develop antibodies to the clotting factors that sub-
sequently prevents these treatments from having
any effect. In such situations the doctor may
administer porcine-derived forms of clotting factor
VIII or prothrombin complex concentrate, which
bypass some of the steps in the coagulation cas-
cade to avoid ANTIBODYactivation.
A promising treatment for mild hemophilia A is
the synthetic HORMONEdesmopressin. Also called
DDAVP, desmopressin is an analog (close chemical
relative) of the endogenous hormone vasopressin,
which the PITUITARY GLANDsecretes. Administered
intravenously or via nasal spray, desmopressin
causes the body to increase blood levels of clotting
factors VIII and IX. However, desmopressin has lit-
tle effect in people who have hemophilia B.
Desmopressin may affect other aspects of the
coagulation cascade and can elevate the BLOOD
PRESSURE.
Blood product treatments for hemophilia carry
the risk of INFECTIONwith various pathogens that
current blood screening technology cannot detect
including HEPATITISA, human T-lymphotropic virus
1 (HTLV-1), west Nile virus, MALARIA, and also
CYTOMEGALOVIRUS (CMV). Though infection with
human immunodeficiency virus (HIV) was a sig-
nificant problem during the 1980s, screening pro-
cedures in effect today have nearly eliminated the
risk for acquiring HIV/AIDSthrough donated blood
products.
Many people who have hemophilia are able to
enjoy a high QUALITY OF LIFEwith ongoing medical
monitoring and lifestyle choices to reduce the risk
for traumatic injury. However, complications such
as JOINTdamage due to frequent bleeding can limit
physical activities. GASTROINTESTINAL BLEEDING is
also a potential complication.Risk Factors and Preventive Measures
Genetic inheritance is the only known risk factor
for hemophilia. Health experts encourage people
who have hemophilia, know they carry the gene
defect for hemophilia, or have a family history of
unusual bleeding to discuss FAMILY PLANNINGwith a
genetic counselor who can advise of the risks that
children will either carry or have hemophilia.
Much research currently focuses on perfecting
recombinant technologies to provide clotting fac-
tor therapies free from risk of infection and anti-
body development. Other research efforts are
exploring the potential for GENE THERAPYthat can
repair the damaged genes, though this potential
has not yet yielded practical results.
See also ANTIBODY; COAGULATION; GENETIC COUN-
SELING; GENETIC DISORDERS; INHERITANCE PATTERNS; VON
WILLEBRAND’S DISEASE.144 The Blood and Lymph