Immune response of heterologous versus homologous prime-boost regimens with adenoviral vectored and mRNA COVID-19 vaccines in immunocompromised patients.

Due to rare but major adverse reactions to the AstraZeneca adenoviral ChAdOx1-S-nCoV-19 vaccine (ChAd), German health authorities recommended adults under 60 who received one dose of ChAd, to receive a second dose of the BioNTech mRNA BNT162b2 vaccine (BNT) as a booster. Studies in the general population suggest an enhanced efficacy of the heterologous (ChAd-BNT) compared to the homologous (BNT-BNT) vaccination regimen. However, an analysis of the efficacy in patient populations with a high risk of severe COVID-19 due to acquired immunodeficiency is still missing. We therefore compared both vaccination regimens in healthy controls, patients with gynecological tumors after chemotherapy, patients on dialysis and patients with rheumatic diseases concerning the humoral and cellular immune response. The humoral and cellular immune response differed substantially in healthy controls compared to patients with acquired immunodeficiency. Overall, the most significant differences between the two immunization regimens were found in neutralizing antibodies. These were always higher after a heterologous immunization. Healthy controls responded well to both vaccination regimens. However, the formation of neutralizing antibodies was more pronounced after a heterologous immunization. Dialysis patients, on the other hand, only developed an adequate humoral and particularly cellular immune response after a heterologous immunization. Tumor and rheumatic patients also - to a weaker extent compared to dialysis patients - benefited from a heterologous immunization. In conclusion, the heterologous COVID-19 vaccination regimens (ChAd-BNT) seem to have an advantage over the homologous vaccination regimens, especially in immunocompromised patients such as patients with end-stage kidney disease treated with hemodialysis.

Urinary T Cells Identify Renal Antineutrophil Cytoplasmic Antibody-Associated Vasculitis and Predict Prognosis: A Proof of Concept Study.

Introduction: Necrotizing crescentic glomerulonephritis is a major contributor to morbidity and mortality in Antineutrophil cytoplasmic antibodies (ANCA)-associated vasculitis (AAV). Because therapy relies on immunosuppressive agents with potentially severe adverse effects, a reliable noninvasive biomarker of disease activity is needed to guide treatment. Methods: We used flow cytometry to quantify T cell subsets in blood and urine samples from 95 patients with AAV and 8 controls to evaluate their biomarker characteristics. These were compared to soluble markers, monocyte chemoattractant protein-1 (MCP-1), soluble CD163 (sCD163), soluble CD25 (sCD25), and complement C5a (C5a), measured using multiplex analysis. Available kidney biopsies (n = 21) were classified according to Berden. Results: Patients with active renal AAV (rAAV) showed significantly higher urinary cell counts than those in remission, or those with extrarenal manifestation, or healthy controls. Urinary T cells showed robust discrimination of disease activity with superior performance compared to MCP-1 and sCD163. Patients whose kidney biopsies had been classified as "crescentic" according to Berden classification showed higher urinary T cell counts. Discordant regulatory T cells (Treg) proportions and CD4+/CD8+ ratio in blood and urine suggested that urinary cells reflect tissue migration rather than mere micro-bleeding. Furthermore, urinary Treg and T helper cells (TH17) patterns were associated with clinical response and risk of renal relapse. Conclusion: Urinary T cells reflect the renal inflammatory milieu in AAV and provide further insights into the pathogenesis of this chronic condition. Their promising potential as noninvasive diagnostic and prognostic biomarkers deserves further exploitation.

Impact of hypertension on long-term humoral and cellular response to SARS-CoV-2 infection.

