Contents and Diagnostic Value of β2-MG and UPQ in Patients with Renal Injury from Mercury Poisoning

Abstract

Objective: We aimed to explore the changes of β₂-microglobulin (β₂-MG) and urinary protein quantity (UPQ) in mercury poisoning-induced renal injury and their diagnostic significance. Methods: 25 inpatients with mercury poisoning admitted to our hospital from January 2019 to January 2022 were selected as the study group, and 25 healthy controls with no history of mercury exposure were enrolled as the control group. Urine β₂-MG was detected by immunoturbidimetric method in midstream urine, UPQ was determined quantitatively by 24 h urine protein, and serum creatinine (Scr) and blood urea nitrogen (BUN) levels were detected by fasting venous blood in the morning. Then the receiver operating characteristic (ROC) curve was used to analyze the diagnostic efficacy of each index for renal injury caused by mercury poisoning. Results: The β₂-MG and UPQ of the study group were (0.17 ± 0.12) mg/24 h and (0.14 ± 0.09) mg/24 h respectively, which were significantly higher than the average level of the control group (both p < 0.05). However, the mean levels of Scr and BUN in the study group were (63.64 ± 7.21) μmol/L and (5.08 ± 0.80) mmol/L, respectively, showing no statistical difference compared with the control group (both p > 0.05). The ROC results showed that the area under the curve (AUC) values of β₂-MG and UPQ for the diagnosis of mercury poisoning-induced renal injury were 0.586 and 0.617, respectively, while the AUC value of the three combined diagnosis was 0.828, which was significantly higher than that of each parameter alone. Conclusions: Urine β₂-MG and UPQ levels are significantly increased in patients with mercury poisoning. The efficacy of the combined three in diagnosing renal injury caused by mercury poisoning is encouraging, contributing immensely to the clinical diagnosis of renal injury caused by mercury poisoning.