Endostatin, soluble tumour necrosis factor receptor 1 and soluble tumour necrosis factor receptor 2 cannot predict new onset of microalbuminuria in patients with type 2 diabetes

AIMS

Inflammation and angiogenesis play an important role in the development of early diabetic kidney disease. We investigated the association of soluble Tumour Necrosis Factor Receptor 1 (sTNF-R1), sTNF-R2 and endostatin with new onset microalbuminuria in normoalbuminuric patients with diabetes mellitus type 2.

METHODS

We conducted a case control study to assess serum levels of sTNF-R1, sTNF-R2 and endostatin in 169 patients with new onset microalbuminuria and in 188 matched normoalbuminuric, diabetic controls. Baseline serum samples from participants of the ROADMAP (Randomized Olmesartan and Diabetes Microalbuminuria Prevention) and observational follow-up (ROADMAP-OFU) studies were used.

RESULTS

Endostatin and sTNF-R1 but not sTNF-R2 were increased at baseline in patients with future microalbuminuria. In the multivariate analysis, each log2 increment in endostatin levels was associated with an increase of only 6% in the risk of development of microalbuminuria (adjusted HR (95% CI) 1.006 (1.001-1011). sTNF-R1 and sTNF-R2 levels were conversely associated with microalbuminuria, but the results did not reach statistical significance. The respective adjusted HRs (95% CI) were 1.305 (0.928-1.774) and 0.874 (0.711-1.074).

CONCLUSIONS

sTNF-R1 and sTNF-R2 failed to predict the occurrence of microalbuminuria in normoalbuminuric patients with type 2 diabetes. Likewise, the utility of endostatin in predicting new onset proteinuria is limited.

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.

Impact of first-line use of caplacizumab on treatment outcomes in immune thrombotic thrombocytopenic purpura

BACKGROUND

The von Willebrand factor-directed nanobody caplacizumab has greatly changed the treatment of immune thrombotic thrombocytopenic purpura (iTTP) in recent years. Data from randomized controlled trials established efficacy and safety.

OBJECTIVES

This study aims to address open questions regarding patient selection, tailoring of therapy duration, obstacles in prescribing caplacizumab in iTTP, effect on adjunct treatment, and outcomes in the real-world setting.

METHODS

We report retrospective, observational cohorts of 113 iTTP episodes treated with caplacizumab and 119 historical control episodes treated without caplacizumab. We aggregated data from the caplacizumab phase II/III trials and real-world data from France, the United Kingdom, Germany, and Austria (846 episodes, 396 treated with caplacizumab, and 450 historical controls).

RESULTS

Caplacizumab was efficacious in iTTP, independent of the timing of therapy initiation, but curtailed the time of active iTTP only when used in the first-line therapy within 72 hours after diagnosis and until at least partial ADAMTS13-activity remission. Aggregated data from multiple study populations showed that caplacizumab use resulted in significant absolute risk reduction of 2.87% for iTTP-related mortality (number needed to treat 35) and a relative risk reduction of 59%.

CONCLUSION

Caplacizumab should be used in first line and until ADAMTS13-remission, lowers iTTP-related mortality and refractoriness, and decreases the number of daily plasma exchange and hospital stay. This trial is registered at www.

CLINICALTRIALS

gov as #NCT04985318.

Alternate-day dosing of caplacizumab for immune-mediated thrombotic thrombocytopenic purpura

BACKGROUND

The anti-von Willebrand factor (VWF) nanobody caplacizumab directly prevents the fatal microthrombi formation in immune-mediated thrombotic thrombocytopenic purpura (iTTP), thereby adding a new therapeutic principle to the treatment of this disorder. However, real-world treatment modalities beyond clinical trials remain heterogeneous.

METHODS

Here, we describe the risks and benefits of an alternate-day dosing regimen for caplacizumab by thoroughly analyzing the timing and outcome of this approach in a retrospective cohort of 25 iTTP patients treated with caplacizumab at seven different medical centers in Austria and Germany between 2018 and 2021.

RESULTS

Alternate-day dosing of caplacizumab appeared feasible and led to persisting normal platelet counts in most patients. Five patients experienced iTTP exacerbations or relapses that led to the resumption of daily caplacizumab application. VWF activity was repeatedly measured in 16 of 25 patients and documented sufficient suppression by caplacizumab after 24 and 48 h in line with published pharmacodynamics.

CONCLUSION

Extension of caplacizumab application intervals from daily to alternate-day dosing may be safely considered in selected patients after 3 to 4 weeks of daily treatment. Earlier modifications may be discussed in low-risk patients but require close monitoring for clinical and laboratory features of thrombotic microangiopathy.

Monocyte chemoattractant protein-1 predicts the development of diabetic nephropathy

AIM

Diabetic nephropathy (DN) is a devastating complication of diabetes mellitus (DM). Therefore, screening strategies in order to prevent its development and/or retard its progression are of paramount importance. We investigated if monocyte chemoattractant protein-1 (MCP-1) was associated with new onset microalbuminuria-the earliest sign of the albuminuric phenotype of DN- in patients with type 2 DM and normoalbuminuria.

METHODS

We measured MCP-1 in serum and urine samples from patients of the Randomized Olmesartan And Diabetes Microalbuminuria Prevention (ROADMAP) study and its Observational Follow-up (OFU) cohort. A case control design was used with inclusion of 172 patients who developed microalbuminuria (MA) and of 188 well matched controls who remained normoalbuminuric.

RESULTS

The median duration of follow-up for the ROADMAP cohorts was 6.5 years, whereas the mean time until occurrence of MA was 53.2 months. In the multivariate analysis, serum and urine MCP-1 remained significant predictors of new onset MA. The risk for MA increased continuously with increasing serum and urine MCP-1 levels but reached statistical significance only in the highest quartiles. The risk associations were stronger with serum MCP-1.