It was shown that hypertension delays SARS CoV-2 viral clearance and exacerbates airway hyperinflammation in the respiratory tract. However, it is unknown whether hypertension determines the long-term cellular and humoral response to SARS Cov2. Health care workers (HCWs) after an outbreak of SARS Cov-2 infections were analyzed. Infected HCWs were not vaccinated before blood collection. 5-14 months (median 7 months) after detection of SARS CoV-2 infection, blood was taken to analyze humoral response (S1 IgG and SARS CoV-2 neutralizing antibodies) and cellular (T cell responses to SARS-CoV-2 with Lymphocyte Transformation Test). To identify clinical factors that determine the immune response, a multivariate regression analysis was done considering age, BMI, sex, diabetes, hypertension, smoking, COPD, asthma and time between PCR positivity and blood collection as confounding factors. Infected hypertensive HCWs more often needed to be hospitalized than non-hypertensive HCWs, but were less likely to develop anosmia and myalgia. The long-term humoral and cellular immune response was significantly strengthened in hypertensive versus normotensive infected HCWs. Multivariate regression analysis revealed that hypertension was independently associated with the humoral response to SARS CoV-2 infection. Multivariate regression analysis using same confounding factors for the humoral response showed a clear trend for an association with the cellular response to SARS CoV-2 infection as well. In conclusion, SARS CoV-2 infection strengthened immune response to SARS CoV-2 infection in hypertensive HCWs independent of other risk factors.

Protective α1-antitrypsin effects in autoimmune vasculitis are compromised by methionine oxidation.

BackgroundAntineutrophil cytoplasmic autoantibody-associated (ANCA-associated) vasculitidies (AAV) are life-threatening systemic autoimmune conditions. ANCAs directed against proteinase 3 (PR3) or myeloperoxidase (MPO) bind their cell surface-presented antigen, activate neutrophils, and cause vasculitis. An imbalance between PR3 and its major inhibitor α1-antitrypsin (AAT) was proposed to underlie PR3- but not MPO-AAV. We measured AAT and PR3 in healthy individuals and patients with AAV and studied protective AAT effects pertaining to PR3- and MPO-ANCA.MethodsPlasma and blood neutrophils were assessed for PR3 and AAT. WT, mutant, and oxidation-resistant AAT species were produced to characterize AAT-PR3 interactions by flow cytometry, immunoblotting, fluorescence resonance energy transfer assays, and surface plasmon resonance measurements. Neutrophil activation was measured using the ferricytochrome C assay and AAT methionine-oxidation by Parallel Reaction Monitoring.ResultsWe found significantly increased PR3 and AAT pools in patients with both PR3- and MPO-AAV; however, only in PR3-AAV did the PR3 pool correlate with the ANCA titer, inflammatory response, and disease severity. Mechanistically, AAT prevented PR3 from binding to CD177, thereby reducing neutrophil surface antigen for ligation by PR3-ANCA. Active patients with PR3-AAV showed critical methionine-oxidation in plasma AAT that was recapitulated by ANCA-activated neutrophils. The protective PR3-related AAT effects were compromised by methionine-oxidation in the AAT reactive center loop but preserved when 2 critical methionines were substituted with valine and leucine.ConclusionPathogenic differences between PR3- and MPO-AAV are related to AAT regulation of membrane-PR3, attenuating neutrophil activation by PR3-ANCA rather than MPO-ANCA. Oxidation-resistant AAT could serve as adjunctive therapy in PR3-AAV.FUNDINGThis work was supported by KE 576/10-1 from the Deutsche Forschungsgemeinschaft, SCHR 771/8-1 from the Deutsche Forschungsgemeinschaft, grant 394046635 - SFB 1365 from the Deutsche Forschungsgemeinschaft, and ECRC grants.

Head-to-head comparison of two SGLT-2 inhibitors on AKI outcomes in a rat ischemia-reperfusion model.

