Research article
Validation of the Oxford classification of IgA nephropathy for pediatric patients from China
1 Research Institute of Nephrology, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China
2 Department of Nephrology, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
3 Department of Nephrology, Yuying Children’s Hospital Affiliated to Wenzhou Medical College, Wenzhou, Zhejiang, China
4 Department of Pediatrics, Jinling Hospital, Nanjing University School of Medicine, Nanjing, China
5 Department of Nephrology and Rheumatology, Children’s Hospital of Shanghai Jiaotong University, Shanghai, China
6 Department of Nephrology and Rheumatology, Children’s Hospital of Fudan University, Shanghai, China
7 Department of Pediatrics, The first affiliated hospital of henan college of TCM, Zhengzhou, China
8 Department of Epidemiology and Biostatistics & Ministry of Education Key Lab for Modern Toxicology, School of Public Health, Nanjing Medical University, Nanjing, China
9 Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
BMC Nephrology 2012, 13:158 doi:10.1186/1471-2369-13-158
Published: 27 November 2012Abstract
Background
The Oxford classification of IgA nephropathy (IgAN) provides a useful tool for prediction of renal prognosis. However, the application of this classification in children with IgAN needs validation in different patient populations.
Methods
A total of 218 children with IgAN from 7 renal centers in China were enrolled. The inclusion criteria was similar to the original Oxford study.
Results
There were 98 patients (45%) with mesangial proliferation (M1), 51 patients (23%) with endocapillary proliferation (E1), 136 patients (62%) with segmental sclerosis/adhesion lesion (S1), 13 patients (6%) with moderate tubulointerstitial fibrosis (T1 26-50% of cortex scarred), and only 2 patients (1%) with severe tubulointerstitial fibrosis (T2, >50% of cortex scarred). During a median follow-up duration of 56 months, 24 children (12.4%) developed ESRD or 50% decline in renal function. In univariate COX analysis, we found that tubular atrophy/interstitial fibrosis (HR 4.3, 95%CI 1.8-10.5, P < 0.001) and segmental glomerulosclerosis (HR 9.2 1.2-68.6, P = 0.03) were significant predictors of renal outcome. However, mesangial hypercellularity, endocapillary proliferation, crescents, and necrosis were not associated with renal prognosis. In the multivariate COX regression model, none of these pathologic lesions were shown to be independent risk factors of unfavorable renal outcome except for tubular atrophy/interstitial fibrosis (HR 2.9, 95%CI 1.0-7.9 P = 0.04).
Conclusions
We confirmed tubular atrophy/interstitial fibrosis was the only feature independently associated with renal outcomes in Chinese children with IgAN.
