Specific Antibody in Blood May Be Biomarker of Kidney Disease in Lupus Patients

The presence of anti-ficolin-3 antibodies could be a biomarker to diagnose active lupus disease with kidney involvement, according to a study published in the journal Plos One.

Ficolin-3 is important in the context of auto-immunity because it was first characterized in the blood of lupus patients as a target of autoantibodies. But the significance of this observation has, to date, not been investigated in detail.

Researchers led by Dr. Chantal Dumestre-Pérard, of Université Grenoble Alpes in France, analyzed blood samples from 165 lupus patients and 48 healthy controls, and determined the levels of anti-ficolin-3 antibodies.

They found a highly significant difference in the levels of anti-ficolin-3 antibodies between the two groups, with antibodies detected in the blood of 56 (34%) of the lupus patients. Importantly, the team saw that levels of anti-ficolin-3 antibodies were significantly higher in lupus patients with active disease and lupus nephritis (kidney inflammation) than in patients with active disease but no kidney involvement.

To determine disease activity, researchers used the SLEDAI (systemic lupus erythematosus disease activity index score), which assesses clinical manifestations across an array of measures: seizure, psychosis, decreased mental function and other neurological problems, visual disturbance, hair loss, rash, muscle weakness, arthritis, blood vessel inflammation, mouth sores, chest pain that gets worse with deep breathing, inflammation of the pleura (tissue protecting the lungs) and pericardium (membrane surrounding the heart) and fever. They also looked laboratory results of tests given, including urine analysis, blood complement levels, anti-DNA antibody levels, and platelet and white blood cell counts.

The researchers found that the levels of anti-ficolin-3 antibodies correlated with SLEDAI scores. In other words, the higher the level of anti-ficolin-3 antibodies in a patient, the higher that patient’s SLEDAI score.

They concluded in their study, “Association between the Presence of Autoantibodies Targeting Ficolin-3 and Active Nephritis in Patients with Systemic Lupus Erythematosus,” that anti-ficolin-3 antibodies could be useful in helping to diagnose active nephritis in lupus patients, but suggest that further studies are needed to confirm the diagnostic value of this potential biomarker.

Lupus is characterized by the presence of autoantibodies in the blood that attack a patient’s own tissues and organs, resulting in systemic inflammation and damage.