Substrates of Factor XIII-A: roles in thrombosis and wound healing.

FXIII (Factor XIII) is a Ca²+-dependent enzyme which forms covalent ϵ-(γ-glutamyl)lysine cross-links between the γ-carboxy-amine group of a glutamine residue and the ϵ-amino group of a lysine residue. FXIII was originally identified as a protein involved in fibrin clot stabilization; however, additional extracellular and intracellular roles for FXIII have been identified which influence thrombus resolution and tissue repair. The present review discusses the substrates of FXIIIa (activated FXIII) involved in thrombosis and wound healing with a particular focus on: (i) the influence of plasma FXIIIa on the formation of stable fibrin clots able to withstand mechanical and enzymatic breakdown through fibrin-fibrin cross-linking and cross-linking of fibrinolysis inhibitors, in particular α2-antiplasmin; (ii) the role of intracellular FXIIIa in clot retraction through cross-linking of platelet cytoskeleton proteins, including actin, myosin, filamin and vinculin; (iii) the role of intracellular FXIIIa in cross-linking the cytoplasmic tails of monocyte AT1Rs (angiotensin type 1 receptors) and potential effects on the development of atherosclerosis; and (iv) the role of FXIIIa on matrix deposition and tissue repair, including cross-linking of extracellular matrix proteins, such as fibronectin, collagen and von Willebrand factor, and the effects on matrix deposition and cell-matrix interactions. The review highlights the central role of FXIIIa in the regulation of thrombus stability, thrombus regulation, cell-matrix interactions and wound healing, which is supported by observations in FXIII-deficient humans and animals.

Critical role of factor XIII in the initial stages of carbon tetrachloride-induced adult liver remodeling.

The transglutaminase-mediated, covalent cross-linking of proteins is an essential step in tissue remodeling after injury. This process provides tissues with extra rigidity and resistance against proteolytic degradation. Plasma coagulation factor XIII (FXIII) is a transglutaminase that promotes cross-linking of the extracellular matrix (ECM) components fibrin and fibronectin to form a provisional matrix in response to tissue damage. However, the functional requirement for this FXIII-mediated cross-linked provisional matrix in adult tissue remodeling remains to be defined. Although it has been proposed that the formation FXIII-mediated fibrin-fibronectin provisional matrix is a critical step for ECM remodeling, we show in an FXIII subunit A-deficient murine model of acute liver injury that the lack of FXIII subunit A did not interfere with collagen reconstruction and resolution after liver injury. Furthermore, FXIIIA deficiency caused significantly increased hepatocyte apoptosis and a delay in hepatocyte regeneration after injury, which were accompanied by a significantly high induction of p53 expression. These findings suggest novel functions of FXIII that the FXIII-mediated covalently cross-linked matrix could promote survival signals for hepatocytes in adult tissue remodeling.

Surgical wound healing in bleeding disorders.

Animal experiments have shown that a number of bleeding disorders may affect wound healing (WH), including haemophilia B, deficiency of factor XIII and abnormalities of fibrinogen. Therefore, normal healing requires adequate haemostatic function for the appropriate time frame (up to 4 weeks in the clean and uncontaminated wound). Many factors may affect WH, including impaired haemostasis, diabetes, poor nutrition, insufficient oxygenation, infection, smoking, alcoholism, old age, stress and obesity. The gold standard for the correct care of surgical wounds in patients with bleeding disorders includes wound dressing and comprehensive standard care (haemostasis, nutritional support, treatment of co-morbidities, offloading, reperfusion therapy and compression). Although complications of surgical wounds healing in patients with bleeding disorders are uncommon, a low level of the deficient factor for an insufficient period of time could cause WH complications such as haematomas, infection, and skin necrosis and dehiscence. Clinical experience and animal experiments appear to indicate that, to get a satisfactory healing of surgical wounds and avoid potential complications of WH, a good level of haemostasis is necessary for 2-3 weeks after surgery. However, many treaters would regard this recommendation at odds with (i.e. more aggressive than) current standards. Unfortunately no additional clinical evidence for this recommendation can be provided.

Administration of factor XIII B subunit increased plasma factor XIII A subunit levels in factor XIII B subunit knock-out mice.

