Abstract
Background: Henoch-Schonlein purpura nephritis (HSPN) and IgA nephropathy (IgAN) have many pathological and immunological features in common, and it has been suggested that these two diseases are clinical variants of the same disease process. However, since Henoch-Schonlein purpura (HSP) is a systemic vasculitis, often preceded by upper respiratory infections, it is suggested that HSP is caused by more prominent antigenic stimulations than that of IgAN. We previously reported that the glomerular infiltrating CD8 positive cells and the glomerular expression of α-smooth muscle actin (α-SMA) were the predictors of disease progression of IgAN. The aim of this study is to determine whether the renal infiltration of CD8 positive cells, and the expression of α-SMA and transforming growth factor-β (TGP-β) are similar between in HSPN and in IgAN.
Methods: Twenty-six children including 6 patients with HSPN and 20 patients with IgAN enrolled in this study. We assessed glomerular and interstitial infiltration of CD8 positive cells and the expression of α-SMA and TGF-β using an indirect immunofluorescent method on the renal tissues of the biopsy materials. We analyzed their relation with the degree of proteinuria and renal histological changes in HSPN, and compared them between in HSPN and in IgAN.
Results: In HSPN, the degree of interstitial infiltration of CD8 positive cells was correlated with urinary protein (p=0.0458). There were no correlations for the infiltration of the glomerular CD8 cells, and the expression of α-SMA and TGF-β with urinary protein and histological findings. In comparison between HSPN and IgAN, there were no significant differences of clinical and laboratory findings except for age (HSPN<IgAN, p=0.0056). The number of glomerular CD8 positive cells was significantly higher in HSPN than in IgAN (p=0.0051). The renal expression of α-SMA and TGF-β were similar between in HSPN and in IgAN.
Conclusions: These results suggest that antigenic stimulations, which could promote the infiltration of CD8 positive cells into the glomeruli, affect more prominently the patients with HSPN than those with IgAN.
