One-stage and chromogenic FVIII:C assay discrepancy in mild haemophilia A and the relationship with the mutation and bleeding phenotype.
The discrepancy of the levels of factor VIII activity (FVIII:C) by different assays in some mild and moderate haemophilic A patients has been long known. Specific mutations affecting FVIII:C discrepancies have been described. No consensus exit as to which method most accurately represents the FVIII cofactor function in vivo and which has a better correlation with the haemorrhagic clinical expression. We studied 163 mild A haemophiliacs, and detected discrepancies in 20% of the patients, most of whom presented higher levels of FVIII:C with the one-stage assay. In nine families, the FVIII mutation was found, while three showed mutations not previously described (Leu1978Phe and Ser1791Pro associated with higher levels of FVIII:C by one-stage method; Arg1639His in a patient with low level of FVIII:C by the one-stage, but normal, chromogenic assay). Assessing the level of FVIII:C by different methods could help to learn the possible haemorrhagic expressions of patients.
Congenital Coagulopathies Unit, La Fe University Hospital, Valencia, Spain. cid_ana@gva.es
A R
AR
Cid
M
M
Calabuig
V
V
Cortina
P
P
Casaña
S
S
Haya
A
A
Moret
N
N
Cabrera
J A
JA
Aznar
D000293:Adolescent; D000328:Adult; D001780:Blood Coagulation Tests / Q000379:methods; D002648:Child; D002863:Chromogenic Compounds; D005169:Factor VIII / Q000235:genetics / Q000378:metabolism*; D006467:Hemophilia A / Q000097:blood* / Q000150:complications / Q000235:genetics; D006470:Hemorrhage / Q000097:blood / Q000209:etiology / Q000235:genetics; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation; D010641:Phenotype; D015203:Reproducibility of Results; D055815:Young Adult
D002863:Chromogenic Compounds; D005169:Factor VIII