydration status in patients on hemodialysis

The distribution volume of uric acid is affected by the amount of extracellular water (ECW), while urea distribution volume can be considered as total body water (TBW). Thus, the ratio of distribution volumes of uric acid and urea can be paralleled to and be considered as the proxy of ECW/TBW. A total of 108 patients at our facility was included. The uric acid and urea distribution volume ratio (UUVdR) calculated from the single-pool model, which was measured within 1 month of the time when the bioimpedance index was measured. ECW/TBW at the end of the HD session was measured by InBody S10. We investigated the association between the UUVdR and the ECW/TBW values and the factors affecting the residuals of the regression equation. We also evaluated the predictive ability of overhydration or dehydration in randomly selected two groups, i.e., the training group and the validation group. ECW/TBW correlated highly with UUVdR. Multivariate analysis demonstrated that only creatinine and ECW/TBW were significantly associated with regression residuals. The cutoff values of UUVdR for overhydration and dehydration were 0.666 and 0.579, respectively, in the training group. Their AUC were 0.872 and 0.898, respectively. The sensitivity and specificity values in the validation group were 0.571 and 0.868 for overhydration, and 0.444 and 0.953 for dehydration, respectively. UUVdR might be a proxy of hydration status in hemodialysis patients. It may be possible to predict hydration status without dedicated devices in the epidemiological study.

A multi-institutional, observational study of outcomes after catheter placement for peritoneal dialysis in Japan

BACKGROUND

This multi-institutional, observational study examined whether the outcomes after peritoneal dialysis (PD) catheter placement in Japan meet the audit criteria of the International Society for Peritoneal Dialysis (ISPD) guideline and identified factors affecting technique survival and perioperative complications.

METHODS

Adult patients who underwent first PD catheter placement for end-stage kidney disease between April 2019 and March 2021 were followed until PD withdrawal, kidney transplantation, transfer to other facilities, death, 1 year after PD start or March 2022, whichever came first. Primary outcomes were time to catheter patency failure and technique failure, and perioperative infectious complications within 30 days of catheter placement. Secondary outcomes were perioperative complications. Appropriate statistical analyses were performed to identify factors associated with the outcomes of interest.

RESULTS

Of the total 409 patients, 8 who underwent the embedded catheter technique did not have externalised catheters. Of the 401 remaining patients, catheter patency failure occurred in 25 (6.2%). Technical failure at 12 months after PD catheter placement calculated from cumulative incidence function was 15.3%. On Cox proportional hazards model analysis, serum albumin (hazard ratio (HR) 0.44; 95% confidence interval (CI) 0.27-0.70) and straight type catheter (HR 2.14; 95% CI 1.24-3.69) were the independent risk factors for technique failure. On logistic regression analysis, diabetes mellitus was the only independent risk factor for perioperative infectious complications (odds ratio 2.70, 95% CI 1.30-5.58). The occurrence rate of perioperative complications generally met the audit criteria of the ISPD guidelines.

CONCLUSION

PD catheter placement in Japan was proven to be safe and appropriate.

Matrix metalloproteinase-10 deficiency has protective effects against peritoneal inflammation and fibrosis via transcription factor NFκΒ pathway inhibition

One of the most common causes of discontinued peritoneal dialysis is impaired peritoneal function. However, its molecular mechanisms remain unclear. Previously, by microarray analysis of mouse peritoneum, we showed that MMP (matrix metalloproteinase)-10 expression is significantly increased in mice with peritoneal fibrosis, but its function remains unknown. Chlorhexidine gluconate (CG) was intraperitoneally injected to wild-type and MMP-10 knockout mice to induce fibrosis to elucidate the role of MMP-10 on peritoneal injury. We also examined function of peritoneal macrophages and mesothelial cells obtained from wild-type and MMP-10 knockout mice, MMP-10-overexpressing macrophage-like RAW 264.7 cells and MeT-5A mesothelial cells, investigated MMP-10 expression on peritoneal biopsy specimens, and the association between serum proMMP-10 and peritoneal solute transfer rates determined by peritoneal equilibration test on patients. MMP-10 was expressed in cells positive for WT1, a mesothelial marker, and for MAC-2, a macrophage marker, in the thickened peritoneum of both mice and patients. Serum proMMP-10 levels were well correlated with peritoneal solute transfer rates. Peritoneal fibrosis, inflammation, and high peritoneal solute transfer rates induced by CG were all ameliorated by MMP-10 deletion, with reduction of CD31-positive vessels and VEGF-A-positive cells. Expression of inflammatory mediators and phosphorylation of NFκΒ subunit p65 at S536 were suppressed in both MMP-10 knockout macrophages and mesothelial cells in response to lipopolysaccharide stimulation. Overexpression of MMP-10 in RAW 264.7 and MeT-5A cells upregulated pro-inflammatory cytokines with phosphorylation of NFκΒ subunit p65. Thus, our results suggest that inflammatory responses induced by MMP-10 are mediated through the NFκΒ pathway, and that systemic deletion of MMP-10 ameliorates peritoneal inflammation and fibrosis caused by NFκΒ activation of peritoneal macrophages and mesothelial cells.

