Assessment of serum concentration and urinary excretion of tumor necrosis factor receptor 1 and 2 and their potential as markers of immunoglobulin A nephropathy activity.

BACKGROUND

Tumor necrosis factor receptor 1 (TNFR1) and 2 (TNFR2) can be cleaved from the cell surface and circulate alone or in combination with tumor necrosis factor alpha (TNF-α). These soluble receptors may play a key role in regulating the inflammatory response.

OBJECTIVES

The study aimed to evaluate the role of TNFRs in regulating the inflammatory response in immunoglobulin A nephropathy (IgAN).

MATERIAL AND METHODS

The study included 26 patients with newly diagnosed and biopsy-confirmed IgAN and 20 healthy controls. Study material included blood and fresh urine collected the morning before kidney biopsy and therapy. The serum concentrations of TNFR1 (STNFR1) and TNFR2 (STNFR2) and urinary excretion of TNFR1 (UTNFR1) and TNFR2 (UTNFR2) were determined with immunoassay. Subsequently, the data were evaluated statistically.

RESULTS

The STNFR1 and STNFR2 levels were higher in IgAN patients than in healthy subjects (4747.87 pg/mL and 2817.62 pg/mL compared to 2755.68 pg/mL (95% CI: from -2948.41 to -1035.97; p = 0.001) and 1437.83 pg/mL (95% CI: from -1958.50 to -419.60; p = 0.001). The power of the test was 98.5% for STNFR1 and 96% for STNFR2. Urinary concentrations only increased for TNFR1 (3551.29 compared to 2338.95 pg/mg of creatinine (Cr) (95% CI: from -2247.03 to -177.66; p = 0.023). The STNFR1 marker was characterized by a sensitivity of 73.08% and a specificity of 90.00% (p < 0.001).

CONCLUSIONS

Our results suggest that TNFR1 and TNFR2 are good markers of TNF-α pathway activation in IgAN patients.