Serum Amyloid A Is a Biomarker of Disease Activity and Health-Related Quality-of-Life in Patients with Antineutrophil Cytoplasmic Antibody-Associated Vasculitis.

Taejun Yoon,Sang-Won Lee,Yong-Beom Park,Sung Soo Ahn,Jason Jungsik Song,Juyoung Yoo,Paolo Cameli

doi:10.1155/2020/8847306

Abstract

Serum amyloid A (SAA) is one of the acute phase proteins synthesized in hepatocytes and secreted by various inflammation or infectious stimuli. We investigated the clinical implication of measuring SAA in patients with antineutrophil cytoplasmic antibody- (ANCA-) associated vasculitis (AAV). Seventy-five patients who had been classified as AAV and enrolled in our prospective observational cohort for AAV patients were included. Clinical and laboratory data were obtained on the day of blood sampling, and SAA was measured by ELISA kits. Birmingham Vasculitis Activity Score (BVAS) and Short-Form 36-Item Health Survey (SF-36) were assessed for disease activity and health-related quality-of-life (HRQoL) measures. We stratified patients into having high BVAS when the BVAS was over the median values, and those with either low SF-36 PCS or low SF-36 MCS were defined as having poor HRQoL. Multivariate logistic regression analysis was conducted to estimate independent predictors of high BVAS. The relative risk (RR) was analyzed using the contingency tables and the chi-squared test. SAA was positively correlated with BVAS (r = 0.642) and FFS (r = 0.367) and was inversely correlated with both the SF-36 physical component summary (r = −0.456) and mental component summary scores (r = −0.394). Furthermore, SAA was significantly correlated with acute phase reactants ESR (r = 0.611) and CRP (r = 0.629). Patients with high BVAS exhibited significantly higher SAA than those with low BVAS (1317.1 ng/mL vs. 423.1 ng/mL). In multivariable logistic regression analysis, serum albumin (odds ratio (OR) 0.132) and SAA > 1173.6 ng/mL (OR 15.132) were independently associated with high BVAS. The risk of having high BVAS and poor HRQoL in patients with SAA > 1173.6 ng/mL was higher than in those with SAA ≤ 1173.6 ng/mL (RR 3.419 and 1.493). Our results suggest that SAA might be a useful biomarker in assessing disease activity and HRQoL in AAV.

Highlights

Antineutrophil cytoplasmic antibody- (ANCA-) associated vasculitis (AAV) is a group of the systemic vasculitides affecting small vessels such as microscopic polyangiitis (MPA), granulomatosis with polyangiitis (GPA), and eosinophilic granulomatosis with polyangiitis (EGPA), which exhibit necrotizing vasculitis in arterioles, capillaries, and venules [1]
We have demonstrated the clinical significance of several AAV activityrelated indices consisting of serum concentrations of endogenous proteins or equations of laboratory data for predicting the cross-sectional activity of AAV based on Birmingham Vasculitis Activity Score (BVAS) [6, 7]
The clinical utility of these indices may not exceed that of BVAS, owing to the paucity of reliable biomarkers available, it is meaningful to search for novel markers that hold clinical implications in AAV which are expected to possess a complementary role in assessing AAV activity

Summary

Introduction

Antineutrophil cytoplasmic antibody- (ANCA-) associated vasculitis (AAV) is a group of the systemic vasculitides affecting small vessels such as microscopic polyangiitis (MPA), granulomatosis with polyangiitis (GPA), and eosinophilic granulomatosis with polyangiitis (EGPA), which exhibit necrotizing vasculitis in arterioles, capillaries, and venules [1]. EGPA is composed of 3 phases such as allergic, Disease Markers eosinophilic, and vasculitis phases and is characterized by asthma, sinusitis, peripheral eosinophilia, eosinophil infiltration, and organ damages in lungs and nerves [3]. Since BVAS covers a wide range of nine systemic categories with differently weighted scores based on the severity of each symptom, it has been considered the most reliable tool to assess AAV activity to date [5]. The clinical utility of these indices may not exceed that of BVAS, owing to the paucity of reliable biomarkers available, it is meaningful to search for novel markers that hold clinical implications in AAV which are expected to possess a complementary role in assessing AAV activity

Methods

Results

Conclusion