Generation of Conditional KO Mice of CCN2 and Its Function in the Kidney

CCN2 has been shown to be closely involved in the progression of renal fibrosis, indicating the potential of CCN2 inhibition as a therapeutic target. Although the examination of the renal disease phenotypes of adult CCN2 knockout mice has yielded valuable scientific insights, perinatal death has limited studies of CCN2 in vivo. Conditional knockout technology has become widely used to delete genes in the target cell populations or time points using cell-specific Cre recombinase-expressing mice. Therefore, several lines of CCN2-floxed mice have been developed to assess the functional role of CCN2 in adult mice.CCN2 levels are elevated in renal fibrosis and proliferative glomerulonephritis, making them suitable disease models for assessing the effects of CCN2 deletion on the kidney. Renal fibrosis is characterized by glomerulosclerosis and tubulointerstitial fibrosis and transforming growth factor-β. CCN2 is increased in fibrosis and modulates a number of downstream signaling pathways involved in the fibrogenic properties of TGF-β. Unilateral ureteral obstruction is one of the most widely used models of renal tubulointerstitial fibrosis. In addition, anti-glomerular basement membrane antibody glomerulonephritis has become the most widely used model for evaluating the effect of increased renal CCN2 expression. Herein, we describe the construction of CCN2-floxed mice and inducible systemic CCN2 conditional knockout mice and methods for the operation of unilateral ureteral obstruction and the induction of anti-glomerular basement membrane antibody glomerulonephritis.

Relationship between resistance index and recirculation rate in vascular access

Background

The state of vascular access affects the efficiency of hemodialysis. Poor blood flow of vascular access causes recirculation, which reduces treatment efficiency. In the clinical setting, the resistance index (RI) is a commonly used parameter to evaluate the state of vascular access. However, there are few reports investigating the direct relationship between RI and the recirculation rate. In this study, the relationship between RI and the recirculation rate was investigated using computational fluid dynamics analysis.

Methods

We created a three-dimensional model that mimics vascular access in hemodialysis patients. Next, we input various blood flow waveforms (RI 0.00, 0.50, 0.60, 0.80, and 0.94) into the vascular model. Then, two needles were punctured into the blood vessel model. Blood was removed from the vessel by one needle at a rate of 200 ml/min and returned by the other needle at the same speed. The recirculation rate was calculated using the backflow from the blood return needle.

Results

The recirculation rates for the blood flow waveforms of RI 0.00, 0.50, 0.60, 0.80, and 0.94 were 0.00%, 0.29%, 0.44%, 11.6%, and 28.1%, respectively. The recirculation rate was higher for blood flow with higher RI. In addition, more recirculation occurred during the diastolic phase, when blood flow was slow.

Conclusions

When the minimum blood flow was slower than the hemodialysis blood removal speed, both backflow and the recirculation rate increased. Sufficient diastolic blood flow needs to be maintained to suppress recirculation.

Acute Tubulointerstitial Nephritis in Rosai-Dorfman Disease Mimicking IgG4-related Disease

Rosai-Dorfman-Destombes disease (RDD) is a non-Langerhans cell histiocytosis characterized by the accumulation of histiocytes inside the lymph nodes or extranodally. The association between RDD and IgG4-related disease (IgG4-RD) is discussed. We herein report a case of RDD manifesting as acute tubulointerstitial nephritis mimicking IgG4-RD. The first renal biopsy showed severe tubulointerstitial nephritis with infiltration of S100-positive histiocytes and IgG4-positive plasma cells; storiform fibrosis and obliterative phlebitis were not confirmed. After prednisolone therapy, IgG4-positive cells and S100-positive histiocytes were decreased, but the IgG4/IgG ratio increased despite clinical improvement. These findings indicated extranodal RDD in the kidney presenting as tubulointerstitial nephritis.

