Tissue engineered trachea, 5 years on...
What happened to the lady given a laboratory-grown trachea 5 years ago?
This week, writing in the Lancet, the team who re-grew a replacement windpipe for a woman with severe respiratory complications caused by tuberculosis, have reported on her long-term outcome.
The patient, Claudia Castillo, who was 30 at the time of her surgery, was the world's first recipient of a "new" trachea grown using tissue engineering.
What Karolinska Institute scientist Paolo Macchiarini did in 2008 was to use detergent to "decellularise" - remove all of the cells from - a trachea obtained from a donor patient who had died of a stroke.
The removal of the donor cells left behind just a scaffold of connective tissue, to which the team added stem cells collected from Castillo's bone marrow and airway-lining cells collected from her nose.
Incubated in a bioreactor, the cells completely repopulated the connective tissue, resulting in a genetically compatible replacement trachea, which was implanted a few days later.
The woman made a rapid recovery and left hospital shortly afterwards, but has been followed-up regularly ever since, using CT, bronchoscopy and biopsy tests every 3-6 months.
Now, the researchers have published the long-term results of this first-of-a-kind therapy. They confirm that the woman's graft tissue remains healthy and, critically, there has been no evidence of tumour formation, which is a major concern where stem cell therapies are concerned.
The woman has also shown no evidence of an immune response to the donor tissue and enjoys a normal work and social life. She has, however, experienced a repeated narrowing in part of her airway, but not within the region replaced by the graft.
"These clinical results," the team conclude, "provide evidence that a tissue-engineering strategy including decellularisation of a human trachea... is safe and promising."