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Biomarker Research May 2023Blood tests would be much easier to implement in the clinical diagnosis of Alzheimer's disease (AD) as minimally invasive measurements. Multiple inspection technologies...
BACKGROUND
Blood tests would be much easier to implement in the clinical diagnosis of Alzheimer's disease (AD) as minimally invasive measurements. Multiple inspection technologies promoted AD-associated blood biomarkers' exploration. However, there was a lack of further screening and validation for these explored blood-based biomarkers. We selected four potential biomarkers to explore their plasma levels in AD and amnestic mild cognitive impairment (aMCI) and developed a composite panel for AD and aMCI screening.
METHOD
The plasma concentrations of soluble low-density lipoprotein receptor-associated protein 1 (sLRP1), Gelsolin (GSN), Kallikrein 4 (KLK4) and Caspase 3 were measured in the discovery and validation cohort. The receiver operating characteristic (ROC) curve was generated to assess the classification panel with the area under the curve (AUC).
RESULTS
A total of 233 participants (26 CN, 27 aMCI, and 26 AD in the discovery cohort, and 51 CN, 50 aMCI, and 53 AD in the validation cohort) with complete data were included in the study. The plasma concentrations of sLRP1 and Caspase 3 were significantly decreased in AD and aMCI when compared with those in the CN group. Compared with the CN group, the concentrations of KLK4 and GSN were increased in AD, but not in MCI. Interestingly, one of four proteins, sLRP1 in plasma level was higher in Apolipoprotein E (APOE) ε4 non-carriers than that in APOE ε4 carriers, especially among CN and MCI. No significant difference was found between females and males in the plasma levels of four proteins. The composite panel is based on four blood biomarkers accurately classifying AD from CN (AUC = 0.903-0.928), and MCI from CN (AUC = 0.846-0.865). Moreover, dynamic changes in the plasma levels of four proteins exhibited a significant correlation with cognitive assessment.
CONCLUSIONS
Altogether, these findings indicate that the plasma levels of sLRP1, KLK4, GSN and Caspase 3 changed with the progression of AD. And their combination could be used to develop a panel for classifying AD and aMCI with high accuracy, which would provide an alternative approach for developing a blood-based test for AD and aMCI screening.
PubMed: 37194047
DOI: 10.1186/s40364-023-00485-6 -
Allergology International : Official... Jul 2023Hereditary angioedema (HAE) is a rare disorder characterized by cutaneous and submucosal swelling caused mostly by excessive local bradykinin production. Bradykinin is a... (Review)
Review
Hereditary angioedema (HAE) is a rare disorder characterized by cutaneous and submucosal swelling caused mostly by excessive local bradykinin production. Bradykinin is a vasoactive peptide generated by the limited proteolysis of high molecular weight kininogen (HMWK) by plasma kallikrein via the contact activation system. The contact activation system occurs not only in solution but also on the cell surface. Factor XII (FXII), prekallikrein, and HMWK are assembled on the endothelial cell surface via several proteins, including a trimer of a receptor for globular C1q domain in a Zn-dependent manner, and the reciprocal activation on the cell surface is believed to be physiologically important in vivo. Thus, the contact activation system leads to the activation of coagulation, complement, inflammation, and fibrinolysis. C1-inhibitor (C1-INH) is a plasma protease inhibitor that is a member of the serpin family. It mainly inhibits activated FXII (FXIIa), plasma kallikrein, and C1s. C1-INH hereditary deficiency induces HAE (HAE-C1-INH) due to excessive bradykinin production via the incomplete inhibition of plasma kallikrein and FXIIa through the low C1-INH level. HAE is also observed in patients with normal C1-INH (HAEnCI) who carry pathogenic variants in genes of factor XII, plasminogen, angiopoietin 1, kininogen, myoferlin, and heparan sulfate 3-O-sulfotransferase 6, which are associated with bradykinin production and/or vascular permeability. HAE-causing pathways triggered by pathogenic variants in patients with HAE-C1-INH and HAEnCI are reviewed and discussed.
