Fluvastin therapy affects TAFI concentration in kidney transplant recipients

Atorvastatin downregulates plasma procarboxypeptidase U concentrations and improves fibrinolytic potential dose-dependently in hyperlipidemic individuals

BACKGROUND

Statins efficiently lower cholesterol and also exert pleiotropic effects that extend beyond lipid lowering. In a recent pilot study, valuable information on the carboxypeptidase U (CPU) system in hyperlipidemia and the effect of statin therapy was collected. It was shown that proCPU levels are increased in hyperlipidemic patients. Statins significantly decreased proCPU levels and improved plasma fibrinolysis. Furthermore, it was suggested that patients with high baseline proCPU levels are most likely to benefit from statin therapy.

OBJECTIVES

We aimed to further substantiate the effect of hyperlipidemia and statin therapy on CPU-related parameters in a larger cohort of hyperlipidemic and statin-treated individuals.

METHODS

Blood was collected from 141 individuals treated with different dosages of atorvastatin (10-80 mg), 38 normolipidemic, and 37 hyperlipidemic controls. Lipid parameters and markers of fibrinolysis (proCPU and clot lysis time) were determined and compared between the groups.

RESULTS

Pilot study results of high proCPU concentrations in hyperlipidemic patients and the proCPU-reducing effect of atorvastatin were confirmed. Accordingly, an improvement in plasma fibrinolytic potential was seen under the influence of atorvastatin. High interindividual variation in proCPU concentrations was observed in the hyperlipidemic cohort, with up to 80% higher proCPU levels compared with normolipidemic controls. Furthermore, proCPU concentration and the dosage of atorvastatin were inversely correlated.

CONCLUSIONS

This study clearly shows that plasma proCPU concentrations and its expected effect on the fibrinolytic rate (as measured by clot lysis time) are increased in hyperlipidemic patients and that these effects can be normalized (and even further reduced compared with normolipidemic patients) by atorvastatin treatment.

Systematic Review and Meta-Analysis of the Effect of Statins on Circulating E-Selectin, L-Selectin, and P-Selectin

The pleiotropic effects of statins might involve preventing inflammatory cell adhesion to the endothelium, which is a critical step in the pathogenesis of atherosclerosis. We conducted a systematic review and meta-analysis of the effects of statins on the circulating cell adhesion molecules E-Selectin, L-Selectin, and P-Selectin. A literature search was conducted in PubMed, Web of Science, and Scopus, from inception to July 2021. Risk of bias and certainty of evidence were assessed using the Joanna Briggs Institute Critical Appraisal Checklist and GRADE, respectively. In 61 studies, statins significantly reduced P-selectin (standard mean difference, SMD = -0.39, 95% CI -0.55 to -0.22, p < 0.001; moderate certainty of evidence), L-selectin (SMD = -0.49, 95% CI -0.89 to -0.10, p = 0.014; very low certainty of evidence), and E-Selectin (SMD = -0.73, 95% CI -1.02 to -0.43, p < 0.001; moderate certainty of evidence), independently of baseline lipid profile and other study and patient characteristics. The corresponding pooled SMD values in sensitivity analysis were not substantially altered when individual studies were sequentially removed. Simvastatin had a significant lowering effect on both P-selectin and E-selectin. Therefore, statins significantly reduce circulating selectins. Further studies are required to investigate whether selectin lowering mediates cardiovascular risk reduction with these agents. (PROSPERO registration number: CRD42021282778).

Effect of Statin Therapy on the Carboxypeptidase U (CPU, TAFIa, CPB2) System in Patients With Hyperlipidemia: A Proof-of-concept Observational Study

PURPOSE

Statins are commonly used in patients with hypercholesterolemia to lower their cholesterol levels and to reduce their cardiovascular risk. There is also considerable evidence that statins possess a range of cholesterol-independent effects, including profibrinolytic properties. This pilot study aimed to explore the influence of statins on procarboxypeptidase U (proCPU) biology and to search for possible effects and associations that can be followed up in a larger study.

METHODS

Blood was collected from 16 patients with hyperlipidemia, before and after 3 months of statin therapy (simvastatin 20 mg or atorvastatin 20 mg). Fifteen age-matched normolipemic persons served as control subjects. Lipid parameters and markers of inflammation and fibrinolysis (proCPU levels and clot lysis times) were determined in all samples.

FINDINGS

Mean (SD) proCPU levels were significantly higher in patients with hypercholesterolemia compared to control subjects (1186 [189] U/L vs 1061 [60] U/L). Treatment of these patients with a statin led to a significant average decrease of 11.6% in proCPU levels and brought the proCPU concentrations to the same level as in the control subjects. On a functional level, enhancement in plasma fibrinolytic potential was observed in the statin group, with the largest improvement in fibrinolysis seen in patients with the highest baseline proCPU levels and largest proCPU decrease upon statin treatment.

