Poster Session II: Bleeding disorders (congenital and acquired)
Congenital factor VII deficiency (FVII) is the least rare among uncommon hereditary bleeding disorders (1:500 000). This coagulopathy, inherited in an autosomal recessive pattern, is characterized by a bleeding tendency, varied prognosis and a lack of correlation between clinical phenotypes and biological analysis.
The objective of our study was to describe and to explore the clinical and the biological features of FVII deficiency in the South of Tunisia.
Our FVII-deficient cohort consisted of 88 patients whose FVII activity was less than 50% and who were referred to our laboratory from January 2000 to December 2018 because of a prolonged prothrombin time (PT) or hemorrhagic manifestations. The FVII deficiency was considered as severe for FVII coagulant activities (FVII:C) <2%, moderate for rates between 2 and 19% and minor for values between 20 and 49%. The statistical analysis was based on Chi-squared test.
The mean age of the patients was 22 years old ranging between 21 months and 63 years old and the sex ratio was about 0.83. Among 88 patients, belonging to 58 unrelated Tunisian families, 45 cases (51.2%) were diagnosed accidentally during presurgical screening, 28 cases (31.8%) were noticed following family screening and 15 patients (17%) were discovered due to bleeding accidents. Clinically, 64 patients (72.7%) were asymptomatic whereas the bleeding frequency was about 27.3%. Clinical examination revealed several bleeding manifestations as follows: gingivorrhagia noticed in 12 patients (50%), followed by epistaxis in nine patients (37.5%). Four cases had hematemesis (16.6%), hematoma was found in three (12.5%) and one of the patients had a cerebral haemorrhage (4.2%). Added to that, some bleeding signs, not commonly related to the FVII deficiency, had been noticed such as: menorrhagia, haemoperitoneum, hematuria and bruising. The laboratory severity of each patient was also determined: FVII deficiency was classified as severe in 3.4%, moderate in 14.8% and minor in 81.8% of cases. With reference to statistics, results showed a weak correlation between clinical data and biological levels of FVII:C (p = 0.004). In fact, 15 patients with a minor FVII deficiency had presented haemorrhages with a variable bleeding severity; while one of the patients was asymptomatic despite the severity of his defect.
Our study, in accordance with the literature, revealed a great interindividual heterogeneity of the clinical phenotype of FVII deficiency. In addition, bleeding severity did not necessarily correlate with FVII:C and varies markedly between individuals with a similar FVII:C. This would explain the delay and the underestimation of the diagnosis. In addition, the family screening had a prominent effect in improving the earliness of the diagnosis and in ensuring an adequate monitoring of these Tunisian patients.