PMID: 9192760Jun 15, 1997Paper

The missense mutation Arg593 --> Cys is related to antibody formation in a patient with mild hemophilia A.

Blood
K FijnvandraatJ Voorberg

Abstract

The development of inhibitory antibodies to factor VIII in patients affected by a mild form of hemophilia A (factor VIII > 0.05 IU/mL) is considered a rare event. In this study, we evaluated the relationship between genotype and anti-factor VIII antibody formation in a patient with mild hemophilia A. Mutation analysis showed that a missense mutation in the factor VIII gene leading to replacement of Arg593 by Cys in the A2 domain of factor VIII was associated with hemophilia A in this patient. The anti-factor VIII antibodies present in the patient's plasma were characterized using metabolically labeled factor VIII fragments expressed in insect cells. The anti-factor VIII antibodies, composed of subclasses IgG2 and IgG4, reacted with both the fragment corresponding to the factor VIII heavy chain and the A2 domain. The Arg593 --> Cys substitution was introduced into the cDNA encoding the A2 domain of factor VIII and the resulting construct was expressed in insect cells. Strikingly, the metabolically labeled A2 domain carrying the Arg593 --> Cys mutation was not recognized by the anti-factor VIII antibodies present in the plasma of the patient. These data indicate that the anti-factor VIII antibodies are exclusively directed agains...Continue Reading

Related Concepts

Related Feeds

Blood Clotting Disorders

Thrombophilia includes conditions with increased tendency for excessive blood clotting. Blood clotting occurs when the body has insufficient amounts of specialized proteins that make blood clot and stop bleeding. Here is the latest research on blood clotting disorders.

Autoimmune Diseases

Autoimmune diseases occur as a result of an attack by the immune system on the body’s own tissues resulting in damage and dysfunction. There are different types of autoimmune diseases, in which there is a complex and unknown interaction between genetics and the environment. Discover the latest research on autoimmune diseases here.