Brain-specific biomarkers in urine as a non-invasive approach to monitor neuronal and glial damage.

BACKGROUND AND PURPOSE: This study evaluates the quantitative measurability of glial fibrillary acidic protein (GFAP), neurofilament light chain (NfL), ubiquitin carboxy-terminal hydrolase L1 (UCH-L1) and total tau (t-tau) in urine of patients with acute cerebral damage. METHODS: Serum and urine samples were prospectively collected from patients with an acute ischemic stroke or intracerebral hemorrhage (target group) and compared to healthy subjects (control group); samples were measured using ultrasensitive single-molecule arrays (Simoa®). Glomerular barrier function was assessed based on albumin-creatinine ratio (ACR); biomarker-creatinine ratios were calculated for correction of urine dilution. RESULTS: Ninety-three urine-serum pairs in the target group and 10 urine-serum pairs in the control group were measured. The mean absolute concentration ± standard deviation in urine of the target and control groups were 184.7 ± 362.4 pg/ml and 27.3 ± 24.1 pg/ml for GFAP (r = 0.3 [Wilcoxon effect size], p = 0.007), 17.5 ± 38.6 pg/ml and 0.9 ± 0.3 pg/ml for NfL (r = 0.4, p < 0.005), 320.2 ± 443.3 pg/ml and 109.6 ± 116.8 pg/ml for UCH-L1 (r = 0.26, p = 0.014), and 219.5 ± 255.8 pg/ml and 21.1 ± 27.1 pg/ml for t-tau (r = 0.37, p < 0.005), respectively, whereas biomarker-creatinine ratio was significantly different only for NfL (r = 0.29, p = 0.015) and t-tau (r = 0.32, p < 0.01). In patients with intact glomerular barrier (ACR < 30 mg/g), only NfL in urine was significantly different between the target and control group and showed a significant correlation with the respective serum concentrations (r = 0.58 [Pearson's correlation-coefficient], p < 0.005). CONCLUSION: All four investigated biomarkers could be measured in urine, with NfL and t-tau showing the strongest effect size after correction for urine dilution. NfL revealed the most accurate relation between serum and urine concentrations in patients with intact kidney function.

Impact of Moderna mRNA-1273 Booster Vaccine on Fully Vaccinated High-Risk Chronic Dialysis Patients after Loss of Humoral Response.

The long-term effect of protection by two doses of SARS-CoV-2 vaccination in patients receiving chronic intermittent hemodialysis (CIHD) is an urging question. We investigated the humoral and cellular immune response of 42 CIHD patients who had received two doses of SARS-CoV-2 vaccine, and again after a booster vaccine with mRNA-1273 six months later. We measured antibody levels and SARS-CoV-2-specific surrogate neutralizing antibodies (SNA). Functional T cell immune response to vaccination was assessed by quantifying interferon-γ (IFN-γ) and IL-2 secreting T cells specific for SARS-CoV-2 using an ELISpot assay. Our data reveal a moderate immune response after the second dose of vaccination, with significantly decreasing SARS-CoV-2-specific antibody levels and less than half of the study group showed neutralizing antibodies six months afterwards. Booster vaccines increased the humoral response dramatically and led to a response rate of 89.2% for antibody levels and a response rate of 94.6% for SNA. Measurement in a no response/low response (NR/LR) subgroup of our cohort, which differed from the whole group in age and rate of immunosuppressive drugs, indicated failure of a corresponding T cell response after the booster vaccine. We strongly argue in favor of a regular testing of surrogate neutralizing antibodies and consecutive booster vaccinations for CIHD patients to provide a stronger and persistent immunity.

Incidence, Risk Factors, and Outcome of Acute Kidney Injury in Neurocritical Care.

