Congenital Factor XIII Deficiency Research Articles

Disruption of Structural Disulfides of Coagulation FXIII-B Subunit; Functional Implications for a Rare Bleeding Disorder.

Congenital FXIII deficiency is a rare bleeding disorder in which mutations are detected in F13A1 and F13B genes that express the two subunits of coagulation FXIII, the catalytic FXIII-A, and protective FXIII-B. Mutations in FXIII-B subunit are considerably rarer compared to FXIII-A. Three mutations in the F13B gene have been reported on its structural disulfide bonds. In the present study, we investigate the structural and functional importance of all 20 structural disulfide bonds in FXIII-B subunit. All disulfide bonds were ablated by individually mutating one of its contributory cysteine’s, and these variants were transiently expressed in HEK293t cell lines. The expression products were studied for stability, secretion, the effect on oligomeric state, and on FXIII-A activation. The structural flexibility of these disulfide bonds was studied using classical MD simulation performed on a FXIII-B subunit monomer model. All 20 FXIII-B were found to be important for the secretion and stability of the protein since ablation of any of these led to a secretion deficit. However, the degree of effect that the disruption of disulfide bond had on the protein differed between individual disulfide bonds reflecting a functional hierarchy/diversity within these disulfide bonds.

Identification of novel pathogenic F13A1 mutation and novel NBEAL2 gene missense mutation in a pedigree with hereditary congenital factor XIII deficiency

The genetic defects of a 12-year-old patient with factor XIII deficiency (FXIIID) and eight pedigree members suspected with FXIIID were studied. Clinical diagnosis, pedigree investigation, phenotypic study and genetic analysis were performed. DNA sequence analysis revealed that the proband had a novel deletion mutation of F13A1 gene (NM_000129: exon 12: c.1652delC: p.Thr551LysfsTer26) which he inherited from both the parents who were heterozygous for the same 1652delC deletion. This frameshift (p.Thr551LysfsTer26) led in homozygous form to severe FXIIID. Additionally, a homozygous missense mutation of NBEAL2 gene (NM_015175: exon 13: c.1367C > T: p.Ala456Val) was identified in the proband. Again, the mutation was inherited from both the parents who were heterozygous for the same c.1367C > T novel mutation. Other members of the pedigree were also revealed to be heterozygous for the same proband's F13A1 and NBEAL2 genes mutations. We first report a pedigree with pathogenic F13A1 gene mutation and a novel mutant NBEAL2 gene.

A Unique Factor XIII Mutation in Southeastern Iran with an Unexpectedly High Prevalence: Khash Factor XIII.

Congenital factor XIII (FXIII) deficiency is an extremely rare hemorrhagic disorder characterized by a deficiency of FXIII and associated with a high rate of morbidity and mortality. The disorder is more frequent in Iran, especially in Khash, a city in the southeast of the country. As identified in the current report, the prevalence of FXIII deficiency in this city is 1 homozygote per approximately 500 population (which is ∼4,000 times higher than the worldwide prevalence) with 3.5% heterozygotes. The disorder is accompanied by a high rate of mortality in rural areas of Khash, given an averaged observed rate of approximately three deaths per each family with FXIII deficiency, mostly due to late-diagnosis and/or misdiagnosis, and fetal consequences of both umbilical cord and central nervous system bleeding. Almost all patients with FXIII deficiency in the southeast Iran have a unique mutation in F13A gene (Trp187Arg), which leads to a severe FXIII deficiency. This mutation is used for pre-marriage and prenatal diagnosis, as well as for carrier detection and diagnostic confirmation. Fibrogammin P has been used worldwide for about one decade, along with different therapeutic regimens for prophylaxis treatment, major and minor surgeries, and successful delivery. Due to the rapid increase in the number of patients identified to have congenital FXIII deficiency, and the high rate of related morbidity and mortality, a comprehensive regional preventive program is necessary to prevent further expansion of this condition and decrease the burden on the health care system. The area of Khash city provides novel insights into severe FXIII deficiency due to its high prevalence in this region. This report also provides a review of FXIII deficiency, its diagnosis, prevalence, molecular basis, clinical manifestations, management, and treatment, with a particular focus on Iran, representing a hotspot for this disorder.