Factor XIII (FXIII) is a proenzyme of plasma transglutaminase consisting of enzymatic A (FXIII-A) and noncatalytic B subunits (FXIII-B), and acts in hemostasis and wound healing. We freshly generated mice lacking either FXIII-A or FXIII-B to investigate the physiological functions of FXIII in vivo. Mice carrying the disrupted allele were born at the expected Mendelian ratios, and the homozygous mice were viable and fertile under specific pathogen-free conditions. Although all homozygous and heterozygous mice showed no marked difference from the wild-type animals in general appearance, homozygous mice of either FXIII-A- or FXIII-B-deficiency did have prolonged bleeding times. It was confirmed that thrombin-dependent amine incorporation and fibrin-crosslinking in plasma were undetectable in the FXIII-A-deficient mice and markedly reduced in the FXIII-B-deficient mice; however, the gene expression of each subunit was regulated independently. Recombinant human FXIII-B (rFXIII-B) was expressed in a baculovirus expression system. When rFXIII-B was injected into FXIII-B-deficient mice, FXIII-A levels, fibrin crosslinking, and amine-incorporation activities increased in their plasma, indicating that FXIII-B assisted the maintenance of FXIII-A levels in the circulation. These mouse strains will be useful in exploring the possible pathophysiological roles of each subunit in vivo.

Novel Factor XIII variant identified through whole-genome sequencing in a child with intracranial hemorrhage.

Pediatric stroke can be either hemorrhagic or ischemic, with ∼5% of hemorrhagic strokes being caused by genetic coagulopathies. We report an 8 mo old presenting with a hemorrhagic stroke caused by severe Factor XIII deficiency (OMIM # 613225) in whom rapid whole-genome sequencing identified a novel variant in the F13A1 gene c.1352_1353delAT (p.His451ArgfsTer29).

Mild factor XIII deficiency and concurrent hypofibrinogenemia: effect of pregnancy.

Factor XIII (FXIII) deficiency is a rare bleeding disorder. Patients with mild congenital FXIII deficiency tend to be asymptomatic, but may demonstrate significant bleeding symptoms with surgery, trauma, and pregnancy. Postpartum hemorrhage has been described in mild FXIII deficiency. We present a case of mild FXIII deficiency and concurrent hypofibrinogenemia manifested by recurrent postpartum hemorrhage, menorrhagia, and miscarriage. Mutational analysis identified a previously unreported heterozygous mutation of the FXIIIA subunit (p.Trp315Arg). No mutation was noted in the fibrinogen gene. FXIII levels decreased approximately 50% from nonpregnant levels to their nadir during labor, whereas fibrinogen levels rose approximately 1.5-fold from decreased nonpregnant levels to their peak at the time of labor. This case illustrates the course of mild FXIII and fibrinogen deficiencies during pregnancy, labor, and postpartum, and raises possible management options for prevention of antepartum and postpartum hemorrhage in women with these deficiencies.

Clinico-hematologic profile of factor XIII-deficient patients.

A retrospective analysis of clinico-hematologic parameters of 18 factor XIII-deficient patients was carried out. The hematologic tests included activated partial thromboplastin time (APTT), prothrombin time (PT), and clot solubility. Laboratory diagnosis of FXIII deficiency was made where bleeding time, PT, APTT, and thrombin time were normal and the clot solubility test result with 5M urea was positive. Factor XIII level with family screening was performed using commercially available kits. History of prolonged bleeding from the umbilical stump was present in four (22.2%) patients. The most common site of bleeding was the skin (11 of 18 patients). Three patients were given prophylaxis (FFP in two, factor XIII in one). A high prevalence of recurrent abortion in female patients with FXIII deficiency (two of the three patients in this study) was observed.

Airway Compromise and Perioperative Management of a Patient with Acquired Factor XIII Inhibitor.

Perioral hematomas can lead to acute airway compromise and can present significant challenges in both direct and indirect approaches to airway instrumentation. In patients with normal cell counts and routine coagulation tests, spontaneous hematomas are rare, but when encountered, they elicit a limited differential diagnosis that includes von Willebrand factor deficiency, platelet dysfunction, and the acquired factor XIII (FXIII) deficiency. Although spontaneous hematoma formation resulting from FXIII inhibition has been reported, we describe what may be the first reported case of FXIII inhibitor-related hematoma leading to acute airway compromise. Successful management of this patient required multidisciplinary cooperation among anesthesiologists, intensivists, otolaryngologists, and hematologists.

Coagulation factor XIII: a multifunctional transglutaminase with clinical potential in a range of conditions.

