Grading of acute and chronic renal lesions in Henoch-Schonlein purpura

The renal outcome of 34 patients with Henoch-Schonlein purpura nephritis wa s assessed clinically and by grading acute and chronic renal lesions using a system we applied to primary IgA nephropathy. On a median follow-up perio d of 65 months, hypertension and the serum levels of creatinine and protein uria at the time of renal biopsy were correlated with renal survival. Acute glomerular lesions including mesangial hypercellularity, endocapillary pro liferation, necrosis, cellular crescents, and leukocytes infiltration were observed, respectively, in 41%, 12%, 50%, 29%, and 32% of the cases. Of the se, only glomerular necrotizing lesion and cellular crescent were correlate d with the renal survival. Chronic renal lesions based on a grading system applied to primary IgA nephropathy and assessing the extent of glomerular s clerosis (glomerular grading), of tubular loss and interstitial fibrosis (t ubulointerstitial grading), and of hyaline arteriolosclerosis demonstrated correlation between these lesions, as well as with renal survival. On follo w-up, these chronic renal lesions were predictors of subsequent clinical ev ents associated with disease progression, such as impaired renal function, significant proteinuria, and development of hypertension. Despite some limi tations related to the relatively small size, this series indicates that di stinction of acute and chronic lesions of Henoch-Schonlein purpura nephriti s is important for both the prognosis and management of patients.