Expression and CpG island methylation pattern of MMP-2 and MMP-9 genes in patients with congenital factor XIII deficiency and intracranial hemorrhage

ABSTRACTObjectives: Congenital factor XIII (FXIII) deficiency is a rare severe bleeding disorder. Intracranial hemorrhage (ICH) is the leading cause of mortality and morbidity in FXIII deficiency. However, its pathogenesis is not well understood yet. In this study, we investigated the expression and CpG island methylation status of matrix metalloproteinase-2 (MMP-2) and MMP-9 in patients with FXIII deficiency and ICH.Methods: Forty patients with FXIII deficiency including twenty patients with ICH, and twenty without ICH were recruited as case and control groups, respectively. Methylation status was determined by bisulfite sequencing polymerase chain reaction (PCR), and gene expression was assessed by quantitative real-time PCR.Results and discussion: We found an unmethylated pattern for both MMP-2 and MMP-9 genes in the case group. Both genes were partially methylated in the control group, while the percentage of methylated CpGs was significantly higher in MMP-9 than MMP-2 (P = 0.001). Furthermore, higher expression of MMP-9 (in both the mRNA and protein levels) was found in the case than control group (P = 0.008 and P = 0.009, respectively). On the other hand, there was no significant difference in MMP-2 expression level (neither mRNA nor protein) between the two groups (P = 0.12 and P = 0.25, respectively).Conclusion: Our findings indicated that MMP-9 over-expression might be related to ICH in FXIII deficiency, and gene methylation effectively regulates its expression. Future researches will expand our understanding of the pathogenesis of ICH in congenital FXIII deficiency.

Plasma Derived FXIII Prophylaxis in Two Patients with Congenital FXIII Deficiency. Mexican Experience