Coagulation factor XIII (FXIII), a plasma transglutaminase, is best known as the final enzyme in the coagulation cascade, where it is responsible for cross-linking of fibrin. However, a growing body of evidence has demonstrated that FXIII targets a wide range of additional substrates that have important roles in health and disease. These include antifibrinolytic proteins, with cross-linking of α2-antiplasmin to fibrin, and potentially fibrinogen, being the principal mechanism(s) whereby plasmin-mediated clot degradation is minimised. FXIII also acts on endothelial cell VEGFR-2 and αvß3 integrin, which ultimately leads to downregulation of the antiangiogenic protein thrombospondin-1, promoting angiogenesis and neovascularisation. Under infectious disease conditions, FXIII cross-links bacterial surface proteins to fibrinogen, resulting in immobilisation and killing, while during wound healing, FXIII induces cross-linking of the provisional matrix. The latter process has been shown to influence the interaction of leukocytes with the provisional extracellular matrix and promote wound healing. Through these actions, there are good rationales for evaluating the therapeutic potential of FXIII in diseases in which tissue repair is dysregulated or perturbed, including systemic sclerosis (scleroderma), invasive bacterial infections, and tissue repair, for instance healing of venous leg ulcers or myocardial injuries. Adequate levels of FXIII are also required in patients undergoing surgery to prevent or treat perioperative bleeding, and its augmentation in patients with/at risk for perioperative bleeding may also have potential clinical benefit. While there are preclinical and/or clinical data to support the use of FXIII in a range of settings, further clinical evaluation in these underexplored applications is warranted.

Depletion of plasma factor XIII prevents disseminated intravascular coagulation-induced organ damage.

The impact of clot stability affecting the vasculopathy and tissue necrosis in Shwartzman reaction was investigated using plasma Factor XIII A2-depleted rabbit (FXIII-DR). Plasma Factor XIIIA2 (FXIIIA2) was depleted by infusion of the mono-specific goat anti-rabbit FXIIIA2 IgG. Generalized Shwartzman reaction (GSR) was induced by priming and challenged by i.v. injection of LPS and local Shwartzman reaction (LSR) was primed by intradermal injection of LPS and challenged by i.v. injection of LPS. Histological examination of the GSR animals showed, extensive thrombi accumulation in renal tubules and bilateral cortical necrosis of kidney in 8 out of 10 rabbits but none in the FXIII-DR. Fibrinogen levels were elevated to 3 approximately 4 fold at 24 h and lowered at 48 h whereas a steady rise was seen in the FXIII-DR. FDP levels in GSR animals were significantly elevated at 24 h and further increased at 48 h but only slightly elevated in the FXIII-DR. Examination of the LSR tissues after 48 h showed an acute onset of progressive cutaneous vascular thrombosis, purpura, and secondary hemorrhagic necrosis whereas neither fibrin deposit nor necrosis of tissue were detected in FXIII-DR despite of an early edema formation. Fibrinogen levels were also increased two fold at 24 h but returned to basal levels at 48 h in control LSR animals but not affected at all in FXIII-DR. These results suggest that during the severe inflammatory conditions such as sepsis, the fibrinolytic system is functionally sufficient to dissipate the pathogenic accumulation of disseminated intravascular clots and exudated fibrin clots if those clots were prevented from getting crosslinked in plasma.

Transglutaminases in disease.

Transglutaminases (TGases) are enzymes that are widely used in many biological systems for generic tissue stabilization purposes. Mutations resulting in lost activity underlie several serious disorders. In addition, new evidence documents that they may also be aberrantly activated in tissues and cells and contribute to a variety of diseases, including neurodegenerative diseases such as Alzheimer's and Huntington's diseases. In these cases, the TGases appear to be a factor in the formation of inappropriate proteinaceous aggregates that may be cytotoxic. In other cases such as celiac disease, however, TGases are involved in the generation of autoantibodies. Further, in diseases such as progressive supranuclear palsy, Huntington's, Alzheimer's and Parkinson's diseases, the aberrant activation of TGases may be caused by oxidative stress and inflammation. This review will examine the role and activation of TGases in a variety of diseases.

Male fertility in factor XIII deficiency.

Seven homozygotes for F-XIII deficiency were found in a large inbred Israeli-Arab kindred. One affected woman had early abortions. Two affected men and one probably affected man had children, two of whom also were affected. Paternity was confirmed by segregation of HLAs and erythrocyte antigens and enzymes. This is the first documentation of normal male fertility in unequivocally affected patients. Clinical variability or genetic heterogeneity may account for previously reported male infertility.

