小児期IgA腎症第1篇80症例の臨床病理学的研究

抄録

Renal biopsy specimens from 86 children with IgA nephropathy (47 boys, 33 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 (EDD) by electron microscopy (EM) followed by comparison with clinical features. In the 285 cases studied by IF, the total incidence of this disease was 28.1%. Seventyfive percent of children were discovered by mass-screening urinalysis. Gross hematuria attack occurred in 65% and elevated serum IgA levels were discovered in 16% of patients. Transient azotemia and hypertension were the major presenting features in 4% and 8% of children, respectively. Only 4% of children presented nephrotic syndrome (s-Albumin<2.5 g/dl) and IF study revealed capillary wall immunoglobulin deposition and electronmicroscopically EDD were observed along the glomerular basement membrane (GBM). Combined therapy with immunosuppressive, anticoagulants and antiplatelet drugs was more efficacious for the group with capillary wall immune deposits and GBM EDD than the group without these changes. In the group with mesangial deposits alone, minimal glomerular alterations, focal segmental proliferative glomerulonephritis (GN) and diffuse proliferative GN (DPGN, slight) were predominant light microscopic findings and urinary abnormalities were slight to mild. On the other hand, the group with capillary wall deposits often demonstrated DPGN (moderate to severe) with extracapillary proliferation and severe urinary abnormalities. During a mean follow-up of 45 months, none of the children had progressed to endstage renal disease except for one boy, being introduced to hemodialysis 9 years after discovery of proteinuria. According to these results, the histological findings closely par-alleled both the clinical features and courses. Immune deposits along the capillary walls and the glomerular basement membrane alterations would seem to be an useful prognostic indicator of the course of IgA nephropathy in children.