Though there is no cure for haemophilia, it can be controlled with regular infusions of the deficient clotting factor, i.e. factor VIII in haemophilia A or factor IX in haemophilia B. Some haemophiliacs develop antibodies (inhibitors) against the replacement factors given to them, so the amount of the factor has to be increased or non-human replacement products must be given, such as porcine factor VIII.
If a patient becomes refractory to replacement coagulation factor as a result of circulating inhibitors, this may be overcome with recombinant human factor VII (NovoSeven®), which is registered for this indication in many countries.
In western countries, common standards of care fall into one of two categories: prophylaxis or on-demand. Prophylaxis involves the infusion of clotting factor on a regular schedule in order to keep clotting levels sufficiently high to prevent spontaneous bleeding episodes. On-demand treatment involves treating bleeding episodes once they arise. In 2007, a clinical trial was published in the New England Journal of Medicine comparing on-demand treatment of boys (< 30 months) with Haemophilia A with prophylactic treatment (infusions of 25 IU/kg body weight of Factor VIII every other day) in respect to its effect on the prevention of joint-diseases. When the boys reached 6 years of age, 93% of those in the prophylaxis group and 55% of those in the episodic-therapy group had a normal index joint-structure on MRI. [6] Prophylactic treatment, however, resulted in average costs of $300,000 per year. The author of an editorial published in the same issue of the New England Journal of Medicine demands more clinical studies addressing the cost-effectiveness of prophylactic treatment. [7]
Armour and other pharmaceutical companies knowingly sold blood clotting products contaminated with HIV and hepatitis C to ten thousand haemophiliacs across America in the late 1970's and early mid 1980's. When the Federal Government banned their products from being sold in America, they promptly turned around and sold the HIV contaminated factor products overseas in Europe and Japan. [8]
Later criminal and civil lawsuits were brought against these manufacturers [8] and the Armour Pharmaceutical subsidiary of French chemical company Rhone-Poulenc. In Europe and Japan several high level executives received prison terms as a result of their knowingly selling HIV contaminated products to innocent haemophiliacs.
In America the pharmaceutical companies eventually paid out around 650 million dollars to compensate the haemophiliacs who were infected with HIV.
As a direct result of the contamination of the blood supply in the late 1970s and early/mid 1980s with viruses such as Hepatitis and HIV, new methods were developed in the production of clotting factor products. The initial response was to heat-treat (pasteurize) plasma-derived factor concentrate, followed by the development of monoclonal factor concentrates, which use a combination of heat treatment and affinity chromatography to inactivate any viral agents in the pooled plasma from which the factor concentrate is derived. The Lindsay Tribunal in Ireland investigated, among other things, the slow adoption of the new methods.
Since 1993 (Dr. Mary Nugent), recombinant factor products (which are typically cultured in Chinese hamster ovary (CHO) tissue culture cells and involve little, if any human plasma products) have become available and are widely used in wealthier western countries. While recombinant clotting factor products offer higher purity and safety, they are, like concentrate, extremely expensive, and not generally available in the developing world. In many cases, factor products of any sort are difficult to obtain in developing countries.
It was claimed that Rasputin was successful at treating the Tsarevich Alexei of Russia's haemophilia: however, to this day it is unclear how he accomplished this.
People affected with Hemophilia are recommended to do some specific exercises for elbow, knee, and ankles like stretching of calves, ankle circles, elbow flexion, and Quadriceps set etc. These exercises are recommended after an internal bleed occurs and on a daily basis to strengthen the muscles and joints to prevent new bleeding problems.
Wednesday, December 19, 2007
Treatment of Haemophilia
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