Validation of the Oxford classification of IgA nephropathy for pediatric patients from China.

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.

[Renal expression of macrophage migration inhibitory factor in children with Henoch-Sch-nlein purpura nephritis].

OBJECTIVE: To examine the expression of macrophage migration inhibitory factor (MIF) in renal tissues obtained from children with Henoch-Sch-nlein purpura nephritis (HSPN). METHODS: The renal tissue samples were obtained from 11 children with different pathological grades of HSPN and 8 children with thin glomerular basement membrane disease (controls). The MIF expression was measured by immunohistochemistry. The correlation between MIF expression and 24 hrs urinary protein excretions was evaluated using a linear correlation analysis. RESULTS: MIF expression was seldom found in renal tissues obtained from controls. However, a significantly increased MIF expression was found and was concordant with the increased severity of renal pathology in renal tissues obtained from children with HSPN. The MIF expression in renal tissues of grade III-IV of renal pathology was significantly higher than that in grade I-II in children with HSPN (p<0.01). In children with HSPN, there was an increased MIF expression in renal tissues with crescent formation and inflammatory cell infiltration. Renal MIF expression was significantly positively correlated with 24 hrs urinary protein excretions in children with HSPN (p<0.01). CONCLUSIONS: MIF may play an important role in renal injury of HSPN. Up-regulation of MIF expression may reflect the degree of renal lesions in HSPN.