Fibrinogen Beta Chain Research Articles

Proteomic identification of plasma biomarkers in uterine leiomyoma

Recent progresses in quantitative proteomics have offered opportunities to discover plasma proteins as biomarkers for tracking the progression and for understanding the molecular mechanisms of uterine leiomyomas. In the present study, plasma samples were analyzed by fluorescence two-dimensional differential gel electrophoresis (2D-DIGE) and differentially expressed proteins were identified by matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). In total, 20 proteins have been firmly identified representing 13 unique gene products. These proteins mainly functioned in transportation (such as apolipoprotein A-I) and coagulation (such as fibrinogen gamma chain). Additionally, our quantitative proteomic approach has identified numerous previous reported plasma markers of uterine leiomyomas such as alpha-1-antitrypsin. On the contrary, we have presented several putative uterine leiomyomas biomarkers including afamin, apolipoprotein A-I, carbonic anhydrase 1, fibrinogen beta chain, fibrinogen gamma chain, gelsolin, hemopexin, leucine-rich alpha-2-glycoprotein, serotransferrin and vitamin D-binding protein which have not been reported and may be associated with the progression and development of the disease. In summary, we report a comprehensive patient-based proteomic approach for the identification of potential plasma biomarkers for uterine leiomyomas. The potential of utilizing these markers for screening and treating uterine leiomyomas warrants further investigations.

Proteomic analysis of plasma from cows affected with milk fever using two-dimensional differential in-gel electrophoresis and mass spectrometry

Milk fever is an important metabolic disorder of dairy cows after calving, and is characterized by hypocalcemia, tetany, lateral recumbency, and eventual coma. To date, there have been many reports about the pathogenesis and pathophysiology of milk fever, but the plasma protein profile in milk fever has not been reported. The aim of our study was to investigate novel pathophysiological changes in the plasma proteome of cows affected with milk fever. Plasma samples were collected from eight Holstein cows with milk fever (T), and eight control Holstein cows without milk fever (C), at an intensive Holstein dairy farm in Heilongjiang province, China. Samples were analyzed by fluorescence two-dimensional (2D) differential in-gel electrophoresis (DIGE), followed by in-gel digestion, and matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF-MS) for peptide mass fingerprinting of selected protein spots. Eight of the 23 differential protein spots in the plasma of T and C cows were isolated and identified by 2D-DIGE and MALDI-TOF-MS. The protein spots represented five unique proteins, and had significant alterations in spot volume as determined by DeCyder differential in-gel analysis (DIA) software. The upregulated proteins were identified as serpin peptidase inhibitor (angiotensin), which regulates blood pressure and maintains fluid and electrolyte homeostasis, and endopin 2B which is involved in neural regulation. The downregulated proteins were serum albumin, which acts as a transport protein, fibrinogen beta chain which is involved in blood coagulation, and IgG heavy-chain C-region (IgG-CH) which participates in the immune response. In conclusion, we were able to use proteomic technologies to identify several novel plasma proteins in cows affected with milk fever. These findings may reveal new pathophysiological changes that occur in cows with milk fever.

A proteomic analysis of human follicular fluid in women undergoing IVF cycles

A proteomic analysis of human follicular fluid in women undergoing IVF cycles

Fibrinogen Beta-Chain -C148T Polymorphism is Associated with Increased Fibrinogen, C-Reactive Protein, and Interleukin-6 in Patients Undergoing Coronary Artery Bypass Grafting

