Analysis of factors associated with concurrent acute renal tubular injury in idiopathic membranous nephropathy patients

Objective  To explore the influencing factors the combination of acute renal tubular injury （ARTI） in patients with idiopathic membranous nephropathy （IMN） in a multi-ethnic area of Guangxi.

Methods  From April 2013 to October 2021, 155 patients with IMN diagnosed by renal biopsy and hospitalized at Hechi People's Hospital were recruited. They were assigned into two groups of with ARTI （n = 43） and without （n = 112）.

Results  Multifactorial Logistic analysis revealed that serum β2 microglobulin （β2-MG） was independently associated with ARTI in IMN patients （OR = 1.06, 95%CI: 1.01 to 1.12, P = 0.014）. AUC value for ROC curve analysis of serum β2 microglobulin for diagnosing ARTI was 0.748. An optimal threshold value of 2.65 mg/L corresponded to a sensitivity of 81.4% and a specificity of 58.04%. According to serum β2 microglobulin level, they were assigned into three groups of low, medium and high. The odds of ARTI spiked 5.01 and 22.89 folds in medium and high groups as compared with low group. And the results of trend test indicated that the odds of ARTI in IMN patients increased with a rising serum β2 microglobulin concentration （P＜0.001）. Stratified interaction test analysis revealed an interaction between serum β2 microglobulin and ARTI in IMN patients among gender, differential degrees of hypoproteinemia and ethnicity （P for interaction ＜0.05）.

Conclusion  Serum β2 microglobulin is independently associated with ARTI in IMN patients. And an interaction exists between gender, differential levels of hypoproteinemia and ethnicity.