SCID Article

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This is off Medscape's web site.

Severe Combined Immunodeficiency Corrected by Gene Therapy

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WESTPORT, Apr 28 (Reuters Health) - Gene therapy has successfully restored

the immune systems of two children with severe combined immunodeficiency-X1

(SCID-X1), according to a report in the April 28th issue of Science.

Dr. Alain Fischer, of Hopital Necker, in Paris, France, and colleagues note

that the underlying cause of SCID-X1 is mutation of the gene for the gamma-c

cytokine receptor subunit, which prevents the differentiation of lymphoid

progenitors into T and NK cells. The investigators transfected CD34+ cells

from the patients ex vivo with a normal gamma-c gene sequence, and then

reinfused the cells.

Within 15 days of the infusion, the researchers detected peripheral blood

mononuclear cells that contained the normal gene. After 10 months of

follow-up, the two patients had normal levels of T, B and NK cells for their

age.

" As a likely consequence of development and sustained function of the immune

system, clinical improvement was observed in both patients, " the authors

write. About 3 months after undergoing gene therapy, both patients left their

sterile protective environment and are growing and developing normally,

according to the report. Another patient is also doing well 4 months after

gene therapy.

The researchers conclude that " these results pave the way for a possible

extension of this therapeutic approach to other genetic diseases

characterized by defective cell-subset generation, such as other forms of

SCID. " However, they note that follow-up is needed to evaluate the long-term

effects of the therapy.

The results indicate that gene therapy still holds much promise, despite some

early setbacks, according to Dr. W. French , of the University of

Southern California in Los Angeles. In an editorial that accompanies the

study, Dr. says, " no other area of medicine holds as much promise

for providing cures for the many devastating diseases that now ravage

humankind. "

Science 2000;288:627-629,669-672.