AIMP1 Blood Levels Might Indicate Disease Severity in AAV Patients, Study Reveals

People with ANCA-associated vasculitis who have high levels of a protein called aminoacyl-tRNA synthetase-interacting multifunctional protein-1 (AIMP1) in their blood serum might be at higher risk of developing a severe form of the disease, a study has found.

The study, “Serum Aminoacyl-tRNA Synthetase-Interacting Multifunctional Protein-1 Can Predict Severe Antineutrophil Cytoplasmic Antibody-Associated Vasculitis: A Pilot Monocentric Study,” was published in the journal BioMed Research International.

Anti-neutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis is a group of autoimmune diseases characterized by inflammation and damage to small blood vessels, triggered by uncontrolled production of ANCA autoantibodies.

Inflammatory factors often are used as surrogate markers of disease activity  in clinical practice, but there is still no reliable biomarker for AAV patients.

AIMP1 is a protein that regulates the secretion of inflammatory molecules and could play a role in the development of this autoimmune disease. The protein has shown potential as a biomarker for rheumatoid arthritis and systemic lupus erythematosus (SLE), but no studies have addressed its clinical association with ANCA-associated vasculitis.

Now, researchers in Korea investigated whether blood levels of AIMP1 correlated with disease severity, as assessed using the Birmingham vasculitis activity score (BVAS).

The study enrolled 61 patients from the prospective Severance Hospital ANCA-associated VasculitidEs (SHAVE) group. Each patient was evaluated according to the BVAS index to determine disease severity and underwent laboratory tests to assess the levels of AIMP1.

Overall, 20 patients had severe ANCA-associated vasculitis. They more frequently experienced symptoms in the kidney, increased levels of ANCAs, higher neutrophil count, and higher BVAS scores than their non-severe counterparts (41 patients).

Patients with the severe form of the disease also had significantly higher levels of AIMP1; statistical analyses showed that high levels of the protein were associated with disease severity. AIMP1 was the only molecule in the blood serum that showed this association. Therefore, it could serve as an independent marker of disease severity, the researchers said.

“This study has a strength in that it is the first demonstration of the clinical value of serum AIMP1 as a marker for cross-sectional analyses of severe and nonsevere [ANCA-associated vasculitis] cases,” they added.

Future studies, including more patients and comparing the levels of AIMP1 in ANCA-associated vasculitis patients to those of healthy people and patients with other autoimmune diseases, should further validate these findings.