A Clinicopathological Study of Idiopathic Membranous Nephropathy in Children

ABSTRACT

PURPOSE: Idiopathic Membranous Nephropathy(IMN) is a rare renal disease in children. To help better understanding of its clinical course and treatment strategies, we reviewed the clinical manifestations and pathological findings of children with IMN. METHODS: Among 58 cases with MN, from 1977 to 2003, 42(72.4%) were hepatitis B virus (HBV) associated and 16(27.6%), 6 males and 10 females, were idiopathic. All cases diagnosed after 2000 were IMN. Several clinicopathological findings(sex, onset age, proteinuria, serum albumin, cholesterol, creatinine clearance, tubulointerstitial changes, glomerular sclerosis, hypertension, renal vein thrombosis, the use of ACE inhibitor, and immunosuppressive therapy) were compared between the remission and the non-remission group of the patients with IMN. RESULTS: The median onset age was 13.4 years. Clinical manifestations were nephrotic syndrome(7 cases, 43.8%), gross hematuria(5 cases, 31.3%) and microscopic hematuria with proteinuria(3 cases, 18.8%). Hypertension, hypocalcemic tetany and renal vein thrombosis were accompanied in 2, 1 and 2 cases, respectively. In addition to the typical findings of MN, the kidney biopsies showed segmental sclerosis(5 cases, 31.3%) or global sclerosis(6 cases, 37.5 %), diffuse crescents(1 case), and mild(11 cases, 68.7%) or moderate tubulointerstitial changes(3 cases, 18.8%). Thirteen cases(86.7%) received oral steroid. Among them 2 cases received cyclophophamide and 1 received cyclosporin as well. Ten cases(62.5%) received ACE inhibitors. In the patients followed up, 7 cases(46.7%) became free from proteinuria (remission group) while 8(53.3%) presented continous proteinuria (non-remission group), two (13.3%) of which progressed to renal failure. Clinicopathological findings showed no significant differences between the two groups. CONCLUSION: With HBV vaccination, HBV associated MN decreased markedly and IMN has taken up most of MN in children. For better understanding of this rare disease, a prospective multicenter study of the clinical course and treatment strategies should be done