Two women whose hearts were severely damaged by Chagas' disease (see Box) showed remarkable recovery three months after stem cells from their own bone marrow were transplanted into their heart. Dr. Lilian Joensen reports
Chagas disease is caused by the protozoan parasite Trypanosoma cruzi (T. cruzi), which enters the body through broken skin. These can be introduced by infected blood-sucking 'Assassin bugs' (which live in the cracks and crevices of poor-quality houses in rural areas), through transfusion with infected blood, or transmitted from infected mother to foetus. Usually a small sore develops where the parasite enters. Within a few days, fever and swollen lymph nodes may develop. This acute phase may cause illness and death, especially in young children. More commonly, the patients enter phase without symptoms, lasting several months or years, during which time the parasites invade most organs of the body, often causing damage to the heart, intestine and oesophagus, and progressive weakness. About 32% of those infected die from organ damages during the chronic phase.
The geographical distribution of the human T. cruzi infection extends from Mexico to the South of Argentina. The disease affects 16-18 million people and some 100 million, i.e. about 25% of the population of Latin America is at risk of acquiring Chagas disease.
In Argentina there are 2 300 000 people who contracted Chagas' disease, and at least 40 000 of them suffer from severe heart problems as a consequence of the disease.
The new treatment on the two patients from San Juan Province offers much hope.
So much so that the Secretariat of Science, Technology and Productive Innovation (SeCyT) has contributed 1 200 000 pesos to a group of local medical doctors directed by Dr. Jorge Carlos Traianini at Presidente Perón Hospital in Avellaneda (Buenos Aires Province), so they can treat 50 more patients from all over the country.
Dr. Rubén Carrizo Páez, Chief of the Chagas Programme in Rawson Hospital in San Juan Province, could not believe his eyes when he saw one of his patients coming towards him. It was the same woman, who three months before, had to stop several times just to walk 300 metres to take the bus. But now, she was arriving by bike, after 5 kms of pedalling, and with no evidence of over-exertion.
The 51 year-old patient, and another woman, a year younger with the same disease, are the only two Argentineans on whom the revolutionary therapy has been tried. This therapy promises to return the hearts of people with this disease to their full vigour and capacity to contract and deliver blood properly to the body.
The therapy involves 'autologous' transplant (where the donor is also the recipient) of stem cells from the bone marrow. The cells are delivered to the walls of the heart through a catheter to the coronary artery, where, after 50 minutes, the cells start to find their way to the areas that are most fibrous and scarred, to repair the damage. It looks like magic, but it is not.
This new treatment was initiated by Dr. Jorge Carlos Traianini, Chief of the Service of Cardiosurgery of Presidente Perón's Hospital in Buenos Aires Province, who, together with his team, co-ordinated by Dr. Noemí Lagos, have already performed 33 transplants of different kinds of stem and myoblast cells (muscle precursor cells) to severe cardiac lesions, including infarcts of long standing, with remarkable recovery of cardiovascular function.
The new clinical trials involving 50 patients from all over the country, if successful, will make the treatment generally available to patients in no more than two and a half years. The intention is to make the treatment available at a cost as low as U$S 500.
"In reality, we don't know why these stem cells help the heart muscles to work better," said Dr. Lagos. "It is possible that new blood vessels are generated and also new muscle cells, but it is not clear. Our aim is to be able to know the intrinsic mechanisms of how this happens. But for now the clinical results overcome all known explanations".
Dr. Traianini added that, contrary to the traditional concept that the heart was an organ incapable of regeneration, the results show the opposite is the case; these new therapies take maximal advantage of this auto-repairing ability of the heart.
Article first published 13/01/05
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