Sources of variation in factor VIII, von Willebrand factor and fibrinogen measurements: Implications for detecting deficiencies and increased plasma levels

Novel biomarkers in patients with uncontrolled hypertension with and without kidney damage

INTRODUCTION

Estimated glomerular filtration rate (eGFR) and urine albumin/creatinine ratio (ACR) are insensitive biomarkers for early detection of hypertension-mediated organ damage (HMOD). In this nationwide cross-sectional study, we assessed potential biomarkers for early HMOD in healthy persons and patients with hypertension. We hypothesised that plasma levels of biomarkers: (1) are different between healthy controls and patients with hypertension, (2): can classify patients with hypertension according to the degree of hypertension severity.

DESIGN AND METHODS

Patients with hypertension prescribed ≥2 antihypertensive agents were selected from a multicentre study. Healthy controls were selected from an ongoing study of living kidney donor candidates. Uncontrolled hypertension was defined as systolic daytime ambulatory blood pressure ≥135 mmHg. Kidney HMOD was defined by ACR > 3.0 mg/mmol or eGFR < 60 mL/min/1.73 m2. Patients with hypertension were categorised into three groups: (1) controlled hypertension; (2) uncontrolled hypertension without kidney HMOD; (3) uncontrolled hypertension with kidney HMOD. Fifteen biomarkers were analysed using a Luminex bead-based immunoassay, and nine fell within the specified analytical range.

RESULTS

Plasma levels of Interleukin 1 receptor antagonist (IL-1RA), neutrophil gelatinase-associated lipocalin (NGAL) and uromodulin were significantly different between healthy controls (n = 39) and patients with hypertension (n = 176). In regression models, with controlled hypertension (n = 55) as the reference category, none of the biomarkers were associated with uncontrolled hypertension without (n = 59) and with (n = 62) kidney HMOD. In models adjusted for cardiovascular risk factors and eGFR, osteopontin (OPN) was associated with uncontrolled hypertension without kidney HMOD (odds ratio (OR) 1.77 (1.05-2.98), p = 0.03), and regulated upon activation normal T-cell expressed and secreted (RANTES) with uncontrolled hypertension with kidney HMOD (OR 0.57 (0.34-0.95), p = 0.03).

CONCLUSIONS

None of the biomarkers could differentiate our hypertension groups when established risk factors were considered. Plasma OPN may identify patients with uncontrolled hypertension at risk for kidney HMOD.

Systemic inflammation in midlife is associated with late-life functional limitations

Systemic inflammation generally coexists with functional limitations that seriously affect quality of life. This study aimed to investigate the association between systemic inflammation in midlife and the risk of functional limitations in late-life. A total of 10,044 participants with an average age of 53.9 ± 5.7 years at baseline were included in a cohort study. At the last follow-up, the prevalence of impaired activities of daily living (ADLs), instrumental activities of daily living (IADLs), and lower extremity function (LEF) was 14.7%, 21.6%, and 50.3%, respectively. The values of four inflammatory biomarkers were used to calculate the inflammation composite score. Compared with the participants in the lowest quartile of the inflammation composite score (Q1), those in the highest quartile (Q4) exhibited an odds ratio (OR) of 1.589 and a 95% confidence interval (CI) of 1.335-1.892 for impaired ADLs, an OR of 1.426 and a 95% CI of 1.228-1.657 for impaired IADLs, and an OR of 1.728 and a 95% CI of 1.526-1.957 for impaired LEF. The association between systemic inflammation and functional limitations was partly mediated by cardiac and brain function. The present study provides evidence that systemic inflammation in midlife is associated with a higher risk of late-life functional limitations. Protecting vital organ functions in midlife may have a positive impact on reducing the risk of future functional limitations.Trial registration: www.clinicaltrials.gov ; Unique identifier: NCT00005131.

