According to scientists from the National Institute of Allergy and Infectious Diseases, gene therapy can safely restore the immunity of older kids and young adults afflicted with a rare immunodeficiency disorder.
Gene therapy appeared to have benefitted SCID-X1 or X-linked severe combined immunodeficiency, a rare genetic disorder caused by IL2RG gene mutations and mostly affecting men.
SCID-X1, also referred to as “Bubble Boy disease,” prevents infection-battling immune cells from developing properly. This leaves patients highly prone to potentially fatal infections.
A genetically matched sibling can donate stem cells to a patient through hematopoietic stem cell transplantation, but those without one typically receives stem cells from a parent, only partially restoring immunity.
Those patients need lifelong therapy and are still hounded by chronic infections and other medical issues such as malnutrition, warts, and progressive gut and lung diseases.
“These patients are alive, but they suffer the long-term consequences of the partial immune reconstitution and continue to face problems,” said Dr. Suk See De Ravin, staff clinician at NIH, at a press briefing.
Dr. De Ravin and her team tested gene therapy with low-dose chemotherapy in five patients between ages seven to 24, who were struck with deteriorating immunity despite transplants from a parent. Using a lentiviral vector created in partnership with St. Jude Children’s Research Hospital, they delivered a normal gene to the cells, which were then put back into the patient after low-dose chemo.
Their findings showed that the first two patients substantially improved in immunity and clinical condition, while one remained improved three years post-treatment. But two years after the gene therapy, the second patient died of infection-induced lung damage that had existed previously.
The three remaining patients received treatment three to six months ago and are starting to show immune function improvements. The researchers are still monitoring them.
Dr. De Ravin, however, noted that gene therapy appeared to have been unable to cure existing damage in patients, as showed by one death after treatment. “This supports a need for early intervention to improve immunity before such damage occurs,” she said.
The study results are set to be presented at the 57th American Society of Hematology’s Annual Meeting in Florida.
Photo: Ken Bosma | Flickr
