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Thrombosis Research Sep 2022Ranging from bleeding to thrombosis, the clinical features of congenital fibrinogen qualitative disorders, including dysfibrinogenemia and hypodysfibrinogenemia, are... (Review)
Review
Ranging from bleeding to thrombosis, the clinical features of congenital fibrinogen qualitative disorders, including dysfibrinogenemia and hypodysfibrinogenemia, are highly heterogeneous. Although the associations between some specific fibrinogen mutations and the thrombotic phenotypes have been well elucidated, the underlying mechanism between fibrinogen variants and bleeding events remains underestimated. After systematically reviewing the literature of (hypo-)dysfibrinogenemia patients with bleeding phenotypes, we identified several well-characterized bleeding-related fibrinogen variants in those patients. Several possible pathomechanisms are proposed to explain the genotype-phenotype associations: 1, mutations in the NH-terminal portion of the Aα chain hamper fibrinogen fitting into the active site cleft of thrombin and drastically slow the conversion of fibrinogen into monomeric fibrin; 2, mutations adding new N-linked glycosylation sites introduce bulky and negatively charged carbohydrate side chains and undermine the alignment of fibrin monomers during polymerization; 3, mutations generating unpaired cysteine form extra disulfide bonds between the abnormal fibrinogen chains and produce highly branched and fragile fibrin networks; 4, truncation mutations in the fibrinogen αC regions impair the lateral fibril aggregation, as well as factor XIII crosslinking, endothelial cell and platelet binding. These established relationships between specific variants and the bleeding tendency will help manage (hypo-)dysfibrinogenemia patients to avoid adverse bleeding outcomes.
Topics: Afibrinogenemia; Blood Coagulation Tests; Fibrin; Fibrinogen; Fibrinogens, Abnormal; Hemorrhage; Humans; Thrombosis
PubMed: 35853369
DOI: 10.1016/j.thromres.2022.07.005 -
Haemophilia : the Official Journal of... Sep 2019Hereditary fibrinogen disorders (HFD) are rare quantitative or qualitative fibrinogen anomalies, including afibrinogenaemia (A), hypofibrinogenaemia (H),...
INTRODUCTION
Hereditary fibrinogen disorders (HFD) are rare quantitative or qualitative fibrinogen anomalies, including afibrinogenaemia (A), hypofibrinogenaemia (H), dysfibrinogenaemia (D) and hypodysfibrinogenaemia (HD). As fibrinogen plays an essential role in pregnancy, we addressed the issue of obstetrical and postpartum complications in women with HFD.
METHODS
A systematic literature review, restricted to English manuscripts, was conducted according to the PRISMA guidelines. We searched through the MEDLINE database for English articles, published from January 1985 until November 2018, focusing on pregnancy in A, H, D and HD. A total of 198 articles were identified, 15 articles were added from other sources. Overall, 213 articles were screened and 54 were included in the final analysis.
RESULTS
A total of 188 pregnancies from 70 women were analysed. About half of pregnancies resulted in miscarriage; more specifically in 15 (42.9%), 36 (46.8%), 27 (42.9%) and 4 (30.8%) of A, H, D and HD patients, respectively. Preterm complications were also frequent (33.5%). Metrorrhagia, mainly in the first trimester, was observed in 21.7% of the pregnancies. Placenta abruption was reported in 5 (14.3%), 4 (5.2%), 5 (7.9%) and 1 (7.7%) of A, H, D and HD, respectively. A total of 24 (12.7%) deliveries were complicated by postpartum thrombotic events (3.2%) or postpartum haemorrhage (9.6%). A fibrinogen replacement therapy was introduced in 30% of pregnancies, as prophylaxis (81.1%) or on demand (18.9%).
CONCLUSION
These results suggest that women with HFD are at high risk of obstetrical and postpartum complications. Prospective international registries may allow to identify more precisely the incidence of obstetrical and postpartum adverse outcomes and their management.
Topics: Adult; Afibrinogenemia; Female; Humans; Obstetrics; Postpartum Hemorrhage; Pregnancy
PubMed: 31368232
DOI: 10.1111/hae.13825