Detection of Carriers of Haemophilia

Summary

Protein with antihaemophilic factor antigenicity (AHF-like protein) and the biological activity of antihaemophilic factor (AHF activity) was measured in 13 obligatory and 21 suspected carriers of haemophilia and 20 normals. The mean level of AHF-like protein was significantly higher in the obligatory and suspected carriers but there was a wide range of values. The ratio of AHF activity to AHF-like protein was significantly lowered. In 31 of 34 cases a diagnosis of the carrier status could be made by the use of this ratio. In 18 the AHF activity was within the normal range and in 15 of these the ratio could be used to diagnose the carrier status. The ratio was not diagnostic in 3 obligatory carriers. Estimation of the ratio of AHF activity to AHF-like protein is a valuable adjunct to genetic counselling in haemophilia.

• References

• 1 Bennett E, and Huehns E. R. 1970; Immunological differentiation of 3 types of haemophilia and identification of some female carriers. Lancet 11: 956.
• 2 Biggs R, Austen D. E. G, Denson K. W. E, Rizza C. R, and Borrett R. 1972; Mode of action of antibodies which destroy factor VIII. i. Antibodies which have second-order concentration graphs. British Journal of Haematology 23: 125.
• 3 Ekert H, Helliger H, and Mijntz R. H. 1972; AHF-related protein and precipitation reactions. British Medical Journal 4: 789.
• 4 Hardisty R. M, and Ingram G. I. C. 1965. Bleeding disorders. Investigation and Management. Blackwell Scientific Publications; Oxford:
• 5 Hoyer L. W. 1972; Immunologic studies of antihaemophilic factor (AHF, factor VIII). III. Comparative binding properties of human and rabbit anti-AHF. Blood 39: 481.
• 6 Newman J, Johnson A. J, Karpatkin M. H, and Puszkin S. 1972; Methods for the production of clinically effective intermediate and high-purity factor VIII concentrates. British Journal of Haematology 21: 1.
• 7 Rapaport S. I, Patch M. J, and Moore F. J. 1960; Antihaemophilic globulin levels in carriers of haemophilia. Journal of Clinical Investigation 39: 1619.
• 8 Zimmerman T. S, Ratnoff O. D, and Littell S. A. 1971; Detection of carriers of classic haemophilia using immunologic assay for antihaemophilic factor (VIII). Journal of Clinical Investigation 50: 255.
• 9 Zimmerman T. S, Ratnoff O. D, and Powell A. E. 1971; Immunologic differentiation of classical haemophilia (Factor VIII deficiency) and von Willebrand’s disease. Journal of Clinical Investigation 50: 244.