Coagulation factor XIII, endothelial damage and systemic sclerosis.

In the blood coagulation process, Factor XIII (F XIII) is responsible for the stabilization of the fibrin clot. The hypothesized ability of this blood coagulation factor to affect collagen synthesis and degradation led to its use in the treatment of scleroderma. However, the complex mechanism of action of F XIII remains unclear. The aim of our study was to assess possible effects of F XIII on endothelial damage, regarded as an early pathogenic event in systemic sclerosis (SSc). Thus, we measured plasma levels of von Willebrand factor antigen (vWF:Ag), a marker of endothelial cell injury, in 22 patients with SSc, 9 of whom were treated with F XIII and 13 who do not receive the drug. The plasma concentration of F XIII has also been analyzed. Interestingly, the vWF:Ag plasma levels within the group of SSc patients treated with F XIII were significantly lower than those of untreated SSc individuals (p < 0. 02). On the other hand, the highest mean value of vWF:Ag was found in a subset of untreated subjects having SSc with severe lung involvement, supporting a strict relationship between elevated levels of vWF:Ag and severity of the disease. In contrast, plasma concentration of F XIII resulted normal in all but 3 SSc patients, ruling out a deficiency of this blood coagulation factor as promoting the occurrence of SSc. These preliminary findings seem to support the hypothesis that F XIII may play an improving role on endothelial damage, other than the initially suggested action on collagen metabolism, in SSc.

[Factor XIII in man: a review]. / Der Faktor XIII des Menschen: eine Ubersicht.

Activated by calcium and thrombin, factor XIII (FXIIIa) cross-links fibrin, thus increasing the stability of the fibrin clot. Furthermore, the hemostatic and reparative function of factor XIIIa is mediated by cross-linking other proteins like alpha(2)-plasmin-inhibitor, fibronectin, and collagen. The FXIII Val34Leu polymorphism plays a role in athero- and thrombogenesis. FXIII deficiency is an autosomal recessive disorder. The most common symptom is the bleeding tendency of the umbilical cord some days after birth. The diagnosis is confirmed by a solubility clot test in urea (5 mol/l) and then differentiated with an incorporation assay and immuno-electrophoresis. The bleeding tendency typically becomes obvious when FXIIIa activity is <1-2%. Severe bleeding episodes, however, may even occur with FXIIIa activities of 30-50%, especially in heterozygous persons. The sometimes life-threatening bleeding tendency of the inherited FXIII deficiency can be treated with FXIII concentrates. Acquired FXIII deficiency occurs in several internal diseases and after major surgery. The clinical significance is not completely clear. Moreover, FXIII is applied locally as a component of fibrin glues.

[Clinical course and management of severe congenital factor XIII deficiency]. / Krankheitsbild und Behandlung des schweren homozygoten Faktor-XIII-Mangels.

Severe homozygous factor XIII deficiency was first described in Switzerland, in 1961. At present 14 patients are known here. Nine are of Swiss origin, the others are immigrants from eastern Europe. A 27-year-old woman with many haemorrhages during childhood immigrated to Switzerland and went through four episodes of haemorrhagic corpus luteum cyst rupture with life-threatening blood loss into the abdomen and three haemorrhages into the retroperitoneal muscles causing sensomotoric palsies, before the diagnosis was established. A monthly prophylactic replacement therapy of 500 IE factor XIII concentrate was started. Since then no signs of haemorrhage occurred. For the last trimester of pregnancy treatment intervals were shortened and dosage increased. Haemorrhage from the umbilical cord for weeks, subcutaneous haematomas, intracranial haemorrhage, muscle haemorrhage and wound bleeding with impaired wound healing as well as tendency to marked scar formation are characteristic for severe homozygous factor XIII deficiency. Without replacement therapy women suffer from obligate abortion. Diagnosis is made by the solubility of fibrin clots in urea (5 mol/l) or monochloroacetic acid (1-2%). For confirmation and monitoring of replacement therapy a quantitative incorporation assay is used. Replacement therapy is necessary in case of haemorrhage, injury, and surgery. Because of the high risk of intracranial haemorrhage prophylaxis is strongly recommended.

Occurrence and recurrence of spontaneous chronic subdural haematoma is associated with a factor XIII deficiency.