INTRODUCTIONFXIII is a proγtransglutaminase circulates in plasma as heterotetramers (FXIII-A2B2) composed of two carrier subunits and two catalytic subunits (FXIII-A2). Is mltifunctional protein presents in platelets, megakaryocytes, monocytes and monocyte-derived cells. FXIII is crucial in vital biological processes. Patients with severe FXIIID present with delayed wound healing, recurrent spontaneous miscarriage, and umbilical cord bleeding as well as intracranial hemorrhage. Congenital FXIIID is an autosomal recessive disorder, affects 1-3 per million people worldwide.Diagnosis is reach by the clot solubility test results when levels of FXIII are below 5 U/dl.Functional FXIII activity assay should be used for this purpose, with molecular diagnosis for confirmation of disease, however is not always available.Severely affected require regular replacement therapy that traditionally used FFP and cryoprecipitate; they now receive FXIII concentrate and recombinant FXIII (rFXIII) that is FXIII-A dimer.CASE8 yo male, mother with history of excesive menstrual bledding, aunt with APS. Obteined a term, by C-section, no complications. Onfalorexis at 7 day with bleeding, Circumcision at 6 mo, excesive bleeding reported. At 2 yo subgaleal hematoma, secondary a trauma, after that he suffered an epidural hematoma, secondary a trauma, cryoprecipitates are transfused, he stayed in the Hospital for 20 days, multiple times suffer of lower limbs hematomas.In 2014 the labs report of Factor XIII <4%, he started with cryoprecipitates, sent him to our centre. Decided repeted the coags and FXIII test, just the urea test; reported as abnormal activity.At this time he suffered for multiples hematomas in the lower right limb & prerotulian bursa of the knee (at least 2 every month), incapacitating him for wandering, so in 2016 decide to start prophylaxis with cryoprecipitates every 3 weeks ( 4 bags), Despite the treatment, continued with multiple bruises, presented 2 more hematomas en the lower limb, In 2017 the patient present anaphylaxis secondary to the administration of cryos and had the opportunity to get the plasma derived-FXIII, in January 2018 we started prophylaxis 23Ukg once a month, since then, the patient has zero bleeds, he suffered a trauma with no bruises or signs of bleed. Nowadays good clinical response, no bleeds, in rehabilitation strengthening his muscles and improving ambulation. CASE 13 yo female, no familiar history, onfalorexis excesive bleeding requiered stay in the Hospital for 10 days, treatment with cautery of the umbilical cord. Presented at 8yo to ER with hip pain, multiples bruises, The initial approach for coagulopathy were done ( PT, aPTT, Fib, agregometry) NORMAL, VWf 68% FVIII 66% missdiagnosed vWD, multiples muscle bleeds, menstrual bleeding treated a demand with cryoprecipitates, after a gym class a year ago, she refered leg numbess, hip pain, decreased tone and muscle strength, MRI iagnosed an espinal cord hematoma (T8-L1), requiered treatment by neurosurgery hemilaminectomy & hematoma drainage, so she start with cryo 5 bags every 8 hrs for one week after that we decide continued every 12 hr until the complete resolution after 14 days.She discharged with prophylaxis with cryoprecipitates twice a week (5 bags) for three months, Nowadays she walks with a cane, sensibility is complete resolved, and ocasionally she needs drain bladder. We stop the prophylaxis with cryo and after 3 months, we decided to re approach the patient since she had major bleeding not completely explained by vWD, We founded normal ( PT, aPTT, Fib, vW) FXIII <4%, so she start prophylaxis with plasma derived FXII in her first month, with a good clinical response. DISCUSSION Factor XIII is a rare cause of coagulopaty in the world, the initial laboratory is always normal since Factor XIII is the final stage and helps in these stabilization. The clinical signs always is the stone gold for the diagnosis, a pivotal data is the bleeding of the umbilical cord or ICH.Prophylaxis has demostrated that is necessary for those patients who has regular bleeds with aparently good response.We need to follow this patient clinical and monitoring the labs, this is the first 2 patients in Mexico that receive FXIII prophylaxis.We need to continue searching for deficient patients, because the clinical suspicion is the cornerstone of the diagnosis, since receiving timely treatment this is seen in the high quality of life they may have. DisclosuresNo relevant conflicts of interest to declare.

Proline 36 of the Factor XIII Activation Peptide Plays a Crucial Role in Substrate Recognition and Zymogen Activation.

The activation peptide of blood coagulation factor XIII (AP-FXIII) has important functions in stabilizing the FXIII-A2 dimer and regulating FXIII activation. Contributions of many of its 37 amino acids to these functions have been described. However, the role of proline 36, which is adjacent to the thrombin cleavage site at Arg37, has not yet been studied in detail. We approached this question when we came across a patient with congenital FXIII deficiency in whom we detected a novel Pro36Ser mutation. We expressed the mutant FXIII-A Pro36Ser protein in Chinese hamster ovary cells and found that this mutation does not influence FXIII-A expression but significantly inhibits proteolytic activation by thrombin. The enzymatic transglutaminase activity is not affected as it can be induced in the presence of high Ca2+ concentrations. We performed nuclear magnetic resonance analysis to investigate AP-FXIII-thrombin interactions, which showed that the mutant Ser36 peptide binds less well to the thrombin surface than the native Pro36 peptide. The Arg37 at the P1 position still makes strong interactions with the active site cleft but the P4-P2 residues (34VVS36) appear to be less well positioned to contact the neighbouring thrombin active site region. In conclusion, we have characterized a novel mutation in AP-FXIII representing only the fourth case of the rare FXIII-A type II deficiency. This case served as a perfect in vivo model to shed light on the crucial role of Pro36 in the proteolytic activation of FXIII-A. Our results contribute to the understanding of structure-function relationship in FXIII.