CONCLUSIONS

MCP-1 is a marker and possibly a mediator of early diabetic nephropathy. Further prospective studies are necessary to test whether diabetic patients with elevated MCP-1 levels would benefit from specific therapeutic interventions.

[SGLT2 inhibitors: What is new?]

Inhibitoren des Natrium-Glukose-Kotransporters 2 (SGTL2i, Gliflozine) wurden ursprünglich zur Diabetestherapie entwickelt, zeigten jedoch in den Zulassungsstudien unerwartete positive Effekte auf Herz- und Nierenfunktion. Im vergangenen Jahr wurden die Ergebnisse mehrerer großer Phase-III-Studien publiziert, welche die Effekte dieser Medikamentenklasse bei chronischer Niereninsuffizienz und Herzinsuffizienz auch ohne diabetische Grunderkrankung untersuchten. Die überwiegend positiven Ergebnisse haben dazu geführt, dass sich der Einsatzbereich von SGLT2i stetig erweitert. Der vorliegende Artikel soll einen Überblick über die neuesten Endpunktstudien zu SGLT2i geben und Konsequenzen für die Praxis aufzeigen, den Wissensstand zu Risiken und Nebenwirkungen wiedergeben und aktuelle Hypothesen zum Wirkmechanismus dieser Medikamentenklasse zusammenfassen.

Is ravulizumab the new treatment of choice for atypical hemolytic uremic syndrome (aHUS)?

Ravulizumab, a new long-acting C5 inhibitor, recently received FDA approval for the treatment of aHUS. Rates of complete thrombotic microangiopathy response were similar to those observed in major eculizumab trials; however, fewer patients in the ravulizumab study were able to stop dialysis, probably due to differences in the study populations. Until additional data/analyses are available, eculizumab remains the drug of choice for an acute aHUS episode, whereas ravulizumab has several advantages in maintenance treatment.

Long-Term Efficacy and Safety of the Long-Acting Complement C5 Inhibitor Ravulizumab for the Treatment of Atypical Hemolytic Uremic Syndrome in Adults

Introduction

Atypical hemolytic uremic syndrome (aHUS) is a rare, complex, multisystem disease of dysregulated complement activity, characterized by progressive thrombotic microangiopathy (TMA), acute kidney injury, and multiorgan dysfunction, which often progresses to chronic kidney disease. Results from the prospective clinical trial of ravulizumab (NCT02949128) reveal rapid resolution of TMA in patients with aHUS, with sustained efficacy and safety in a 26-week initial evaluation period.

Methods

The aim of this analysis was to characterize the long-term efficacy and the safety profile of ravulizumab in adults with aHUS who had completed the initial evaluation period of the trial. Complete TMA response, hematologic and kidney functions, and safety were evaluated for all patients available for follow-up in the extension period (median follow-up: 76.7 weeks; range: 0.6–118.3). This trial included a total of 58 patients, 49 of whom entered the extension period.

Results

A total of 4 additional patients achieved complete TMA response during the follow-up period. Normalization of platelet count, serum lactate dehydrogenase (LDH), and hemoglobin observed in the 26-week initial evaluation period was sustained until the last available follow-up, as were the improvements in the estimated glomerular filtration rate (eGFR) and patient quality of life. All efficacy endpoints were correlated with the sustained inhibition of complement C5. Most adverse events (AEs) occurred early during the initial evaluation period and decreased substantially during the extension period. No patient developed a meningococcal infection or died during the extension period.

Conclusion

This analysis reveals that ravulizumab administered every 8 weeks is efficacious with an acceptable safety profile for the long-term treatment of adults with aHUS and provides additional clinical benefit beyond 6 months of treatment.

Treatment of acquired thrombotic thrombocytopenic purpura without plasma exchange in selected patients under caplacizumab

BACKGROUND

Acquired thrombotic thrombocytopenic purpura (aTTP) is a rare, life-threatening autoimmune thrombotic microangiopathy. Current standard of care is therapeutic plasma exchange, immunosuppression, and caplacizumab, an anti-von Willebrand factor nanobody, which is effective in treating aTTP episodes.

PATIENTS/METHODS

Here we report on seven episodes of aTTP treated without plasma exchange in six female patients in Germany and Austria. Two episodes were initial presentations of aTTP; in five instances, patients experienced a relapse. In four episodes, moderate to severe organ dysfunction was observed; three cases presented with a mild course. All patients received caplacizumab immediately once aTTP was suspected or diagnosed, and plasma exchange was omitted based on shared decision making between patient and the treating physicians.

RESULTS

We observed a rapid and robust increase of platelet counts already after the first dose of caplacizumab, leading to a doubling of platelet counts within 17 hours (median), platelet counts normalized (>150 G/L) after median 84 hours. Lactate dehydrogenase, as a surrogate parameter of organ damage, improved in parallel to the platelet counts, indicating resolving microangiopathy.

CONCLUSIONS

In conclusion, in selected cases of acute bouts of aTTP, it seems feasible to delay or omit plasma exchange if platelet counts increase and organ function is stable after start of caplacizumab therapy.

SO054ONE-YEAR EFFICACY AND SAFETY OF THE LONG ACTING C5 INHIBITOR RAVULIZUMAB FOR THE TREATMENT OF ATYPICAL HAEMOLYTIC URAEMIC SYNDROME (AHUS) IN ADULTS

Background and Aims

Ravulizumab is a long-acting C5 inhibitor, derived from eculizumab, that is dosed every 8 weeks. Ravulizumab was approved in the United States for patients with atypical haemolytic uraemic syndrome (aHUS) and it is currently under evaluation in the EU based on the phase 3 trial (NCT02949128) efficacy and safety results at 26 weeks in patients with aHUS. Here, we report longer term efficacy and safety of ravulizumab obtained from the trial during the ongoing extension period.

