Hemophilia and related bleeding disorders: a story of dismay and success.

Known since the beginning of the first millennium, the hemophilias are among the most frequent inherited disorders of blood coagulation and definitely the most severe. In the 1970s, with the availability of concentrated preparations of the deficient coagulation factors VIII and IX and with the large-scale adoption of home treatment, hemophilia care became one of the most gratifying examples of successful secondary prevention of a chronic disease. Unfortunately, in the early 1980s it was recognized that factor concentrates prepared from plasma pooled from thousands of donors transmitted the hepatitis and the human immunodeficiency viruses. The scientific community reacted promptly to the devastation brought about by hepatitis and AIDS. The last 15 years of the second millennium have witnessed the development of methods that, when applied during concentrate manufacturing, inactivate viruses escaping the screening procedures. The adoption of these measures has reduced dramatically the risk of transmission of bloodborne infections. The production of recombinant factors and their availability for patients' treatment epitomize progress in hemophilia care through DNA technology. Methods based on the polymerase chain reaction (PCR) have unraveled an array of gene lesions associated with hemophilia, permitting improved secondary control of the disease through carrier detection in women from affected families and prenatal termination of their affected male infants. This article will review the aforementioned areas of progress and discuss unresolved problems (such as treatment of patients with antibodies, the risk of new infectious complications, and the issue of secondary tumors). Hopes and expectations for further improvement in the third millennium and particularly the prospects of hemophilia cure though gene replacement therapy will also be mentioned.