Topics: Humans; Angioedemas, Hereditary; Factor XII; Bradykinin; Plasma Kallikrein; Kininogen, High-Molecular-Weight; Complement C1 Inhibitor Protein; Molecular Biology
PubMed: 37169642
DOI: 10.1016/j.alit.2023.04.004 -
Journal of Asthma and Allergy 2023Hereditary angioedema (HAE) is a rare, chronic, and debilitating genetic disorder characterized by recurrent and unpredictable swelling episodes that primarily affect... (Review)
Review
Hereditary angioedema (HAE) is a rare, chronic, and debilitating genetic disorder characterized by recurrent and unpredictable swelling episodes that primarily affect the subcutaneous and/or submucosal tissues of the extremities, larynx, face, abdomen, and genitals. Most cases of HAE are caused by mutations in the serpin family G member 1 gene (), which encodes C1-esterase inhibitor (C1-INH) protein. Mutations in lead to deficient (type I HAE-C1-INH) or dysfunctional (type II HAE-C1-INH) C1-INH protein and subsequent dysregulation of the kallikrein-bradykinin cascade. However, some patients present with a third type of HAE (HAE-nI-C1-INH), which was first described in the year 2000 and is characterized by an absence of mutations in . Although mutations in the coagulation factor XII, angiopoietin-1, plasminogen, kininogen-1, myoferlin, and heparan sulfate-glucosamine 3-O-sulfotransferase-6 genes have been identified in some patients with HAE-nI-C1-INH, genetic cause is still unknown in many cases, hindering full elucidation of the pathology of this HAE subtype. Diagnosis of HAE-nI-C1-INH is also further complicated by the fact that patients typically demonstrate normal plasma levels of C1-INH and complement component 4 protein and normal C1-INH functionality during laboratory analysis. Therefore, we review the challenges associated with diagnosing, treating, and living with HAE-nI-C1-INH. We conclude that raising awareness of the presenting features of HAE-nI-C1-INH within the clinical setting and among the general public is critical to aid earlier suspicion and diagnosis of the disease. Furthermore, adopting an individualized approach to HAE-nI-C1-INH treatment is essential to help address the current and significant unmet needs in this patient population.
PubMed: 37124440
DOI: 10.2147/JAA.S398333 -
Journal of Thrombosis and Haemostasis :... Sep 2023High-molecular weight kininogen (HK) circulates in plasma as a complex with zymogen prekallikrein (PK). HK is both a substrate and a cofactor for activated plasma...
BACKGROUND
High-molecular weight kininogen (HK) circulates in plasma as a complex with zymogen prekallikrein (PK). HK is both a substrate and a cofactor for activated plasma kallikrein, and the principal exosite interactions occur between PK N-terminal apple domains and the C-terminal D6 domain of HK.
OBJECTIVES
To determine the structure of the complex formed between PK apple domains and an HKD6 fragment and compare this with the coagulation factor XI (FXI)-HK complex.
METHODS
We produced recombinant FXI and PK heavy chains (HCs) spanning all 4 apple domains. We cocrystallized PKHC (and subsequently FXIHC) with a 31-amino acid synthetic peptide spanning HK residues Ser565-Lys595 and determined the crystal structure. We also analyzed the full-length FXI-HK complex in solution using hydrogen deuterium exchange mass spectrometry.
RESULTS
The 2.3Å PKHC-HK peptide crystal structure revealed that the HKD6 sequence WIPDIQ (Trp569-Gln574) binds to the apple 1 domain and HK FNPISDFPDT (Phe582-Thr591) binds to the apple 2 domain with a flexible intervening sequence resulting in a bent double conformation. A second 3.2Å FXIHC-HK peptide crystal structure revealed a similar interaction with the apple 2 domain but an alternate, straightened conformation of the HK peptide where residues LSFN (Leu579-Asn583) interacts with a unique pocket formed between the apple 2 and 3 domains. HDX-MS of full length FXI-HK complex in solution confirmed interactions with both apple 2 and apple 3.
CONCLUSIONS
The alternate conformations and exosite binding of the HKD6 peptide likely reflects the diverging relationship of HK to the functions of PK and FXI.
Topics: Humans; Kininogen, High-Molecular-Weight; Factor XI; Prekallikrein; Molecular Weight; Binding Sites; Kininogens; Peptides
PubMed: 37068593
DOI: 10.1016/j.jtha.2023.03.042 -
Research and Practice in Thrombosis and... Feb 2023The contact system (CAS) is part of the coagulation system, consisting of a group of plasma proteins stimulating inflammation, coagulation, and fibrinolysis when...
BACKGROUND
The contact system (CAS) is part of the coagulation system, consisting of a group of plasma proteins stimulating inflammation, coagulation, and fibrinolysis when activated. CAS can be triggered by several activating surfaces, and CAS may play a potential role in thrombus formation. Combined oral contraceptives (COCs) are known to increase the risk of venous thromboembolism, and COCs induce various prothrombotic changes in the coagulation system, whereas the effect of COC on CAS has not been thoroughly investigated.
OBJECTIVES
To investigate CAS in COC users compared with nonusers.
METHODS
Blood samples from 62 study subjects, 30 COC users, and 32 nonusers, were analyzed. Coagulation factor XII (FXII), prekallikrein (PK), H-Kininogen (HK), cleaved HK (cHK), C1-esterase inhibitor (C1-inh), and the endogenous kallikrein potential (EKP) were measured.
