AUTHOR=Xu Ri-Cong , Guo Jian-Ying , Cao Tao , Xu Yi , Liao Ying , Chen Yu-Na , Song Hai-Ying , Chen Xiao-Jie , Guan Mi-Jie , Tang Fei , Xiang Qiong , Chen Xing-Lin , Wan Qi-Jun 

TITLE=A mixed-method evaluation of the relationship between Oxford classification scores and longitudinal changes in proteinuria in patients with immunoglobulin A nephropathy

JOURNAL=Frontiers in Endocrinology

VOLUME=Volume 13 - 2022

YEAR=2023

URL=https://www.frontiersin.org/journals/endocrinology/articles/10.3389/fendo.2022.890900

DOI=10.3389/fendo.2022.890900

ISSN=1664-2392

ABSTRACT=Introduction: This study aimed to investigate the relationship between Oxford Classification scores and longitudinal changes in proteinuria in patients with immunoglobulin A nephropathy (IgAN). Methods: The study was a single-center retrospective cohort study involving 358 patients with primary IgAN who were treated at the Shenzhen Second People's Hospital, China, between January 2011 and May 2021. Multivariate linear regression and generalized additive mixed models (GAMMs), adjusted for traditional risk confounders, were used to evaluate the correlation between scores for mesangial hypercellularity (M), endocapillary hypercellularity (E), segmental glomerulosclerosis (S), tubular atrophy/interstitial fibrosis (T), and crescents (C) (known as the Oxford Classification MEST-C score system), with proteinuria/creatinine ratio (PCR) at the time of renal biopsy and longitudinal changes in PCR, respectively. Results:The median PCR was 853 mg/g, and it increased on average by 68.48 mg/g per year in these patients. Compared with patients without relative lesions, those with E present (E1) (537.28; 95% confidence interval [CI], 19.68–1054.88 mg/g) and C > 0 (C1/2) (447.10; 95% CI, 20.89–873.32 mg/g) were associated with increased PCR levels at the time of renal biopsy. What’s more, S present (S1) (126.47; 95% CI, 75.56–177.39 mg/g per year) was associated with the fastest PCR increase; E1 (57.53; 95% CI, 5.10–109.96 mg/g per year) and T >25% (T1/2) (65.34; 95% CI, 15.61–115.07 mg/g per year) were also correlated with a faster PCR increase. Associations between S1 (94.38; 95% CI, 56.53–132.22 mg/g per year) and E1 (66.35; 95% CI, 26.86–105.84 mg/g per year) and PCR change could also be observed in patients with normal kidney function. Conclusions:Overall, E1 and C1/2 were independently associated with raised proteinuria levels at the time of renal biopsy, and S1, E1, and T1/2 were independently associated with a longitudinal increase in proteinuria in the patients with IgAN, suggesting that currently available treatments might not be satisfactory. Individual therapy development might benefit from the use of the Oxford Classification system.