NEW YORK, Oct 04 (Reuters Health) -- High doses of chemotherapy followed by stem cell transplantation might help some patients with severe, drug-resistant rheumatoid arthritis (RA), according to researchers who for the first time used the radical procedure to treat RA.
Unlike the more common osteoarthritis, in which damage to joints causes stiffness and pain, RA is an autoimmune disease. The immune system attacks the joints, resulting in chronic inflammation, tenderness and pain; if the disease progresses to its severe stage, it erodes the joints, weakens surrounding muscles, and can be disabling.
The patient, a 39-year-old man, suffered from severe joint deterioration, had undergone total hip replacement and had failed to respond to standard RA therapy. Their patient's identical twin brother donated stem cells, the primitive cells of the body that give rise to more complex cells, including immune cells.
Two years after the chemotherapy-transplant regimen, the man swims, bikes and has no joint pain or other arthritis symptoms, his physicians report in the October 5th issue of the Annals of Internal Medicine. Dr. Ian Wicks of the Royal Melbourne Hospital in Victoria, Australia, led the experimental procedure.
In an effort to stop the man's abnormal immune response, Wicks' team used high doses of chemotherapy to effectively wipe out his immune system, then rebuilt it using his twin's stem cells. Because stem cells generate the T cells that lead the immune-system attack, the researchers hoped the transplant would allow their patient to adopt his brother's healthy immune system.
Before the procedure, Wicks and colleagues found that the patient and his twin had "T cell repertoires" that were similar but had certain genetic differences. Sixteen weeks after receiving the new stem cells, however, the man's T cell repertoire was "almost identical" to his brother's. This adoption of his twin's immune system is the "most likely explanation for his profound clinical response," the researchers concluded.
They were, however, cautious about their results, noting only that this treatment benefits people with "treatment-resistant autoimmune disease who have an identical, disease-free twin." Chemotherapy, typically used against cancer, carries side effects such as nausea, vomiting and severe fatigue; and any transplant poses the risk of rejection. In this case, the patient suffered from temporary fever and skin rash after the transplant.
RA affects about 2 million Americans, including children, according to the Arthritis Foundation in Atlanta. There is no cure, but anti-rheumatic drugs can often relieve pain and inflammation and halt the progression of the disease.
