Potential Utility of Cardiorenal Biomarkers for Prediction and Prognostication of Worsening Renal Function in Acute Heart Failure

BackgroundMultiple different pathophysiologic processes can contribute to worsening renal function (WRF) in acute heart failure.Methods and ResultsWe retrospectively analyzed 787 patients with acute heart failure for the relationship between changes in serum creatinine and biomarkers including brain natriuretic peptide, high sensitivity cardiac troponin I, galectin 3, serum neutrophil gelatinase-associated lipocalin, and urine neutrophil gelatinase-associated lipocalin. WRF was defined as an increase of greater than or equal to 0.3 mg/dL or 50% in creatinine within first 5 days of hospitalization. WRF was observed in 25% of patients. Changes in biomarkers and creatinine were poorly correlated (r ≤ 0.21) and no biomarker predicted WRF better than creatinine. In the multivariable Cox analysis, brain natriuretic peptide and high sensitivity cardiac troponin I, but not WRF, were significantly associated with the 1-year composite of death or heart failure hospitalization. WRF with an increasing urine neutrophil gelatinase-associated lipocalin predicted an increased risk of heart failure hospitalization.ConclusionsBiomarkers were not able to predict WRF better than creatinine. The 1-year outcomes were associated with biomarkers of cardiac stress and injury but not with WRF, whereas a kidney injury biomarker may prognosticate WRF for heart failure hospitalization.     

A clinical study assessing the pharmacokinetics,efficacy and safety of AlphaNine®, a high‐purity factor IX concentrate,in patients with severe haemophilia B

Summary. Effective treatment with factor IX (FIX) requires a thorough consideration of the properties of the concentrate to be used as replacement therapy, to date, the only available treatment for haemophilia B. The aim of the study was to determine the pharmacokinetics, clinical efficacy and safety in routine clinical use of AlphaNine^®, a high‐purity human FIX concentrate. This open, single‐arm, multicentre, non‐randomized trial included 25 subjects (age ≥ 12) with moderate/severe haemophilia B. Pharmacokinetics was assessed at baseline and after a 6‐month follow‐up. The degree of haemostasis control achieved was evaluated during a 12‐month follow‐up. Safety was evaluated in terms of tolerance, thrombogenicity, immunogenicity and viral safety. Mean recovery was 1.01 ± 0.19 IU dL^?1 per IU kg^?1 at baseline and 1.23 ± 0.34 IU dL^?1 per IU kg^?1 6 months later. Terminal half‐life was 34.5 ± 6.2 h and 33.7 ± 5.4 h, respectively. Ratios of each parameter between the two pharmacokinetic studies were all close to 1. A total of 1,576,890 IU AlphaNine^® were administered in 889 infusions (mean dose per infusion: 1774 IU; 3.2 infusions per month per patient). The main reasons for infusion were mild/moderate bleeding (62.3%) and prophylaxis (20.5% continuous, 15.6% intermittent). Overall, 93.0% of the efficacy assessments were rated as excellent/good and 88.8% of bleedings resolved after the first infusion. Twenty‐one adverse events were reported in eight patients, none of which was considered related to the study medication. AlphaNine^® showed a pharmacokinetic profile in agreement with that of other plasma‐derived FIX concentrates and provides safe and clinically effective substitution therapy for patients with haemophilia B.     

Shear stress is required for the endocytic uptake of the factor VIII‐von Willebrand factor complex by macrophages

