A study on correlation of measures of urinary protein and albumin with progression of IgA nephropathy

Objective To explore the association between urine albumin-to-creatinine ratio (ACR), protein-to-creatinine ratio and 24-hour urine protein in patients with IgA nephropathy (IgAN), and to evaluate the association of these measurements with clinical and pathological findings of IgAN, thus predicting the progression of IgA nephropathy. Methods We collected the data of those patients diagnosed with IgA nephropathy by kidney biopsy performed from May 2017 to April 2018 in the First Affiliated Hospital of Anhui Medical University, and recorded ACR, protein-to-creatinine ratio, 24-hour urine protein, glomerular filtration rate (eGFR), blood pressure, and the Oxford classification. The relationship between urine albumin-to-creatinine ratio, protein-to-creatinine ratio and 24-hour urine protein was analyzed, and the relationship between the three indices and blood pressure, glomerular filtration rate and Oxford classification was discussed separately. Results In the patients with IgAN, ACR, protein-to-creatinine ratio, and 24-hour urine protein, were highly correlated, with the highest correlation between ACR and urine protein-to-creatinine ratio (r_s=0.929, P<0.01). They showed good relationships with eGFR and Oxford classification type T and C. There was no statistically significant difference between hypertension, Oxford classification type M, E, S and the above three indices. Conclusions ACR, protein-to-creatinine ratio, and 24-hour urine protein have close relationship. There is significant correlation between the above three indices and glomerular filtration rate and Oxford classification type T and C.