NTproBNP and ST2 as predictors for all-cause and cardiovascular mortality in elderly patients with symptoms suggestive for heart failure.

BACKGROUND: A new biomarker, suppression of tumorigenicity 2 (ST2) has been introduced as a marker for fibrosis and hypertrophy. Its clinical value in comparison with N-terminal pro-hormone of brain natriuretic peptide /Amino-terminal pro-B-type natriuretic peptide (NTproBNP) in predicting mortality in elderly patients with symptoms of heart failure (HF) is still unclear. AIM: To evaluate the prognostic value for all-cause- and cardiovascular mortality of ST2 or NTproBNP and the combination of these biomarkers. PATIENTS AND METHODS: One hundred seventy patients patients with clinical symptoms of HF (77 (45%) were with verified HF) were recruited from one selected primary health care center (PHC) in Sweden and echocardiography was performed in all patients. Blood samples were obtained from 159 patients and stored frozen at -70 °C. NTproBNP was analyzed at a central core laboratory using a clinically available immunoassay.ST2 was analyzed with Critical Diagnostics Presage ST2 ELISA immunoassay. RESULTS: We studied 159 patients (mean age 77 ± 8.3 years, 70% women). During ten years of follow up 78 patients had died, out of which 50 deaths were for cardiovascular reasons. Continuous NTproBNP and ST2 were both significantly associated with all-cause mortality (1.0001; 1.00001-1.0002, p = 0.04 and 1.03; 1.003-1.06, p = 0.03), NTproBNP but not ST2 remained significant for cardiovascular mortality after adjustments (1.0001; 1.00001-1.0002, p = 0.03 and 1.01; 0.77-1.06, p = 0.53), respectively. NTproBNP above median (>328 ng/L) compared to below median was significantly associated with all-cause mortality(HR: 4.0; CI :2.46-6.61; p < 0.001) and cardiovascular mortality (HR: 6.1; CI: 3.11-11.95; p < 0.001). Corresponding analysis for ST2 above median (25.6 ng/L) was not significantly associated neither with all-cause mortality (HR; 1.4; CI: 0.89-2.77) nor cardiovascular mortality (HR: 1.3; CI: 0.73-2.23) and no significant interaction of NTproBNP and ST2 (OR: 1.1; CI: 0.42-3.12) was found. CONCLUSION: In elderly patients with symptoms of heart failure ST2 was not superior to NTproBNP to predict all cause or cardiovascular mortality. Furthermore, it is unclear if the combination of ST2 and NTproBNP will improve long-term prognostication beyond what is achieved by NTproBNP alone.

Anaemia, but not iron deficiency, is associated with clinical symptoms and quality of life in patients with severe heart failure and palliative home care: A substudy of the PREFER trial.

BACKGROUND: To explore the relationships between anaemia or iron deficiency (ID) and symptoms, quality of life (QoL), morbidity, and mortality. METHODS: A post-hoc, non-prespecified, explorative substudy of the prospective randomized PREFER trial. One centre study of outpatients with severe HF and palliative need managed with advanced home care. Associations between anaemia, ID, and the Edmonton Symptom Assessment Scale (ESAS), Euro QoL (EQ-5D), Kansas City Cardiomyopathy Questions (KCCQ) were examined only at baseline but at 6months for morbidity and mortality. RESULTS: Seventy-two patients (51 males, 21 females), aged 79.2±9.1years. Thirty-nine patients (54%) had anaemia and 34 had ID (47%). Anaemia was correlated to depression (r=0.37; p=0.001), anxiety (r=0.25; p=0.04), and reduced well-being (r=0.26; p=0.03) in the ESAS; mobility (r=0.33; p=0.005), pain/discomfort (r=0.27; p=0.02), and visual analogue scale of health state (r=-0.28; p=0.02) in the EQ-5D; and physical limitation (r=-0.27; p=0.02), symptom stability; (r=-0.43; p<0.001); (r=-0.25; p=0.033), social limitation;(r=-0.26; p=0.03), overall summary score; (r=-0.24, p=0.046) and clinical summary score; (r=-0.27; p=0.02) in the KCCQ. ID did not correlate to any assessment item. Anaemia was univariably associated with any hospitalization (OR: 3.0; CI: 1.05-8.50, p=0.04), but not to mortality. ID was not significantly associated with any hospitalization or mortality. CONCLUSION: Anaemia, but not ID, was associated although weakly with symptoms and QoL in patients with advanced HF and palliative home care.