IMPLICATIONS

Increased proCPU levels are present in patients with hyperlipidemia. Statin treatment significantly decreased proCPU levels and improved plasma fibrinolysis in these patients. Moreover, our study indicates that patients with high baseline proCPU levels are most likely to benefit from statin therapy. The latter should be examined further in a large cohort.

Carboxypeptidase U (CPU, TAFIa, CPB2) in Thromboembolic Disease: What Do We Know Three Decades after Its Discovery?

Procarboxypeptidase U (proCPU, TAFI, proCPB2) is a basic carboxypeptidase zymogen that is converted by thrombin(-thrombomodulin) or plasmin into the active carboxypeptidase U (CPU, TAFIa, CPB2), a potent attenuator of fibrinolysis. As CPU forms a molecular link between coagulation and fibrinolysis, the development of CPU inhibitors as profibrinolytic agents constitutes an attractive new concept to improve endogenous fibrinolysis or to increase the efficacy of thrombolytic therapy in thromboembolic diseases. Furthermore, extensive research has been conducted on the in vivo role of CPU in (the acute phase of) thromboembolic disease, as well as on the hypothesis that high proCPU levels and the Thr/Ile325 polymorphism may cause a thrombotic predisposition. In this paper, an overview is given of the methods available for measuring proCPU, CPU, and inactivated CPU (CPUi), together with a summary of the clinical data generated so far, ranging from the current knowledge on proCPU concentrations and polymorphisms as potential thromboembolic risk factors to the positioning of different CPU forms (proCPU, CPU, and CPUi) as diagnostic markers for thromboembolic disease, and the potential benefit of pharmacological inhibition of the CPU pathway.

Effects of Exercise and Sport in Solid Organ Transplant Recipients: A Review

Solid organ transplantation is the criterion standard treatment for many with end-organ failure and can offer a new independence from the burden of disease. However solid organ transplant recipients (SOTRs) remain at high risk of cardiovascular (CV) disease, and poor quality of life and physical functioning. Increasing physical activity and exercise can improve the health of the general population; however, the effects on those with a transplant remain unclear. Intensive exercise and sporting activity has the potential to be beneficial, although there remain concerns particularly around the effects on immune function and the CV system. This review summarizes what is known about the effects of exercise on determinants of health in SOTRs and then collates the available literature investigating the consequences of intensive exercise and sport on the health of SOTR. There is a paucity of high-quality research, with most evidence being case studies or anecdotal; this is understandable given the relatively few numbers of SOTRs who are performing sport and exercise at a high level. However, if suitable evidence-based guidelines are to be formed and SOTRs are to be given reassurances that their activity levels are not detrimental to their transplanted organ and overall health, then more high-quality studies are required.

Elevated thrombin activatable fibrinolysis inhibitor (TAFI) antigen levels in overt and subclinical hypothyroid patients were reduced by levothyroxine replacement

The influence of hypothyroidism on haemostasis is an active research area. Not only bleeding tendency but also hypercoagulable states have been reported in hypothyroid patients. Decreased and increased fibrinolytic activity in hypothyroid patients has been shown in several studies. Thrombin activatable fibrinolysis inhibitor (TAFI) is an inhibitor of fibrinolysis, which has been recently isolated from human plasma. The aim of our study was to determine plasma TAFI antigen levels in overt and subclinical hypothyroidism, and to investigate the effect of levothyroxine treatment on TAFI levels. The study was performed in age- and sex-matched 30 overt hypothyroid, 30 subclinical hypothyroid patients, and 30 healthy controls. Blood samples were obtained from patients with overt and subclinical hypothyroidism before levothyroxine replacement, and one month after achieving a euthyroid state with levothyroxine. TAFI antigen levels were measured using Enzyme-Linked ImmunoSorbent Assay kits (Affinity Biologicals; Ontario, Canada). In baseline evaluation both the overt and subclinical hypothyroid groups had higher TAFI antigen levels than control group (p<0.05). High levels of TAFI antigen were correlated with the degree of thyroid failure. After achieving euthyroid state with levothyroxine replacement, TAFI antigen levels decreased significantly in patients with overt and subclinical hypothyroidism (p<0.05). Our data suggest that there are elevated plasma levels of TAFI antigen both in overt and subclinical hypothyroidism, which may be associated with hypofibrinolysis and elevated risk of thrombosis. Normalization of thyroid state by levothyroxine replacement seems to be effective in lowering of TAFI antigen levels in hypothyroidism.

