Control of fibrinogen biosynthesis: role of the FFA/albumin ratio

Effect of Training-Detraining Phases of Multicomponent Exercises and BCAA Supplementation on Inflammatory Markers and Albumin Levels in Frail Older Persons

Nowadays, it is accepted that the regular practice of exercise and branched-chain amino acids supplementation (BCAAs) can benefit the immune responses in older persons, prevent the occurrence of physical frailty (PF), cognitive decline, and aging-related comorbidities. However, the impact of their combination (as non-pharmacological interventions) in albumin and the inflammatory markers is not fully understood. Therefore, we investigated the effect of a 40-week multifactorial intervention [MIP, multicomponent exercise (ME) associated or not with BCAAs] on plasma levels of inflammatory markers and albumin in frail older persons (≥75 years old) living at residential care homes (RCH). This study consisted of a prospective, naturalistic, controlled clinical trial with four arms of multifactorial and experimental (interventions-wahshout-interventions) design. The intervention groups were ME + BCAAs (n = 8), ME (n = 7), BCAAs (n = 7), and control group (n = 13). Lower limb muscle-strength, cognitive profile, and PF tests were concomitantly evaluated with plasma levels of albumin, anti- and pro-inflammatory cytokines [Interleukin-10 (IL-10) and Tumor Necrosis Factor-alpha (TNF-α) respectively], TNF-α/IL-10 ratio, and myeloperoxidase (MPO) activity at four different time-points: Baseline (T1), after 16 weeks of multifactorial intervention (T2), then after a subsequent 8 weeks washout period (T3) and finally, after an additional 16 weeks of multifactorial intervention (T4). Improvement of cognitive profile and muscle strength-related albumin levels, as well as reduction in the TNF-α levels were found particularly in ME plus BCAAs group. No significant variations were observed over time for TNF-α/IL-10 ratio or MPO activity. Overall, the study showed that MIP triggered slight alterations in the inflammatory and physical function of the frail older participants, which could provide independence and higher quality of life for this population.

Medium-Chain Acylcarnitines Are Associated With Cardioembolic Stroke and Stroke Recurrence

Objective—

Stroke is a heterogeneous disease with diverse causes, which affect the risk of recurrence. This study aimed to identify novel biomarkers that are clinically relevant to the diagnosis of cardioembolic stroke (CE) and the prediction of stroke recurrence using metabolomics.

Approach and Results—

We obtained blood samples and clinical data from a consecutively registered, hospital-based acute stroke registry and from healthy controls. Mass-spectrometry–based profiling was performed, and several metabolomic signatures were selected for the discrimination of CE and stroke recurrence, coupled with multivariate statistical analysis. Finally, 190 acute ischemic stroke participants (43 CE patients and 147 non-CE patients) and 30 control participants were included. We obtained 29 metabolomics signatures, and of these, 2 medium-chain acylcarnitines (decanoylcarnitine and octanoylcarnitine) were selected as independent discriminants for CE (odds ratio, 2.839; 95% CI, 1.241–6.493 for decanoylcarnitine; odds ratio, 2.839; 95% CI, 1.241–6.493 for octanoylcarnitine). Elevated medium-chain acylcarnitines were also associated with a higher risk of stroke recurrence (hazard ratio, 3.767; 95% CI, 1.276–11.117 for decanoylcarnitine; hazard ratio, 5.519; 95% CI, 1.22–18.781 for octanoylcarnitine). The levels of decanoylcarnitine and octanoylcarnitine were correlated as known surrogate markers of CE. The levels of decanoylcarnitine and octanoylcarnitine were significantly higher in stroke patients with a high-risk potential of cardioembolism than in those with low or intermediate risk.

Conclusions—

Metabolomics provided an improved understanding of CE pathogenesis and stroke recurrence. We have identified decanoylcarnitine and octanoylcarnitine as novel biomarkers for CE and stroke recurrence.

