Michael Jordan, MD.

Michael Jordan, MD

Abatacept, a drug already approved for treating rheumatoid arthritis (RA), has shown promise in treating children with LRBA deficiency, a debilitating genetic immune disorder.

Michael Jordan, MD, Division of Immunobiology at Cincinnati Children’s, was senior author of the study, which involved researchers from around the country. The findings were reported in the July 2015 issue of Science.

Lipopolysaccharide-responsive     beige-like anchor (LRBA), is a gene essential for the normal function of the immune system. Mutations in the gene cause immunodeficiencies and autoimmune disorders, including one known as common variable immunodeficiency (CVID).

For the study, six patients with CVID took abatacept for periods up to eight years. The study found, “... patients with LRBA deficiency manifested a dramatic and sustained improvement in response to abatacept.”

Abatacept appeared to regulate the inhibitory immune receptor CTLA4. Normally, CTLA4 is expressed on the cell surface, where it prevents autoimmune activation. Patients with CVID cannot replace CTLA4 on the cell surface.

Because CTLA4 dysfunction is also present in RA, researchers suspected that abatacept might also work to treat LRBA deficiency. Besides improving patients’ lung disease, the drug also appeared to decrease infection risk.

Researchers plan to continue exploring the safety and effectiveness of the drug.