Catridecacog: a breakthrough in the treatment of congenital factor XIII A-subunit deficiency?

Clinical Profile of Congenital Factor XIII Deficiency in Children

OBJECTIVES

Congenital Factor 13 Deficiency (FXIIID) is a rare bleeding disorder (RBD) of autosomal recessive inheritance, with an incidence of 1 in 3-5 million. The clinical symptomatology, diagnosis, and management of FXIIID are described.

METHODS

A retrospective chart review of children with FXIIID was performed from January 2000 through October 2021 at a tertiary care center in Southern India. The diagnosis was performed by the Urea clot solubility test (UCST) and Factor XIII antigen assay.

RESULTS

Twenty children (representing 16 families) were included. Male: Female ratio was 1.5:1. The median age of symptom onset was 6 mo, and the median age of diagnosis was 1 y, demonstrating a delay in diagnosis. Consanguinity was present in 15 (75%) with 4 children having affected siblings. Clinical symptomatology ranged from mucosal bleeds to intracranial bleeds and hemarthrosis, with many children having a history of prolonged umbilical bleeding in their neonatal period. Fourteen children were on cryoprecipitate prophylaxis. Four children had breakthrough bleeds due to irregular prophylaxis, including one intracranial bleed due to a delay in cryoprecipitate prophylaxis during the covid pandemic.

CONCLUSIONS

Congenital FXIIID presents with a wide range of bleeding manifestations. The high prevalence of consanguinity in Southern India can be a cause of FXIIID's high prevalence in this region. There is a propensity for intracranial bleeding with a significant number having this at first presentation. Regular prophylaxis is required and feasible to prevent potentially fatal bleeds.

Role, Laboratory Assessment and Clinical Relevance of Fibrin, Factor XIII and Endogenous Fibrinolysis in Arterial and Venous Thrombosis

Diseases such as myocardial infarction, ischaemic stroke, peripheral vascular disease and venous thromboembolism are major contributors to morbidity and mortality. Procoagulant, anticoagulant and fibrinolytic pathways are finely regulated in healthy individuals and dysregulated procoagulant, anticoagulant and fibrinolytic pathways lead to arterial and venous thrombosis. In this review article, we discuss the (patho)physiological role and laboratory assessment of fibrin, factor XIII and endogenous fibrinolysis, which are key players in the terminal phase of the coagulation cascade and fibrinolysis. Finally, we present the most up-to-date evidence for their involvement in various disease states and assessment of cardiovascular risk.

Factor XIII polymorphism and risk of aneurysmal subarachnoid haemorrhage in a south Indian population

BACKGROUND

The rupture of a brain aneurysm causes bleeding in the subarachnoid space and is known as aneurysmal subarachnoid haemorrhage (aSAH). In our study, we evaluated the association of factor XIII polymorphism and the risk of Aneurysmal subarachnoid haemorrhage (aSAH) in South Indian population.

METHODS

The study was performed in 200 subjects with aSAH and 205 healthy control subjects. Genotyping of rs5985(c.103G > T (p.Val35Leu)) and rs5982(c.1694C > T (p.Pro564Leu)) polymorphism was performed by Taqman® allelic discrimination assay.

RESULTS

In our study, Val/Leu genotype frequency was higher in control subjects (18%) compared to aSAH patients (9%).The Val/Leu genotype was associated with lower risk of aSAH (OR = 0.48, 95%CI = 0.26-0.88, p = 0.02). When compared with Val allele, Leu allele was significantly associated with lower risk of aSAH (OR = 0.55, 95%CI = 0.32-0.95, p = 0.03). In subtyping, we found a significant association of Leu/Leu genotype with the Basilar top aneurysm (OR = 3.59, 95%CI = 1.11-11.64, p = 0.03). In c.1694C > T (p.Pro565Leu) variant, Pro/Pro Vs Pro/Leu genotype (OR = 2.06, 95%CI = 1.10-3.85, p = 0.02) was significantly associated with higher risk of aSAH. The 564Leu allelic frequency in aSAH patients (36%) was higher when compared with that in healthy controls (30%) in our study. When allele frequency (Pro Vs Leu) was compared, 564Leu allele was found to be significantly associated with higher aSAH risk (OR = 1.36, 95%CI = 1.01-1.83, p = 0.04). (OR = 1.36, 95%CI = 1.01-1.83, p = 0.04). Regarding rs5985 and rs5982, significant association was found in the log-additive model (OR = 0.57, 95%CI = 0.33-0.97, p = 0.034; OR = 1.32, 95%CI = 1.00-1.72, p = 0.043).