The CREDENCE trial testing canagliflozin and the EMPA-REG OUTCOME trial testing empagliflozin suggest different effects on acute kidney injury (AKI). AKI diagnosis was mainly made based on changes of serum creatinine (sCr) although this also reflect mode of action of SGLT-2 inhibitors. We analyzed both compounds in a rat AKI model. The renal ischemia-reperfusion injury (I/R) model was used. Four groups were analyzed: sham, I/R+placebo, I/R+canagliflozin (30 mg/kg/day), I/R+ empagliflozin (10 mg/kg/day). Glucose excretion was comparable in both treatment groups indicating comparable SGLT-2 inhibition. Comparing GFR surrogate markers after I/R (sCr and blood urea nitrogen (BUN)), sCr peaked 24 h after I/R, BUN after 48 h, respectively, in the placebo treated I/R group. At all investigated time points after I/R sCr and BUN was higher in the I/R + canagliflozin group as compared to placebo treated rats, whereas the empagliflozin group did not differ from the placebo group. I/R led to tubular dilatation and necrosis. Empagliflozin was able to reduce that finding whereas canagliflozin had no effect. Treatment with empagliflozin also resulted in a significant reduction in an improved inflammatory score (p = 0.006). Renal expression of kidney injury molecule-1 (KIM-1) increased after I/R and empagliflozin but not canagliflozin significantly alleviated KIM-1 expression. I/R reduced urinary miR-26a excretion. Empagliflozin but not canagliflozin was able to restore normal levels of urinary miR-26a. This study in an AKI model confirmed safety data in the EMPA-REG OUTCOME trial suggesting that empagliflozin might reduce AKI risk. The empagliflozin effects on KIM-1 and miR-26a might indicate beneficial regulation of inflammation. These data should stimulate clinical studies with AKI risk as primary endpoint.

T-cell proliferation assay for the detection of SARS-CoV-2-specific T-cells.

Both infection with and vaccination against SARS-CoV-2 trigger a complex B-cell and T-cell response. Methods for the analysis of the B-cell response are now well established. However, reliable methods for measuring the T-cell response are less well established and their usefulness in clinical settings still needs to be proven. Here, we have developed and validated a T-cell proliferation assay based on 3H thymidine incorporation. The assay is using SARS-CoV-2 derived peptide pools that cover the spike (S), the nucleocapsid (N) and the membrane (M) protein for stimulation. We have compared this novel SARS-CoV-2 lymphocyte transformation test (SARS-CoV-2 LTT) to an established ELISA assay detecting Immunoglobulin G (IgG) antibodies to the S1 subunit of the SARS-CoV-2 spike protein. The study was carried out using blood samples from both vaccinated and infected health care workers as well as from a non-infected control group. Our novel SARS-CoV-2 LTT shows excellent discrimination of infected and/or vaccinated individuals versus unexposed controls, with the ROC analysis showing an area under the curve (AUC) of > 0.95. No false positives were recorded as all unexposed controls had a negative LTT result. When using peptide pools not only representing the S protein (found in all currently approved vaccines) but also the N and M proteins (not contained in the vast majority of vaccines), the novel SARS-CoV-2 LTT can also discriminate T-cell responses resulting from vaccination against those induced by infection.

NGAL/hepcidin-25 ratio and AKI subtypes in patients following cardiac surgery: a prospective observational study.

BACKGROUND: Acute kidney injury (AKI) subtypes combining kidney functional parameters and injury biomarkers may have prognostic value. We aimed to determine whether neutrophil gelatinase-associated lipocalin (NGAL)/hepcidin-25 ratio (urinary concentrations of NGAL divided by that of hepcidin-25) defined subtypes are of prognostic relevance in cardiac surgery patients. METHODS: We studied 198 higher-risk cardiac surgery patients. We allocated patients to four groups: Kidney Disease Improving Global Outcomes (KDIGO)-AKI-negative and NGAL/hepcidin-25 ratio-negative (no AKI), KDIGO AKI-negative and NGAL/hepcidin-25 ratio-positive (subclinical AKI), KDIGO AKI-positive and NGAL/hepcidin-25 ratio-negative (clinical AKI), KDIGO AKI-positive and NGAL/hepcidin-25 ratio-positive (combined AKI). Outcomes included in-hospital mortality (primary) and long-term mortality (secondary). RESULTS: We identified 127 (61.6%) patients with no AKI, 13 (6.6%) with subclinical, 40 (20.2%) with clinical and 18 (9.1%) with combined AKI. Subclinical AKI patients had a 23-fold greater in-hospital mortality than no AKI patients. For combined AKI vs. no AKI or clinical AKI, findings were stronger (odds ratios (ORs): 126 and 39, respectively). After adjusting for EuroScore, volume of intraoperative packed red blood cells, and aortic cross-clamp time, subclinical and combined AKI remained associated with greater in-hospital mortality than no AKI and clinical AKI (adjusted ORs: 28.118, 95% CI 1.465-539.703; 3.737, 95% CI 1.746-7.998). Cox proportional hazard models found a significant association of biomarker-informed AKI subtypes with long-term survival compared with no AKI (adjusted ORs: pooled subclinical and clinical AKI: 1.885, 95% CI 1.003-3.542; combined AKI: 1.792, 95% CI 1.367-2.350). CONCLUSIONS: In the presence or absence of KDIGO clinical criteria for AKI, the urinary NGAL/hepcidin-25-ratio appears to detect prognostically relevant AKI subtypes. TRIAL REGISTRATION NUMBER: NCT00672334, clinicaltrials.gov, date of registration: 6th May 2008, https://clinicaltrials.gov/ct2/show/NCT00672334 . Definition of AKI subtypes: subclinical AKI (KDIGO negative AND Ratio-positive), clinical AKI (KDIGO positive AND Ratio-negative) and combined AKI (KDIGO positive AND Ratio-positive) with urinary NGAL/hepcidin-25 ratio-positive cut-off at 85% specificity for in-hospital death. AKI, acute kidney injury. AUC, area under the curve. NGAL, neutrophil gelatinase-associated lipocalin. KDIGO, Kidney Disease Improving Global Outcomes Initiative AKI definition.

