Dr Andy Ho says stem cells have not been proven safe or effective ("Why it's wise to steer clear of stem cell clinics"; last Friday).
Japan, South Korea, the United States and Hong Kong commonly practise procedures involving the transfer of stromal vascular fraction (SVF), and there have been no reported complications in medical literature.
It is well accepted that SVF has a high concentration of stem cells, which are efficacious in cosmetic surgery to improve soft tissue quality. In orthopaedics, SVF is known to improve arthritis, tendonitis and degenerative spine disease.
Dr Ho noted that neither SVF nor any other stem cell product offered at US stem cell clinics has been licensed by the Food and Drug Administration (FDA).
However, the lack of licensing does not carry a negative implication to that particular procedure.
For instance, autologous fat transplant - a commonly accepted practice in cosmetic surgery, plastic surgery and orthopaedics - is not licensed by the FDA.
Dr Ho also said one risk of SVF is pulmonary embolism, which is frequently fatal. However, it is well known that SVF transfer does not cause fatal pulmonary embolism.
Another risk is the growth of inappropriate tissues, according to Dr Ho. This is also not the case.
He added that the use of blood stem cells in treating blood cancers is safe because their use is consistent with the source tissue's properties.
But, very often, blood stem cells have to be obtained from the bone marrow of a donor, which can give rise to potentially fatal complications, such as graft versus host disease.
Dr Ho also found it unacceptable to use cells from fat - from which SVF is derived - to treat conditions in other tissues, such as the heart, brain, knee, hips, cartilage and face.
But stem cells have been known to be able to differentiate into different kinds of tissue, so are their abilities to induce healing in different kinds of tissues.
Developments in stem cell medicine have occurred rapidly in recent years. Denying such advancement in modern medicine, instead of trying to understand it, is a sad regression of our medical society.
- Joseph Wang Chi Yuan (Dr)