Predictive value of neutrophil/lymphocyte ratio in renal prognosis of patients with granulomatosis with polyangiitis.

INTRODUCTION: Granulomatosis with polyangiitis (GPA) is a rare necrotizing vasculitis, which usually involves the upper and lower respiratory systems and kidneys and often have a relapsing course. Neutrophil/lymphocyte ratio (NLR) has been shown to be a useful marker predicting not only progressive disease, but also mortality in various inflammatory diseases. We aimed to investigate the roles of NLR in predicting the extend of clinical involvement and prognosis of patients with GPA.

MATERIALS AND METHODS: Consecutive newly diagnosed GPA patients who had follow-up for at least 6 months between 2010 and 2016 at Gazi University Internal Medicine-Rheumatology clinic were retrospectively analyzed.

RESULTS: Fifty-three newly diagnosed GPA patients were studied. NLR was significantly higher in the GPA group compared with the control group (4.50 [min-max: 0.07-34.81] vs 1.77 [min-max: 1.04-2.90], respectively, p < .001). NLR significantly correlated with ESR and CRP levels (r = .40 and r = .48, respectively, p < .001 for both).

DISCUSSION: GPA is a vasculitis with a significant morbidity and mortality (REF). Renal involvement usually presents with crescentric glomerulonephritis, resulting in significant and permanent loss of renal functions and end-stage kidney disease. Higher NLR at baseline is associated with worse renal outcome. Our findings suggest that baseline NLR could have a predictive value for renal prognosis. We have also demonstrated a significant correlation between NLR and BVAS activity scores. Our data suggest that GPA patients with a significantly high NLR at baseline might need closer follow-up for persistent disease activity.