Method

This phase 3 trial was a single arm, global, open label study in adults (≥18 years of age) with aHUS naïve to complement-inhibitor therapy. Ravulizumab was administered by intravenous infusion (IV) every 8 weeks during the maintenance phase. Patients fulfilling laboratory criteria for active TMA, ADAMTS13&gt;5%, and negative STEC-HUS testing were eligible.

Patients that completed the 26-week initial evaluation period could enter the extension period. The primary endpoint was complete TMA response (normalisation of platelet count and lactate dehydrogenase [LDH], and ≥ 25% improvement in serum creatinine from baseline, measured at 2 separate assessments obtained at least 28 days apart). Secondary endpoints included changes from baseline in haematological parameters, kidney function, and FACIT-fatigue scores. Treatment emergent adverse events were also evaluated. Here, interim cumulative data on primary and secondary endpoints through at least 52 weeks are reported.

Results

Forty-seven of 56 enrolled patients completed the initial evaluation period and received at least one dose of ravulizumab in the extension period. All patients achieved complete inhibition of terminal complement as demonstrated by sustained suppression of free-C5 (&lt;0.5 ug/mL). The proportion of patients achieving the individual components of complete TMA response improved during the extension period (Figure). At last follow-up, the number of patients achieving complete TMA response increased from 30/56 (53.6%) in the initial evaluation period to 34/56 (60.7%). Of the four additional patients that reached complete TMA response, three had a previous kidney transplant and one initiated treatment one month after TMA presentation. Improvement in FACIT-fatigue observed in the initial evaluation period was sustained in the extension period.

Although three new SAEs were reported during the extension period, there were no further fatal adverse events. As in the primary analysis period, no meningococcal infections occurred through the last patient follow-up.

Conclusion

In the extension period of the phase 3 trial, ravulizumab continued to have a good benefit: risk profile. At last follow-up, the cumulative efficacy of ravulizumab to treat complement mediated TMA in patients with aHUS improved to 61% from 54% in the initial evaluation period. Most AEs occurred in the first 26 weeks, and there were no meningococcal infections identified in the study. These results suggest that with ravulizumab further improvement in efficacy is possible with longer treatment with no compromise in safety and improved convenience of 8-week dosing intervals.

Influence of pre-treatment blood pressure levels on antihypertensive drug benefits in diabetics: the roadmap experience

Purpose: Most guidelines for treatment of hypertension in the setting of diabetes recommend a blood pressure (BP) target of <130/80 mmHg. However, uncertainty exists about the extent, effectiveness and safety of lowering BP in diabetics. To expand the evidence on this issue, we analysed data from the Randomised Olmesartan and Diabetes MicroAlbuminuria Prevention (ROADMAP) study population.Material: Substudy with blood pressure readings.Methods: The response after initiation of therapy and adequacy of BP control across patients with different BP levels at baseline were analysed.Results: BP at randomisation was 136.2(15.3)/80.6(9.5) [mean (SD)] mmHg with a range of 87-213/37-123 mmHg. At 1 year, mean BP was 127 (11.9)/75 (8.1) mmHg and the overall control rate (<130/80 mmHg) exceeded 61% in this population. The mean reductions in systolic [-9.4 (15.4) mmHg] and diastolic BP [-5.4 (9.5) mmHg] were highly dependent on the BP stage at Visit 1. At 1 year, treatment decreased the prevalence of patients with baseline BP levels of >160/100 from 9 to 2%[[mean BP change -31 (15.7)/ -14 (9.8) mmHg]] and of 140-159/90-99 mmHg from 32 to 11% [[mean BP change -16(12.7)/ -8.9 (8.7) mmHg]], with corresponding increases in the prevalence of patients with baseline BP levels of 120-139/80-99 from 48 to 65% [[mean BP change -4.1 (10.6)/ -3.1 (7.8) mmHg]]and of <120/80 from 11 to 22% [[mean BP change +5.9 (11.8)/+2.5 (8.6) mmHg]]. These effects did not change significantly thereafter and were maintained throughout follow-up.Conclusion: Blood pressure control is feasible in patients with diabetes without nephropathy, independent of baseline BP values. Asymmetric BP-lowering in the first year after starting therapy represents a true antihypertensive effect with sustainable shifts in BP severity.

Efficacy of Electrical Baroreflex Activation Is Independent of Peripheral Chemoreceptor Modulation

Arterial baroreflex activation through electrical carotid sinus stimulation has been developed for the treatment of resistant hypertension. Previous studies suggested that the peripheral chemoreflex is tonically active in hypertensive patients and may inhibit baroreflex responses. We hypothesized that peripheral chemoreflex activation attenuates baroreflex efficacy evoked by electrical carotid sinus stimulation. We screened 35 patients with an implanted electrical carotid sinus stimulator. Of those, 11 patients with consistent acute depressor response were selected (7 men/4 women, age: 67±8 years, body mass index: 31.6±5.2 kg/m², 6±2 antihypertensive drug classes). We assessed responses to electrical baroreflex stimulation during normoxia, isocapnic hypoxia (SpO₂: 79.0±1.5%), and hyperoxia (40% end-tidal O₂ fraction) by measuring heart rate, blood pressure, ventilation, oxygen saturation, end-tidal CO₂ and O₂ fractions, and muscle sympathetic nerve activity. During normoxia, baroreflex activation reduced systolic blood pressure from 164±27 to 151±25 mm Hg (mean±SD, P<0.001), heart rate from 64±13 to 61±13 bpm (P=0.002), and muscle sympathetic nerve activity from 42±12 to 36±12 bursts/min (P=0.004). Hypoxia increased systolic blood pressure 8±12 mm Hg (P=0.057), heart rate 10±6 bpm (P<0.001), muscle sympathetic nerve activity 7±7 bursts/min (P=0.031), and ventilation 10±7 L/min (P=0.002). However, responses to electrical carotid sinus stimulation did not differ between hypoxic and hyperoxic conditions: systolic blood pressure: -15±7 versus -14±8 mm Hg (P=0.938), heart rate: -2±3 versus -2±2 bpm (P=0.701), and muscle sympathetic nerve activity: -6±4 versus -4±3 bursts/min (P=0.531). We conclude that moderate peripheral chemoreflex activation does not attenuate acute responses to electrical baroreflex activation therapy in patients with resistant hypertension. These patients provided insight into human baroreflex-chemoreflex interactions that could not be gained otherwise.