PURPOSE: Acute kidney injury (AKI) is a severe complication in medical and surgical intensive care units accounting for a high morbidity and mortality. Incidence, risk factors, and prognostic impact of this deleterious condition are well established in this setting. Data concerning the neurocritically ill patients is scarce. Therefore, aim of this study was to determine the incidence of AKI and elucidate risk factors in this special population. METHODS: Patients admitted to a specialized neurocritical care unit between 2005 and 2011 with a length of stay above 48 hours were analyzed retrospectively for incidence, cause, and outcome of AKI (AKI Network-stage ≥2). RESULTS: The study population comprised 681 neurocritically ill patients from a mixed neurosurgical and neurological intensive care unit. The prevalence of chronic kidney disease (CKD) was 8.4% (57/681). Overall incidence of AKI was 11.6% with 36 (45.6%) patients developing dialysis-requiring AKI. Sepsis was the main cause of AKI in nearly 50% of patients. Acute kidney injury and renal replacement therapy are independent predictors of worse outcome (hazard ratio [HR]: 3.704; 95% confidence interval [CI]: 1.867-7.350; P < .001; and HR: 2.848; CI: 1.301-6.325; P = .009). Chronic kidney disease was the strongest independent risk factor (odds ratio: 12.473; CI: 5.944-26.172; P < .001), whereas surgical intervention or contrast agents were not associated with AKI. CONCLUSIONS: Acute kidney injury in neurocritical care has a high incidence and is a crucial risk factor for mortality independently of the underlying neurocritical condition. Sepsis is the main cause of AKI in this setting. Therefore, careful prevention of infectious complications and considering CKD in treatment decisions may lower the incidence of AKI and hereby improve outcome in neurocritical care.

A randomized controlled trial of the effect of spironolactone on left ventricular mass in hemodialysis patients.

Mineralocorticoid receptor antagonists have beneficial effects on left ventricular remodeling, cardiac fibrosis, and arrhythmia in heart failure, but efficacy and safety in dialysis patients is less clear. We evaluated the effect of spironolactone on left ventricular mass (LVM), an independent predictor of all-cause and cardiovascular mortality, in hemodialysis patients. In this placebo-controlled, parallel-group trial, 97 hemodialysis patients (23% female; mean age 60.3 years) were randomized to spironolactone 50 mg once daily (n=50) or placebo (n=47). The primary efficacy endpoint was change in LVM index (LVMi) from baseline to 40 weeks as determined by cardiac magnetic resonance imaging. Safety endpoints were development of hyperkalemia and change in residual renal function. There was no significant change in LVMi in participants randomized to spironolactone compared to placebo (-2.86±11.87 vs. 0.41±10.84 g/m2). There was also no difference in the secondary outcomes of mean 24-hour systolic or diastolic ambulatory blood pressure, left ventricular ejection fraction, 6-minute walk test distance, or New York Heart Association functional class. Moderate hyperkalemia (pre-dialysis potassium levels of 6.0-6.5 mmol/L) was more frequent with spironolactone treatment (155 vs. 80 events), but severe hyperkalemia (≥6.5 mmol/L) was not (14 vs. 24 events). Changes in residual urine volume and measured glomerular filtration rate did not differ between groups. There were no deaths in the spironolactone group and 4 deaths in the placebo group. Thus, treatment with 50 mg spironolactone did not change left ventricular mass index, cardiac function, or blood pressure in hemodialysis patients. Spironolactone increased the frequency of moderate hyperkalemia, but did not increase severe hyperkalemia.

Key role of renal biopsy in management of progressive chronic kidney disease in liver graft recipients.