Free Fatty Acid Is Associated with Thrombogenicity in Cardioembolic Stroke

Background: Recently, the role of free fatty acids (FFAs) in thromboembolism has re-emerged in the context of cardioembolic stroke. Therefore, we attempted to determine the role of FFAs in embolic risk in various potential sources of cardioembolism (PSCE). We hypothesized that if elevated FFA levels in stroke patients are associated with thrombogenesis, then patients with a well-known high risk of embolic sources would have high FFA levels. Methods: Data collected from 2 hospital-based stroke registries were analyzed to investigate the association between FFA and PSCE. Results: A total of 2,770 acute stroke patients, including 539 with cardioembolic stroke, were selected for analysis. FFA was an independent predictor for cardioembolism (OR 2.755, 95% CI 2.221-3.417, p < 0.001). Among the PSCE, FFA levels were significantly associated with high risk of atrial fibrillation (AF), valvular heart disease, congestive heart failure with low ejection fraction, left atrial thrombus, left ventricular thrombus, left atrial smoke, and ventricular wall motion abnormality. FFA levels increased with the number of PSCE per patient without interaction with the presence of AF. Conclusions: Among acute stroke patients, FFA levels increased in groups with higher risk of cardioembolic stroke irrespective of the presence of AF. These results suggest that enhanced thrombogenicity could be the main mechanism to explain the elevated FFA levels in patients with cardioembolic stroke.

Repeated quantitative measurements of De Novo synthesis of albumin and fibrinogen

The possibility of using two different isotopomers, for the incorporation of isotopically labeled amino acids, was explored to enable longitudinal studies of de novo synthesis of two export liver proteins, albumin and fibrinogen. The agreement of the synthesis rates between the two different labels was evaluated along with the reproducibility of repeated experiments using different time intervals. Healthy volunteers were studied in a standardized fed state. Protocol A (n = 10) involved two measurements 48 hours apart. Protocol B (n = 6) involved three measurements at baseline and five hours and then seven days after the initial measurement. De novo synthesis of albumin and fibrinogen by the incorporation of D5-phenylalanine or D8-phenylalanine were measured using the flooding dose technique. Albumin and fibrinogen were isolated from plasma using standard techniques. Fractional and absolute synthesis rates were calculated. Repeated measurements employing the two isotoptomers showed good agreement for albumin fractional synthesis rate after 48 hours (p = 0.92) and after 7 days (p = 0.99), with a coefficient of variation of 5.9% when using the same isotopic label. For fibrinogen, the coefficient of variation for the fractional synthesis rate employing the same isotopic label was 16.6%. Repeated measurements after 48 hours and seven days showed less agreement although there was no statistical difference (P = 0.32 and P = 0.30 respectively). Repeated measurement after five hours showed a statistical significant difference for the fractional synthesis rate of fibrinogen (p = 0.008) but not for albumin (p = 0.12). Repeated measurements of albumin de novo synthesis more than 48 hours apart show acceptable agreement using either one or two different isotopic labels. For fibrinogen the larger intra-individual scatter necessitates larger study groups to detect changes in longitudinal studies. Repeated measurements within 48 hours need to be validated further.

[Inventive activity of the Departments of Protein Structure and Function, and Molecular Immunology of the Palladin Institute of Biochemistry of NAS of Ukraine. Part II. National breakthrough in the study and diagnostics of human hemostasis system]