Acute kidney injury and adverse renal events in patients receiving SGLT2-inhibitors: A systematic review and meta-analysis

BACKGROUND

Sodium-glucose cotransporter-2 inhibitors (SGLT2is) represent a new class of oral hypoglycemic agents used in the treatment of type 2 diabetes mellitus. They have a positive effect on the progression of chronic kidney disease, but there is a concern that they might cause acute kidney injury (AKI).

METHODS AND FINDINGS

We conducted a systematic review and meta-analysis of the effect of SGLT2is on renal adverse events (AEs) in randomized controlled trials and controlled observational studies. PubMed, EMBASE, Cochrane library, and ClinicalTrials.gov were searched without date restriction until 27 September 2019. Data extraction was performed using a standardized data form, and any discrepancies were resolved by consensus. One hundred and twelve randomized trials (n = 96,722) and 4 observational studies with 5 cohorts (n = 83,934) with a minimum follow-up of 12 weeks that provided information on at least 1 adverse renal outcome (AKI, combined renal AE, or hypovolemia-related events) were included. In 30 trials, 410 serious AEs due to AKI were reported. SGLT2is reduced the odds of suffering AKI by 36% (odds ratio [OR] 0.64 [95% confidence interval (CI) 0.53-0.78], p < 0.001). A total of 1,089 AKI events of any severity (AEs and serious AEs [SAEs]) were published in 41 trials (OR 0.75 [95% CI 0.66-0.84], p < 0.001). Empagliflozin, dapagliflozin, and canagliflozin had a comparable benefit on the SAE and AE rate. AEs related to hypovolemia were more commonly reported in SGLT2i-treated patients (OR 1.20 [95% CI 1.10-1.31], p < 0.001). In the observational studies, 777 AKI events were reported. The odds of suffering AKI were reduced in patients receiving SGLT2is (OR 0.40 [95% CI 0.33-0.48], p < 0.001). Limitations of this study are the reliance on nonadjudicated safety endpoints, discrepant inclusion criteria and baseline hypoglycemic therapy between studies, inconsistent definitions of renal AEs and hypovolemia, varying follow-up times in different studies, and a lack of information on the severity of AKI (stages I-III).

CONCLUSIONS

SGLT2is reduced the odds of suffering AKI with and without hospitalization in randomized trials and the real-world setting, despite the fact that more AEs related to hypovolemia are reported.

Incidence of acquired thrombotic thrombocytopenic purpura in Germany: a hospital level study

Background

Acquired thrombotic thrombocytopenic Purpura (aTTP) is a life-threatening ultra-orphan disease with a reported annual incidence between 1.5 and 6.0 cases per million in Europe and mainly affecting otherwise young and healthy adults aged 40 years on average. The goal of this study was to assess the incidence of aTTP in Germany.

Methods

A systematic review was performed to determine the published evidence on the aTTP epidemiology in Germany. To obtain additional evidence on the proportion of aTTP cases within the national Thrombotic Microangiopathy (TMA) population a hospital-level study was performed, using a retrospective data collection approach. Diagnosis of aTTP was confirmed if ADAMTS13 level were < 10% and/or the medical records explicitly mentioned aTTP diagnosis. The aggregated hospital data were then projected to the national level using logistic regression techniques.

Results

The systematic literature search did not provide incidence estimates of aTTP in Germany. Eight centers (≈27% of the top 30 TMA hospitals) delivered data according to a predefined data collection form. On average (year 2014–2016) a total number of 172 aTTP episodes per year was projected (95% confidence interval [95%CI]: 132–212). The majority were newly diagnosed aTTP cases (n = 121; 95%CI: 105–129), and 51 were recurrent aTTP cases (95%CI: 27–84). The average annual projected incidence (year 2014–2016) of aTTP episodes was 2.10 per million inhabitants in Germany (95%CI: 1.60–2.58).

Conclusions

The determined annual incidence of newly diagnosed aTTP cases and the overall annual incidence of aTTP episodes in Germany confirm the ultra-orphan character of aTTP. An external validation against international registries (France, UK and USA) shows that our findings are quite comparable with those international incidence rates.

Renale Denervation: Die Zeit ist noch nicht reif für den kommerziellen Einsatz

Eine blutdrucksenkende Wirkung der renalen Denervation ist bisher nur in Studien mit kurzer Nachbeobachtungsdauer (6 Monate) gesichert. Der placebokorrigierte Blutdruckeffekt ist gering und beträgt systolisch 4 – 8 mmHg. Den gleichen Effekt erreicht man mit einer antihypertensiven medikamentösen Therapie, die nur einen Bruchteil kostet und wofür ein kardiovaskulärer Vorteil belegt ist. Auch ist derzeit unklar, wie lange der Effekt einer renalen Denervation anhält. Im Tiermodell ist eine rasche Re-Innervation dokumentiert. Daher kann zum jetzigen Zeitpunkt der Einsatz einer renalen Denervation nicht empfohlen werden. Mehrere Fragen müssen in randomisierten, geblindeten Studien zuvor beantwortet sein: 1) Wie umfangreich muss die Ablation sein und wie sind die Langzeitergebnisse nach 3 – 5 Jahren? 2) Führen unterschiedliche Ablationstechniken zu unterschiedlichen Kurz- und Langzeitergebnissen? 3) Gibt es Patientenkollektive, die besonders profitieren? 4) Werden die kardiovaskuläre Morbidität und Letalität gesenkt? Bis diese Ergebnisse vorliegen, bleibt die medikamentöse Therapie mit Fixkombinationen das Mittel der Wahl.

