RELEVANCE OF PERIGLOMERULAR MYOFIBROBLASTS IN PROGRESSION OF HUMAN GLOMERULONEPHRITIS

To clarify the pathological and clinical significance of periglomerula r alpha-smooth muscle actin (alpha-SMA)-positive cells, we examined 51 needle-biopsy specimens from patients with human glomerulonephritis, Immunoelectron microscopy confirmed these cells were myofibroblasts sh owing characteristic features with abundant alpha-SMA-positive thin my ofilaments. Nonsclerotic glomeruli with periglomerular myofibroblasts were larger in the Bowman's capsular planar area than nonsclerotic glo meruli without periglomerular myofibroblasts (24.7 +/- 6.0 x 10(3) mu m(2) v 19.9 +/- 8.5 x 10(3) mu m(2); P < 0.01). We studied the correla tion between the clinical prognosis and the extent of periglomerular m yofibroblasts in 24 patients with IgA nephropathy, Patients were divid ed into two groups; those with plasma creatinine levels within normal range at biopsy and significantly elevated at follow-up were designate d group 1 (poor prognosis), and patients with plasma creatinine levels within normal range at biopsy and not significantly elevated at follo w-up were designated group 2 (fair prognosis), In the kidneys of group 1 patients, periglomerular alpha-SMA was expressed more intensively t han it was in the kidneys of group 2 patients (alpha-SMA expression sc ore, 1.0 +/- 0.48 v 0.52 +/- 0.54; P < 0.05). These findings indicate that periglomerular myofibroblasts appeared surrounding the nonsclerot ic hypertrophic glomeruli, which may lead finally to glomerulosclerosi s, This report suggests that interaction between the glomerular cells and the periglomerular myofibroblasts may have a role in the progressi on of glomerular diseases. (C) 1998 by the National Kidney Foundation, Inc.