Risk of graft loss in kidney transplant recipients after aortic valve replacement.

Surgical aortic valve replacement (SAVR) in kidney transplant recipients (KTR) is associated with high morbidity and mortality, and an increased risk of postoperative graft failure potentially leading to graft loss. Transcatheter aortic valve implantation (TAVI) emerged as an alternative in high-risk patients. However, data on TAVI in kidney transplant recipients are limited. We performed a retrospective analysis of 40 KTR in which aortic valve replacement was performed at our center between 2005 and 2015. The outcomes and follow-up of TAVI (n=20; 2010-2015) and SAVR (n=20; 2005-2015) were analyzed with respect to patient and graft survival. Baseline characteristics in both groups were comparable. Hospital stay after TAVI was significantly shorter compared to SAVR (19 [11.5-21.75] days vs. 33 [21-62] days, p=0.001). Acute graft failure occurred more frequently after SAVR (45% vs. 89.5%; p=0.006). Thirty-day mortality was 10% in both groups. However, in-hospital mortality reached 25% in the SAVR group (TAVI 10%), indicating a more complicated course after surgery. Moreover, during a median follow-up time of 1928 days in TAVI patients and 2717 days in patients after SAVR, graft loss occurred only in the surgically treated group (n=7). While one-year survival after TAVR was 90% compared to 69% after SAVR, long-term follow-up showed comparable results (at 5 years: TAVI 58% vs. 52% SAVR; log-rank-test: p=0.86). In KTR, TAVI can be performed with good mid- to long-term results. Compared to SAVR, renal outcomes seem to be improved after TAVI, suggesting better graft survival.

Acute kidney injury after in-hospital cardiac arrest in a predominant internal medicine and cardiology patient population: incidence, risk factors, and impact on survival.

INTRODUCTION: Prognosis of survivors from cardiac arrest is generally poor. Acute kidney injury (AKI) is a common finding in these patients. In general, AKI is well characterized as a marker of adverse outcome. In-hospital cardiac arrest (IHCA) represents a special subset of cardiac arrest scenarios with differential predisposing factors and courses after the event, compared to out-of-hospital resuscitations. Data about AKI in survivors after in-hospital cardiac arrest are scarce. METHODS: In this study, we retrospectively analyzed patients after IHCA for incidence and risk factors of AKI and its prognostic impact on mortality. For inclusion in the analysis, patients had to survive at least 48 h after IHCA. RESULTS: A total of 238 IHCA events with successful resuscitation and survival beyond 48 h after the initial event were recorded. Of those, 89.9% were patients of internal medicine, and 10.1% of patients from surgery, neurology or other departments. In 120/238 patients (50.4%), AKI was diagnosed. In 28 patients (23.3%), transient or permanent renal replacement therapy had to be initiated. Male gender, preexisting chronic kidney disease and a non-shockable first ECG rhythm during resuscitation were significantly associated with a higher incidence of AKI in IHCA-survivors. In-hospital mortality in survivors from IHCA without AKI was 29.7%, and 60.8% in patients after IHCA who developed AKI (p < 0.01 between groups).By multivariate analysis, AKI after IHCA persisted as an independent predictor of in-hospital mortality (HR 3.7 (95% CI 2.14-6.33, p ≤ 0.01)). CONCLUSION: In this cohort of survivors from IHCA, AKI is a frequent finding, with adverse impact on outcome. Therefore, therapeutic strategies to prevent AKI in post-IHCA patients are warranted.

Consistent alteration of chain length-specific ceramides in human and mouse fibrotic kidneys.