Curiouser and curiouser: recent advances in measurement of thrombin-activatable fibrinolysis inhibitor (TAFI) and in understanding its molecular genetics, gene regulation, and biological roles

The thrombin-activatable fibrinolysis inhibitor (TAFI) pathway defines a novel molecular connection between blood coagulation and both fibrinolysis and inflammation. TAFI is a plasma zymogen that can be activated by thrombin, the thrombin-thrombomodulin complex, or plasmin. The activated form of TAFI (TAFIa) attenuates fibrinolysis by removing the carboxyl-terminal lysine residues from partially degraded fibrin that mediate positive feedback in the fibrinolytic cascade. A role for TAFIa in modulating inflammation is suggested by the ability of this enzyme to down-regulate pericellular plasminogen activation and to inactivate the inflammatory peptides bradykinin and the anaphylatoxins C3a and C5a. The focus of this review is on recent advances in the clinical measurement of the TAFI pathway in human subjects and what this has revealed in terms of the molecular genetics of TAFI, the biological variation in plasma TAFI antigen levels, potential regulators of expression of the gene encoding TAFI, and the TAFI pathway as a risk factor for the development of vascular diseases. Although this field is in its infancy, much recent progress has been made and the available data suggest that the TAFI pathway is an intriguing new player in a variety of physiological and pathophysiological contexts.

Fluvastatin in the treatment of dyslipidemia associated with chronic kidney failure and renal transplantation

Premature atherosclerotic coronary heart disease driven by multiple risk factors is a major cause of morbidity and mortality among the 6 million patients in the United States with chronic renal failure. Consensus is that kidney failure and renal transplantation patients should be treated aggressively for dyslipidemia. Major medical literature databases were searched for published information about fluvastatin, a HMG-CoA reductase inhibitor, used in patients with impaired renal function. This article characterizes the dyslipidemia observed in these clinical settings and reviews the clinical experience with fluvastatin.

Metabolic syndrome accompanied by hypercholesterolemia is strongly associated with proinflammatory state and impairment of fibrinolysis in patients with type 2 diabetes: synergistic effects of plasminogen activator inhibitor-1 and thrombin-activatable fibrinolysis inhibitor

OBJECTIVE

To determine whether plasma concentrations of thrombin-activatable fibrinolysis inhibitor (TAFI) in patients with type 2 diabetes were associated with components of metabolic syndrome (MS), including high-sensitivity C-reactive protein (hs-CRP), plasminogen activator inhibitor (PAI)-1, and LDL cholesterol.

RESEARCH DESIGN AND METHODS

We studied 136 consecutive patients with type 2 diabetes. Diagnosis of MS was diagnosed by current criteria. Hypercholesterolemia (HC) was defined as serum LDL cholesterol >140 mg/dl (3.6 mmol/l) or treatment with a statin. For comparisons, diabetic patients were divided into four groups: those with no MS and no HC (n = 38), with MS but not HC (n = 39), with no MS but with HC (n = 26), and with both MS and HC (n = 33).

RESULTS

Considering all patients with type 2 diabetes, plasma PAI-1 was strongly associated with MS components such as BMI, triglyceride, alanine aminotransferase, a homeostasis model assessment of insulin resistance, and hs-CRP. Plasma TAFI only correlated positively and independently with LDL cholesterol. Plasma concentrations of plasmin-alpha2-antiplasmin complex (PAP), a measure of fibrinolytic activity in blood, showed a significant negative correlation with plasma PAI-1 but not TAFI. Diabetic patients with both MS and HC had the highest serum hs-CRP concentrations and the lowest plasma PAP concentrations.

CONCLUSIONS

LDL cholesterol is a main determinant of plasma TAFI in patients with type 2 diabetes. Coexistence of MS and HC synergistically accelerates inflammation and impairment of fibrinolysis via elevated concentrations of both TAFI and PAI-1, which inhibit fibrinolysis.

Thrombin-activatable fibrinolysis inhibitor in kidney transplant recipient with dyslipidemia

Kidney transplant recipients are not only prone to dyslipidemia but also have a high risk of cardiovascular death. Impairment of the fibrinolytic system is thought to be one factor playing a role in development of thrombotic complications. Thrombin-activatable fibrinolysis inhibitor (TAFI) is a glycoprotein, linking coagulation and fibrinolysis. The purpose of this study was to assess TAFI concentrations and activities in renal transplant recipients stratified based upon serum cholesterol values above 220 mg/dL or below 200 mg/dL. The groups did not differ regarding age, creatinine clearance, BMI, time after transplantation, albumin, fibrinogen, thrombomodulin, or PAP. Additionally, we evaluated thrombin activity (thrombin-antithrombin complex TAT, prothrombin fragments 1 + 2); TAFI activator; thrombomodulin (TM), catalyzer of TAFI activation; and the degree of plasmin generation (plasmin-antiplasmin complex PAP) using commercially available kits. In patients with hyperlipidemia significantly higher TAFI concentrations and activities may contribute to prolonged ECLT and lowered fibrinolytic activity index (FAI). Increased levels of F1 + 2 and TAT were observed in hypercholesterolemic patients, indicating enhanced thrombin generation. Elevated TAFI concentration, and activities and enhanced thrombin generation observed in hypercholesterolemic kidney transplant recipients may contribute to hypofibrinolysis and progression of atherosclerosis in this group of patients.