A large case series on surgical outcomes in congenital factor XIII deficiency patients in Iran

Background The lack of accepted standardized surgical guidelines leads to dependence on the treating physicians' and centers' experiences. Aim Our aim is to evaluate the surgical outcomes of a large group of congenital factor XIII deficiency (FXIIID) patients. Methods A case series study was conducted prior to surgery on congenital FXIIID patients in two major referral centers located in Iran from 2010 to 2016. All patients were on prophylaxis using plasma factor XIII concentrate (10 U kg-1 , every 28 days) except for three patients. Single doses of 10 U kg-1 or 30 U kg-1 plasma factor XIII concentrate were given before a minor procedure and circumcision, respectively. Two doses of plasma factor XIII concentrate, one 30 U kg-1 prior to the procedure and the second dose of 30 U kg-1 on postoperative day 3, were given for major surgery. The dose was 50 U kg-1 both before and after neurosurgical procedures. Results One hundred and sixty-two FXIIID patients underwent minor, major and obstetrical/gynecological surgeries. Median age of the patients was 14 years (ages ranged 15 days to 47 years). The male-to-female ratio was 89/73. Five postoperative complications, two bleeding and three thrombosis, were recorded. Conclusion Our study showed excellent hemostasis in FXIIID patients undergoing surgeries. During the period of these surgeries, we observed only 1.8% postoperative complications. Surgery can be performed safely in FXIIID patients, and our proposed treatment regimens lead to adequate hemostatic coverage with minimal risk, for both minor and major surgeries.

Intracranial Hemorrhage: A Devastating Outcome of Congenital Bleeding Disorders-Prevalence, Diagnosis, and Management, with a Special Focus on Congenital Factor XIII Deficiency.

Intracranial hemorrhage (ICH) is a medical emergency. In congenital bleeding disorders, ICH is a devastating presentation accompanied with a high rate of morbidity and mortality. The prevalence of ICH is highly variable among congenital bleeding disorders, with the highest incidence observed in factor (F) XIII deficiency (FXIIID) (∼30%). This life-threatening presentation is less common in afibrinogenemia, FVIII, FIX, FVII, and FX deficiencies, and is rare in severe FV and FII deficiencies, type 3 von Willebrand disease and inherited platelet function disorders (IPFDs). In FXIIID, this diathesis most often occurs after trauma in children, whereas spontaneous ICH is more frequent in adults. About 15% of patients with FXIIID and ICH die; the bleeding causes 80% of deaths in this coagulopathy. Although in FXIIID, the bleed most commonly is intraparenchymal (> 90%), epidural, subdural, and subarachnoid hemorrhages also have been reported, albeit rarely. As this life-threatening bleeding causes neurological complications, early diagnosis can prevent further expansion of the hematoma and secondary damage. Neuroimaging plays a crucial role in the diagnosis of ICH, but signs and symptoms in patients with severe FXIIID should trigger replacement therapy even before establishment of the diagnosis. Although a high dose of FXIII concentrate can reduce the rate of morbidity and mortality of ICH in FXIIID, it may occasionally trigger inhibitor development, thus complicating ICH management and future prophylaxis. Nevertheless, replacement therapy is the mainstay of treatment for ICH in FXIIID. Neurosurgery is performed in patients with FXIIID and epidural hematoma and a hemorrhage diameter exceeding 2 cm or a volume of ICH is more than 30 cm3. Contact sports are not recommended in people with FXIIID as they can elicit ICH. However, a considerable number of safe sports and activities have been suggested to have more benefits than dangers for patients with congenital bleeding disorders, and are hence suitable for these patients.