RESULTS
COC users had significantly higher FXII (median, 38.4 vs 28.9 mg/L) and lower C1-inh levels (0.20 vs 0.23 g/L) than nonusers. The levels of PK and HK were not significantly different. Measurement of EKP indicated an increased capacity of CAS in COC users (1860 vs 1500 nmol/L × min), and increased plasma levels of cHK (2.02 vs 1.07 μg/L) indicated an increased activity .
CONCLUSION
This study demonstrates an increased CAS capacity in women using COC compared with nonusers and also an increased activity . The results indicate that increased contact activation may contribute to the increased thrombotic risk caused by COC.
PubMed: 37063763
DOI: 10.1016/j.rpth.2023.100118 -
Therapeutics and Clinical Risk... 2023Hereditary angioedema (HAE) is a condition characterized by episodes of cutaneous and submucosal edema. Angioedema of the extremities and abdominal attacks are the most... (Review)
Review
Hereditary angioedema (HAE) is a condition characterized by episodes of cutaneous and submucosal edema. Angioedema of the extremities and abdominal attacks are the most common manifestations of the disease. It can also affect the upper airways with the potential of becoming life-threatening. The two most common causes of HAE are a deficiency of C1 inhibitor (classified as type 1 HAE) or a dysfunction of C1 inhibitor (type 2 HAE). A malfunction or deficiency of C1 inhibitor leads to an overactivated plasma kallikrein (an inflammatory vasoactive peptide), that increases bradykinin, mediating the angioedema episodes in patients with HAE. To minimize the difficulties of this pathology and to improve patients' quality of life, prevention of this condition is essential. Berotralstat is a unique option for oral administration for routine prophylaxis. This drug acts by binding to kallikrein and reducing its plasma activity, lowering bradykinin levels. Open-label studies have demonstrated the effectiveness of a single daily dose of berotralstat 150 mg in preventing HAE attacks. This review aims to examine studies performed to elucidate the efficacy, safety, and tolerability of berotralstat.
PubMed: 37021074
DOI: 10.2147/TCRM.S310376 -
Journal of Thrombosis and Haemostasis :... Jun 2023Venous thromboembolism (VTE) is associated with excessive coagulation activity, which in part can be attributed to activation of contact system. However, the knowledge...
BACKGROUND
Venous thromboembolism (VTE) is associated with excessive coagulation activity, which in part can be attributed to activation of contact system. However, the knowledge regarding the impact of contact activation in acute VTE is limited.
OBJECTIVE
To unravel the involvement of contact activation in acute VTE.
METHODS
Contact activation was investigated in patients with acute VTE (n = 321) and population controls without a history of VTE (n = 300). For comparison, Factor XI(a) levels, activity, and plasma kallikrein (PKa) activity were determined in plasma samples with an activated partial thromboplastin time- or thrombin generation-based assay (free FXI concentration [FXI:c] and calibrated automated thrombogram:FXIa, respectively) and with enzyme-linked immunosorbent assays for enzyme-inhibitor complexes (FXIa:alpha-1-antitrypsin [α1AT], FXIa:antithrombin [AT], FXIa:C1-inhibitor [C1Inh], and PKa:C1-inh).
RESULTS
In patients with VTE, higher FXI:c levels (124 ± 37% vs 114 ± 28%), but lower calibrated automated thrombogram:FXIa levels were apparent. This was accompanied by increased FXIa:α1AT, FXIa:AT, and PKa:C1-inh levels in patients compared with controls (312pM [238-424] vs 203pM [144-288]; 29pM [23-38] vs 23pM [20-30]; 1.9nM [1.2-4.7] vs 1.4nM [0.7-3.5], respectively), whereas FXIa:C1-inh levels did not differ. Logistic regression models showed good discriminatory values for FXI:c and FXIa:α1AT (area under the curve = 0.64 [0.6/0.69] and 0.73 [0.69/0.77], respectively). After a 2-year follow-up, 81 recurrent VTE events or deaths occurred in the patient cohort, for which the baseline levels of FXIa:α1AT and FXIa:C1Inh had a significant prognostic value (Hazard ratios per SD [95% CI], 1.26 [1.10-1.45]; p =.0012 and 1.19 [1.05-1.36]; p =.0082, respectively).
CONCLUSION
Our study revealed elevated FXIa levels and activity in acute VTE, which was also associated with recurrent VTE, suggesting an important risk contribution of FXI activation to VTE. The evidence provided by this study supports the utility of FXIa inhibition in the setting of acute VTE.