Free vitamin D is independently associated with systolic blood pressure in diabetic patients with impaired kidney function.

Vitamin D contributes to blood pressure (BP) regulation. We compared the association of BP in diabetic patients with either total vitamin D - the standard way of analyzing the vitamin D status - or free vitamin D, because only free vitamin D passes the cell membrane and interacts with the nuclear vitamin D receptor (VDR). An analytical cross-sectional study was conducted with 178 diabetic patients with impaired kidney function. Free and total vitamin D concentrations were measured in all patients. Multiple linear regression analysis considering patient age, sex, body mass index, height, smoking and drinking situation, the use of antihypertensive drugs, cholecalciferol treatment, C-reactive protein and estimated glomerular filtration rate as confounding factors were conducted to compare the association of free and total vitamin D with systolic and diastolic blood pressure (SBP and DBP). Multiple linear regression analysis revealed that neither SBP nor DBP was correlated with total vitamin D (SBP, 95% CI -0.405 ~ 0.159, p = 0.390; DBP, 95% CI -0.131 ~ 0.142, p = 0.933) (Table 2). However, the concentration of free vitamin D was independently associated with SBP (95% CI -2.691 ~ -0.210; p = 0.022) (Table 3), but not with DBP (95% CI -0.934 ~ 0.285; p = 0.293). In conclusion, free - but not total - vitamin D serum concentrations in patients with diabetes and impaired kidney function are inversely correlated with SBP. This study suggests that free vitamin D measurements might be more clinically relevant - as compared to measurements of total vitamin D - to adjust vitamin D therapy in diabetic patients with impaired kidney function.

Urinary biomarkers to predict severe fluid overload after cardiac surgery: a pilot study.

Aim: To assess the predictive ability of urinary and plasma biomarkers and clinical routine parameters for subsequent severe fluid overload. Patients & methods: In a pilot study, we studied 100 adult patients after cardiac surgery. On intensive care unit admission, we measured biomarkers in urine (midkine, IL-6, neutrophil gelatinase-associated lipocalin [NGAL], hepcidin-25) and plasma (creatinine, urea, B-type natriuretic peptide, lactate, C-reactive protein, leukocytes, IL-6, NGAL, hepcidin-25) to predict postoperative severe fluid overload. Results: Urinary midkine, IL-6, NGAL and hepcidin-25 (all AUCs ≥0.79) predicted postoperative severe fluid overload (n = 5 patients). Urinary NGAL/hepcidin-25 ratio (AUC 0.867) predicted postoperative severe fluid overload after adjustment to EuroScore and need for norepinephrine on surgery day (odds ratio: 2.4). Conclusion: Urinary biomarkers on intensive care unit admission might be helpful to predict subsequent severe fluid overload after cardiac surgery.

