PID Treatment

What is gene therapy?

In its current available form, Gene Therapy (GT) is an experimental therapy that aims to replace the defective gene with a copy of the healthy gene. This allows the cell to start producing normal protein in hopes of curing the disease. Scientists have found that one of the most efficient ways to introduce the corrected gene into the cell is to use modified viruses. Scientists first inactivate the virus so that it cannot produce disease and then "load" it with the "normal gene"(for example, the WASP Gene in the case of WAS). These "loaded" viruses, referred to as "vectors", are then used to introduce the normal gene into the patient.

Because gene therapy is experimental, it only occurs at a few hospitals in the world. Patients are required to be enrolled on a research study to receive this treatment. Your doctor can help you in determining if you / your child are eligible for a research study. All research studies, including those involving gene therapy, are required to be registered before they begin on a publicly accessible website. The most common website is ClinicalTrials.gov. You can go to this website and search the name of your / your child’s condition along with gene therapy to see what trials may be available. Gene therapy trials for Wiskott-Aldrich Syndrome, Chronic Granulomatous Disease, ADA SCID and XSCID are ongoing.

What happens during GT?

The following are the four basic steps of gene therapy.

  1. The vector is prepared and loaded with the normal gene, in preparation for introduction into the patient.
  2. Doctors collect blood-forming stem cells from the patient's bone marrow or the blood. These cells are then grown in large numbers outside the body. Next, these cells are mixed with the vector. The virus infects these cells, converting them to repaired cells.
  3. The patient is then given chemotherapy, in preparation for GT. This helps make space in the marrow for the repaired cells to multiply and to make sure that the patient’s body does not reject the repaired cells.
  4. The repaired cells are now introduced into the patient in a process similar to blood transfusion.

These repaired cells then continue to multiply, forming more numbers of normal cells. Over time, the repaired cells should produce enough to cure the patient.