[Human genetics in atypical hemolytic uremic syndrome-its role in diagnosis and treatment]

The atypical hemolytic uremic syndrome (aHUS), one of the three major forms of thrombotic microangiopathy, is characterized by genetic alterations in the area of the complement cascade, which can be detected in 40%-60% of all patients with aHUS. Mutations in over 10 different genes have now been identified. The most frequent and clinically relevant of these are mutations that result in a decreased or absent function of factor H, the formation of hybrid genes, or the formation of autoantibodies against factor H. Although genetics are not required for the diagnosis of aHUS, it is of great importance for the decision on how long to treat with the C5 inhibitor eculizumab. Also, knowledge of genetic alterations is absolutely essential if a living related donor is considered, in order to protect the living donor and recipient from developing aHUS.

Systemic Inflammation Precedes Microalbuminuria in Diabetes

Aim

The aim of the case-control study was to investigate if serum biomarkers indicative of vascular inflammation and endothelial dysfunction can predict the development of microalbuminuria in patients with diabetes mellitus type 2.

Methods

Among participants enrolled in the ROADMAP (Randomized Olmesartan And Diabetes MicroAlbuminuria Prevention) and observational follow-up (OFU) studies, a panel of 15 serum biomarkers was quantified from samples obtained at initiation of the study and tested for associations with the development of new-onset microalbuminuria during follow-up. A case-control study was conducted with inclusion of 172 patients with microalbuminuria and 188 matched controls. Nonparametric inferential, nonlinear regression, mediation, and bootstrapping statistical methods were used for the analysis.

Results

The median follow-up time was 37 months. At baseline, mean concentrations of C-X-C motif chemokine ligand 16 (CXCL-16), transforming growth factor (TGF)–β1 and angiopoietin-2 were higher in patients with subsequent microalbuminuria. In the multivariate analysis, after adjustment for age, sex, body mass index, glycated hemoglobin, duration of diabetes, low-density lipoprotein (LDL), smoking status, blood pressure, baseline urine albumin-to-creatinine ratio (UACR), estimated glomerular filtration rate (eGFR), time of follow-up and cardiovascular disease, CXCL-16 (odds ratio [OR] 2.60, 95% confidence interval [CI] 1.71–3.96), angiopoietin-2 (OR 1.50, 95% CI 1.14–1.98) and TGF-β1 (OR 1.03, 95% CI 1.01–1.04) remained significant predictors of new-onset microalbuminuria (P < 0.001). Inclusion of these biomarkers in conventional clinical risk models for prediction of microalbuminuria increased the area under the curve (AUC) from 0.638 to 0.760 (P < 0.001).

Conclusion

In patients with type 2 diabetes, elevated plasma levels of CXCL-16, angiopoietin-2, and TGF-β1 are independently predictive of microalbuminuria. Thus, these serum markers improve renal risk models beyond established clinical risk factors.

Outcomes in patients with atypical hemolytic uremic syndrome treated with eculizumab in a long-term observational study

BACKGROUND

There are limited long-term outcome data in eculizumab-treated patients with atypical hemolytic uremic syndrome (aHUS). We report final results from the largest prospective, observational, multicenter study of patients with aHUS treated with eculizumab.

METHODS

Patients with aHUS who participated in any of five parent eculizumab trials and received at least one eculizumab infusion were eligible for enrollment in a long-term follow-up study. Rates of thrombotic microangiopathy (TMA) manifestations off versus on eculizumab were evaluated. Additional endpoints included change from baseline estimated glomerular filtration rate (eGFR), long-term renal outcomes, and serious targeted treatment-emergent adverse events.

RESULTS

Among 93 patients (0-80 years of age), 51 (55%) remained on eculizumab and 42 (45%) discontinued; for those who discontinued, 21 (50%) reinitiated therapy. Patients who reinitiated eculizumab had similar baseline clinical characteristics to patients who remained on eculizumab, with higher likelihood of genetic/autoimmune complement abnormalities, more prior TMAs, and longer disease course versus those who did not reinitiate. Mean eGFR improved rapidly and remained stable for up to 6 years on eculizumab. In patients who discontinued, there was a trend toward decreasing renal function over time from discontinuation. Additionally, off-treatment TMA manifestation rates were higher in those aged < 18 years at diagnosis, with identified genetic/autoimmune complement abnormalities, or history of multiple TMAs prior to eculizumab initiation. The safety profile was consistent with previous studies. Three definite and one possible meningococcal infections related to eculizumab were reported and resolved with treatment. Three deaths unrelated to eculizumab were reported.

CONCLUSIONS

The current study confirms the efficacy and safety of eculizumab in aHUS, particularly with regard to long-term renal function and TMA events. Pediatric age at disease onset and presence of genetic or autoimmune complement abnormalities are risk factors for TMA events off treatment. Overall, patients who discontinue eculizumab may be at risk for additional TMA manifestations and renal function decreases. Discontinuation of eculizumab, with careful monitoring, is an option in select patients with consideration of patient preference, organ function normalization, and risk factors for relapse, including mutational analysis, age of onset, and history of multiple TMA episodes.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01522170 , January 31, 2012.

