Abstract
Background
IgA nephropathy (IgAN) is the most common primary glomerulonephritis (GN) in western countries and Henoch-Schönlein purpura nephritis (HSPN) is the most common form of vasculitis in childhood. Renal biopsy findings in both nephropathies are often similar and are characterized by mesangioproliferative GN with mesangial or mesangiocapillary IgA and C3c deposits. Aim of this study was to investigate the significances of glomerular C4d-deposition as discriminating factor between pediatric HSPN and IgAN
Methods
We retrospectively analysed patient records and renal biopsies from 53 pediatric patients from one single center with a median age of 10.5 years [range 2.3–18 years]. Twenty-two patients suffered from IgAN and 31 from HSPN. Work-up of all renal biopsies was performed using standard protocols including immunohistochemistry for C4d.
Results
Pediatric IgAN patients were older, presented more often with gross hematuria, lower rates of proteinuria and less endocapillary hypercellularity on histology compared to HSPN patients. However, the rate of glomerular C4d-positivity was not different between IgAN (36%) and HSPN (42%). Comparing all cases with positive versus negative glomerular C4d-staining, pediatric patients with glomerular C4d-positivity showed lesser gross hematuria, but slightly more proteinuria, hypertension, higher rates of immunosuppressive treatment and renal insufficiency at last follow-up compared to C4d-negative patients.
Conclusions
In conclusion, glomerular C4d does not differ between pediatric HSPN and IgAN as the rate of C4d-positivity was comparable in our study. However, in individual cases of pediatric IgAN and most importantly HSPN glomerular C4d-positivity may indicate a more severe course of the disease and might thus be helpful for therapeutic decisions.
Primary manifestation of Henoch-Schonlein purpura during immunosuppressive treatment
