Serum TNF-α Level Is Associated with Disease Severity in Adult Patients with Immunoglobulin A Vasculitis Nephritis

Abstract

Background. Tumor necrosis factor-α (TNF-α) is a proinflammatory factor involved in the pathogenesis of immunoglobulin A vasculitis (IgAV). The association between serum TNF-α and disease severity in adult patients with IgAV nephritis (IgAV-N) has been inadequately evaluated. Methods. Serum TNF-α was measured by chemiluminescence immunoassay in 53 renal biopsy-proved IgAV-N patients, 53 healthy controls, and 53 IgA nephropathy (IgAN) patients. The correlations of clinicopathologic parameters of IgAV-N patients with serum TNF-α were analyzed. Results. In this cross-sectional study, the median age of IgAV-N patients was 29 (25-37) years, and 67.9% were female. Serum TNF-α was significantly higher in the IgAV-N group than in the healthy group [7.4 (5.7-9.4) pg/mL vs. 5.9 (5.0, 7.1) pg/mL, $P=0.001$ ], but comparable with sex, age, and estimated glomerular filtration rate (eGFR) grade-matched IgAN patients. Serum creatinine ( $P=0.006$ ) and serum cystatin C ( $P=0.001$ ) were positively correlated with serum TNF-α level, while albumin ( $P=0.014$ ) and eGFR ( $P=0.021$ ) were negatively correlated with serum TNF-α level. Multivariate linear regression analysis revealed that eGFR ( $P=0.007$ ) was an independent clinical predictor of serum TNF-α. Patients with higher pathological classification grade also had higher serum TNF-α. Conclusions. Serum TNF-α is associated with renal function and the pathological classification of adult patients with IgAV-N. TNF-α is a potential biomarker for the assessment of IgAV-N severity.