[Macrophage infiltration in IgA nephropathy and Henoch-Schönlein purpura nephritis--1. Relationship to clinicopathological findings].

Renal biopsy specimens from 42 children with IgA nephropathy and 23 with Henoch-Schönlein purpura nephritis (HSPN) were examined to investigate the relationship between intraglomerular and interstitial infiltrating macrophage populations and their clinicopathological findings. Macrophages were stained by monoclonal antibody (CD68) using the ABC method. Intraglomerular and interstitial macrophages were significantly increased in HSPN (2.48 +/- 2.71/glomerular cross-section: gcs, 11.54 +/- 11.67/mm2) compared with IgA nephropathy (1.36 +/- 1.09/gcs, 5.30 +/- 4.53/mm2). Infiltrating macrophages were significantly increased in both renal disease compared with minimal change nephrotic syndrome (0.29 +/- 0.12/gcs, 1.36 +/- 0.82/mm2). Infiltrating macrophages tended to decline with the lapse of time between the renal biopsy and the discovery of the renal disease, especially in HSPN. Increase in glomerular macrophages in HSPN was associated with the severity of their clinicopathological findings, but this was not the case in IgA nephropathy. Interstitial macrophages were increased in patients with severe clinicopathological findings in both disease. Patients having both proteinuria and hematuria showed many infiltrating macrophages compared to those with proteinuria or hematuria alone. These findings suggest that intraglomerular and interstitial infiltrating macrophages play important roles in the acute and early phase of IgA nephropathy and HSPN in children.