AIMS: Chronic kidney disease (CKD) is a common complication after liver transplantation (LT). The etiology of CKD is broad and may only be assessed accurately by renal histology. The current study aimed to analyze the safety of renal biopsy in daily clinical practice as well as its usefulness regarding management of CKD after LT. METHODS: We performed a retrospective analysis of clinical data and renal biopsies obtained from patients with severe renal impairment (overt proteinuria, progressive deterioration of renal function) after LT with respect to safety, etiology of renal disease, and therapeutic consequences. RESULTS: Renal biopsies were obtained from 14 patients at median (minimum-maximum) 3 (0.2-12) years after LT. No major complications associated with renal biopsy were observed. Histomorphological alterations were varied (nephrosclerosis, n = 5; IgA-glomerulonephritis, n = 4; tenofovir-associated nephropathy, membranoproliferative glomerulonephritis type 1, membranous glomerulonephritis, amyloid A amyloidosis, and calcineurin inhibitor nephropathy, n = 1, respectively). The diagnosis of specific renal diseases other than calcineurin-inhibitor nephrotoxicity facilitated specific treaments and avoided unnecessary modification of immunosuppression in the majority of patients. CONCLUSIONS: Renal biopsy in patients with CKD after LT seems safe and may offer specific therapeutic options. Furthermore, unnecessary changes of immunosuppression can be avoided in a considerable number of patients.

How to Prevent Renal Cachexia? A Clinical Randomized Pilot Study Testing Oral Supplemental Nutrition in Hemodialysis Patients With and Without Human Immunodeficiency Virus Infection.

OBJECTIVE: End-stage renal disease associates with catabolism and sarcopenia. Hypothetically, peroral supplemental nutrition over 6 months prevents catabolism in hemodialysis patients. DESIGN: Prospective randomized pilot study (ClinicalTrials.gov Identifier: NCT00687050). SUBJECTS: Twenty-three hemodialysis patients (15 males and 7 females) with or without human immunodeficiency virus (HIV) infection of 2 ambulatory hemodialysis centers. INTERVENTION: HIV-positive hemodialysis patients (n = 7, Group 1) were started on supplemental nutrition drinks (250 kcal/day), HIV-negative hemodialysis patients (n = 16, Group 2) were randomized to supplemental nutrition drinks (250 kcal/day) or received none. MAIN OUTCOME MEASURES: Body impedance analysis, anthropometric measures, magnetic resonance imaging results for mid-iliopsoas muscle cross-sectional area and laboratory parameters including albumin, cytokines at baseline, and at 6 months follow-up. RESULTS: Seven patients in Group 1 (mean age: 50.6 ± 9.6 years) and 16 patients in Group 2 (mean age: 54.0 ± 13.3 years) were recruited. Serum creatinine (Group 1: 6.4 ± 3.0 mg/dL; Group 2: 10.7 ± 2.5 mg/dL; P < .01), Body impedance analysis-derived phase angle alpha (Group 1: 5.1 ± 1.2; Group 2: 6.9 ± 1.6; P < .01), mid-arm circumference (Group 1: 26.1 ± 1.3 cm; Group 2: 29.6 ± 2.4 cm; P < .01) were less in Group 1 versus Group 2 patients at baseline suggesting that HIV-positive hemodialysis patients had a poorer nutritional status at baseline. At 6-month follow-up, mortality was higher in Group 1 patients (29%) than in Group 2 patients (6%). There was no significant treatment effect on nutritional status in survivors of Group 1 or in the supplemental nutrition arm of Group 2 when compared with baseline or to untreated controls. CONCLUSIONS: A new oral supplemental nutrition over 6 months had no treatment effect in surviving HIV-positive hemodialysis patients or in maintenance hemodialysis patients without HIV infection. The limitations of this study were small study size and unexpected high mortality among HIV-positive hemodialysis patients.

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.

Pretransplant human leukocyte antigen antibodies detected by single-antigen bead assay are a risk factor for long-term kidney graft loss even in the absence of donor-specific antibodies.

