Usefulness of urinary collagen IV excretion for predicting the severity of Henoch-Schönlein nephropathy children

THE AIM OF THE STUDY The aim of the study was to evaluate the usefulness of urinary collagen IV (Col IV) excretion for predicting the severity of autoimmune renal inflammation in children with HSN (Henoch-Schönlein nephritis). MATERIAL AND METHODS We studied 26 children, in whom HSN was diagnosed based on kidney biopsy. In all patients, urinalysis was performed and 24-hour urinary protein excretion was measured at the onset of the disease. All kidney biopsies were also scored using the Oxford classification: M - mesangial hypercellularity score (M0 absent, M1 present); E - presence of endocapillary proliferation (E0 absent, E1 present), S - segmental glomerulosclerosis/adhesion (S0 absent, S1 present), T - tubular atrophy/interstitial fibrosis (T0 ≤ 25%, T1 26-50%, T2 > 50%). The MEST score was calculated as the sum of M + E + S + T. RESULTS Urinary Col IV level was significantly higher in the study group than in control group. Urinary Col IV level was insignificantly higher in group A (nephrotic proteinuria) compared to the B (non-nephrotic proteinuria) and C (without proteinuria).We found no significant differences in the age at the disease onset, severity of proteinuria, and Col IV between groups 1 (S0, T0) and 2.(S1,T1/T2). The MEST score was significantly higher in group 2 than group 1. CONCLUSIONS Urinary Col IV excretion in children with HSN may be related to the lesions severity by the Oxford classification but seems to be associated with the mean value (the MEST score). In younger children, a more aggressive disease course is observed, and thus earlier and more aggressive treatment should be considered in this group.