Eculizumab prevents thrombotic microangiopathy in patients with atypical haemolytic uraemic syndrome in a long-term observational study

Background

Eculizumab, a terminal complement inhibitor, is approved for atypical haemolytic uraemic syndrome (aHUS) to inhibit complement-mediated thrombotic microangiopathy (TMA).

Methods

In five parent studies, eculizumab effectively prevented TMA and improved renal and haematologic outcomes in patients with aHUS; therefore, these patients could enrol in this long-term, prospective, observational and multicentre study. The primary endpoint was the TMA manifestation rate off and on eculizumab post-parent study. Post hoc analyses evaluated rates during labelled versus non-labelled dosing regimens, and in those with versus without identified complement abnormalities. Serious targeted treatment-emergent adverse events (TEAEs) were evaluated.

Results

Of 87 patients in the current study, 39 and 76 had off- and on-treatment periods, respectively; 17 (44%) with off periods reinitiated eculizumab. TMA manifestation rate per 100 patient-years was 19.9 off and 7.3 on treatment [hazard ratio (HR), 4.7; P = 0.0008]; rates were highest off treatment and lowest during labelled regimens. TMA manifestations with hospitalizations/serious AEs occurred more frequently off versus on treatment. TMA rates were higher among patients with identified complement abnormalities (HR, 4.5; P = 0.0082). Serious targeted TEAEs occurred at similar rates off and on treatment.

Conclusions

As expected, patients with aHUS have increased risk of TMA manifestations after discontinuation of eculizumab or in the setting of non-labelled eculizumab dosing. Collectively, results show that maintaining eculizumab treatment minimizes risk of TMA, particularly in patients with identified complement abnormalities. Future studies are needed to further characterize TMA and longer term outcomes on labelled or non-labelled eculizumab regimens and after discontinuation of treatment.

C-C motif-ligand 2 inhibition with emapticap pegol (NOX-E36) in type 2 diabetic patients with albuminuria

Background

Emapticap pegol (NOX-E36) is a Spiegelmer® that specifically binds and inhibits the pro-inflammatory chemokine C-C motif-ligand 2 (CCL2) (also called monocyte-chemotactic protein 1). The objective of this exploratory study was to evaluate the safety and tolerability as well as the renoprotective and anti-diabetic potential of emapticap in type 2 diabetic patients with albuminuria.

Methods

A randomized, double-blind, placebo-controlled Phase IIa study was initiated in 75 albuminuric type 2 diabetics. Emapticap at 0.5 mg/kg and placebo were administered subcutaneously twice weekly for 12 weeks to 50 and 25 patients, respectively, followed by a treatment-free phase of 12 weeks.

Results

Twice weekly subcutaneous treatment with emapticap over 3 months was generally safe and well tolerated and reduced the urinary albumin/creatinine ratio (ACR) from baseline to Week 12 by 29% (P < 0.05); versus placebo a non-significant ACR reduction of 15% was observed (P = 0.221). The maximum difference, 26% (P = 0.064) between emapticap and placebo, was seen 8 weeks after discontinuation of treatment. At Week 12, the HbA1c changed by −0.31% in the emapticap versus +0.05% in the placebo group (P = 0.146). The maximum difference for HbA1c was observed 4 weeks after the last dose with −0.35% for emapticap versus +0.12% for placebo (P = 0.026). No relevant change in blood pressure or estimated glomerular filtration rate was seen between the treatment groups throughout the study. A post hoc analysis with exclusion of patients with major protocol violations, dual RAS blockade or haematuria increased the ACR difference between the two treatment arms to 32% at Week 12 (P = 0.014) and 39% at Week 20 (P = 0.010).

Conclusions

Inhibition of the CCL2/CCL2 receptor axis with emapticap pegol was generally safe and well tolerated. Beneficial effects on ACR and HbA1c were observed in this exploratory study, which were maintained after cessation of treatment. Taken together, emapticap may have disease-modifying effects that warrant further investigation in adequately powered confirmatory studies.

Probing depth is an independent risk factor for HbA1c levels in diabetic patients under physical training: a cross-sectional pilot-study

BACKGROUND

This cross-sectional study investigates the potential association between active periodontal disease and high HbA1c levels in type-2-diabetes mellitus subjects under physical training.

METHODS

Women and men with a diagnosis of non-insulin-dependent diabetes mellitus and ongoing physical and an ongoing exercise program were included. Periodontal conditions were assessed according to the CDC-AAP case definitions. Venous blood samples were collected for the quantitative analysis of HbA1c. Associations between the variables were examined with univariate and multivariate regression models.

RESULTS

Forty-four subjects with a mean age of 63.4 ± 7.0 years were examined. Twenty-nine subjects had no periodontitis, 11 had a moderate and 4 had a severe form of periodontal disease. High fasting serum glucose (p < 0.0001), high BMI scores (p = 0.001), low diastolic blood pressure (p = 0.030) and high probing depth (p = 0.036) were significantly associated with high HbA1c levels.

CONCLUSIONS

Within the limitations of this study HbA1c levels are positively associated with high probing pocket depth in patients with non-insulin-dependent diabetes mellitus under physical exercise training. Control and management of active periodontal diseases in non-insulin-dependent patients with diabetes mellitus is reasonable in order to maximize therapeutic outcome of lifestyle interventions.

Life-Threatening Complications of Extracorporeal Treatment in Patients with Severe Eosinophilia

We report three patients with massive eosinophilia of different etiology who developed bronchoconstriction, hypotension, and shock shortly after dialysis or leukapheresis had been begun. In two cases, ethylene oxide-free materials had been used ruling out an allergic reaction related to this compound. Degranulation of eosinophils with release of eosinophil peroxidase may have caused the observed adverse reactions, as suggested by in vitro experiments with blood from the three patients. Our observations draw attention to the fact that extracorporeal therapies may initiate life-threatening complications in patients with severe eosinophilia.