Lay abstract Aim: To assess whether proteins in the urine or blood or clinical routine laboratory parameters can predict severe body fluid overload after cardiac surgery. Patients & methods: In a pilot study, we studied 100 adult patients after cardiac surgery. After surgery, we measured proteins in the urine (midkine, IL-6, neutrophil gelatinase-associated lipocalin [NGAL], hepcidin-25) and blood (creatinine, urea, B-type natriuretic peptide, lactate, C-reactive protein, leukocytes, IL-6, NGAL, hepcidin-25) to predict postoperative severe fluid overload. Results: Urinary midkine, IL-6, NGAL and hepcidin-25 predicted postoperative severe fluid overload (n = 5 patients). Urinary NGAL/hepcidin-25 ratio predicted postoperative severe fluid overload after adjustment to important covariates. Conclusion: Urinary biomarkers might be helpful to predict subsequent severe fluid overload after cardiac surgery.

Urinary Neutrophil Gelatinase-Associated Lipocalin/Hepcidin-25 Ratio for Early Identification of Patients at Risk for Renal Replacement Therapy After Cardiac Surgery: A Substudy of the BICARBONATE Trial.

BACKGROUND: Acute kidney injury requiring renal replacement therapy (AKI-RRT) is strongly associated with mortality after cardiac surgery; however, options for early identification of patients at high risk for AKI-RRT are extremely limited. Early after cardiac surgery, the predictive ability for AKI-RRT even of one of the most extensively evaluated novel urinary biomarkers, neutrophil gelatinase-associated lipocalin (NGAL), appears to be only moderate. We aimed to determine whether the NGAL/hepcidin-25 ratio (urinary concentrations of NGAL divided by that of hepcidin-25) early after surgery may compare favorably to NGAL for identification of high-risk patients after cardiac surgery. METHODS: This is a prospective substudy of the BICARBONATE trial, a multicenter parallel-randomized controlled trial comparing perioperative bicarbonate infusion for AKI prevention to usual patient care. At a tertiary referral center, 198 patients at increased kidney risk undergoing cardiac surgery with cardiopulmonary bypass were included into the present study. The primary outcome measure was defined as AKI-RRT. Secondary outcomes were in-hospital mortality and long-term mortality. We compared area under the curve of the receiver operating characteristic (AUC-ROC) of urinary NGAL with that of the urinary NGAL/hepcidin-25 ratio within 60 minutes after end of surgery. We compared adjusted AUC and performed cross-validated reclassification statistics of the (logarithmic) urinary NGAL/hepcidin-25 ratio adjusted to Cleveland risk score/EuroScore, cross-clamp time, age, volume of packed red blood cells, and (logarithmic) urinary NGAL concentration. The association of the NGAL/hepcidin-25 ratio with long-term patient survival was assessed using Cox proportional hazard regression analysis adjusting for EuroScore, aortic cross-clamp time, packed red blood cells and urinary NGAL. RESULTS: Patients with AKI-RRT (n = 13) had 13.7-times higher NGAL and 3.3-times lower hepcidin-25 concentrations resulting in 46.9-times higher NGAL/hepcidin-25 ratio early after surgery compared to patients without AKI-RRT. The NGAL/hepcidin-25 ratio had higher AUC-ROC compared with NGAL for risk of AKI-RRT and in-hospital mortality (unadjusted AUC-ROC difference 0.087, 95% confidence interval [CI], 0.036-0.138, P < .001; 0.082, 95% CI, 0.018-0.146, P = .012). For AKI-RRT, the NGAL/hepcidin-25 ratio increased adjusted category-free net reclassification improvement (cfNRI; 0.952, 95% CI, 0.437-1.468; P < .001) and integrated discrimination improvement (IDI; 0.040, 95% CI, 0.008-0.073; P = .016) but not AUC difference. For in-hospital mortality, the ratio improved AUC of the reference model (AUC difference 0.056, 95% CI, 0.003-0.108; P = .037) and cfNRI but not IDI. The urinary NGAL/hepcidin-25 ratio remained significantly associated with long-term mortality after adjusting for the model covariates. CONCLUSIONS: The urinary NGAL/hepcidin-25 ratio appears to early identify high-risk patients and outperform NGAL after cardiac surgery. Confirmation of our findings in other cardiac surgery centers is now needed.

