Pediatric Clinics of North America - CIPERJ

Pediatr Clin N Am 55 (2008) 357–376
Advances in Hemophilia: Experimental
Aspects and Therapy
Nidra I. Rodriguez, MD a,b, *, W. Keith Hoots, MD a,b
a Division of Pediatrics, Hematology Section, The University of Texas
Health Science Center, 6411 Fannin, Houston, TX 77030, USA
b Gulf States Hemophilia and Thrombophilia Center, 6655 Travis,
Suite 400 HMC, Houston, TX 77030, USA
Hemophilia A or B is an X-linked recessive disorder that results from the
deficiency of blood coagulation factor VIII or IX, respectively (Fig. 1). Hemophilia
is classified based on the level of factor VIII or IX activity as severe
(!1%), moderate (1%–5%), or mild (O5%–40%). The type and frequency
of bleeding in hemophilia vary according to its severity. For example, patients
who have severe hemophilia present with spontaneous bleeding into
the joints or muscles, soft tissue bleeding, and life-threatening hemorrhage
in addition to episodes of minor bleeding. Patients who have moderate
hemophilia present less commonly with spontaneous bleeding but frequently
experience bleeding after minor trauma. Finally, patients who have mild
hemophilia typically present bleeding only after surgery or major trauma.
Musculoskeletal bleeding is the most common type of bleeding in hemophilia.
Such bleeding can result in arthropathy, a common complication
seen in the patient population that has this disease. In general, hemophilia
treatment consists of replacing the missing coagulation protein with clotting
factor concentrates when bleeding episodes occur (treatment on demand) or
by scheduled infusions of clotting factor several times per week (prophylaxis).
The development of neutralizing antibodies or inhibitors against factor VIII
or IX is another complication encountered as a result of hemophilia treatment.
Multiple factor VIII and IX concentrates are available and categorized
based on their source (plasma derived versus recombinant), purity, and viral
inactivation methods [1]. Recombinant products are categorized further
based on the presence or absence of animal/human protein in the cell culture
* Corresponding author. Gulf States Hemophilia and Thrombophilia Center, 6655
Travis, Suite 400 HMC, Houston, TX 77030.
E-mail address: nidra.i.rodriguez@uth.tmc.edu (N.I. Rodriguez).
0031-3955/08/$ - see front matter Ó 2008 Elsevier Inc. All rights reserved.
doi:10.1016/j.pcl.2008.01.010
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