[Invasive treatment of hypertension : Update 2016]

Invasive treatment methods-more specifically renal denervation and baroreceptor activator therapy-have been used for the treatment of therapy-resistant hypertension for several years now. In particular, renal denervation has aroused great interest because it was easy to perform and the first studies provided very promising results. Meanwhile, however, three randomized, blinded studies have been published, and none showed a significant benefit of renal denervation compared to a sham procedure. In addition, in several studies it was demonstrated that intensification of drug therapy, particularly with spironolactone, is at least comparable. Carotid sinus node baroreceptor activator therapy tends to be superior to renal denervation, but the probe currently used is not optimal. The first results by inserting an arteriovenous shunt between the iliac artery and vein are promising, but lack long-term safety data. Currently, all invasive treatment procedures should be performed within the framework of studies or accurate register surveys.

Clinical and Laboratory Consequences of Platelet Transfusion in Shiga Toxin-Mediated Hemolytic Uremic Syndrome

Recent studies suggest that platelet transfusions are harmful in patients with thrombotic thrombocytopenic purpura, an entity of thrombotic microangiopathies. As the typical or Shiga toxin-producing Escherichia coli-induced hemolytic uremic syndrome (STEC-HUS) is also classified as thrombotic microangiopathy, we complement these data with an analysis of 250 patients from the German O104:H4 STEC-HUS outbreak. The effect of platelet transfusion in 44 patients who received platelet transfusions vs 206 control patients was investigated. Criteria for both groups were severe thrombocytopenia less than 50/nL, severe hemolysis with administration of packed red blood cells, and a complicated clinical course with admission to intensive care units. Readouts were clinical complications and changes in routine clinical chemistry and whole blood count. Chemistry values at admission and demographic parameters were comparable. Platelet transfusions were administered in 44 cases a median of 7 (interquartile range, 6-9) days after diarrhea onset. After platelet transfusion, we observed a transient and slight increase in inflammation parameters. No significant difference in major complications such as seizures, or requirement for ventilation or renal replacement therapy could be observed. Thrombotic events such as thrombosis or embolism were comparably rare in both groups (2.3% in platelet transfused vs 4.4% in controls, P=not significant). The mortality was not significantly different (0% vs 2.6%, P=not significant) in our study cohort, but overall in the outbreak, 6 of 711 STEC-HUS patients in Germany died of a procedural-related bleeding complications. In conclusion, platelet transfusions seem comparably safe in adult STEC-HUS patients, considering both the possible necessity for invasive procedures and potential risk for severe bleeding.

Acute Response to Unilateral Unipolar Electrical Carotid Sinus Stimulation in Patients With Resistant Arterial Hypertension

Bilateral bipolar electric carotid sinus stimulation acutely reduced muscle sympathetic nerve activity (MSNA) and blood pressure (BP) in patients with resistant arterial hypertension but is no longer available. The second-generation device uses a smaller unilateral unipolar disk electrode to reduce invasiveness while saving battery life. We hypothesized that the second-generation device acutely lowers BP and MSNA in treatment-resistant hypertensive patients. Eighteen treatment-resistant hypertensive patients (9 women/9 men; 53±11 years; 33±5 kg/m(2)) on stable medications have been included in the study. We monitored finger and brachial BP, heart rate, and MSNA. Without stimulation, BP was 165±31/91±18 mm Hg, heart rate was 75±17 bpm, and MSNA was 48±14 bursts per minute. Acute stimulation with intensities producing side effects that were tolerable in the short term elicited interindividually variable changes in systolic BP (-16.9±15.0 mm Hg; range, 0.0 to -40.8 mm Hg; P=0.002), heart rate (-3.6±3.6 bpm; P=0.004), and MSNA (-2.0±5.8 bursts per minute; P=0.375). Stimulation intensities had to be lowered in 12 patients to avoid side effects at the expense of efficacy (systolic BP, -6.3±7.0 mm Hg; range, 2.8 to -14.5 mm Hg; P=0.028 and heart rate, -1.5±2.3 bpm; P=0.078; comparison against responses with side effects). Reductions in diastolic BP and MSNA (total activity) were correlated (r(2)=0.329; P=0.025). In our patient cohort, unilateral unipolar electric baroreflex stimulation acutely lowered BP. However, side effects may limit efficacy. The approach should be tested in a controlled comparative study.

Spike rate of multi-unit muscle sympathetic nerve fibers after catheter-based renal nerve ablation

Patients with treatment-resistant arterial hypertension exhibited profound reductions in single sympathetic vasoconstrictor fiber firing rates after renal nerve ablation. In contrast, integrated multi-unit muscle sympathetic nerve activity (MSNA) changed little or not at all. We hypothesized that conventional MSNA analysis may have missed single fiber discharges, thus, obscuring sympathetic inhibition after renal denervation. We studied patients with difficult-to-control arterial hypertension (age 45-74 years) before, 6 (n = 11), and 12 months (n = 8) after renal nerve ablation. Electrocardiogram, respiration, brachial, and finger arterial blood pressure (BP), as well as the MSNA and raw MSNA signals were analyzed. We detected MSNA action-potential spikes using 2 stage kurtosis wavelet denoising techniques to assess mean, median, and maximum spike rates for each beat-to-beat interval. Supine heart rate and systolic BP did not change at 6 (ΔHR: -2 ± 3 bpm; ΔSBP: 2 ± 9 mm Hg) or at 12 months (ΔHR: -1 ± 3 mm Hg, ΔSBP: -1 ± 9 mm Hg) after renal nerve ablation. Mean burst frequency and mean spike frequency at baseline were 34 ± 3 bursts per minute and 8 ± 1 spikes per second. Both measurements did not change at 6 months (-1.4 ± 3.6 bursts/minute; -0.6 ± 1.4 spikes/second) or at 12 months (-2.5 ± 4.0 bursts/minute; -2.0 ± 1.6 spikes/second) after renal nerve ablation. After renal nerve ablation, BP decreased in 3 of 11 patients. BP and MSNA spike frequency changes were not correlated (slope = -0.06; P = .369). Spike rate analysis of multi-unit MSNA neurograms further suggests that profound sympathetic inhibition is not a consistent finding after renal nerve ablation.

