Serum Progranulin as a Potential Marker for Disease Activity and Thrombotic Events in Patients with Antineutrophil Cytoplasmic Antibody-Associated Vasculitis.

OBJECTIVE

Progranulin (PGRN) is a secreted glycoprotein that can have pro-inflammatory or anti-inflammatory effects, depending on the disease. The serum and urinary levels and mechanism of action of PGRN in antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) are unclear.

METHODS

Thirty patients with active AAV were enrolled from May 2022 to May 2024; 28 were myeloperoxidase-positive, and two were proteinase 3-positive. A healthy control cohort consisted of five male and five female volunteers. Age, gender, AAV subtype, and laboratory data were collected. Using an enzyme-linked immunosorbent assay, Whole blood and urine samples were collected for measurements of PGRN.

RESULTS

The median patient age was 69.0 years (range: 58.8-75.5); 56.7% of them were female, and 94.3% of them were MPO-ANCA-positive. Compared with healthy controls, the AAV patients had higher serum PGRN levels (52.0±30.9 vs. 3.3±1.7 ng/mL, P<0.05) and lower urinary PGRN levels. The serum PGRN level also had a positive correlation with the Birmingham vasculitis activity score (r=0.776, P<0.001), and moderate positive correlations with coagulation-related parameters (activated partial thromboplastin time, fibrin degradation products, and D-dimer). Patients who subsequently developed thrombotic events had higher serum PGRN levels than those without thrombotic events.

CONCLUSION

The serum PGRN level was associated with disease activity and coagulation abnormalities in patients with active AAV, particularly in those with MPO-ANCA positivity. Although serum PGRN had a positive association with thrombotic events, its elevation may be influenced by renal dysfunction and systemic inflammation. Therefore, serum PGRN may serve as an activity-related biomarker rather than a disease-specific marker in AAV.