Summary
Although the incidence of haemophilia A is reportedly uniform across ethnic groups,
the prevalence varies in different countries. This suggests variability in the effectiveness
of diagnostic strategies which is of particular importance in the recognition of milder
forms of the disease. To assess the different laboratory tests that are used in the
diagnosis and subsequent management of haemophilia A we carried out a web-based survey
of established haemophilia centres. This was sent to 13 haemophilia physicians from
haemophilia-treatment centres in Germany, Italy, Spain, South Africa, Taiwan, Norway,
Canada, UK and the USA. The survey asked for details of clotting tests, the use of
genetic analysis and the use of global haemostatic assays in haemophilia A cases.
The results show considerable variation in the laboratory methods used for the screening,
diagnosis and monitoring of haemophilia A. There is variability in the techniques
used even for longstanding, standardised assays such as the one-stage factor assay.
There is marked regional variability in the use of molecular diagnosis. Assessment
of haemophilia A requires accurate and sensitive assays. Some laboratories continue
to rely on a single-factor assay in the diagnosis of non-severe disease, although
cases with assay discrepancy may be missed by this strategy. Global assays are becoming
important in the evaluation and management of patients. However, standardisation and
the correlation with clinical outcomes require further study. Genetic diagnosis in
patients with haemophilia remains underutilised in USA, possibly because of a lack
of funding.
Keywords
Haemophilia - diagnosis - laboratory assays - genetic analysis