Summary. Background: Low‐density lipoprotein (LDL) receptor family members contribute to the cellular uptake of factor VIII. How von Willebrand factor fits into this endocytic pathway has remained poorly understood. Objectives: It has been suggested that macrophages contribute to the clearance of the factor VIII (FVIII)‐von Willebrand factor (VWF) complex. We now assessed the mechanisms of uptake employing human monocyte‐derived macrophages. Methods: A confocal microscopy study was employed to study the uptake by monocyte‐derived macrophages of a functional green fluorescent FVIII‐GFP derivative in the presence and absence of VWF. Results: The results revealed that FVIII‐GFP is internalized by macrophages. We found that FVIII‐GFP co‐localizes with LDL receptor‐related protein (LRP), and that the LRP antagonist Receptor Associated Protein (RAP) blocks the uptake of FVIII‐GFP. However, FVIII‐GFP was not detected in the macrophages in the presence of VWF, suggesting that the FVIII‐VWF complex is not internalized by these cells at all. Apart from static conditions, we also investigated the effect of shear stress on the uptake of FVIII‐GFP in presence of VWF. Immunofluorescence studies demonstrated that VWF does not block endocytosis of FVIII‐GFP under flow conditions. Moreover, VWF itself was also internalized by the macrophages. Strikingly, in the presence of RAP, endocytosis of FVIII‐GFP and VWF was inhibited. Conclusion: The results show that shear stress is required for macrophages to internalize both constituents of the FVIII‐VWF complex.     

Detection and cloning of human DNA sequences related to the mouse mammary tumor virus genome.

Sequences related to the mouse mammary tumor virus (MMTV) genome have been detected in fragments of restricted human cellular DNA. These results were obtained by using recombinant DNA containing the MMTV proviral genome and lowering the stringency of blot-hybridization conditions. The MMTV genome also reacts with unique families of fragments in restricted cellular DNA from other mammalian species but not with salmon sperm DNA. A clone that reacted with labeled MMTV proviral DNA was selected from a human DNA library in Charon 4A. Under stringent conditions, a 3.7-kilobase MMTV-related EcoRI fragment of this clone hybridized with many of the same EcoRI restriction fragments of human cellular DNA detectable with MMTV proviral DNA under low-stringency conditions. Specific fragments of the human clone were shown to contain sequences related to the molecularly cloned gag, pol, and env regions of the MMTV genome.     

F8 gene dosage defects in atypical patients with severe haemophilia A

Summary. We performed molecular analysis of the factor 8 gene (F8) in 272 unrelated Spanish patients with haemophilia A (HA) and detected a mutation by routine analysis in 267 of them (98.1%). No mutation was detected in the remaining five patients despite clinical and laboratory confirmation of HA. The aim is to describe the molecular alterations in F8 discovered by gene dosage methodologies in three of these patients. For methodology, F8 sequencing, intragenic marker analysis, multiplex ligation-dependent probe amplification and quantitative real time-PCR were followed. One patient had Klinefelter syndrome (47,XXY) and a large deletion spanning exons 1-12 masked by the other F8 allele; the second patient showed a large duplication spanning exons 2-10 and the third patient revealed a non-contiguous double duplication of exons 14 and 23-25. The remaining two patients had mild HA and dosage results were normal. The application of gene dosage methods is useful to define haemophilic patients in whom mutations are not detected using other routine methods. Nevertheless, in a small percentage of patients (<1%), no molecular pathology can be identified after testing several genetic methodologies.     

Activated N-ras in a human rectal carcinoma cell line associated with clonal homozygosity in myb locus-restriction fragment polymorphism

An N-ras transforming gene was detected in human rectal carcinoma-derived cells (7060) and molecularly cloned. The genetic lesion responsible for the transforming activity of the 7060 oncogene was localized to a single nucleotide transition from A to T in codon 61 of the predicted protein. This lesion in the second exon results in substitution of histidine for glutamine at this position. We also found an EcoRI restriction fragment length polymorphism, consisting of two alleles, of the human c-myb gene. The 7060-transformed epithelial cells showed the homozygous phenotype, while normal fibroblasts of the same patient showed the heterozygous phenotype. This suggests a relationship between the phenotypic change in the c-myb locus and the induction of the 7060 tumor.     

Intra-articular hyaluronic acid in the treatment of haemophilic chronic arthropathy

We report our preliminary experience with the use of hyaluronic acid (Synvisc) in 29 joints from 25 different haemophilic patients (17 knees, six shoulders, four ankles, one elbow and one hip). All the joints were grade III of our classification, characterized by synovial thickening, axial deformities and muscle atrophy (chronic arthropathy). In view of the very satisfactory results obtained with this procedure, we have substituted Synvisc for the previous use of intra-articular long-standing corticosteroids that we had been used for some years. This method is theoretically more physiological and does not destroy the joint cartilage further, as corticosteroids can.