The fibrinogen beta-chain (FGB) -C148T polymorphism is linked with plasma fibrinogen concentration in the general population. We examined whether the -C148T polymorphism is associated with pre- and early postoperative levels of fibrinogen, C-reactive protein (CRP), and interleukin-6 (IL-6) in 243 consecutive patients undergoing coronary artery bypass grafting (CABG) surgery. Plasma inflammatory markers were measured prior to and 5–7 days after surgery. The -C148T polymorphism was analyzed with the restriction fragment-length polymorphism method. The genotype distribution was as follows: CC—142 (58%), CT—85 (35%), and TT—16 (7%). Carriers of the -148T allele had higher preoperative plasma fibrinogen (4.42 ± 0.14 vs. 4.07 ± 0.11 mg/L, p = 0.04) and CRP levels (7.49 ± 1.2 vs. 4.26 ± 1.0 mg/L, p = 0.04) compared with non-carriers; 5 to 7 days after CABG, patients carrying -148T allele had increased CRP (70.4 ± 5.0 vs. 51.6 ± 4.25 mg/L, p = 0.005) and IL-6 levels (22.34 ± 2.64 vs. 15.53 ± 2.28 pg/L, p = 0.05), but not fibrinogen, compared with the remaining subjects. In-hospital nonfatal stroke occurred more frequently in -148T allele carriers (4% vs. 0%, p = 0.02). No genotype-associated differences were found in the occurrence of postoperative myocardial infarction and death. Presence of the -148T allele has also been associated with longer intensive care stay and intubation time (p = 0.01). Multivariate analysis identified the CT+TT genotype as an independent predictor of pre- and postoperative CRP levels. The results indicate that the presence of the -148T FGB allele determines higher pre- and postoperative levels of inflammatory markers, which might be associated with in-hospital clinical outcomes.

A liver enhancer in the fibrinogen gene cluster

AbstractThe plasma concentration of fibrinogen varies in the healthy human population between 1.5 and 3.5 g/L. Understanding the basis of this variability has clinical importance because elevated fibrinogen levels are associated with increased cardiovascular disease risk. To identify novel regulatory elements involved in the control of fibrinogen expression, we used sequence conservation and in silico–predicted regulatory potential to select 14 conserved noncoding sequences (CNCs) within the conserved block of synteny containing the fibrinogen locus. The regulatory potential of each CNC was tested in vitro using a luciferase reporter gene assay in fibrinogen-expressing hepatoma cell lines (HuH7 and HepG2). 4 potential enhancers were tested for their ability to direct enhanced green fluorescent protein expression in zebrafish embryos. CNC12, a sequence equidistant from the human fibrinogen alpha and beta chain genes, activates strong liver enhanced green fluorescent protein expression in injected embryos and their transgenic progeny. A transgenic assay in embryonic day 14.5 mouse embryos confirmed the ability of CNC12 to activate transcription in the liver. While additional experiments are necessary to prove the role of CNC12 in the regulation of fibrinogen, our study reveals a novel regulatory element in the fibrinogen locus that is active in the liver and may contribute to variable fibrinogen expression in humans.

Differential gene expression profile in the liver of the marine puffer fish Takifugu rubripes induced by intramuscular administration of tetrodotoxin

Marine puffer fish accumulate a high level of tetrodotoxin (TTX) in the liver and ovary, but the underlying mechanism of this toxification is unclear. To elucidate the genes related to toxification of the marine puffer fish, we examined the hepatic gene expression profile of the marine puffer fish Takifugu rubripes by suppression subtractive hybridization in response to the intramuscular administration of 0.50 mg TTX/kg body weight into the caudal muscle. The accumulation of TTX in the liver reached 68 ± 4% that of the administered dose within 12 h of administration. A total of 1048 clones from the subtracted cDNA libraries were successfully sequenced. The nucleotide sequence of 92 of the 1048 clones was identified as a hepcidin precursor. Reverse transcription-polymerase chain reaction experiments revealed that hepcidin precursors were highly expressed in the TTX-administered group. In addition, complement C3 (31 clones), serotransferrin (30 clones), apolipoprotein A-1 (14 clones), high temperature adaptation protein Wap65-2 (14 clones), complement C7 (12 clones), fibrinogen beta chain (12 clones), and 70 kDa heat-shock protein 4 (11 clones) were obtained. This study confirmed that the intramuscular administration of TTX increases the gene expression of the acute-phase response proteins in the liver of puffer fish T. rubripes.