Peritoneal Dialysis Guidelines 2019 Part 2: Main Text (Position paper of the Japanese Society for Dialysis Therapy)

Background

This article is a duplicated publication from the Japanese version of “2019 JSDT Guidelines for Peritoneal Dialysis” with permission from the Japanese Society for Dialysis Therapy (JSDT). This clinical practice guideline (CPG) was developed primarily by the Working Group on Revision of Peritoneal Dialysis (PD) Guidelines of the Japanese Society for Dialysis Therapy. Recently, the definition and creation process for CPGs have become far more rigorous; traditional methods and formats no longer adhere to current standards. To improve the reliability of international transmission of our findings, CPGs are created in compliance with the methodologies developed by the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) working group. Part 2 of this PD guideline is the first CPG developed by our society that conforms to the GRADE approach.

Methods

Detailed processes were created in accordance with the Cochrane handbook and the GRADE approach developed by the GRADE working group.

Results

Clinical question (CQ)1: Is the use of renin-angiotensin system inhibitors (RAS inhibitors), such as angiotensin-converting enzyme inhibitors (ACEI) and angiotensin receptor blockers (ARB), effective in PD patients?

Recommendation: We suggest the usage of RAS inhibitors (ACEI and ARB) in PD patients (GRADE 2C).

CQ2: Icodextrin or glucose solution: which is more useful as a dialysate among patients with PD?

Recommendation: We suggest using icodextrin when managing body fluids in PD patients (GRADE 2C).

CQ3: Is it better to apply or not apply mupirocin/gentamicin ointment to the exit site?

Recommendation: We suggest not applying mupirocin/gentamicin ointment to the exit sites of PD patients (GRADE 2C).

CQ4: Which surgical approach is more desirable when a PD catheter is placed, open surgery or laparoscopic surgery?

No recommendation.

CQ5: Which administration route of antibiotics is better in PD patients with peritonitis, intravenous or intraperitoneal?

Recommendation: We suggest intraperitoneal administration of antibiotics in PD patients with peritonitis (GRADE 2C).

Note: The National Insurance does not currently cover intraperitoneal administration.

CQ6: Is peritoneal dialysis or hemodialysis better as the first renal replacement therapy in diabetic patients?

No recommendation.

Conclusions

In the future, we suggest that society members construct their own evidence to answer CQs not brought up in this guideline, and thereby show the achievements of Japan worldwide.

Two episodes of acute dyspnea that were induced by COVID-19 in a peritoneal dialysis patient

Dialysis patients have an increased risk of coronavirus disease 2019 (COVID-19)-related mortality. Acute heart failure is a frequent, lethal complication of COVID-19, and it is a risk factor for mortality in hemodialysis patients. Therefore, it is crucial to rapidly distinguish heart failure from COVID-19 pneumonia. Here, we report a case of two episodes of acute dyspnea that were induced by COVID-19 in a peritoneal dialysis (PD) patient. The first episode of acute dyspnea was an exacerbation of heart failure caused by COVID-19 when the patient had a volume overload status due to a peritoneal dialysis catheter malfunction. Heart failure induced by a catheter malfunction was due to omental wrapping, and it was treated with ultrafiltration by hemodialysis and mini-laparotomy. The patient's acute dyspnea was immediately resolved. The second episode of acute dyspnea was caused by COVID-19 pneumonia, which occurred 1 week after the first episode. This case suggests the importance of identifying heart failure and beginning adequate treatment, in COVID-19 patients with PD.

The Successful Treatment of a Case of HCV-associated Cryoglobulinemic Glomerulonephritis with Rituximab, Direct-acting Antiviral Agents, Plasmapheresis and Long-term Steroid Despite Serologically Persistent Cryoglobulinemia

Novel treatments with rituximab or direct-acting antiviral agents (DAAs) were expected to improve the clinical outcomes of hepatitis C virus (HCV)-associated cryoglobulinemia in the last decade. Recently, however, persistent cases of cryoglobulinemia have been reported, and the ideal approach to treating such cases has not been established. We herein report a case of the successful treatment of HCV-associated cryoglobulinemic glomerulonephritis with rituximab, DAAs, occasional plasmapheresis and long-term steroid, with the patient's renal function and proteinuria improving over the long term despite serologically persistent cryoglobulinemia. This case suggests the efficacy of combination treatment with rituximab, DAAs, occasional plasmapheresis and long-term steroid for persistent cryoglobulinemia.