OBJECTIVE: In some patients, chronic subdural haematoma (cSDH) appears to occur spontaneously with frequent re-bleeding events. The pathophysiology of this phenomenon is still poorly understood. Because coagulation factor XIII (FXIII) is known to be involved in vascular integrity, endothelial barrier function and wound healing, we evaluated the role of FXIII in spontaneous cSDH. METHODS: We prospectively scrutinised the origin of cSDH in 117 patients and identified a subgroup of patients suffering from spontaneous cSDH who were included in this study. We analysed the plasma activity of FXIII and standard coagulation parameters and compared these data to age- and sex-matched healthy controls. We assessed the occurrence of re-bleeding events using clinical and imaging data and compared FXIII activity in patients with and without re-bleeding events. RESULTS: Out of 117 cSDH patients, 18 individuals suffered from spontaneous cSDH in this study. The patients with spontaneous cSDH showed significantly lower FXIII activity than the control group (65% [52.75, 80.25] (median [IQR]) vs. 93% [81, 111], P=0.001), whereas standard coagulation parameters did not differ significantly between the groups. Six patients developed re-bleeding events after haematoma evacuation, and these patients expressed significantly lower FXIII activity compared to the other 12 patients (47.5% [33.5, 64] vs. 78.5% [58, 87], P=0.005). The patient group with FXIII≤68.5% differed significantly from the group with FXIII>68.5% when categorised by the occurrence of re-bleeding events (n=6/9 vs. n=0/9, P=0.009). This cut-off value predicted the re-bleeding events with a sensitivity of 100% and a specificity of 75% (positive predictive value: 66%, negative predictive value: 100%). CONCLUSION: FXIII deficiency may play a pathophysiological role in spontaneous cSDH, so we suggest investigating FXIII activity because it may predict re-bleeding events after treatment. In individuals with considerably low FXIII activity, FXIII substitution may mitigate the chronic nature of this disease.

Reduced difference of α2-plasmin inhibitor levels between plasma and serum in patients with severe factor XIII deficiency, including autoimmune hemorrhaphilia due to anti-factor XIII antibodies.

Coagulation factor XIII/13 (FXIII/13) stabilizes fibrin molecules by creating crosslinks with other fibrin molecules as well as with α2-plasmin inhibitor (α2-PI). "Hemorrhagic acquired FXIII/13 deficiency" was formerly considered rare, but has been increasing recently in Japan. During the 10 months of our nationwide campaign, we diagnosed five new patients with "acquired hemorrhaphilia due to anti-FXIII/13 autoantibodies," after examining 20 newly suspected cases of "hemorrhagic acquired FXIII/13 deficiency." When FXIII/13 activity was reduced to less than 50% of normal, it was proportional to the difference in α2-PI levels between plasma and serum (plasma-serum α2-PI), likely due to its cross-linking to fibrin by activated FXIII/13. Accordingly, decreased amounts of the plasma-serum α2-PI ex vivo may reflect reduced FXIII/13 activity in vivo. The plasma-serum α2-PI may thus also be a useful diagnostic marker for severe FXIII/13 deficiency.

Factor XIII deficiency related recurrent spontaneous intracerebral hemorrhage: a case and literature review.

Spontaneous intracerebral hemorrhage (ICH) in young adults under 50 years of age is an uncommon occurrence associated with considerable morbidity and mortality. The differential diagnosis of ICH in this population differs from that of older individuals and includes vascular, toxic, inflammatory, oncologic, infectious and hematologic conditions. We present a case based observation of a spontaneous and recurrent ICH in a 25-year-old female secondary to undetected Factor XIII (FXIII) deficiency with no prior associated stigmata of hematologic disturbance admitted to a tertiary care neuroscience intensive care unit (NICU). Our patient was admitted after spontaneous development of left thalamic hemorrhage with ventricular extension. Initial management included external drain placement (EVD) and fresh frozen plasma administration. Diagnostic evaluation was unrevealing including CT angiography, magnetic resonance imaging (MRI) with venography, conventional cerebral angiogram, and hematologic and rheumatologic screens. Our patient recovered but represented 6 months later with five foci of spontaneous ICH. She underwent vascular, infectious, oncologic, hematologic, and rheumatologic evaluations. She expired secondary to ICH expansion with uncal herniation. The results of our investigation revealed markedly diminished FXIII activity. The pathophysiology, diagnosis and treatment of this disease are reviewed. FXIII deficiency should be considered in a case of cryptogenic ICH presenting with multifocal, recurrent ICH and a normal coagulation profile. Early diagnosis and initiation of factor replacement therapy offer the best strategies to reduce the morbidities associated with this disease.