Novel tumour‐specific promoters for transcriptional targeting of hepatocellular carcinoma by herpes simplex virus vectors

Hepatocellular carcinoma (HCC) is a cancer of poor prognosis, with limited success in patient treatment, which it makes an excellent target for gene therapy and viral oncolysis. Accordingly, herpes virus simplex type-1 (HSV-1) is one of the most promising viral platforms for transferring therapeutic genes and the development of oncolytic vectors that can target, multiply in, and eradicate hepatoma cells via their lytic cycle. Enhanced efficacy and specificity of HSV-1-based vectors towards HCC may be achieved by using HCC-specific gene promoters to drive selective viral gene expression and accomplish conditional replication and/or to control the expression of therapeutic genes. However, careful verification of promoter function in the context of the replication-competent HSV-1 vectors is required. The present study aimed to identify novel HCC-specific promoters that could efficiently direct transgene expression to HCC cells and maintain their activity during active viral replication. Publicly available microarray data from human HCC biopsies were analysed in order to detect novel candidate genes induced primarily in HCC compared to normal liver. HCC specificity and promoter activity were evaluated by RT-PCR and chromatin immunoprecipitation. Additionally, transcriptional activity of promoters was further evaluated in the context of HSV-1 genome, using luciferase assays in cultured cells and animal models. Eight HCC-specific genes were characterised in this study: Angiopoietin-like-3, Cytochrome P450, family 2, subfamily C, polypeptide 8, Vitronectin, Alcohol dehydrogenase 6-class V, Apolipoprotein B, Fibrinogen beta chain, Inter-alpha-globulin-inhibitor H3 and Inter-alpha-globulin-inhibitor H1. Specific HCC expression and active gene transcription were confirmed in human liver and non-liver cell lines and further evaluated in primary neoplastic cells from hepatitis C and B virus (HCV- and HBV)-associated HCC patients. High promoter activity and specificity in the presence of HSV-1 infection and from within the viral genome, was validated, both in vitro and in vivo. We identified and experimentally characterized novel hepatoma-specific promoters, which were valuable for cancer-specific gene therapy, using HSV-1 vectors.

Proteomic analysis of peritoneal fluid of patients treated by peritoneal dialysis: effect of glucose concentration

Depending on both membrane composition and solute transport rate across the membrane, protein composition of the dialysate of patients receiving peritoneal dialysis (PD) has recently become of great interest. Unfortunately, thus far few studies have focused on dialysate characterization, and further investigations are required to better understand the biological mechanisms influencing PD efficiency. Different classical proteomic approaches were combined with advanced mass spectrometric (MS) techniques to analyse peritoneal fluid (PF) protein composition of adult patients receiving PD. Characterization was performed by using 1D gel electrophoresis combined with nano-RP-HPLC-ESI-MS/MS and shotgun proteomics, while comparative analyses were performed coupling 2D gel electrophoresis with MALDI-TOF MS. The study allowed the identification of 151 different proteins from PF, which are mainly of plasmatic origin. Comparison of PD effluents characterized by different glucose concentrations demonstrated four proteins (apolipoprotein A-IV, fibrinogen beta chain, transthyretin and alpha-1-antitrypsin) to be under-expressed in the highest osmolar solution having 4.25% compared to others having 1.5% and 2.5% glucose. All of them were found to be involved in the inflammatory processes. This study provides a possible platform for future diagnostic and therapeutic applications in the field of PD and allowed the identification of potential targets to be used in preventing inflammatory processes induced by the exposure to dialysis solutions.