Clinical relevance of ELISA- and single-antigen bead assay (SAB)-detected pretransplant HLA antibodies (SAB-HLA-Ab) for kidney graft survival was evaluated retrospectively in 197 patients transplanted between 2002 and 2009 at the University Clinic Frankfurt. Having adjusted for retransplantation and delayed graft function, a significantly increased risk for death-censored graft loss was found in patients with pretransplant SAB-HLA-Ab [HR: 4.46; 95% confidence interval (CI): 1.47-13.48; P = 0.008]. The risk for increased graft loss was also significant in patients with pretransplant SAB-HLA-Ab but without SAB-detected donor-specific Ab (SAB-DSA) (HR: 4.91; 95% CI of 1.43-16.991; P = 0.012). ELISA was not sufficient to identify pretransplant immunized patients with an increased risk for graft loss. In immunized patients, graft loss was predominantly present in patients who received transplants with a mismatch on the HLA-DR locus. In conclusion, even if our study is limited due to small sample size, the results show an increased risk for long-term graft loss in patients with pretransplant SAB-HLA, even in the absence of DSA. SAB-HLA-Ab-positive patients, being negative in ELISA or CDC assay, might profit from a well-HLA-DR-matched graft and intensified immunosuppression.

Direct acute tubular damage contributes to Shigatoxin-mediated kidney failure.

The pathogenesis and therapy of Shigatoxin 2 (Stx2)-mediated kidney failure remain controversial. Our aim was to test whether, during an infection with Stx2-producing E. coli (STEC), Stx2 exerts direct effects on renal tubular epithelium and thereby possibly contributes to acute renal failure. Mice represent a suitable model because they, like humans, express the Stx2-receptor Gb3 in the tubular epithelium but, in contrast to humans, not in glomerular endothelia, and are thus free of glomerular thrombotic microangiopathy (TMA). In wild-type mice, Stx2 caused acute tubular dysfunction with consequent electrolyte disturbance, which was most likely the cause of death. Tubule-specific depletion of Gb3 protected the mice from acute renal failure. In vitro, Stx2 induced secretion of proinflammatory cytokines and apoptosis in human tubular epithelial cells, thus implicating a direct effect of Stx2 on the tubular epithelium. To correlate these results to human disease, kidney biopsies and outcome were analysed in patients with Stx2-associated kidney failure (n = 11, aged 22-44 years). The majority of kidney biopsies showed different stages of an ongoing TMA; however, no glomerular complement activation could be demonstrated. All biopsies, including those without TMA, showed severe acute tubular damage. Due to these findings, patients were treated with supportive therapy without complement-inhibiting antibodies (eculizumab) or immunoadsorption. Despite the severity of the initial disease [creatinine 6.34 (1.31-17.60) mg/dl, lactate dehydrogenase 1944 (753-2792) U/l, platelets 33 (19-124)/nl and haemoglobin 6.2 (5.2-7.8) g/dl; median (range)], all patients were discharged after 33 (range 19-43) days with no neurological symptoms and no dialysis requirement [creatinine 1.39 (range 0.84-2.86) mg/dl]. The creatinine decreased further to 0.90 (range 0.66-1.27) mg/dl after 24 months. Based on these data, one may surmise that acute tubular damage represents a separate pathophysiological mechanism, importantly contributing to Stx2-mediated acute kidney failure. Specifically in young adults, an excellent outcome can be achieved by supportive therapy only.

Regional citrate anticoagulation in therapeutic plasma exchange with fresh frozen plasma--a modified protocol.

