KFAR-SABA, Israel—A laminin peptide previously shown to be the target for autoantibody binding and thought to contribute to renal damage in a mouse model of systemic lupus nephritis is also a target for antibodies in the sera of human systemic lupus erythematosus (SLE) patients. Antibodies against the VRT101 laminin epitope also correlate with human SLE disease activity and can be removed from blood by extracorporeal immunoadsorption without significantly reducing total immunoglobulin levels, Howard Amital, MD, MHA, and colleagues report in Rheumatology.¹

"Anti-VRT101 antibodies are abundantly detected in the serum of patients with SLE and correlate with disease activity. Specific removal of serum anti-VRT101 by extracorporeal plasmapheresis with specific immunoadsorption on the VRT101-coupled sepharose columns may serve as a new therapeutic tool for specific immunoadsorption of pathogenic antibodies in SLE patients," writes Dr. Amital, department head of medicine at Meir Medical Center, in Kfar-Saba, Israel.

The researchers measured anti-VRT101 reactivity and antidouble stranded DNA (dsDNA) reactivity in the serum of patients with lupus and other rheumatic disorders as well as in the serum of healthy controls. They used the SLE Disease Activity Index (SLEDAI)-2k to measure lupus disease activity and special sepharose columns to remove the anti-VRT101 antibodies. Safety of this approach was also tested in normal sheep.

"[A]ntilaminin antibodies may have a prominent role in the induction of lupus nephritis; although some of these antibodies cross-react with DNA, we have shown by immunoadsorption that the affinity of these antibodies to a laminin-derived peptide designated VRT101 is distinct and independent. These results set a profound basis for a clinical trial assessing the efficacy of extracorporeal-specific immunoadsorption of antilaminin antibodies in patients with lupus nephritis," Dr. Amital concludes.

Reference