Proteomic Analysis of the Systemic Response to Radiographic Contrast Media

Abstract Introduction Radiographic contrast media (RCM) have numerous effects on the hemostatic system, inflammatory pathways, and vascular endothelium. Given the increasing number of high-risk patients undergoing radiographic procedures, more information regarding the systemic effects of RCM is needed. Methods Blood samples prior to baseline, 4 and 24 h following elective coronary angiography in 10 patients, were subjected to matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Data are presented as the ratio of the protein mass at 4 (iTRAQ4) and 24 h (iTRAQ24) compared to baseline. A ratio >1.0 and a ratio <1.0 indicate production and consumption, respectively, relative to baseline. Results In this sample, we identified 102 proteins with a confidence interval of ≥90%. Six proteins were identified at each time point in all patients. Of the proteins identified, apolipoprotein A-I, apolipoprotein A-II, complement C3, fibrinogen beta chain, immunoglobulin α, and prothrombin revealed an iTRAQ ratio <1.0 at 4 h when compared to baseline (all with p value <0.05) and a trend toward baseline levels at 24 h. Conclusions Systemic administration of RCM results in a variety of alterations to the proteome. Of interest, there is activation of the thrombotic and inflammatory pathways as well as an interaction with lipoprotein metabolism. These changes are most pronounced at 4 h but may persist through 24 h and may be of clinical relevance in patients at risk for thrombotic- and inflammatory-mediated consequences of atherosclerosis.

Prevalence of the fibrinogen β‐chain, angiotensin‐converting enzyme and plasminogen activator inhibitor‐1 polymorphisms in Costa Rican young adults with thrombotic disease

Thrombotic disease is a multifactorial condition that involves both classical and genetic risk factors. We studied the association between the classical risk factors of hypertension and smoking, and polymorphisms on the genes of the angiotensin-converting enzyme (ACE), the beta-chain of fibrinogen (FG), and the plasminogen activator inhibitor-1 (PAI-1) in patients with venous and arterial thrombosis. The present investigation is a retrospective case-control study. A total of 340 participants were analyzed, including 162 patients and 178 healthy controls. Hypertension and smoking showed a significant association with thrombotic disease (p < 0.05) but FG level was found significant risk factor only for the venous thrombosis (VT) group (p < 0.04). Significant differences between thrombotic groups were found for the studied polymorphisms of PAI-1 (p < 0.0014), but for both FG beta-chain gene polymorphisms, none of the molecular analyses showed a positive sample for any mutating allele (p > 0.05). For the ACE polymorphism, the I allele present a protective effect in the general thrombotic group. This is one of the first reports in a Latin-American population dealing with these molecular markers and thrombotic diseases.

Effects of snake venom proteases on human fibrinogen chains.

Proteomic approach is an effective method to study changes in human plasma proteome. Coagulopathies are commonly encountered in victims of viper envenomation which were treated with an administration of immunoglobulin. Unfortunately, this treatment shows significant risk to the patient due to an anaphylactic reaction. Since Echis carinatus Venom (EV) toxins mainly acts both directly and indirectly on fibrinogen, we planned to establish a suitable analysis of its beta (FIBB) e gamma (FIBG) chains. This study will help us to understand the mechanism of envenomation and to find alternative treatments other than the common treatment with the administration of IgG. We evaluated the EV proteolytic activity on whole human plasma proteome from the blood of an healthy volunteer. Two-dimensional electrophoresis (2-DE) using mini-gel was performed to analyse EV effects on the differents fibrinogen chains. Changes in whole plasma proteome were focused on fibrinogen beta and gamma chains after EV incubation. Protein spots were detected and analyzed using ImageMaster 2D Platinum software. Results were represented as mean +/- standard deviation (mean+/-SD) with p<0.05 as a statistically significant value. 2-DE gel analysis showed that some spots of FIBB disappeared and some spots of FIBG decreased. We found that the proteomic approach is a valid method in studying in-depth causes of different diseases, in particular those are involved in coagulopathies linked with proteins like fibrinogen from victims of viper envenomation.

Purification and Functional Characterisation of Rhinocerase, a Novel Serine Protease from the Venom of Bitis gabonica rhinoceros