Diagnosis and Prediction of CKD Progression by Assessment of Urinary Peptides

Progressive CKD is generally detected at a late stage by a sustained decline in eGFR and/or the presence of significant albuminuria. With the aim of early and improved risk stratification of patients with CKD, we studied urinary peptides in a large cross-sectional multicenter cohort of 1990 individuals, including 522 with follow-up data, using proteome analysis. We validated that a previously established multipeptide urinary biomarker classifier performed significantly better in detecting and predicting progression of CKD than the current clinical standard, urinary albumin. The classifier was also more sensitive for identifying patients with rapidly progressing CKD. Compared with the combination of baseline eGFR and albuminuria (area under the curve [AUC]=0.758), the addition of the multipeptide biomarker classifier significantly improved CKD risk prediction (AUC=0.831) as assessed by the net reclassification index (0.303±-0.065; P<0.001) and integrated discrimination improvement (0.058±0.014; P<0.001). Correlation of individual urinary peptides with CKD stage and progression showed that the peptides that associated with CKD, irrespective of CKD stage or CKD progression, were either fragments of the major circulating proteins, suggesting failure of the glomerular filtration barrier sieving properties, or different collagen fragments, suggesting accumulation of intrarenal extracellular matrix. Furthermore, protein fragments associated with progression of CKD originated mostly from proteins related to inflammation and tissue repair. Results of this study suggest that urinary proteome analysis might significantly improve the current state of the art of CKD detection and outcome prediction and that identification of the urinary peptides allows insight into various ongoing pathophysiologic processes in CKD.

The Randomized Olmesartan and Diabetes Microalbuminuria Prevention (ROADMAP) observational follow-up study: benefits of RAS blockade with olmesartan treatment are sustained after study discontinuation

Background

The Randomized Olmesartan and Diabetes Microalbuminuria Prevention (ROADMAP) study showed that 40 mg Olmesartan medoxomil (OM) versus placebo delayed microalbuminuria onset in patients with type 2 diabetes and normoalbuminuria.

Methods and Results

One thousand seven hundred and fifty‐eight ROADMAP patients (placebo arm: 877; OM arm: 881) participated in the observational follow up (OFU) with an average of 3.3 years. They received standard medical care and micro‐ and macrovascular events were documented. During observational follow‐up 62.9% and 60.1% in the former OM and placebo group, respectively, received treatment with a RAS blocking agent. During the OFU period the systolic blood pressure (SBP) increased to mean values of 135 mm Hg in both groups. Patients who had developed microalbuminuria during ROADMAP had a higher incidence of cardio‐ and cerebrovascular events (OR 1.77, CI 1.03 to 3.03, P=0.039) during the OFU period compared with patients in whom this was not the case. Diabetic retinopathy was significantly reduced in the former OM group (8 [0.9%] versus 23 [2.6%], OR: 0.34, CI 0.15 to 0.78, P=0.011) and the rate of microalbuminuria was numerically reduced. Congestive heart failure requiring hospitalization (3 [0.3%] versus 12 [1.4%], OR: 0.23, CI 0.06 to 0.85, P=0.027) was reduced and there was a trend of reduced cardio‐/cerebrovascular events (OM versus Pb: 73 [8.3%] versus 86 [9.8%] patients). Seven (0.8%) deaths (including 2 CV events) were reported in former placebo patients versus 3 (0.3%) (non‐CV events) in former OM patients.

Conclusions

Development of microalbuminuria is a valid marker for future CV events. RAS blockade with Olmesartan might cause sustained reduction (legacy effect) of micro‐ and macrovascular events.

Renal PKC-ε deficiency attenuates acute kidney injury and ischemic allograft injury via TNF-α-dependent inhibition of apoptosis and inflammation

Acute kidney injury (AKI) increases the risk of morbidity and mortality after major surgery and transplantation. We investigated the effect of PKC-ε deficiency on AKI and ischemic allograft damage after kidney transplantation. PKC-ε-deficient and wild type (WT) control mice were subjected to 35 min of renal pedicle clamping to induce AKI. PKC-ε deficiency was associated with a marked improvement in survival and an attenuated loss of kidney function. Furthermore, functional MRI experiments revealed better renal perfusion in PKC-ε-deficient mice than in WT mice one day after IRI. Acute tubular necrosis and neutrophil infiltration were markedly reduced in PKC-ε-deficient mice. To determine whether this resistance to ischemia-reperfusion injury resulted from changes in local renal cells or infiltrating leukocytes, we studied a life-supporting renal transplant model of ischemic graft injury. We transplanted kidneys from H2b PKC-ε-deficient mice (129/SV) and their corresponding WT littermates into major histocompatibility complex-incompatible H2d recipients (BALB/c) and induced ischemic graft injury by prolonged cold ischemia time. Recipients of WT allografts developed severe renal failure and died within 10 days of transplantation. Recipients of PKC-ε-deficient allografts had better renal function and survival; they had less generation of ROS and upregulation of proinflammatory proteins (i.e., ICAM-1, inducible nitric oxide synthase, and TNF-α) and showed less tubular epithelial cell apoptosis and inflammation in their allografts. These data suggest that local renal PKC-ε expression mediates proapoptotic and proinflammatory signaling and that an inhibitor of PKC-ε signaling could be used to prevent hypoxia-induced AKI.