CONCLUSION

These results suggest that 34Leu allele was a protective factor for lower risk of aSAH whereas 564Leu allele was associated with higher risk of aSAH in South Indian population.

Factor XIII deficiency in south of Tunisia

: Factor XIII deficiency is a rare autosomal recessive disorder of hemostasis characterized by a plasmatic factor XIII level less than 1% in homozygote and bleeding as of the youth. The aim of the study is to describe the clinical features and the outcome of the patients and to determine molecular characteristics. A retrospective study, was conducted on seven patients with factor XIII deficiency in the department of hematology and pediatrics, Hedi Chaker Hospital, Sfax, Tunisia during the period of 14 years (2001-2014). The activity of factor XIII in plasma of the patients was less than 1%. Seven patients from five unrelated families were recorded (four men and three women). Median age at diagnosis was 3.5 years. All patients had consanguineous parents. Six patients presented umbilical bleeding and only three patients had intracranial bleeding. Other bleeding features were seen, including skin and mucosal bleeding, muscular hematoma, and splenic rupture. Recurrent abortions were observed in one patient. The standard screening tests were normal. Genetic analysis identified two mutations interesting the subunit A of factor XIII. All patients received transfusion of fresh frozen plasma monthly. One patient was died because of intracranial hemorrhage.Factor XIII deficiency is a rare bleeding disorder which frequently increases in areas with high consanguinity. In our study, we identified a founder mutation. The prognosis of the disorder is related to hemorrhagic complications especially to life-threatening intracranial bleeding. Prophylaxis consists of factor XIII concentrate or recombinant factor XIII. If these are unavailable, fresh frozen plasma may be used.

Severe bleeding diatheses in an elderly patient with combined type autoantibody against factor XIII A subunit; novel approach to the diagnosis and classification of anti-factor XIII antibodies

INTRODUCTION

Acquired factor XIII (FXIII) deficiency due to autoantibody is a rare, severe bleeding diathesis. Its laboratory diagnosis and classification represents a difficult task.

AIM

Introduction of novel approaches into the diagnosis and characterization of anti-FXIII autoantibody and demonstration of their use in the diagnosis of a patient with autoimmune FXIII deficiency.

METHODS

Factor XIII activity, FXIII antigen levels and the titre of anti-FXIII-A antibody were monitored throughout the course of the disease. FXIII activity was measured by ammonia release assay; FXIII-A₂ B₂ complex, total and free FXIII-B concentrations were determined by ELISAs. The binding constant for the interaction of the autoantibody with recombinant FXIII-A₂ (rFXIII-A₂ ) and FXIII-A₂ B₂ was determined by surface plasmon resonance (SPR). The inhibitory capacity of IgG was expressed as the concentration exerting 50% inhibition of FXIII activation/activity (IC50). The truncation of FXIII-A by thrombin was monitored by western blotting. The inhibition of Ca²⁺ -induced FXIII activation and active FXIII (FXIIIa) were assessed by FXIII activity assay.

RESULTS

The antibody bound to rFXIII-A₂ and FXIII-A₂ B₂ with high affinity and accelerated the decay of supplemented FXIII concentrate. An IC50 value of 170.1 μg IgG·mL^-1 indicated effective FXIII neutralization. The main neutralizing effect of the autoantibody was the inhibition of FXIIIa. After 2 months, due to combined therapeutic modalities, the autoantibody disappeared and FXIII activity significantly elevated.

CONCLUSION

The anti-FXIII-A autoantibody exerted a combined effect including inhibition of FXIIIa and acceleration of FXIII decay in the plasma. IC50 and binding constant determinations added important information to the characterization of the autoantibody.