BackgroundSerine proteases are a major component of viper venoms and are thought to disrupt several distinct elements of the blood coagulation system of envenomed victims. A detailed understanding of the functions of these enzymes is important both for acquiring a fuller understanding of the pathology of envenoming and because these venom proteins have shown potential in treating blood coagulation disorders.Methodology/Principal FindingsIn this study a novel, highly abundant serine protease, which we have named rhinocerase, has been isolated and characterised from the venom of Bitis gabonica rhinoceros using liquid phase isoelectric focusing and gel filtration. Like many viper venom serine proteases, this enzyme is glycosylated; the estimated molecular mass of the native enzyme is approximately 36kDa, which reduces to 31kDa after deglycosylation. The partial amino acid sequence shows similarity to other viper venom serine proteases, but is clearly distinct from the sequence of the only other sequenced serine protease from Bitis gabonica. Other viper venom serine proteases have been shown to exert distinct biological effects, and our preliminary functional characterization of rhinocerase suggest it to be multifunctional. It is capable of degrading α and β chains of fibrinogen, dissolving plasma clots and of hydrolysing a kallikrein substrate.Conclusions/SignificanceA novel multifunctional viper venom serine protease has been isolated and characterised. The activities of the enzyme are consistent with the known in vivo effects of Bitis gabonica envenoming, including bleeding disorders, clotting disorders and hypotension. This study will form the basis for future research to understand the mechanisms of serine protease action, and examine the potential for rhinocerase to be used clinically to reduce the risk of human haemostatic disorders such as heart attacks and strokes.

Proteomics of microparticles after deep venous thrombosis

Background Microparticles (MP) are submicron size membrane vesicles released from activated cells that are associated with thrombosis and inflammation. MP present diverse biological expressions that may be linked to a unique subset of proteins derived from their origin cells. Methods To identify these proteins, plasma samples were taken from 9 patients with deep venous thrombosis (DVT) documented by duplex ultrasound, 9 with leg pain but negative for DVT by duplex, and 6 healthy controls without a history of thrombosis, for fold variation. MP were extracted from platelet-poor plasma, digested separately with trypsin and tagged using iTRAQ reagents. The digests were subjected to 2-D LC separation followed by MALDI tandem mass spectrometry. Peak lists were generated and searched against all human sequences. For protein identification, a minimum of two peptides at 95% confidence was required. Later, iTRAQ ratios were generated comparing relative protein levels of DVT patients to baseline. The proteomic analysis was performed twice for each blood sample. Proteins were considered elevated or depressed if the iTRAQ ratio (R) deviated by 20% change from normal and a p-value less than 0.05. Results Two proteins (Galectin-3 Binding Protein, [Gal3BP], R = 1.76 and Alpha-2 macroglobulin [A2M] R = 1.57) were differentially expressed on DVT patients. Nine proteins were depleted including fibrinogen beta and gamma chain precursors (R = 0.65). Conclusions These proteins influence thrombosis through inflammation, cell shedding, inhibition of fibrinolysis and hemostatic plug formation. Further studies are needed to confirm the mechanistic role of these proteins in the pathogenesis of venous thrombosis in humans.

A novel fragment derived from the beta chain of human fibrinogen, beta43-63, is a potent inhibitor of activated endothelial cells in vitro and in vivo.

Background:Angiogenesis and haemostasis are closely linked within tumours with many haemostatic proteins regulating tumour angiogenesis. Indeed we previously identified a fragment of human fibrinogen, fibrinogen E-fragment (FgnE) with potent anti-angiogenic properties in vitro and cytotoxic effects on tumour vessels in vivo. We therefore investigated which region of FgnE was mediating vessel cytotoxicity.Methods:Human dermal microvascular endothelial cells (ECs) were used to test the efficacy of peptides derived from FgnE on proliferation, migration, differentiation, apoptosis and adhesion before testing the efficacy of an active peptide on tumour vasculature in vivo.Results:We identified a 20-amino-acid peptide derived from the β chain of FgnE, β43–63, which had no effect on EC proliferation or migration but markedly inhibited the ability of activated ECs to form tubules or to adhere to various constituents of the extracellular matrix – collagen IV, fibronectin and vitronectin. Furthermore, our data show that β43–63 interacts with ECs, in part, by binding to αvβ3, so soluble αvβ3 abrogated β43–63 inhibition of tubule formation by activated ECs. Finally, when injected into mice bearing tumour xenografts, β43–63 inhibited tumour vascularisation and induced formation of significant tumour necrosis.Conclusions:Taken together, these data suggest that β43–63 is a novel anti-tumour peptide whose anti-angiogenic effects are mediated by αvβ3.

