Conclusions: Measurements of urinary albumin, total protein, and albumin-to-creatinine ratio are minimally affected by storage at ؊70°C for approximately 2.5 yr. Prolonged storage results in small decreases of urinary albumin and protein that do not substantially affect phenotype classification of overt renal disease.

Background: The transforming growth factor-beta 1 (TGF-β1) has been demonstrated as one of the main factors in the progression of fibrosis and sclerosis glomerular damages. Glomerulonephritis is one common cause of chronic kidney disease (CKD) with the promotion of inflammatory renal damage containing fibrosis and sclerosis glomerular. Objectives: This study aimed to evaluate the TGF-β1 level in CKD patients and compare it with the healthy control group. Methods: This cross-sectional case-control study was carried out on 212 subjects admitted to the Nghe An Friendship General Hospital in Vietnam from March 2018 to February 2020. The case group included 152 patients diagnosed with CKD caused by glomerulonephritis, and the control group included 60 healthy individuals. The TGF-β1 was determined in serum by ELISA method. Results: The serum TGF-β1 concentration of the healthy control group and CKD group was 13.45 ± 7.17 and 32.35 ± 11.74, respectively. The CKD group had a significantly higher TGF-β1 level than the control group (P < 0.05). The CKD group with the eGRP ≥ 60 mL/min/1.73 m2 group had a higher TGF-β1 level than the eGRP < 60 mL/min/1.73 m2 group, and the TGF-β1 level increased from stage 1 to stage 5 (P < 0.001). The TGF-β1 had a medium correlation to urea, creatinine, and hs-CRP. Conclusions: The concentration of TGF-β1 in the CKD group was higher than the control group so that it increased early from the first stage of the disease.