小児期IgA腎症第2篇経時的生検23症例の臨床像と組織像の比較検討

抄録

Renal biopsy specimens from 23 rebiopsied children with IgA nephropathy (15 boys, 8 girls) were reviewed and classified into 4 groups according to the sites of IgA deposition by Immunofluorescent microscopy (IF) and localization of electron dense deposits by electron microscopy (EM) followed by comparison with clinical features. In the group with mesangial deposits alone repeat biopsy specimens obtained after intervals ranging from 1 year to 2 years showed few correlation to urinalysis findings but persisting mesangial proliferative glomerulonephritis and mesangial deposition of IgA. During a mean follow-up period of 5 years and 1 month imparired renal function was not observed despite abnormal urinalysis, so it is highly possible that this group takes a good clinical course. In the group with capillary wall deposits detected by IF and EM subsequent biopsy findings often demonstrated the increase of chronicity index stated as one of the poor prognostic factors. Therefore it is necessary for this group to be treated aggressively with a close observation on clinical progression to end stage renal failure. Repeat biopsy specimens from 3 children still showed measangial deposition of IgA 6, 9 months and 1 year and 7 months after clinical resolution respectively. Histological improvement after combined therapy with immunosuppressive, anticoagulants and antiplatelet drugs occurred more frequently in the group with capillary deposition especially with higher scores of activity index. On the other hand the group with mesangial deposition alone or advanced sclerotic lesion showed no remarkable improvement. One case with progression to terminal renal failure revealed development of mesangial sclerosis, an increase of percentage of glomeruli showing crescent formation, the glomerular basement membrane changes, tubulointerstitial changes as well as vascular changes.