The PCA and LDA analysis on the differential expression of proteins in breast cancer.

Breast cancer is a leading cause of mortality in women. In Malaysia, it is the most common cancer to affect women. The most common form of breast cancer is infiltrating ductal carcinoma (IDC). A proteomic approach was undertaken to identify protein profile changes between cancerous and normal breast tissues from 18 patients. Two protein extracts; aqueous soluble and membrane associated protein extracts were studied. Thirty four differentially expressed proteins were identified. The intensities of the proteins were used as variables in PCA and reduced data of six principal components (PC) were subjected to LDA in order to evaluate the potential of these proteins as collective biomarkers for breast cancer. The protein intensities of SEC13-like 1 (isoform b) and calreticulin contributed the most to the first PC while the protein intensities of fibrinogen beta chain precursor and ATP synthase D chain contributed the most to the second PC. Transthyretin precursor and apolipoprotein A-1 precursor contributed the most to the third PC. The results of LDA indicated good classification of samples into normal and cancerous types when the first 6 PCs were used as the variables. The percentage of correct classification was 91.7% for the originally grouped tissue samples and 88.9% for cross-validated samples.

A genetic variant in the gene encoding fibrinogen beta chain predicted development of hypertension in Chinese men

Fibrinogen, a major determinant of blood viscosity, is an acute phase protein associated with cardiovascular disease. We studied the association of hypertension with single nucleotide polymorphisms (SNPs) in the gene encoding the fibrinogen beta chain (FGB). Three tagging SNPs (rs1025154, rs4220 and rs1044291) were selected from the HapMap database on Han Chinese. Genotypes were determined in 1,294 unrelated subjects from the Hong Kong Cardiovascular Risk Factor Prevalence Study cohort. There were 199 hypertensive subjects at baseline. Among 1,095 subjects normotensive at baseline, 178 developed hypertension during a median follow-up period of 6.4 years. Among the three tagging SNPs, rs4220 showed significant association with hypertension at both baseline (odds ratio [OR]=1.49, p=0.004) and at follow-up (OR=1.32, p=0.013). The minor A allele of this SNP was associated with higher plasma fibrinogen level (beta=0.144, p<0.001 at baseline and beta=0.130, p<0.001 at follow-up). Among subjects normotensive at baseline, this SNP was also associated with the development of hypertension in men (OR=1.52, p=0.022), but not in women. The SNP rs4220 in FGB , which leads to the substitution of arginine by lysine at position 448, is independently associated with plasma fibrinogen level and hypertension in Hong Kong Chinese. This suggests a possible causal role of fibrinogen in hypertension development, especially in men.

The PCA and LDA Analysis on the Differential Expression of Proteins in Breast Cancer

Breast cancer is a leading cause of mortality in women. In Malaysia, it is the most common cancer to affect women. The most common form of breast cancer is infiltrating ductal carcinoma (IDC). A proteomic approach was undertaken to identify protein profile changes between cancerous and normal breast tissues from 18 patients. Two protein extracts; aqueous soluble and membrane associated protein extracts were studied. Thirty four differentially expressed proteins were identified. The intensities of the proteins were used as variables in PCA and reduced data of six principal components (PC) were subjected to LDA in order to evaluate the potential of these proteins as collective biomarkers for breast cancer. The protein intensities of SEC13-like 1 (isoform b) and calreticulin contributed the most to the first PC while the protein intensities of fibrinogen beta chain precursor and ATP synthase D chain contributed the most to the second PC. Transthyretin precursor and apolipoprotein A-1 precursor contributed the most to the third PC. The results of LDA indicated good classification of samples into normal and cancerous types when the first 6 PCs were used as the variables. The percentage of correct classification was 91.7% for the originally grouped tissue samples and 88.9% for cross-validated samples.