BACKGROUND: Several studies revealed alterations of single sphingolipid species, such as chain length-specific ceramides, in plasma and serum of patients with kidney diseases. Here, we investigated whether such alterations occur in kidney tissue from patients and mice suffering from renal fibrosis, the common endpoint of chronic kidney diseases. METHODS: Human fibrotic kidney samples were collected from nephrectomy specimens with hydronephrosis and/or pyelonephritis. Healthy parts from tumor nephrectomies served as nonfibrotic controls. Mouse fibrotic kidney samples were collected from male C57BL/6J mice treated with an adenine-rich diet for 14 days or were subjected to 7 days of unilateral ureteral obstruction (UUO). Kidneys of untreated mice and contralateral kidneys (UUO) served as respective controls. Sphingolipid levels were detected by LC-MS/MS. Fibrotic markers were analyzed by TaqMan® analysis and immunohistology. RESULTS: Very long-chain ceramides Cer d18:1/24:0 and Cer d18:1/24:1 were significantly downregulated in both fibrotic human kidney cortex and fibrotic murine kidney compared to respective control samples. These effects correlate with upregulation of COL1α1, COL3α1 and αSMA expression in fibrotic human kidney cortex and fibrotic mouse kidney. CONCLUSION: We have shown that very long-chain ceramides Cer d18:1/24:0 and Cer d18:1/24:1 are consistently downregulated in fibrotic kidney samples from human and mouse. Our findings support the use of in vivo murine models as appropriate translational means to understand the involvement of ceramides in human kidney diseases. In addition, our study raises interesting questions about the possible manipulation of ceramide metabolism to prevent progression of fibrosis and the use of ceramides as potential biomarkers of chronic kidney disease.

Blood ceramides as novel markers for renal impairment in systemic lupus erythematosus.

BACKGROUND: Lupus nephritis (LN) is the most common organ manifestation in systemic lupus erythematosus (SLE) and associated with a poor prognosis. Still, a noninvasive but reliable method to diagnose LN has not been established. Thus, we evaluated whether blood sphingolipids could serve as valid biomarkers for renal injury. METHODS: In this cross-sectional study, 82 participants were divided into three groups: 36 healthy controls and 17 SLE patients without renal injury (both: estimated glomerular filtration rate (eGFR) ≥ 80 ml/min/1.73 m2 and albumin/creatinine ≤ 30 mg/g) and 29  LN patients. LN patients were identified by renal biopsies and impaired renal function (eGFR < 80 ml/min/1.73 m2 and albumin/creatinine ratio > 30 mg/g). Venous blood was collected from all participants and sphingolipid levels in plasma and serum were measured by LC-MS/MS. RESULTS: Most interesting, concentrations of some specific ceramides, C16ceramide (Cer), C18Cer, C20Cer and C24:1Cer, were elevated in both, plasma and serum samples of patients suffering from biopsy-proven LN and impaired renal function, compared to healthy controls as well as SLE patients without renal injury. C24:1dhCer levels were elevated in plasma and serum samples from LN patients compared to SLE patients. Sphingosine levels were higher in plasma and serum of LN patients compared to healthy controls, but not compared to SLE patients. Sphinganine concentrations were significantly elevated in serum samples from LN patients compared to healthy controls and SLE. S1P and SA1P levels were higher in plasma samples of SLE and LN patients compared to healthy controls. Subsequent ROC analyses of plasma and serum data of the most altered ceramide species (C16Cer, C18Cer, C20Cer, C24:1Cer) between LN patients and SLE patients display a high diagnostic differentiation with significant AUCs especially for C24:1Cer serum levels. Further, C24:1Cer serum levels were not affected by glucocorticoid treatment and did not correlate with other renal markers, such as serum creatinine, eGFR and albumin/creatinine ratio. CONCLUSION: Our data reveal that chain-length specific ceramides in blood, most likely C24:1Cer levels in serum, could act as potent biomarkers for renal impairment in patients suffering from SLE.

Anatomy Revisited: Hemodialysis Catheter Malposition in the Left Ascending Lumbar Vein.

In selected cases, cuffed tunneled catheters via the iliac vein are implanted as a last resort access for hemodialysis. To monitor the correct position, sonography of the inferior vena cava (IVC) is sufficient in most cases. Position control using an X-ray of the abdomen is not routinely recommended when femoral catheters are implanted. In this report, we describe the case of a 59-year-old patient on chronic hemodialysis due to granulomatosis with polyangiitis and complex shunt history with multiple shunt occlusions and revisions. The implantation of an iliac-cuffed tunneled catheter led to complications because the catheter was malpositioned into the left ascending lumbar vein (ALV). It is important to be aware of potential incorrect positioning of dialysis catheters into the ALV. Due to the anatomical relation to the IVC, this happens more frequently on the left side than on the right side. In case of doubt, the correct placement of large-bore catheters via iliac access route should be verified by means of appropriate imaging before hemodialysis is performed.