title: Contribution of the collagen binding activity (VWF:CB) in the range of tests for the diagnosis and classification of von Willebrand disease.
abstract: Von willebrand disease (VWD) is a common inherited bleeding disorder. The diagnosis may need a large panel of tests that differ in term of sensibility and specificity, and because of the effect of multifactorial modifiers (genetic or environmental); there is difficulty in defining diagnostic limits. We performed a panel of tests on 19 patients suffering from recurrent bleeding, to diagnose and classify VWD subtypes, by introducing the von Willebrand factor (VWF) collagen binding test (VWF:CB), then comparing the results with the activity of VWF risticetin cofactor (VWF:RCo) and multimer pattern. We considered 30% limit rate of VWF, as described by many authors, to make the diagnosis of VWD. The diagnosis of type 1 of VWD has been confirmed in 7patients, subtype 2A in 2 patients, subtype 2M in 2 patients and type 3 in 2 patients. We also defined a new group of 6 patients named "uncertain type 1" that didn't fill into the type 1 diagnostic criterion. The comparison between VWF:CB and VWF:RCo showed good correlation for all types of VWD except for type 2 while comparison between VWF:CB and multimer pattern showed good concordance for all types of VWD diagnosed. In conclusion, VWF:CB can be a good alternative to VWF:RCo for the diagnosis of quantitative deficiencies of VWF. It can also replace the multimer pattern study. However, the introduction of VWF:CB didn't help in the diagnosis of the "uncertain type 1" group of patients and cannot be a replacement for qualitative defect.
authors.affiliation: Centre de transfusion sanguine, CHU Bab Eloued, Alger, Algérie.
authors.forename: Meriem Yasmine
authors.initials: MY
authors.lastname: Ferhat-Hamida
authors.affiliation: Centre de transfusion sanguine, CHU Bab Eloued, Alger, Algérie.
authors.forename: Houda
authors.initials: H
authors.lastname: Boukerb
authors.affiliation: Centre de transfusion sanguine, CHU Bab Eloued, Alger, Algérie.
authors.forename: Ghania
authors.initials: G
authors.lastname: Hariti
mesh_terms: D000293:Adolescent; D000328:Adult; D003094:Collagen / Q000378:metabolism*; D005260:Female; D006403:Hematologic Tests; D006801:Humans; D008297:Male; D014842:von Willebrand Diseases / Q000097:blood / Q000145:classification* / Q000175:diagnosis*; D014841:von Willebrand Factor / Q000032:analysis*
chemical_list: D014841:von Willebrand Factor; D003094:Collagen
keywords: VWF:CB; multimers; von Willebrand disease; von Willebrand factor