Osteoprotegerin is an independent risk factor predicting death in stable renal transplant recipients.

BACKGROUND: Vascular calcification is common in chronic kidney disease and is associated with significant cardiovascular morbidity and mortality. One of the important factors regulating vascular calcification is osteoprotegerin (OPG). There are, however, limited data on the impact of OPG on all-cause mortality and graft loss in kidney transplant recipients so far. Given its impact on vascular calcification, the aim of our study is to analyze whether OPG was a risk factor of all-cause mortality and graft loss in 600 stable kidney transplant recipients. MATERIALS AND METHODS: 600 stable renal transplant recipients (367 women, 233 men) were followed for all-cause mortality and graft loss for 3 years. Blood and urine samples for analysis and clinical data were collected at study entry. We performed Kaplan-Meier survival analysis and Cox regression models considering confounding factors such as age, estimated glomerular filtration rate (eGFR), cold ischemia time, HbA1c, phosphorus, calcium, and albumin. RESULTS: 65 patients died, and 38 patients had graft loss during the observation period. The OPG baseline concentrations had no effect on graft loss, whereas Kaplan-Meier survival curve showed that baseline plasma OPG concentrations were associated with all-cause mortality in stable kidney transplant recipients (p < 0.0001, log-rank test). After multiple Cox regression analysis adjusting for age, eGFR, cold ischemia time, HbA1c, phosphorus, calcium, and albumin, plasma levels of OPG remained an independent predictor of all-cause mortality (HR, 1.181; 95%CI 1.035 - 1.347; p = 0.014). CONCLUSION: Baseline plasma OPG is an independent risk factor for all-cause mortality but not graft loss in patients after kidney transplantation.

Relationship Between Vitamin D and Hormones Important for Human Fertility in Reproductive-Aged Women.

Vitamin D deficiency is very common in women of reproductive age. Studies in animals suggests a link between vitamin D and reproductive hormone biosynthesis. A systematic analysis of the correlation of reproductive hormones in reproductive-aged women with both total and free vitamin D was, however, not done so far. This cross-sectional study was performed in 351 healthy reproductive age Caucasian women (median age, 28.0 years; interquartile ranges, 24.7-31.0 years). We measured serum levels of both total and free 25(OH)D, endocrinological, hematological and biochemical parameters. Spearman's rank correlations were performed to assess the correlation between 25(OH)D metabolites and selected parameters. Total vitamin D and free vitamin D measurements correlated well (rho=0.912, p < 0.0001). Both total 25(OH)D and free 25(OH)D showed significant negative correlation with FAI (rho=-0.229, p<0.0001 and rho=-0.195, p<0.0001 for total and free 25(OH)D, respectively); LH (rho=-0.177, p=0.001 and rho=-0.114, p=0.04 for total and free 25(OH)D, respectively), testosterone (rho=-0.174, p=0.001 and rho=-0.190, p<0.0001 for total and free 25(OH)D, respectively) and AMH (rho=-0.130, p=0.015 and rho=-0.107, p=0.047 for total and free 25(OH)D, respectively). Our study showed comparable correlations of both total and free 25(OH)D with endocrinological parameters, i.e. inverse correlations with free androgen index, luteinizing hormone, testosterone, LH/FSH ratio, androstenedione and anti-Müllerian hormone, and also with hematological and biochemical parameters, i.e. inverse correlations with erythrocytes, hsCRP and leukocytes count, and positive correlation with transferrin saturation, mean corpuscular hemoglobin and mean corpuscular volume in healthy reproductive age women.

C-terminal and intact FGF23 in kidney transplant recipients and their associations with overall graft survival.

