Association of transferrin levels with clinical outcomes in ANCA-associated vasculitis

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a rare autoimmune disease characterized by ANCA production and inflammation of small blood vessels, leading to multi-organ involvement. Given systemic inflammation is a feature of AAV, inflammation related proteins may reflect disease status. Transferrin (Tf), a negative acute phase protein, decreases during inflammation, however, its association with AAV activity and clinical outcomes remains unclear.

A total of 261 participants were included. All data were extracted from the electronic medical records, and follow-up data were recorded over a two-year period.

Our results showed that serum Tf levels were significantly reduced in AAV, especially in patients with active disease compared with those in remission (P < 0.0001). Receiver operating characteristic (ROC) analysis identified Tf cut-off values of 194 mg/dL for discriminating active from remission AAV and 259.5 mg/dL for distinguishing remission AAV from healthy controls (P < 0.0001). Serum Tf levels were significantly correlated with inflammatory markers, renal function parameters, Birmingham vasculitis activity score (BVAS), and iron metabolism indicators. Regarding treatment and prognosis, serum Tf levels were negatively correlated with patients' maximum daily glucocorticoid dose (P = 0.0026). In multivariable Cox regression analysis, serum Tf levels independently predicted two-year mortality risk and disease remission.

Our results indicate that serum Tf levels are decreased in patients with AAV and are associated with adverse adverse clinical outcomes. Key Points • Transferrin levels reflect inflammation and disease activity in ANCA-associated vasculitis. • Low transferrin levels indicate poor prognosis in patients with ANCA-associated vasculitis.