Factor XIII Deficiency As Underlying Cause Of Unexplained Bleeding

Factor XIII deficiency (FXIII) is an uncommon coagulation disorder. Congenital FXIII deficiency, generally due to mutations in F13A1 gene, presents with early life- threating hemorrhages in homozygotes. Acquired deficiency, a more rare state, has been associated with certain drugs and inhibitors against FXIII.

We retrospectively analyzed 47 patients (male:female 1:1.3). Study criteria were unexplained hemorrhage, mainly after surgery, or spontaneous intracranial bleeding at perinatal period and no relevant findings in conventional haemostasia assays, from 01/01/2010 to 15/07/2013. FXIII measure was performed by a functional method.

20 out of 47 patients (42.5%) other abnormalities that might contribute to bleeding were detected: 13 had primary haemostasis disorders and 7 had low levels of a coagulation factor different from FXIII. In 10 patients, FXIII deficiency was observed: 4 congenital and 6 acquired. In all acquired deficiencies, the presence of an inhibitor was discarded. Patients with congenital FXIII deficiency, had mucocutaneous bleeding in 75% of cases and hemorrhage after surgery in 50%. However, there was no intracranial hemorrhage. In acquired deficiency (median FXIII 44.5 U/dl at first diagnostic work up), mucocutaneous bleeding appeared in 40% patients and postoperative and intracranial hemorrhage in 100%. In 8/ 10 patients FXIII concentrate was administered, achieving bleeding control in 7. In 3 cases of congenital deficiency, prophylactic substitutive therapy was started enabling a cessation of new bleeding episodes, except for a posttraumatic muscle hematoma; median FXIII levels reached 6.8 U/ dL. 2 patients with acquired deficiency died of non-hemorrhagic complications, 3 patients developed spontaneous remission of the deficiency in a median time of 2 months and 1 is still receiving substitutive therapy.

In congenital deficiency, maintenance of FXIII through levels in the range of 5-10% is enough to avoid bleeding manifestations. The acquired deficiencies have at least the same frequency as congenital, develop hemorrhage episodes at higher levels of factor and respond to therapy in a thrifty way. For those reasons, tests for FXIII are essential for diagnosis in high index clinical suspicious cases, such as unexplained bleeding.

No relevant conflicts of interest to declare.