BACKGROUND: Increased fibroblast growth factor 23 (FGF23) is a risk factor for mortality, cardiovascular disease, and progression of chronic kidney disease. Limited data exist comparing the association of either c-terminal FGF23 (cFGF23) or intact FGF23 (iFGF23) in kidney transplant recipients (KTRs) with overall (all-cause) graft loss. METHODS: We conducted a prospective observational cohort study in 562 stable kidney transplant recipients. Patients were followed for graft loss and all-cause mortality for a median follow-up of 48 months. RESULTS: During a median follow-up of 48 months, 94 patients had overall graft loss (primary graft loss or death with functioning graft). Both cFGF23 and iFGF23 concentrations were significantly higher in patients with overall graft loss than those without (24.59 [11.43-87.82] versus 10.67 [5.99-22.73] pg/ml; p < 0.0001 and 45.24 [18.63-159.00] versus 29.04 [15.23-60.65] pg/ml; p = 0.002 for cFGF23 and iFGF23, respectively). Time-dependent ROC analysis showed that cFGF23 concentrations had a better discriminatory ability than iFGF23 concentrations in predicting overall (all-cause) graft loss. Cox regression analyses adjusted for risk factors showed that cFGF23 (HR for one unit increase of log transformed cFGF23: 1.35; 95% CI, 1.01-1.79; p = 0.043) but not iFGF23 (HR for one unit increase of log transformed iFGF23: 0.97; 95% CI, 0.75-1.25; p = 0.794) was associated with the overall graft loss. CONCLUSION: Elevated cFGF23 concentrations at baseline are independently associated with an increased risk of overall graft loss. iFGF23 measurements were not independently associated with overall graft loss. The cFGF23 ELISA might detect bioactive FGF23 fragments that are not detected by the iFGF23 ELISA.

Predictive Value of Plasma NGAL:Hepcidin-25 for Major Adverse Kidney Events After Cardiac Surgery with Cardiopulmonary Bypass: A Pilot Study.

BACKGROUND: Neutrophil gelatinase-associated lipocalin (NGAL) and hepcidin-25 are involved in catalytic iron-related kidney injury after cardiac surgery with cardiopulmonary bypass. We explored the predictive value of plasma NGAL, plasma hepcidin-25, and the plasma NGAL:hepcidin-25 ratio for major adverse kidney events (MAKE) after cardiac surgery. METHODS: We compared the predictive value of plasma NGAL, hepcidin-25, and plasma NGAL:hepcidin-25 with that of serum creatinine (Cr) and urinary output and protein for primary-endpoint MAKE (acute kidney injury [AKI] stages 2 and 3, persistent AKI >48 hours, acute dialysis, and in-hospital mortality) and secondary-endpoint AKI in 100 cardiac surgery patients at intensive care unit (ICU) admission. We performed ROC curve, logistic regression, and reclassification analyses. RESULTS: At ICU admission, plasma NGAL, plasma NGAL:hepcidin-25, plasma interleukin-6, and Cr predicted MAKE (area under the ROC curve [AUC]: 0.77, 0.79, 0.74, and 0.74, respectively) and AKI (0.73, 0.89, 0.70, and 0.69). For AKI prediction, plasma NGAL:hepcidin-25 had a higher discriminatory power than Cr (AUC difference 0.26 [95% CI 0.00-0.53]). Urinary output and protein, plasma lactate, C-reactive protein, creatine kinase myocardial band, and brain natriuretic peptide did not predict MAKE or AKI (AUC <0.70). Only plasma NGAL:hepcidin-25 correctly reclassified patients according to their MAKE and AKI status (category-free net reclassification improvement: 0.82 [95% CI 0.12-1.52], 1.03 [0.29-1.77]). After adjustment to the Cleveland risk score, plasma NGAL:hepcidin-25 ≥0.9 independently predicted MAKE (adjusted odds ratio 16.34 [95% CI 1.77-150.49], P=0.014). CONCLUSIONS: Plasma NGAL:hepcidin-25 is a promising marker for predicting postoperative MAKE.

Opposite correlation of 25-hydroxy-vitamin D- and 1,25-dihydroxy-vitamin D-metabolites with gestational age, bone- and lipid-biomarkers in pregnant women.

