SAT0547 Prognostic nutritional index for estimating birmingham vasculitis activity score in anca-associated vasculitis

Abstract

BackgroundThe prognostic nutritional index (PNI), which was first introduced by Onodera et al., is calculated based on the serum albumin level and total lymphocyte count in the peripheral blood. It is proposed to be a parameter to reflect immunonutritional status, however, it is also known that albumin and lymphocyte count may decrease in proportion to inflammatory burdens in autoimmune diseases.ObjectivesWe investigated whether PNI at diagnosis can be used for estimating BVAS at diagnosis in antineutrophil cytoplasmic antibody (ANCA) associated vasculitis (AAV) patients.MethodsWe retrospectively reviewed the medical records of 160 patients with AAV. We calculated Birmingham vasculitis activity score (BVAS). We collected laboratory results including erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), while blood cell, lymphocyte and platelet counts and serum albumin. Prognostic nutritional index (PNI) was calculated by (10 x serum albumin (g/dl)+0.005 x lymphocyte count (/mm3)). The association was assessed linear regression analyses. The optimal cut-off of PNI for predicting relapse was set at 36.6. Comparison of cumulative relapse free survival was analysed by the Kaplan-Meier survival analysis.ResultsThe mean age at diagnosis was 55.2 years and 48 patients were male. Eighty-five patients had MPA, 41 patients had GPA and 34 patients had EGPA. The mean BVAS and PNI at diagnosis were 11.9 and 43.4. Forty-three patients experienced relapse of AAV. In univariable linear regression analysis, BVAS was positively correlated with ESR and CRP and was negatively correlated with lymphocyte count, serum albumin level and PNI. In multivariable analysis, BVAS was the most significantly associated with only PNI (standardised β=−0.296). Patients having PNI at diagnosis ≤36.6 exhibited significantly lower cumulative relapse free survival rate than those having PNI at diagnosis >36.6 (p=0.002).Abstract SAT0547 – Table 3Univariable linear regression analysis of BVAS and continuous variables in 160 patients with AAVUnivariable analysis RegressionCoefficient(Crude B)CorrelationCoefficient(R=β)p value Demographic data at diagnosis Age (year old)0.0270.0530.504Acute reactants at diagnosis ESR (mm/hr)0.0440.2180.006 CRP (mg/L)0.0230.1690.033Laboratory results reflecting inflammation at diagnosis White blood cell count (/mm3)0.0000.1040.189 Lymphocyte count (/mm3)−0.002−0.2140.007 Platelet count (x1,000/mm3)0.0030.0600.449 Serum albumin (g/dL)−2.557−0.2620.001PNI−0.252−0.307<0.001BVAS: Birmingham vasculitis activity score; ANCA: antineutrophil cytoplasmic antibody; AAV: ANCA associated vasculitis; ESR: erythrocyte sedimentation rate; CRP: C-reactive protein; PNI: prognostic nutritional index.Abstract SAT0547 – Figure 2The association of PNI at diagnosis with relapse of AAV during the follow-up. We selected the optimal cut-off of PNI at 36.6, divided patients into two groups according to the cut-off and conducted Kaplan-Meier survival analysis. Patients having PNI at diagnosis ≤36.6 exhibited significantly lower cumulative re...