Minimal factor XIII activity level to prevent major spontaneous bleeds

C of 15 IU dL-1 is a proposed target to start prophylaxis for prevention of major bleeding. Background Congenital factor XIII (FXIII) deficiency is a rare bleeding disorder associated with significant bleeding manifestations. The European Network of Rare Bleeding Disorders (EN-RBD) study, performed from 2007 to 2010, showed a strong association between bleeding severity and FXIII activity in plasma of patients with FXIII deficiency. Among these patients, variable levels of FXIII activity, from undetectable to 30%, were associated with a wide range of bleeding severity. Objectives and patients The present cross-sectional study, in the frame of the PRO-RBDD project, a prospective cohort study, analyzed data of 64 patients with FXIII deficiency and different types of clinical and laboratory severity. Results The results of this analysis confirmed that FXIII coagulant activity in plasma is well associated with clinical severity of patients. In addition, 15 IU dL-1 of FXIII activity was identified to be the level under which the probability of spontaneous major bleeding sharply increases (from 50% for levels of 15 IU dL-1 to more than 90% for levels of 5 IU dL-1 or lower). Conclusion The PRO-RBDD study suggests a FXIII coagulant activity level of 15 IU dL-1 as a target to start prophylaxis in order to prevent major bleedings, such as central nervous system or gastrointestinal tract hemorrhages.

Long-term prophylaxis in patients with severe congenital factor XIII deficiency is not complicated by inhibitor formation.

: Congenital factor XIII (FXIII) deficiency is a rare bleeding disorder accompanied by a variety of bleeding events. Severely deficient patients require regular replacement therapy. With development of FXIII concentrate, the risk of viral infections transmitted by fresh frozen plasma and cryoprecipitate is diminished, but the possibility of inhibitor development remains a challenging issue in the management of these patients. The aim of this study was to assess FXIII inhibitor development in Iranian patients with FXIII deficiency (FXIIID). This study enrolled 50 (30 women and 20 men) patients with severe congenital FXIIID from southeast Iran who underwent long-term (more than 4 years or more than 50 injections) prophylaxis with FXIII concentrate (Fibrogammin P, Dade Behring, Marburg, Germany). We evaluated plasma FXIII activity and FXIII inhibitor on day 28 after the last prophylaxis administration. The method for investigation of FXIII inhibitor was based on Bethesda assay. The mean age of the study population was 13.8 ± 8.3 years. The minimum and maximum FXIII activity levels were less than 1-4.5% (mean ± SD, 2.6 ± 0.7%). Our investigations showed that all patients with severe form of FXIIID were treated without inciting inhibitor development. Despite long-term prophylaxis in the studied patients, none was found to have developed FXIII inhibitors.

Severe Congenital Deficiency of Factor XIII: A Brief Report of Morbidity and Mortality Rates of Severe Congenital Deficiency of Factor 13 in Iran

Severe Congenital Deficiency of Factor XIII: A Brief Report of Morbidity and Mortality Rates of Severe Congenital Deficiency of Factor 13 in Iran

先天性第XIII因子欠乏症患者に対する頚椎手術の麻酔経験

先天性第XIII因子欠乏症患者に対する頚椎手術の麻酔経験

A Large-Scale Prospective Cohort Study on Factor XIII Deficiency in Southeast of Iran

