Effect of Rituximab on 24-Hour Urine Protein and Albumin or Renal Function in Patients with Glomerulonephritis

This study aimed to investigate the correlation between the urine protein/creatinine ratio (PCR) and 24 h urine total protein quantity (24hUTP) in morning and random urine and its prediction equation. Rituximab (RTX), a monoclonal antibody that acts on the B cell epitope CD20, has been used in the renal field since 2005 and has become a hot topic in the clinical treatment of many glomerulonephritis diseases. Apart from focusing on the safety and efficacy of RTX in clinical treatment, some scholars are still working on the mechanism of its action in the treatment of renal diseases, trying to find its specific targets in renal tissues. Results. There was no significant difference between morning urine PCR, random urine PCR, and 24hUTP (P=0.81); there was a significant positive correlation between morning urine PCR and 24hUTP (r = 0.90, P < 0.01) and between random urine PCR and 24hUTP (r = 0.95, P < 0.01), and the correlation between random urine PCR and 24hUTP was higher than that between morning urine PCR and 24hUTP. The results of the ROC curve analysis showed that the correlation between morning urine PCR, random urine PCR, and 24hUTP was higher than that between morning urine PCR and 24hUTP in different groups. The optimal threshold values for random urine PCR to predict 2.4hUTP were 0.56 g/g (sensitivity 93.5%; specificity 75.4%), 1.11 g/g (sensitivity 98.3%; specificity 92.4%), and 3.43 g/g (sensitivity 87.9%; specificity 89.9%), respectively. The equations for predicting 24hUTP by morning urine PCR and random urine PCR were as follows: (1) 24hUTP(g) = 0.793 + 0.793 × morning urine PCR + 0.124 × total cholesterol − 0.177 × Alb (coefficient of determination R(2) = 0.87); (2) 24hUTP(g) = 0.369 + 0.856 × random urine PCR + 0.132 × total cholesterol − 0.092 × Alb (coefficient of determination R(2) = 0.92); the prediction equation of random urine was more accurate than that of morning urine. The correlation was not affected by gender, age, 24 h urine volume, etiology, eGFR, Alb, or total cholesterol level, and the correlation between random urine PCR and 24hUTP was higher than that of morning urine PCR. CR prediction equation was used instead of the 24hUTP test.