25-Hydroxyvitamin D (25OHD) and 1,25-dihydroxyvitamin D (1,25(OH)2D) need to be bound to carrier proteins to be transported to their target cells. The majority of either 25OHD or 1,25(OH)2D is bound to vitamin D-binding protein (DBP), a smaller fraction is bound to albumin and only very small amounts of 25OHD or 1,25(OH)2D are free. Albumin-bound 25OHD or 1,25(OH)2D is relatively easily available after dissociation from albumin. Thus, the sum of free and albumin-bound forms is called bioavailable 25OHD and bioavailable 1,25(OH)2D. Total 25OHD and 1,25(OH)2D are defined as the sum of free, albumin-bound and DBP-bound 25OHD and 1,25(OH)2D, respectively. This cross-sectional study in 427 pregnant women compared the correlation of the six vitamin D compounds with biomarkers of bone health, lipid metabolism, kidney function, endocrine parameters, and group B water-soluble vitamins. Among the 25OHD metabolites analysed, total 1,25(OH)2D showed clearly the best correlation with calcium, bone-specific alkaline phosphatase, adiponectin, LDL, HDL, urea, thyroxine, and group B water-soluble vitamins. When comparing the three 25OHD metabolites, both free 25OHD and bioavailable 25OHD showed overall good correlations with calcium, bone-specific alkaline phosphatase, adiponectin, LDL, HDL, urea, thyroxine, triiodothyronine, and group B water-soluble vitamins, The correlations of 1,25(OH)2D and 25OHD metabolites went always in opposite directions. Only PTH correlates always inversely with all six vitamin D compounds. In conclusion, free 25(OH)D and bioavailable 25(OH)D are more precise determinants of the vitamin D status than total 25(OH)D in normal pregnancy, whereas total 1,25(OH)2D is superior to free and bioavailable 1,25(OH)2D. Except for PTH, correlations of 25(OH)D and 1,25(OH)2D metabolites with typical clinical chemistry readouts go in opposite directions.

Inferior vena cava-syndrome.

Inferior vena cava syndrome (IVCS) is caused by agenesis, compression, invasion, or thrombosis of the IVC, or may be associated with Budd-Chiari syndrome. Its incidence and prevalence are unknown. Benign IVCS is separated from malignant IVCS. Both cover a wide clinical spectrum reaching from asymptomatic to highly symptomatic cases correlated to the underlying cause, the acuity, the extent of the venous obstruction, and the recruitment and development of venous collateral circuits. Imaging is necessary to determine the underlying cause of IVCS and to guide clinical decisions. Interventional therapy has changed the therapeutic approach in symptomatic patients. This article provides an overview over IVCS and focuses on interventional therapeutic methods and results.

Superior vena cava syndrome.

The superior vena cava syndrome (SVCS) is caused by compression, invasion, and/or thrombosis of the superior vena cava and/or the brachiocephalic veins. Benign SVCS is separated from malignant SVCS. SVCS comprises a broad clinical spectrum reaching from asymptomatic cases to rare life-threatening emergencies with upper airway obstruction and increased intracranial pressure. Symptoms are correlated to the acuity and extent of the venous obstruction and inversely correlated to the development of the venous collateral circuits. Imaging is necessary to determine the exact underlying cause and to guide further interventions. Interventional therapy has widely changed the therapeutic approach in symptomatic patients. This article provides an overview over this complex syndrome and focuses on interventional therapeutic methods and results.

A patient with chronic kidney disease, primary biliary cirrhosis and metabolic acidosis.

Autoimmune disorders such as rheumatoid arthritis or Sjögren's syndrome can be associated with impaired renal acid excretion. Only few cases of patients with primary biliary cirrhosis (PBC) and distal renal tubular acidosis (dRTA) have been described. Here, we present the case of a 60-year-old woman with PBC and dRTA. Her kidney biopsy showed an absence of markers of acid-secretory Type A intercalated cells (A-ICs) and expression of aquaporin-2, a marker of principal cells, in all cells lining the collecting duct. Moreover, the serum of the patient contained antibodies directed against a subset of cells of the collecting duct. Thus, PBC-related autoantibodies may target acid-secretory A-ICs and thereby impair urinary acidification.