Background: Congenital factor XIII (FXIII) deficiency is an extremely rare bleeding disorder with an estimated incidence of 1 per 2 million which has the highest global incidence in the southeast of Iran. Hence, this cohort study was designed to assess the prevalence of FXIIID, its molecular basis and clinical manifestations of FXIII deficiency (FXIIID) in Sistan and Baluchestan Province, southeast Iran.Methods: All data about the prevalence of this disorder, its genotype and phenotype were collected prospectively from 2010 to 2016.Results: In total , 410 patients were identified within the study period, a prevalence of 1 per ~ 7,000 in this area. The mean age of patients was 12 years (range, 1 month to 55 years), of which 51% (n: 209) were female. The main clinical presentation leading to the diagnosis of FXIIID was umbilical cord bleeding (82%). Three hundred and eighty patients were receiving regular prophylaxis of 10 IU/Kg of FXIII concentrate (Fibrogammin) every 28 days. This therapeutic dose was successful in the management of major and minor bleeding and the prevention of life-threatening bleeding in this cohort. But despite receiving prophylaxis, 63 minor bleeding episodes were recorded: 70% lower extremity ecchymoses, 25% oral cavity bleeding and 5% of menorrhagia. The prophylaxis interval for 5 patients was reduced to 21 days due to these bleeding events. Molecular analysis showed that 407 of the patients had a unique Trp187Arg mutation in exon 4 of the FXIII-A subunit gene, while the three remaining patients did not have a detectable underlying mutation.. During the study period, 70 patients underwent minor and major surgeries that were managed by 10-50 IU/Kg Fibrogammin without any significant bleeding. Furthermore, 32 successful deliveries were reported, consisting of 17 normal deliveries and 14 cases of Caesarian section, with a dose of 10-25 IU/Kg. No blood-borne disease was detected in patients receiving Fibrogammin.Discussion: FXIIID has the highest global incidence in the southeast of Iran. The Trp187Arg mutation im the FXIII-A gene is the sole underlying mutation in this area due to the founder effect. Fibrogammin is a safe and suitable therapeutic choice for prophylaxis and management of major and minor bleeding. DisclosuresNo relevant conflicts of interest to declare.

Safety and Efficacy of Recombinant Factor XIII (FXIII) in Patients with Congenital FXIII A-Subunit Deficiency, Results from the Mentor™2 Trial

Safety and Efficacy of Recombinant Factor XIII (FXIII) in Patients with Congenital FXIII A-Subunit Deficiency, Results from the Mentor™2 Trial

Acquired Factor XIII Deficiency in the Inpatient Setting: Clinical Suspicion, Impact and Treatment: Retrospective Case Series

Introduction: Activated factor XIII (FXIII) stabilizes fibrin clots at the end of the coagulation cascade by bridging fibrin molecules. Disproportionate surgery related bleeding has been reported in association with FXIII deficiency, in patients with normal coagulopathies screening tests, and without a history of previous bleedings.Methods: Retrospective case series. We performed immunological factor XIIIA (FXIIIA) studies in the inpatient setting of the Hospital Italiano de Buenos Aires, between January 2014 and March 2016. FXIIIA below 50% were considered deficient. Patients with suspicion of congenital Factor XIII deficiency or 2 years old or less were excluded. Descriptive statistics were used. Populations were compared with chi-square, Fisher and T test, or Mann Whitney tests with Stata13 software.Results: FXIII was studied in 52 patients; 37 of these (26 females and 11 males) met inclusion and exclusion criteria. Median age was 43 years (range 9-81). Twenty two patients were studied because of disproportionate surgery related bleeding, 11 because of spontaneous bleeding; and 4 not specified. All patients presented normal coagulopathies screening tests, normal Von Willebrand factor and ristocetine cofactor activity and normal platelet function tests. Eleven patients (30%) had FXIIIA less than 50%. Statistically significant differences between groups were found for median drop in hematocrit points [3.5 (IQR 3-10) vs 1.5 (IQR 0-2, p=0.02)] and median number of red cell units transfused [4 (IQR 0-6) vs 0 (0-2), p=0.01]. Differences in rates of minor and major bleedings were not statistically significant. Only one patient of eleven presented FXIII deficiency associated spontaneous bleeding vs 8 out of 20 patients in the postsurgical setting. FXIII concentrate was used in two patients to treat persistent bleeding, resolving in less than 24 hours. Three patients died, none because of bleeding. Five of the 11 patients with FXIII deficiency returned to normal values when FXIII assay was repeated away from acute setting.Discussion: FXIII acquired deficiency is associated with disproportionate bleeding in postsurgical setting in patients without apparent coagulation defects. FXIII deficiency could be underdiagnosed. Patients with FXIII deficiency in our series had more hematocrit drop and more transfusion requirements. We found no association with spontaneous bleeding. Alltough deficiency could be transient, treatment with FXIII concentrate could be useful to manage serious, persistent or life threatening bleedings. DisclosuresNo relevant conflicts of interest to declare.

