Treatment

Though there is no cure for haemophilia, it can be controlled with regular injections 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 Troy.

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.

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.

Date: 2015-01-12; view: 595