Acetylation and glycation of fibrinogen in vitro occur at specific lysine residues in a concentration dependent manner: a mass spectrometric and isotope labeling study.

Aspirin may exert part of its antithrombotic effects through platelet-independent mechanisms. Diabetes is a condition in which the beneficial effects of aspirin are less prominent or absent - a phenomenon called "aspirin resistance". We investigated whether acetylation and glycation occur at specific sites in fibrinogen and if competition between glucose and aspirin in binding to fibrinogen occurs. Our hypothesis was that such competition might be one explanation to "aspirin resistance" in diabetes. After incubation of fibrinogen in vitro with aspirin (0.8 mM, 24 h) or glucose (100 mM, 5-10 days), we found 12 modified sites with mass spectrometric techniques. Acetylations in the α-chain: αK191, αK208, αK224, αK429, αK457, αK539, αK562, in the ß-chain: ßK233, and in the γ-chain: γK170 and γK273. Glycations were found at ßK133 and γK75, alternatively γK85. Notably, the lysine 539 is a site involved in FXIII-mediated cross-linking of fibrin. With isotope labeling in vitro, using [(14)C-acetyl]salicylic acid and [(14)C]glucose, a labeling of 0.013-0.084 and 0.12-0.5 mol of acetylated and glycated adduct/mol fibrinogen, respectively, was found for clinically (12.9-100 µM aspirin) and physiologically (2-8 mM glucose) relevant plasma concentrations. No competition between acetylation and glycation could be demonstrated. Thus, fibrinogen is acetylated at several lysine residues, some of which are involved in the cross-linking of fibrinogen. This may mechanistically explain why aspirin facilitates fibrin degradation. We find no support for the idea that glycation of fibrin(ogen) interferes with acetylation of fibrinogen.

A new beta-chain variant: Hb stockholm [beta 7(A4)GluAsp] causes falsely low Hb A(1c).

A new beta-hemoglobin (Hb) variant, Hb Stockholm [beta7(A4)GluAsp], is described. The variant was characterized by mass spectrometry and DNA sequencing. The new variant is clinically silent but interferes with Hb A(1c) quantification using ion exchange chromatography, causing a falsely low Hb A(1c) level when using the Bio-Rad VARIANT II System.

HPLC and mass spectrometric characterization of a candidate reference material for the alcohol biomarker carbohydrate-deficient transferrin (CDT).

BACKGROUND: Measurement of the alcohol-induced change of the serum transferrin glycoform pattern, carbohydrate-deficient transferrin (CDT), is used as a biomarker for heavy drinking. This study characterized a candidate reference material for CDT measurement derived from isolated human transferrin glycoforms. METHODS: Four transferrin glycoforms were separated from human plasma by standard methods. The identity and purity of the fractions was evaluated by HPLC, using specific absorbance measurement of the iron-transferrin complex at 470 nm, and by mass spectrometry, using ESI Q-Tof MS. A primary candidate reference material was prepared by mixing isolated fractions in transferrin-free plasma in a proportion similar to that in serum and with 0-12% disialotransferrin. A secondary candidate reference material was prepared by spiking a serum pool with 1-9% disialotransferrin. RESULTS: Initial identification of the isolated transferrin fractions as disialo-, trisialo-, tetrasialo- and pentasialotransferrin was based on agreement with established HPLC retention times for authentic serum samples (RRT 0.998-1.004). The presence of single symmetric peaks suggested that the fractions were sufficiently pure. The identity and purity was further based on MS agreement of observed with theoretical molecular masses (Delta(m)<0.03%). The %disialotransferrin target values for the secondary candidate reference material showed good correlation with the measured results by an HPLC candidate reference method (r(2)=0.999). CONCLUSIONS: The separated human transferrin fractions used to prepare the CDT candidate reference material were indicated to contain distinct glycoforms. Having access to a CDT reference material in serum matrix will facilitate comparison of results between different methods and aid in the standardization process.