Disseminated intravascular coagulation with positive D-dimer: a controversial clinical feature in severe congenital factor XIII deficiency in southeast Iran.

Disseminated intravascular coagulation (DIC) is an extremely rare coagulopathy in the rare factor XIII (FXIII) deficiency. Compensated DIC occurs because of injuries that lead to systemic coagulation activation that is amplified by impaired fibrinolysis. This challenge translates into the widespread deposition of fibrin degradation products in the circulation. The aim of this study is to report three cases with severe FXIII deficiency who presented with DIC and positive D-dimer. Here we describe three patients affected by both FXIII deficiency and DIC; two girls aged 17 and 45 days and a 3.5-year-old boy. All patients had a positive family history for FXIII deficiency. Umbilical cord bleeding was the first presentation of FXIII deficiency in all of them, who presented also with ecchymosis; two of them had delayed wound bleeding. DIC occurred simultaneously with intracranial haemorrhage in two patients, whereas the third experienced DIC following extensive haematoma. D-dimer measured in all patients ranged between 5 and 20 μg/ml, whereas fibrinogen degradation product was between 4 and 8 μg/ml.

Factor XIII deficiency enhances thrombin generation due to impaired fibrin polymerization — An effect corrected by Factor XIII replacement

IntroductionFactor XIII (FXIII) cross-links fibrin, completing blood coagulation. Congenital FXIII deficiency is managed with plasma-derived FXIII (pdFXIII) or recombinant FXIII (rFXIII) concentrates. AimAs the mechanisms protecting patients with low FXIII levels (<5IU/dL) from spontaneous bleeds remain unknown we assessed the interplay between thrombin generation (TG), fibrin formation and clot kinetics before and after FXIII administration in three patients with FXIII deficiency. MethodsPatients received initially rFXIII (35IU/kg, A-subunit) following with pdFXIII at 1250IU or 2500IU (12–30IU/kg) monthly. TG (CAT), thromboelastometry (ROTEM), prothrombin fragments F1+2, fibrinogen and FXIII activity (FXIII:C) were measured at baseline and one-hour recovery. ResultsFXIII was at the target level of 20±6IU/dL at the 4-week trough. rFXIII corrected FXIII to 98±15 and high-dose pdFXIII to a level of 90±6, whereas low-dose/half dose pdFXIII reached 45±4IU/dL. Although fibrinogen (Clauss Method) was normal, coagulation in FIBTEM was impaired, which FXIII administration tended to correct. CAT implied 1.6- to 1.9-fold enhanced TG, which FXIII administration normalized. Inhibition of fibrin polymerization by Gly-Pro-Arg-Pro peptide mimicked FXIII deficiency in CAT by enhancing TG both in control and FXIII recovery plasma. Antithrombin, α2-macroblobulin–thrombin complex and prothrombin were normal, whereas F1+2 were elevated compatible with in vivo TG. DiscussionFXIII deficiency impairs fibrinogen function and fibrin formation simultaneously enhancing TG on the poorly polymerizing fibrin strands, when fibrin’s antithrombin I -like function is absent. Our study suggests an inverse link between low FXIII levels and enhanced TG modifying structure-function relationship of fibrin to support hemostasis.

Developing the First Recombinant Factor XIII for Congenital Factor XIII Deficiency: Clinical Challenges and Successes.

