In the current study, based in Germany, the research team treated both children, three-year-old boys diagnosed with WAS soon after birth, by first collecting some of their hematopoietic (blood cell-forming) stem cells. They then transferred normal WAS genes into those cells and returned the cells to the boys' bloodstreams.
After treatment, the patients experienced fewer and less severe infections. Bleeding episodes decreased after platelet counts improved. Severe autoimmune anemia disappeared in one boy and severe eczema completely resolved in the other. Three years after the gene therapy, treatment-limiting adverse effects had not occurred, and the clinical benefits persisted. Significantly, the researchers reported that the treatment corrected thrombocytopenia, a hazardous and difficult-to-treat complication of WAS.
On reporting encouraging results in the first two children, the researchers noted the need to expand the study to additional patients, while conducting longer-term follow-up and analysis.
The study team found increased levels of the normal WAS protein expressed by the gene they had introduced. Orange's laboratory at Children's Hospital performed analytic imaging studies that provided evidence that the corrected immune cells were functioning normally. "Our highly quantitative imaging studies assessed natural killer cells, a critically disabled immune cell in Wiskott-Aldrich patients, and demonstrated a remarkable return to normality after gene therapy," Orange said.
Orange Translates Basic Science to Possible Immunotherapy for WAS
Orange drew on his deep background in investigating how natural killer cells function in the immune system. While a graduate student, in 1996, he discovered that natural killer cells produce cytokines, important signaling proteins, to participate in immun
|Contact: John Ascenzi|
Children's Hospital of Philadelphia