PURPOSE: In membrane-based therapeutic plasma exchange (TPE), regional citrate anticoagulation (RCA) is associated with difficulties because of citrate accumulation and consequent, potentially significant, metabolic complications, especially when using fresh frozen plasma (FFP) as replacement fluid. We modified the technical setup of a commercially available continuous veno-venous hemodialysis RCA module (multiFiltrate Ci-Ca®) to establish an RCA-protocol for TPE. METHODS: Description of the modified technical setup and retrospective analysis of the feasibility of the RCA-protocol for TPE in all patients treated between 2009 and 2010. RESULTS: 411 consecutive TPE with RCA were performed in 42 patients, all using FFP as replacement fluid. Median procedure characteristics were: blood flow 160 ml/min, filtrate flow 36 ml/min, duration 93 min, processed total plasma volume 3600 mL. Trisodium citrate was infused at a rate of 0.43 mmol/min to achieve post-filter ionized calcium levels of <0.4 mmol/l. Calcium substitution rate was 0.19 mmol/min to maintain physiologic iCa levels. RCA was well tolerated with no significant differences in pH, iCa, bicarbonate or potassium after repeated sessions. Clotting events complicated 7.3% of the procedures. Adverse events occurred in 3.4% of TPE procedures; none was severe or fatal. No significant differences were observed comparing the rate of adverse events to those observed in TPE using standard anticoagulation at our center (4.8%). CONCLUSIONS: We describe for the first time a modified protocol for RCA in TPE using an integrated citrate module. Based on our experience, this RCA protocol is a feasible alternative for anticoagulation in TPE with FFP, especially in patients with a high risk of bleeding.

Renal AA-amyloidosis in intravenous drug users--a role for HIV-infection?

BACKGROUND: Chronic renal disease is a serious complication of long-term intravenous drug use (IVDU). Recent reports have postulated a changing pattern of underlying nephropathy over the last decades. METHODS: Retrospective investigation including all patients with prior or present IVDU that underwent renal biopsy because of chronic kidney disease between 01.04.2002 and 31.03.2012 in the city of Frankfurt/Main, Germany. RESULTS: Twenty four patients with IVDU underwent renal biopsy because of progressive chronic kidney disease or proteinuria. Renal AA-amyloidosis was the predominant cause of renal failure in 50% of patients. Membranoproliferative glomerulonephritis (GN) was the second most common cause found in 21%. Patients with AA-amyloidosis were more likely to be HIV infected (67 vs.17%; p=0.036) and tended to have a higher rate of repeated systemic infections (92 vs. 50%; p=0.069). Patients with AA-amyloidosis presented with progressive renal disease and nephrotic-range proteinuria but most patients had no peripheral edema or systemic hypertension. Development of proteinuria preceded the decline of GFR for approximately 1-2 years. CONCLUSIONS: AA-amyloidosis was the predominant cause of progressive renal disease in the last 10 years in patients with IVDU. The highest rate of AA-amyloidosis observed was seen in HIV infected patients with IVDU. We speculate that chronic HIV-infection as well as the associated immunosuppression might promote development of AA-amyloidosis by increasing frequency and duration of infections acquired by IVDU.

Effects of fractionated plasma separation and adsorption on survival in patients with acute-on-chronic liver failure.

BACKGROUND & AIMS: Fractionated plasma separation and adsorption (FPSA) is an extracorporeal procedure that supports liver function by removing endogenous toxins that cause complications from acute-on-chronic liver failure (AOCLF). We performed a randomized trial to investigate survival of patients with AOCLF treated with FPSA. METHODS: Patients with AOCLF were randomly assigned to groups given a combination of FPSA and standard medical therapy (SMT) (FPSA group, n = 77) or only SMT (SMT group, n = 68). The Prometheus liver support system was used to provide 8 to 11 rounds of FPSA (minimum of 4 hours each) for 3 weeks. Primary end points were survival probabilities at days 28 and 90, irrespective of liver transplantation. RESULTS: Baseline clinical parameters and number of transplant patients were similar between study arms. Serum bilirubin level decreased significantly in the FPSA group but not in the SMT group. In an intention-to-treat analysis, the probabilities of survival on day 28 were 66% in the FPSA group and 63% in the SMT group (P = .70); on day 90, they were 47% and 38%, respectively (P = .35). Baseline factors independently associated with poor prognosis were high SOFA score, bleeding, female sex, spontaneous bacterial peritonitis, intermediate increases in serum creatinine concentration, and combination of alcoholic and viral etiology of liver disease. There were no differences between the 2 groups in the incidence of side effects. CONCLUSIONS: Among all patients with AOCLF, extracorporeal liver support with FPSA does not increase the probability of survival. Further studies are needed to assess whether therapy might be beneficial in specific subsets of patients.