Impact of east Japan earthquake disaster with massive tsunami for prevalence of Takotsubo syndrome – a multicenter regional registry before and after east Japan earthquake disaster

Background

Previous studies demonstrated Takotsubo syndrome (TS) was easy provoked by earthquake disaster. However, a previous other regional report demonstrated TS was not increased after 2011 east Japan earthquake disaster. The purpose of this study was to clarify incidence of TS after the earthquake disaster in Iwate prefecture during long term period.

Method

Consecutive hospitalized TS patients were registered during 8 years between 2009 and 2016 in our medical university and five Iwate prefecture hospitals. Moreover, patients were divided into two groups, i.e., those with the inland and those with tsunami-stricken area groups. Prevalence of TS were calculated by standard incidence ratio (SIR) before and after the earthquake disaster. Moreover, long-term prognosis in the both groups was compared using Kaplan-Meier analysis.

Results

A total of 112 TS (male 25 and female 87) were registered from acute coronary syndrome registry in each hospital (n=4,163). Averaged age was 75.3 year-old. A total number of TS just after the two months of the earthquake (March and April 2011) was nine and significance monthly variation was observed comparing with the other months (p=0.029). SIR before and after the disaster is as following Figure. There were no significant differences for long-term prognosis between the two groups (p=0.20).

Conclusion

Incidence of TS was increased in acute phase after east Japan earthquake disaster. However, significance increases were maintained during long-term period, although number of TS was decreased after acute phase. TS is increased not only acute but also chronic phase after the serious earthquake disaster.

Standard incidence ratio

Funding Acknowledgement

Type of funding source: None

Use of vertebral left atrial size for staging of dogs with myxomatous valve disease

INTRODUCTION/OBJECTIVES

The American College of Veterinary Internal Medicine (ACVIM) guidelines suggest that pimobendan should be initiated in dogs which meet all criteria of stage B2 myxomatous mitral valve disease (MMVD): murmur intensity ≥ 3/6, left atrial-to-aortic ratio ≥ 1.6, normalized left ventricular internal diameter in diastole ≥ 1.7, and vertebral heart size > 10.5. Recently, a new radiographic index for left atrial enlargement, vertebral left atrial size (VLAS), was proposed. The objective of the present study was to evaluate whether VLAS is useful in staging MMVD and if it can distinguish between ACVIM stages B1 and B2.

ANIMALS

Ninety-seven client-owned dogs with MMVD were evaluated and classified as ACVIM stage B1, B2, or C-D.

MATERIALS AND METHODS

The echocardiographs and radiographs of all the dogs were retrospectively evaluated to obtain left atrial-to-aortic ratio, normalized left ventricular internal diameter in diastole, and VLAS values. The data were analyzed to assess the correlation between these measurements and VLAS, and the optimal cutoff value of VLAS was determined.

RESULTS

A VLAS cutoff value of 2.6 provided the greatest diagnostic accuracy for identification of dogs with ACVIM stage B2 MMVD (area under the curve, 0.96; sensitivity, 95%; specificity, 84%). A VLAS ≥2.5 exhibited the highest sensitivity (sensitivity, 100%; specificity, 78%), and a VLAS ≥ 3.1 exhibited the highest specificity (sensitivity, 47%; specificity, 100%).

CONCLUSIONS

VLAS is a helpful index for monitoring MMVD using radiography. A VLAS cutoff value of 2.5 could be used to identify dogs that may benefit from echocardiography to determine if they have reached ACVIM stage B2.

Topical application of mupirocin to exit sites in patients on peritoneal dialysis: a systematic review and meta-analysis of randomized controlled trials

Background

The International Society for Peritoneal Dialysis guidelines recommends the topical application of antibiotics on the exit site for the prevention of peritoneal dialysis (PD)-related infections. However, the recommendation is based on meta-analyses on applying nasal mupirocin ointment or observational or retrospective studies. Here, we evaluated the efficacy of topical application of mupirocin on the exit site for the prevention of PD-related infections.

Methods

We searched the databases, MEDLINE and CENTRAL, documenting the topical application of antibiotics on the exit site in PD patients in April 2017. We included only randomized controlled trials (RCTs) with adult patients wherein the effects of mupirocin were examined. Exit site infection (ESI), peritonitis, and technical failure were assessed as the main outcomes.