Congenital factor XIII (FXIII) deficiency is a rare, autosomal recessive bleeding disorder with potentially life-threatening consequences. FXIII is composed of two subunits (A and B), and a deficiency or dysfunction of either can result in FXIII deficiency. Traditionally, FXIII deficiency has been managed by infusing plasma-derived products containing FXIII (fresh frozen plasma, cryoprecipitate, and plasma-derived FXIII concentrates), all of which contain both subunits. Despite the increased safety of plasma-derived products, concern remains regarding potential viral safety issues. This review describes the development, from concept to clinical use, of a recombinant FXIII molecule (containing subunit A only; rFXIII-A2) for congenital FXIII-A subunit deficiency. Unmet needs and ongoing challenges in congenital FXIII deficiency are also discussed. Despite the challenges in developing a product for a very rare bleeding disorder, the information gathered on efficacy, safety, and pharmacokinetics of FXIII replacement therapy represents the largest dataset on congenital FXIII-A subunit deficiency in the world. It also provides evidence for the safety and efficacy of monthly prophylaxis with 35 IU/kg of rFXIII-A2 in patients with FXIII-A subunit deficiency. The issues encountered and overcome, along with lessons learned, may be applied to and encourage the development of new recombinant products for other rare bleeding disorders.

Long Term Follow up Study on a Large Group of Patients with Congenital Factor XIII Deficiency Treated Prophylactically with Fibrogammin P®.

Factor XIII deficiency (FXIIID) is an extremely rare hemorrhagic disorder with a prevalence of 1/3-5 million. Management of disease is performed by fresh frozen plasma (FFP), Cryoprecipitate (CP) or FXIII concentrate (Fibrogammin P®). Our objective was to assess safety and effectiveness of Fibrogammin P® in patients with FXIIID. For this purpose we designed this long-term follow up study on a large group of patients with FXIIID. This prospective study was conducted on 213 patients with FXIIID since 2009 to 2013. Administrated dose for Fibrogammin P® according to clinical situations of patients ranged from 10 to 26 IU/kg every 4 - 6 weeks. All patients in 6-month intervals were checked for human immunodeficiency virus (HIV), hepatitis A, B and C viruses (HAV, HBV, HCV). Twelve percent of participants had at least one ICH episode until 2008 but after administration of Fibrogammin P® did not have any major bleeding or episode of ICH, except in one patient. We also had 7 females with recurrent miscarriage that were managed successfully with a dose of 10 to 26 IU/kg every 4 - 6 weeks. This dose also was quite successful in management of major and minor surgery. None of the participants showed allergic reaction during treatment. A total of 7155450 IU of Fibrogammin P® were infused but nobody was positive for HIV, HAV, HBV, and HCV. We found that Fibrogammin P® is a safe and effective therapeutic choice in management of FXIIID.

Nonclinical analysis of the safety, pharmacodynamics, and pharmacokinetics of plasma-derived human FXIII concentrate in animals.

Factor XIII (FXIII) is a coagulation protein which plays a major role in hemostasis by covalently cross‐linking fibrin molecules, thereby stabilizing the blood clot and increasing resistance to fibrinolysis. FXIII deficiency, either congenital or acquired, is associated with spontaneous bleeding, increased bleeding time, and poor wound healing. Purified plasma‐derived human FXIII concentrate (pd hFXIII) has been available since 1993 for therapeutic use in congenital FXIII deficiency. This set of nonclinical investigations aimed to evaluate the pharmacodynamic effects and assess the safety profile of pd hFXIII. The efficacy and safety of pd hFXIII were evaluated by pharmacodynamic, pharmacokinetic, and toxicity studies in mice and rats, safety pharmacology studies in dogs, neoantigenicity study, local tolerance, and thrombogenicity tests in rabbits. Administration of pd hFXIII resulted in the correction of deficits in clot formation kinetics and strength as measured by thromboelastometry, and was not associated with thrombus formation up to 350 IU/kg in FXIII knockout mice. There was no production of neoantigens resulting from the viral elimination manufacturing steps detected, and no adverse reactions were observed in toxicity studies with single doses up to 3550 IU/kg in mice and 1420 IU/kg in rats; nor from repeat doses of 350 IU/kg in rats. In addition, local tolerance tests revealed a good tolerability profile in rabbits. Overall, this data showed that pd hFXIII was well tolerated and pharmacodynamically active in preclinical animal models, supporting pd hFXIII as a therapy for FXIII deficiency.