Proteome analysis of skin distinguishes acute guttate from chronic plaque psoriasis.

Psoriasis is a disease with considerable heterogeneity in clinical presentation. This is the first study using two-dimensional gel electrophoresis to compare global protein expression patterns in lesional and non-lesional skin from subjects with acute guttate psoriasis associated with streptococcal throat infection and chronic plaque psoriasis. Samples from experimentally induced contact eczema and normal skin from healthy controls were also included. Proteins with statistically significant differences in expression were used in hierarchical cluster analyses resulting in separation of the different samples into groups. Chronic plaque and guttate psoriasis samples were distinctly separated, indicating that they represent discrete phenotypes at the protein expression level. Interestingly, there was a trend in which guttate psoriasis lesions clustered closer to eczema than to chronic plaque psoriasis lesions, indicating that the duration of the inflammatory reaction may affect clustering. Several of the differentially expressed proteins were identified by mass spectrometry.

Polyunsaturated fatty acids including docosahexaenoic and arachidonic acid bind to the retinoid X receptor alpha ligand-binding domain.

Nuclear receptors (NRs) constitute a large and highly conserved family of ligand-activated transcription factors that regulate diverse biological processes such as development, metabolism, and reproduction. As such, NRs have become important drug targets, and the identification of novel NR ligands is a subject of much interest. The retinoid X receptor (RXR) belongs to a subfamily of NRs that bind vitamin A metabolites (i.e. retinoids), including 9-cis-retinoic acid (9-cis-RA). However, although 9-cis-RA has been described as the natural ligand for RXR, its endogenous occurrence has been difficult to confirm. Recently, evidence was provided for the existence of a different natural RXR ligand in mouse brain, the highly enriched polyunsaturated fatty acid (PUFA) docosahexaenoic acid (DHA) (Mata de Urquiza et al. (2000) Science 290, 2140-2144). However, the results suggested that supra-physiological levels of DHA were required for efficient RXR activation. Using a refined method for ligand addition to transfected cells, the current study shows that DHA is a more potent RXR ligand than previously observed, inducing robust RXR activation already at low micromolar concentrations. Furthermore, it is shown that other naturally occurring PUFAs can activate RXR with similar efficiency as DHA. In additional experiments, the binding of fatty acid ligands to RXRalpha is directly demonstrated by electrospray mass spectrometry of the noncovalent complex between the RXR ligand-binding domain (LBD) and its ligands. Data is presented that shows the noncovalent interaction between the RXR LBD and a number of PUFAs including DHA and arachidonic acid, corroborating the results in transfected cells. Taken together, these results show that RXR binds PUFAs in solution and that these compounds induce receptor activation, suggesting that RXR could function as a fatty acid receptor in vivo.

Human apurinic/apyrimidinic endonuclease (Ape1) and its N-terminal truncated form (AN34) are involved in DNA fragmentation during apoptosis.

We previously isolated a 34-kDa nuclease (AN34) from apoptotic human leukemia cells. Here, we identify AN34 as an N-terminally truncated form of human AP endonuclease (Ape1) lacking residues 1-35 (delta35-Ape1). Although Ape1 has hitherto been considered specific for damaged DNA (specific to AP site), recombinant AN34 (delta35-Ape1) possesses significant endonuclease activity on undamaged (normal) DNA and in chromatin. AN34 also displays enhanced 3'-5' exonuclease activity. Caspase-3 activates AN34 in a cell-free system, although caspase-3 cannot cleave Ape1 directly in vitro. We also found that Ape1 itself preferentially cleaves damaged chromatin DNA isolated from cells treated with apoptotic stimuli and that silencing of Ape1 expression decreases apoptotic DNA fragmentation in DFF40/CAD-deficient cells. Thus, we propose that AN34 and Ape1 participate in the process of chromatin fragmentation during apoptosis.