Results

Overall, six RCTs were included in this study. It was uncertain whether the application of mupirocin ointment prevents ESI (rate ratio (RR), 0.36; 95% CI, 0.13–1.05), peritonitis (RR 0.78, 95% CI 0.50–1.21), and technical failure (RR, 1.35; 95% CI, 0.25–7.21). Moreover, a comparison between mupirocin and gentamicin showed no difference in the incidence of ESI (RR, 1.14; 95% CI, 0.27–4.81), peritonitis (RR, 0.85; 95% CI, 0.32–2.26), and technical failure (RR, 0.58; 95% CI, 0.28–1.20).

Conclusions

It remains unclear whether topical application of mupirocin on the exit site has any significant effects on PD-related infection or technical failure. Large-scale RCTs with high methodological quality are required to confirm the efficacy of topical application of antibiotics on the exit site.

Trial registration

UMINR000039267

Urgent-start peritoneal dialysis after laparoscopic dialysis catheter implantation: a single-center experience

Background

Appropriate timing of peritoneal dialysis (PD) catheter implantation and PD initiation is important. Several guidelines suggest starting PD at least 2 weeks after PD catheter implantation. Recently, urgent-start PD is widespread throughout the world. However, the ideal time to start PD after laparoscopic catheter implantation is not known. We investigated the safety and feasibility of early initiation (within 7 days) PD following laparoscopic peritoneal catheter implantation.

Methods

We retrospectively analyzed patients who underwent laparoscopic PD catheter implantation at the Kyoto University Hospital from January 1, 2006, to December 31, 2016. Based on when PD was initiated, the patients were divided into two groups, namely, early group, ≤ 7 days and late group, > 7 days after catheter implantation. Catheter-related complications and catheter survival were analyzed.

Results

We analyzed 29 and 26 patients in early and late groups, respectively. The age, sex, the incidence of diabetes and APD, and the follow-up period were not significantly different between the two groups. The interval from catheter implantation to the start of PD was 4.28 ± 1.83 and 162 ± 157.8 days in the early and late groups, respectively (P < 0.01). In a late group, 17 patients (65.4%) underwent catheter implantation using the Moncrief–Popovich technique. The use of bridge hemodialysis was higher in the early group (P < 0.01). No patients developed dialysate leakage in both groups, and no significant differences were observed for catheter malfunction (24.1% vs. 19.2%, P = 0.66), exit-site infection (ESI, 24.1% vs. 28%, P = 0.87), and peritonitis (7.14% vs. 8.0%, P = 0.91) within 6 months. Furthermore, early initiation of PD did not increase the risk of ESI, peritonitis, and PD withdrawal at 1, 2, and 5 years compared to that in the late group.

Conclusions

Urgent-start of PD with laparoscopic catheter implantation did not increase infection-related complications and PD withdrawal. Laparoscopic PD catheter implantation may allow the initiation of PD earlier than 7 days after implantation.

Deletion of connective tissue growth factor ameliorates peritoneal fibrosis by inhibiting angiogenesis and inflammation

Background

Connective tissue growth factor (CTGF/CCN2) regulates the signalling of other growth factors and promotes fibrosis. CTGF is increased in mice and humans with peritoneal fibrosis. Inhibition of CTGF has not been examined as a potential therapeutic target for peritoneal fibrosis because systemic CTGF knockout mice die at the perinatal stage.

Methods

To study the role of CTGF in peritoneal fibrosis of adult mice, we generated CTGF conditional knockout (cKO) mice by crossing CTGF floxed mice with RosaCreERT2 mice. We administered tamoxifen to Rosa-CTGF cKO mice to delete the CTGF gene throughout the body. We induced peritoneal fibrosis by intraperitoneal injection of chlorhexidine gluconate (CG) in wild-type and Rosa-CTGF cKO mice.

Results

Induction of peritoneal fibrosis in wild-type mice increased CTGF expression and produced severe thickening of the peritoneum. In contrast, CG-treated Rosa-CTGF cKO mice exhibited reduced thickening of the peritoneum. Peritoneal equilibration test revealed that the excessive peritoneal small-solute transport in CG-treated wild-type mice was normalized by CTGF deletion. CG-treated Rosa-CTGF cKO mice exhibited a reduced number of αSMA-, Ki67-, CD31- and MAC-2-positive cells in the peritoneum. Analyses of peritoneal mRNA showed that CG-treated Rosa-CTGF cKO mice exhibited reduced expression of Cd68, Acta2 (αSMA), Pecam1 (CD31) and Vegfa.

Conclusions

These results indicate that a deficiency of CTGF can reduce peritoneal thickening and help to maintain peritoneal function by reducing angiogenesis and inflammation in peritoneal fibrosis. These results suggest that CTGF plays an important role in the progression of peritoneal fibrosis.