Quantitative Organellar Proteomics Analysis of Rough Endoplasmic Reticulum from Normal and Acute Pancreatitis Rat Pancreas

The rough endoplasmic reticulum (RER) is a central organelle for synthesizing and processing digestive enzymes and alteration of ER functions may participate in the pathogenesis of acute pancreatitis (AP). To comprehensively characterize the normal and diseased RER subproteome, this study quantitatively compared the protein compositions of pancreatic RER between normal and AP animals using isobaric tags (iTRAQ) and 2D LC-MALDI-MS/MS. A total of 469 unique proteins were revealed from four independent experiments using two different AP models. These proteins belong to a large number of functional categories including ribosomal proteins, translocon subunits, chaperones, secretory proteins, and glyco- and lipid-processing enzymes. A total of 37 RER proteins (25 unique in arginine-induced, 6 unique in caerulein-induced and 6 common in both models of AP) showed significant changes during AP including translational regulators and digestive enzymes, whereas only mild changes were found in some ER chaperones. The six proteins common to both AP models included a decrease in pancreatic triacylglycerol lipase precursor, Erp27, and prolyl 4-hydroxylase beta polypeptide as well as a dramatic increase in fibrinogen alpha, beta and gamma chains. These results suggest that the early stages of AP involve changes of multiple RER proteins that may affect the synthesis and processing of digestive enzymes.

“Heparinization” and hyperfibrinogenolysis by wasp sting

We report on a patient with coagulation abnormalities induced by a wasp sting anaphylaxis. First, we observed an unclottable activated partial thromboplastin time and a significant anti-Xa activity (equivalent to a therapeutic heparin range), whereas the patient had received no heparin. This phenomenon is probably due to activated mast cells that release mediators such as heparin and tryptase. Heparin can then act as an anticoagulant by binding to antithrombin. This "heparinization" explains the anti-Xa activity contributing to the unclottable activated partial thromboplastin time detected in our patient. Second, we noted an extremely low fibrinogen level in the presence of normal platelet count and only a slight increase of D-dimers (absence of important disseminated intravascular coagulation). This is probably due to serum tryptase released during massive mast cell activation. Tryptase cleaves the alpha and beta chains of fibrinogen. This results in the removal of the thrombin cleavage site and of the critical polymerization site from the fibrinogen beta chain. Thrombin- initiated clot formation is therefore inhibited. Tryptase also acts directly on the fibrinolytic pathway by activating the single-chain urinary-type plasminogen activator, resulting in conversion of plasminogen into plasmin and therefore degradation of fibrinogen and other coagulation factors. This hyperfibrinogenolysis explains both the prolonged clotting times and the low fibrinogen level observed. Although our patient did not bleed, in other settings (trauma, during surgery) patients with anaphylaxis may present bleeding disorders. Although the mechanisms underlying these abnormalities have been described in vitro and in vivo animal trials, this is the first time they are described in a human clinical setting.

A unique plasma proteomic profiling with imbalanced fibrinogen cascade in patients with Kawasaki disease

Kawasaki disease (KD) is the leading cause of acquired heart disease during childhood in the developed countries. The mechanism and biomarkers of KD remain to be determined. In this study, we sought to elucidate potential plasma proteomic markers in KD patients in comparison to that in febrile controls. Plasma samples from KD patients and febrile controls were subjected to two-dimensional polyacrylamide gel electrophoresis analysis. Differential protein displays between KD patients and febrile controls were determined. Fibrinogen beta and gamma chains, alpha-1-antitrypsin (A1AT), CD5 antigen-like precursor (CD5L), and clusterin were increased in KD patients, whereas immunoglobulin free light chains were decreased, as compared with controls. The differential protein displays were validated with enzyme-linked immunosorbent assay tests. We found higher fibrinogen-related proteins (fibrinogen, A1AT, clusterin, and CD5L), along with a lower level of the immunoglobulin free light chains that involve fibrin degradation in KD. Results from this study showing a unique proteomic profiling with abnormal fibrinogen cascade may afford a good biomarker of KD and a better strategy to prevent cardiovascular complications of KD by correcting abnormal fibrin deposition or degradation.