Soluble Tyro-3 and Axl may reflect the current activity and renal involvement in patients with microscopic...

Area of Science:

• Immunology
• Nephrology
• Rheumatology

Background:

• Microscopic polyangiitis (MPA) and granulomatosis with polyangiitis (GPA) are severe forms of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV).
• Accurate assessment of current disease activity and organ involvement is crucial for effective management of MPA and GPA.
• Soluble forms of Tyro-3, Axl, and Mer receptor tyrosine kinases (sTyro-3, sAxl, sMer) are implicated in immune regulation and inflammation.

Purpose of the Study:

• To investigate the potential of serum sTyro-3, sAxl, and sMer levels to reflect current disease activity in MPA and GPA patients.
• To determine if these soluble biomarkers correlate with specific disease indices and organ involvement, particularly renal manifestations.

Main Methods:

• Retrospective review of 76 patients diagnosed with MPA or GPA.
• Measurement of serum sTyro-3, sAxl, and sMer concentrations at diagnosis.
• Correlation analysis with established AAV activity indices: Birmingham Vasculitis Activity Score (BVAS), Five-Factor Score, SF-36, and Vasculitis Damage Index. High activity defined as highest BVAS tertile.

Main Results:

• Serum concentrations of sTyro-3 and sAxl significantly correlated with BVAS and renal manifestation scores.
• sTyro-3 and sAxl levels independently predicted BVAS scores (β=0.343 and β=0.310, respectively).
• sTyro-3 and sAxl were independently associated with renal involvement in MPA and GPA (OR 1.003 and OR 1.055, respectively).

Conclusions:

• Serum sTyro-3 and sAxl levels show potential as biomarkers reflecting current disease activity in MPA and GPA.
• These markers are associated with both systemic disease activity (BVAS) and specific organ damage (renal involvement).
• Further prospective studies are warranted to validate sTyro-3 and sAxl as reliable clinical tools for AAV management.