Connective tissue growth factor is correlated with peritoneal lymphangiogenesis

Lymphatic absorption in the peritoneal cavity may contribute to ultrafiltration failure in peritoneal dialysis (PD). Lymphatic vessels develop during PD-related peritoneal fibrosis. Connective tissue growth factor (CTGF, also called CCN2) is an important determinant of fibrotic tissue remodeling, but little is known about its possible involvement in lymphangiogenesis. In this study, we investigated the relationship between CTGF and peritoneal lymphangiogenesis. A positive correlation was observed between vascular endothelial growth factor-C (VEGF-C), a major lymphangiogenic growth factor, and the CTGF concentration in human PD effluents. CTGF expression was positively correlated with expression of lymphatic markers and VEGF-C in human peritoneal biopsies. We found a positive correlation between the increase in CTGF and the increase in VEGF-C in cultured human peritoneal mesothelial cells (HPMCs) treated with transforming growth factor-β1 (TGF-β1). The diaphragm is a central player in peritoneal lymphatic absorption. CTGF expression was also correlated with expression of VEGF-C and lymphatics in a rat diaphragmatic fibrosis model induced by chlorhexidine gluconate (CG). Furthermore, CTGF gene deletion reduced VEGF-C expression and peritoneal lymphangiogenesis in the mouse CG model. Inhibition of CTGF also reduced VEGF-C upregulation in HPMCs treated with TGF-β1. Our results suggest a close relationship between CTGF and PD-associated lymphangiogenesis.

A Refractory Case of Secondary Membranous Nephropathy Concurrent with IgG4-related Tubulointerstitial Nephritis

A 58-year-old man with type 1 autoimmune pancreatitis was referred to nephrologists for severe proteinuria. Laboratory data revealed a high serum IgG4 level, hypoalbuminemia, and massive proteinuria, which were compatible with nephrotic syndrome. The renal pathological findings confirmed the diagnosis of secondary membranous nephropathy concurrent with IgG4-related tubulointerstitial nephritis. Despite the improvement of interstitial markers, the proteinuria was refractory to prednisolone, requiring cyclosporine to achieve complete remission. Membranous nephropathy is a rare manifestation of IgG4-related kidney disease. This case shows that the therapeutic response to prednisolone significantly differs between glomerular lesions and interstitial lesions of IgG4-related kidney disease.

CTGF in kidney fibrosis and glomerulonephritis

Background

Glomerulonephritis, which causes inflammation in glomeruli, is a common cause of end-stage renal failure. Severe and prolonged inflammation can damage glomeruli and lead to kidney fibrosis. Connective tissue growth factor (CTGF) is a member of the CCN matricellular protein family, consisting of four domains, that regulates the signaling of other growth factors and promotes kidney fibrosis.

Main body of the abstract

CTGF can simultaneously interact with several factors with its four domains. The microenvironment differs depending on the types of cells and tissues and differentiation stages of these cells. The diverse biological actions of CTGF on various types of cells and tissues depend on this difference in microenvironment. In the kidney, CTGF is expressed at low levels in normal condition and its expression is upregulated by kidney fibrosis. CTGF expression is known to be upregulated in the extra-capillary and mesangial lesions of glomerulonephritis in human kidney biopsy samples. In addition to involvement in fibrosis, CTGF modulates the expression of inflammatory mediators, including cytokines and chemokines, through distinct signaling pathways, in various cell systems. In anti-glomerular basement membrane (GBM) glomerulonephritis, systemic CTGF knockout (Rosa-CTGF cKO) mice exhibit 50% reduction of proteinuria and decreased crescent formation and mesangial expansion compared with control mice. In addition to fibrotic markers, the glomerular mRNA expression of Ccl2 is increased in the control mice with anti-GBM glomerulonephritis, and this increase is reduced in Rosa-CTGF cKO mice with nephritis. Accumulation of MAC2-positive cells in glomeruli is also reduced in Rosa-CTGF cKO mice. These results suggest that CTGF may be required for the upregulation of Ccl2 expression not only in anti-GBM glomerulonephritis but also in other types of glomerulonephritis, such as IgA nephropathy; CTGF expression and accumulation of macrophages in the mesangial area have been documented in these glomerular diseases. CTGF induces the expression of inflammatory mediators and promotes cell adhesion.

Short conclusion

CTGF plays an important role in the development of glomerulonephritis by inducing the inflammatory process. CTGF is a potentiate target for the treatment of glomerulonephritis.