Researchers Cure Bubble Boy Disease with Gene Therapy that Involved Using HIV

St. Jude Children’s Research Hospital shows 2-year-old Gael Jesus Pino Alva at the hospital in Memphis. Gael was one of eight babies with “bubble boy disease” who have had it corrected by gene therapy that ironi

St. Jude Children’s Research Hospital shows 2-year-old Gael Jesus Pino Alva at the hospital in Memphis. Gael was one of eight babies with “bubble boy disease” who have had it corrected by gene therapy that ironi

Bubble boy disease, formally known as X-linked severe combined immunodeficiency or SCID-X1, is a rare genetic defect that leaves the baby defenseless against infection. In one famous case, a boy with SCID, David Vetter, lived in a sterile plastic "bubble" until his death at age 12 - hence the disease's nickname.

Three to four months later, seven of the babies were producing multiple types of normal immune cells, including some that had never been produced before in X-SCID patients treated with gene therapy.

That prepared them to rebuild healthy ones from corrected copies of the mutated gene that caused X-SCID, which the researchers inserted into the babies' blood-forming stem cells using an inactive virus.

The study, published April 18 in the New England Journal of Medicine, reports on the condition of the first eight infants treated with this new procedure.

Dr Ewelina Mamcarz of St Jude, an author of the study, said in a statement: "These patients are toddlers now, who are responding to vaccinations and have immune systems to make all immune cells they need for protection from infections as they explore the world and live normal lives".

Currently, the best treatment for SCID-XI is a bone marrow transplant with a tissue-matched sibling donor. But only one-fifth of babies have such donors. So far, no lasting or serious effects have been observed in the babies.

Each human cell has about 25,000 genes, and each gene's DNA sequence contains instructions on how to build certain enzymes and proteins, each of which has a specific job.

The idea of gene therapy is to introduce, remove or change the genetic material in cells to treat a specific disease.

The "correct" gene - used to fix the defect - was inserted into an altered version of one of HIV, the virus that causes AIDS.

Previous gene therapy approaches have been developed to provide alternatives to bone marrow transplants, but the therapies sometimes need to be accompanied by chemotherapy and have been associated with the development of other illnesses including metabolic syndrome and blood disorders such as thalassemia and sickle cell anemia. (The eighth baby produced a healthy immune response after another dose of gene therapy, researchers report.) numerous babies' preexisting infections also cleared.

Most patients were discharged from the hospital within one month.

Health officials investigating case of confirmed 'travel-related' measles in York Region
Public Health is advising people to avoid going to a clinic, hospital or physican's office before calling their facility. The state of Iowa requires students to have two MMR vaccinations to attend school.

"The outcomes have been truly outstanding for our patients", Dr Mamcarz said.

Importantly, she said, patients did not require ongoing treatment, as is often required with other therapies, and no patients had developed leukaemia - a side effect of previous trials.

A study out Wednesday details how scientists turned this enemy virus into a savior, altering it so it couldn't cause disease and then using it to deliver a gene the boys lacked. "So there is right now no early evidence of even a premalignant state in the patients we have treated so far".

Such donations can improve patients' health, but they often can't produce full immunity, the NIH says - which is why gene therapy has seemed so promising.

Charlotte Cunningham-Rundles, MD, PhD, a clinical immunologist at Mount Sinai Hospital in New York City who was not involved in the trial, agreed. None has developed a life-threatening infection since receiving gene therapy, an indication of treatment effectiveness.

It will take some years before researchers know for sure whether the therapy is effective in the long term. The companion NIH trial evaluating the gene therapy in older children and young adults also is continuing to enroll participants.

"In addition to the newly diagnosed infants with XSCID, we believe there are hundreds of patients with the disease who have been treated with hematopoietic stem cell transplantation, but who are experiencing decreasing T cell immunity and increasing incidence of infections". "They are all toddlers now, exploring life, attending daycare, and this part has been extremely rewarding".

The doctors said they have skirted the leukemia problem by implanting "insulators" around the replaced gene, preventing the treatment from accidentally activating adjacent genes and causing cancer.

The results are preliminary, and more research is needed - as is long-term follow-up of the existing patients. The experimental gene therapy was safe overall, according to the researchers, although some participants experienced expected side effects such as a low platelet count following chemotherapy. "Now they have their whole lives ahead of them".

"This is an very bad disease and treating these children young is important".

Recommended News

We are pleased to provide this opportunity to share information, experiences and observations about what's in the news.
Some of the comments may be reprinted elsewhere in the site or in the newspaper.
Thank you for taking the time to offer your thoughts.