Impact of specific preclinical variables on coagulation biomarkers in cancer-associated thrombosis

Coagulation biomarkers are being actively studied for their diagnostic and prognostic value in patients with venous thromboembolism and cancer, as well as in the study of pathogenic mechanisms between cancer and thrombosis. For the results of such studies to be accurate and reproducible, attention must be paid to minimize sources of error in all phases of testing. The pre-analytical phase of laboratory testing is known to be fraught with the majority of errors. Coagulation testing is particularly susceptible to conditions during collection, processing, transport and storage of specimens which can lead to clinically significant errors in results. In addition, changes in pre-analytical conditions can impact different biomarkers differently. Therefore, research studies investigating coagulation biomarkers must carefully standardize not just the analytical phase, but also the pre-analytical phase of testing to ensure accuracy and reliability. We briefly review the impact of pre-analytical conditions on coagulation testing in general, and on specific biomarkers in cancer and thrombosis. In addition, we provide recommendations to reduce pre-analytical errors by developing and sharing standard operating procedures that specifically target standardization of methodologies for collecting specimens and measuring current and emerging coagulation biomarkers in cancer studies.

Pre-analytical issues in the haemostasis laboratory: guidance for the clinical laboratories

Ensuring quality has become a daily requirement in laboratories. In haemostasis, even more than in other disciplines of biology, quality is determined by a pre-analytical step that encompasses all procedures, starting with the formulation of the medical question, and includes patient preparation, sample collection, handling, transportation, processing, and storage until time of analysis. This step, based on a variety of manual activities, is the most vulnerable part of the total testing process and is a major component of the reliability and validity of results in haemostasis and constitutes the most important source of erroneous or un-interpretable results. Pre-analytical errors may occur throughout the testing process and arise from unsuitable, inappropriate or wrongly handled procedures. Problems may arise during the collection of blood specimens such as misidentification of the sample, use of inadequate devices or needles, incorrect order of draw, prolonged tourniquet placing, unsuccessful attempts to locate the vein, incorrect use of additive tubes, collection of unsuitable samples for quality or quantity, inappropriate mixing of a sample, etc. Some factors can alter the result of a sample constituent after collection during transportation, preparation and storage. Laboratory errors can often have serious adverse consequences. Lack of standardized procedures for sample collection accounts for most of the errors encountered within the total testing process. They can also have clinical consequences as well as a significant impact on patient care, especially those related to specialized tests as these are often considered as "diagnostic". Controlling pre-analytical variables is critical since this has a direct influence on the quality of results and on their clinical reliability. The accurate standardization of the pre-analytical phase is of pivotal importance for achieving reliable results of coagulation tests and should reduce the side effects of the influence factors. This review is a summary of the most important recommendations regarding the importance of pre-analytical factors for coagulation testing and should be a tool to increase awareness about the importance of pre-analytical factors for coagulation testing.

Primary and secondary haemostasis changes related to aging

Life expectancy has increased in many countries as a result the world's population is aging. The projections indicate that the proportion of the elderly in a few decades will increase significantly. Aging carries with it a series of physiological changes; one of them is an imbalance in the hemostatic system. Thus the levels or activity of various proteins involved, such as most coagulation factors, natural anticoagulants and the fibrinolytic system are altered so that the hemostatic balance leans toward thrombosis. Also, platelet activity suggests a state of abnormal activation (P-selectin, beta thromboglobulin and platelet factor). In this review we will systematically examine the alterations in the hemostatic components that occur during aging. Therefore, understanding these hemostatic changes could contribute to developing strategies for the proper management of health in old age.

Phase II prospective open-label trial of recombinant interleukin-11 in women with mild von Willebrand disease and refractory menorrhagia

Lack of effective treatment for menorrhagia is the greatest unmet healthcare need in women with von Willebrand disease (VWD). We conducted a single-centre phase II clinical trial to determine efficacy and safety of recombinant IL-11 (rhIL-11, Neumega®) given subcutaneously for up to seven days during six consecutive menstrual cycles each in seven women with mild VWD and menorrhagia refractory to haemostatic or hormonal agents. rhIL-11 reduced menstrual bleeding severity as measured by pictorial blood assessment chart (PBAC) ≥ 50% (to <100) in 71% of subjects, cycle severity ≥ 50% in 71%, and bleeding duration ≥ 2 days in 85%, all p ≤ 0.01. After rhIL-11, plasma VWF:RCo increased 1.1-fold, but did not correlate with PBAC, r=0.116, bleeding duration, r=0.318, or cycle severity, r=-0.295, or hsCRP, r=-0.003, all p>0.05. Platelet VWF mRNA expression by quantitative PCR increased mean four-fold (1.0-13.5). rhIL-11 was well tolerated with grade 1 or less fluid retention, flushing, conjunctival erythema, and local bruising. In summary, rhIL-11 reduces menorrhagia safely and warrants further study.