Topics: Humans; Factor XIa; Venous Thromboembolism; Factor XI; Venous Thrombosis; Blood Coagulation; Plasma Kallikrein; Anticoagulants; Antithrombin III
PubMed: 37003466
DOI: 10.1016/j.jtha.2023.02.031 -
Journal of Thrombosis and Haemostasis :... Apr 2023Human serum albumin (HSA) is the most abundant plasma protein and is sensitive to glycation in vivo. The chronic hyperglycemic conditions in patients with diabetes...
BACKGROUND
Human serum albumin (HSA) is the most abundant plasma protein and is sensitive to glycation in vivo. The chronic hyperglycemic conditions in patients with diabetes mellitus (DM) induce a nonenzymatic Maillard reaction that denatures plasma proteins and forms advanced glycation end products (AGEs). HSA-AGE is a prevalent misfolded protein in patients with DM and is associated with factor XII activation and downstream proinflammatory kallikrein-kinin system activity without any associated procoagulant activity of the intrinsic pathway.
OBJECTIVES
This study aimed to determine the relevance of HSA-AGE toward diabetic pathophysiology.
METHODS
The plasma obtained from patients with DM and euglycemic volunteers was probed for activation of FXII, prekallikrein (PK), and cleaved high-molecular-weight kininogen by immunoblotting. Constitutive plasma kallikrein activity was determined via chromogenic assay. Activation and kinetic modulation of FXII, PK, FXI, FIX, and FX via in vitro-generated HSA-AGE were explored using chromogenic assays, plasma-clotting assays, and an in vitro flow model using whole blood.
RESULTS
Plasma obtained from patients with DM contained increased plasma AGEs, activated FXIIa, and resultant cleaved cleaved high-molecular-weight kininogen. Elevated constitutive plasma kallikrein enzymatic activity was identified, which positively correlated with glycated hemoglobin levels, representing the first evidence of this phenomenon. HSA-AGE, generated in vitro, triggered FXIIa-dependent PK activation but limited the intrinsic coagulation pathway activation by inhibiting FXIa and FIXa-dependent FX activation in plasma.
CONCLUSION
These data indicate a proinflammatory role of HSA-AGEs in the pathophysiology of DM via FXII and kallikrein-kinin system activation. A procoagulant effect of FXII activation was lost through the inhibition of FXIa and FIXa-dependent FX activation by HSA-AGEs.
Topics: Humans; Kallikreins; Plasma Kallikrein; Kinins; Factor XIIa; Kininogen, High-Molecular-Weight; Prekallikrein; Albumins; Glycation End Products, Advanced
PubMed: 36990522
DOI: 10.1016/j.jtha.2022.12.015 -
Journal of Thrombosis and Haemostasis :... Aug 2023Patients with liver diseases are in a hypercoagulable state, as evidenced by enhanced in vitro thrombin generating capacity and elevated plasma levels of markers of...
BACKGROUND
Patients with liver diseases are in a hypercoagulable state, as evidenced by enhanced in vitro thrombin generating capacity and elevated plasma levels of markers of in vivo thrombin generation. However, it is unknown by which mechanism in vivo activation of coagulation occurs.
OBJECTIVES
We aimed to clarify the mechanisms underlying enhanced in vivo thrombin generation to provide a rationale for targeted anticoagulant therapy.
PATIENTS/METHODS
Overall, 191 patients diagnosed with stable or acutely decompensated cirrhosis, acute liver failure or injury, acute-on-chronic liver failure, or sepsis without underlying chronic liver disease were recruited from King's College Hospital, London, from 2017 to 2021 and compared with reference values of 41 healthy controls. We measured levels of markers of in vivo activation of coagulation and activation of the intrinsic and extrinsic pathways, their respective zymogens, and natural anticoagulants.
RESULTS
Thrombin-antithrombin complexes, prothrombin fragment 1+2 (F1+2), and D-dimer levels were increased in acute and chronic liver disease, proportional to disease severity. Plasma levels of free activated factor XII (FXIIa), C1-esterase-inhibitor (C1inh)-FXIIa, C1inh-factor XI, C1inh-plasma kallikrein, factor-VIIa-antithrombin-complexes, and activated FVII were reduced in acute and chronic liver disease, even after adjusting for zymogen levels, which were also substantially reduced. Natural anticoagulants antithrombin and protein C were profoundly reduced in liver patients.
CONCLUSIONS
This study provides evidence of enhanced thrombin generation in liver disease without detectable activation of the intrinsic or extrinsic pathway. We propose that defective anticoagulant mechanisms highly amplify the low-grade activation of coagulation by either pathway.
Topics: Humans; Thrombin; Blood Coagulation; Anticoagulants; Liver Diseases; Antithrombins
PubMed: 36990155
DOI: 10.1016/j.jtha.2023.03.017