Immunoadsorption with single-use columns for the management of bleeding in acquired hemophilia A: a series of nine cases.

BACKGROUND: Acquired hemophilia A in a setting of bleeding or required surgery frequently places patients into a state of critical illness with high mortality. In this context immunoadsorption (IA) can be used to eliminate coagulation inhibitors quickly to employ recombinant coagulation factors more effectively. However, since acquired hemophilia is a rare condition the therapy is little standardized. METHODS: We report on a retrospective analysis of nine cases of acquired hemophilia A treated with IA using disposable adsorber columns. Data collection was performed by retrospectively reviewing the patients' files regarding clinical course, mode of therapy, inhibitor titers, and coagulation status. RESULTS: Inhibitor titers were effectively reduced in all but one patient following the treatment with IA. In two out of seven patients surviving the acute bleeding an inhibitor relapse occurred. The overall remission rate was determined as 77.8% within a median follow-up of 613 days. In two of our nine patients fatal outcome resulted due to major bleeding complications. IA treatment showed good tolerability and no fatal complications were caused. CONCLUSION: The presented cases support our assumption that patients with acquired hemophilia A benefit from IA with disposable columns in a setting of acute bleeding. This modality of IA is able to eliminate inhibitors reliably and quickly. IA in general is substantially speeding up the progress of therapy preventing bleeding complications constantly threatening the patient and reducing the dosages of coagulation factor therapy. We encourage IA with disposable columns in all bleeding patients with acquired hemophilia to aggressively lower the inhibitors.

Severe rhabdomyolysis, acute renal failure and posterior encephalopathy after 'magic mushroom' abuse.

We report the case of a 25-year-old, hepatitis C-infected man, who presented with severe rhabdomyolysis and acute renal failure, and later developed posterior encephalopathy with cortical blindness after the ingestion of magic mushrooms. Conventional respiratory and cardiovascular support including mechanical ventilation, continuous veno-venous hemodialysis and corticosteroids led to improvement and the patient recovered completely over the following months. Magic mushrooms are becoming increasingly fashionable among drug users, as they are believed to be more harmless than other hallucinogenic designer drugs. So far, little is known about their possible severe side effects.

The course of ADAMTS-13 activity and inhibitor titre in the treatment of thrombotic thrombocytopenic purpura with plasma exchange and vincristine.

The therapeutic efficacy of plasma exchange (PE) in thrombotic thrombocytopenic purpura (TTP) is attributed to the restoration in ADAMTS-13 (a disintegrin and metalloproteinase with thrombospondin motif-13) activity by substitution of the enzyme and removal of ADAMTS-13-neutralizing autoantibodies. We explored this rationale by analysing ADAMTS-13 activity and corresponding inhibitor levels during PE-treatment in 27 episodes from 23 adults with TTP. All patients with an initial episode of TTP (n = 14) and nine of 11 patients with a relapse showed severe ADAMTS-13 deficiency. ADAMTS-13 inhibitors were detected in 81% of these patients. Twenty-one patients responded to PE-therapy and two patients died. For patients with severe ADAMTS-13 deficiency, 15 patients (71%) showed a PE-induced recovery in ADAMTS-13 activity and six patients (29%) had persistent severe ADAMTS-13 deficiency despite clinical response. Three patients with recurrent TTP demonstrated a permanent increase in inhibitor titre during therapy. Six patients (43%) with an initial episode of TTP displayed a transient increase in inhibitor titre during PE-therapy, which was associated with deterioration in clinical and haematological symptoms of TTP. Treatment with vincristine induced an immediate increase in platelet count and ADAMTS-13 activity in seven of eight patients. We conclude that ADAMTS-13 activity and inhibitor levels, as measured using current methodology, do not solely determine the clinical course of TTP.