The scientists of Protein Structure and Function, and Molecular Immunology Departments of the Palladin Institute of Biochemistry (NAS of Ukraine) under the supervision of member of NASU and NAMSU, prof. S. V. Komisarenko and corresponding member of NASU prof. E. V. Lugovskoy have made the real breakthrough in the field of research of the mechanisms of fibrin polymerization and formation of fibrin framework of thrombi. The immunodiagnostic test-systems for the evaluation of the risk of thrombus formation were developed for the first time. Researches have obtained the monoclonal antibodies to fibrinogen, fibrin, D-dimer and their fragments. These monoclonal antibodies were used as molecular probes for the localization of newly detected fibrin polymerization sites. Obtained antibodies with high affinity interact with fibrinogen, D-dimer and soluble fibrin – main markers of the risk of thrombus formation. They were used for the development of the immunodiagnostic test-systems to quantify these markers in human blood plasma for the evaluation of the state of haemostasis system, detection of prethrombotic states, disseminated intravascular coagulation, detection of thrombosis and monitoring of antithrombotic and fibrinolytic therapy. The successful trial of developed test-systems was carried out in clinics of Ukraine, and the State registration was obtained for the implementation of them into the clinical practice. Presented works were awarded State prize of Ukraine in Science and technology.

Fibrinogen reduction and bleeding complications in plasma exchange, immunoadsorption and a combination of the two

BACKGROUND

Immunoadsorption (IAS) and therapeutic plasma exchange (TPE) are considered safe although fibrinogen is removed. To date no comparison of fibrinogen reduction and associated risk of bleeding in apheresis exists.

METHODS

Retrospective analysis of TPE, three IAS adsorbers, and combined TPE/IAS regarding fibrinogen reduction and bleeding incidence in 67 patients (1,032 treatments).

RESULTS

TPE and TPE/IAS reduced fibrinogen by 64 ± 11% and 58 ± 9%, leading to concentrations <100 mg/dl in 20 and 17% of treatments, respectively. IAS decreased fibrinogen less than TPE (26 ± 6%, p < 0.0001), resulting in fibrinogen concentrations <100 mg/dl in 1% of treatments. The processed volume correlated with reduction in TPE (r = 0.64, p < 0.01), but not in IAS. Bleeding occurred in 1.3% (IAS), 2.3% (TPE) and 3.1% (TPE/IAS) of treatments.

CONCLUSION

Hypofibrinogenemia occurs in 20% of patients after TPE and TPE/IAS, but rarely after IAS. IAS removes fibrinogen independently of volume processed. Overall, bleeding is rare in apheresis.

Relation of insulin-like growth factor-I and IGF binding protein 3 with markers of inflammation: results of a population-based study

OBJECTIVE

Previous studies in acromegaly and growth hormone deficiency observed inverse associations between insulin-like growth factor-I (IGF-I) levels and inflammatory biomarkers including high-sensitive C-reactive protein (hsCRP), interleukin-6 or fibrinogen. We aimed to assess the relations between IGF-I or IGF binding protein 3 (IGFBP-3) levels and hsCRP, interleukin-6, fibrinogen and white blood cell count (WBC) in a population-based sample.

DESIGN AND PATIENTS

Data from 3480 subjects from the population-based Study of Health in Pomerania (SHIP) were used. IGF-I, IGFBP-3 and inflammatory biomarkers were measured. Analysis of variance (anova), quantile regression models and logistic regression models, adjusted for age, smoking, diabetes mellitus and waist circumference, were performed.

MEASUREMENTS AND RESULTS

anova and/or quantile regression showed inverse associations between IGF-I and hsCRP as well as positive associations between IGF-I and fibrinogen among both sexes. Furthermore, the odds of elevated fibrinogen levels increased with increasing IGF-I levels (per SD IGF-I increase: men: odds ratio (OR) 1·35 [95% confidence interval (CI) 1·04, 1·55]; women: OR 1·44 [95% CI 1·21, 1·71]) in both sexes, whereas the odds of increased hsCRP (women: OR 0·46 [95% CI 0·36, 0·58]) and interleukin-6 (men: odds ratio (OR) 0·77 [95% CI 0·61, 0·96]; women: OR 0·69 [95% CI 0·55, 0·86]) decreased.

CONCLUSION

Serum IGF-I levels are associated with inflammatory biomarkers including hsCRP, interleukin-6 and fibrinogen. Further experimental studies are needed to elucidate the mechanisms underlying the relation between the GH/IGF axis and the inflammatory system.