DECREASE OF MESANGIAL MATRIX AFTER IMMUNOSUPPRESSIVE THERAPY IN CHILDREN WITH REVERSIBLE MEMBRANOPROLIFERATIVE GLOMERULONEPHRITIS TYPE-I

We followed the course of membrano proliferative glomerulonephritis (M PGN) type I after immunosuppressive therapy in 10 children. At diagnos is all patients had abnormal urinary findings. After a mean follow-up of 14 years all but one patient showed normal urinalysis and renal fun ction. Glomerular morphometry revealed an increase in the ratio of mes angial matrix area to glomerular area (M/G%) in all patients. After im munosuppressive treatment, a second biopsy was performed, which showed a significantly decreased M/G% in 4 patients. In 3 of the remaining 6 , the mean M/G% was significantly lower in a third biopsy when compare d with the first. In addition, there was a negative correlation betwee n M/G% and duration from onset disease to biopsy (r = -0.46, p < 0.05) . Fifteen biopsies (6 initial and 9 repeat biopsies) were examined for the staining of various extracellular matrices. In the initial biopsy type IV collagen, type V collagen and fibronectin were increased in e xpanded mesangial areas. Type III collagen was found segmentally in a few biopsies only. M/G% correlated with the grade of type IV collagen, type V collagen and fibronectin staining. These findings suggest that a reversible clinical course of MPGN type I in children is paralleled by a decrease of mesangial matrix expansion.