There is an adage saying that sometimes when good things are done, bad things happen. In the case of hemophilia, a counter reply could be that when bad things occur, sometimes good things happen. Recalling the dark days of the early 1980s, the days when HIV and hepatitis-contaminated AHF concentrates leading to premature death, there is a remarkable contrast with the present treatment of hemophilia that has been emerged over the past thirty years. Life expectancy in hemophilia was cut short because of AIDS, the result of HIV contaminated concentrates.
In contrast, in 2011 life expectancy in hemophilia is more than sixty years and nearly approaching normal longevity. This remarkable advance came into being because of the great tragedy of AIDS. Research following the discovery of HIV has resulted in safe, deviralized plasma-derived AHF and recombinant AHF. Since the beginning of their use as FVIII and FIX replacement treatment there have been no instances of virally transmitted diseases from AHF concentrates. The safety and dependability of these products has allowed children to progress without deformities or suffering from agonizing painful joint bleeds. The threat of intracranial hemorrhage, that claimed the lives of children in the past, has been greatly reduced.
Although the development of recombinant AHF was complex, the experience has been valuable in preparation for the next generation of treatment modalities. Added to this experience has been the discovery of the nature of the retrovirus, HIV. The acquired knowledge is now being applied to the development of gene transfer to hopefully cure, not just treat, hemophilia. When gene transfer becomes successful in the treatment of hemophilia, rather than AFH infusions every two or three days, a person would require an injection treatment only every four or five years or maybe even only once in their lifetime. Hemophilia is regarded as a model system for developing the strategies for the treatment of genetic disorders.
Researchers have developed adeno-associated viral vectors that transfer the inserted FIX gene into the muscles of mice and canines as well myotube cultures of human muscle cells resulting in the production of human Factor IX. After discovering that some mutations in hemophilia are the result of transposons, segments of DNA that jump around or are transposed, attempts are under way to insert the FIX gene into a transposon to deliver the transposed gene to cells that could make FIX. Hemophilia research has advance because there are model animals, mice and canines, for experimentation before applying the developed methods to humans.
Although there are hurdles to jump in the pathway to curing hemophilia by gene transfer, for FVIII and FIX, the progress made so far is exciting and appears to be as likely to make as great a change in hemophilia care within the next thirty years as was witnessed in the last thirty years.
Although infection with hepatitis and HIV were tragic events in the past treatment of hemophilia, they were the impetus that spurred progress in new treatment modalities. The memories of those who died will be brightened when gene transfer becomes a reality and hemophilia is cured.