JUXTAGLOMERULAR BODY ABNORMALITIES IN YOUTH-ONSET DIABETIC SUBJECTS

Abnormal microalbuminuria in insulin-dependent diabetic subjects (IDDS ) is significantly associated with pre-clinical nephropathy. In youth- onset IDDS declining plasma renin activity is significantly associated with improved albumin excretion, while persistently elevated renin ac tivity is associated with continued abnormal microalbuminuria. To dete rmine if these changes are reflected in changes in cell count in the j uxtaglomerular body and if biopsy findings correlate with abnormal mic roalbuminuria, renal tissue of 20 IDDS (Study IDDS) ages 16 to 31 year s, evaluated concurrently for plasma renin activity and microalbuminur ia, were examined by light microscopy. Biopsy or autopsy specimens fro m 21 normal subjects and 32 IDDS (Non-Study IDDS), ages 2 to 25, were also examined. Specimens from the majority of prepubertal and all pube rtal and postpubertal Non-Study IDDS and all Study IDDS independently of status of microalbuminuria had morphologic abnormalities. Normal or mesangially expanded glomeruli were found in association with expande d juxtagomerular bodies and increased cell number, or with sclerotic b odies and decreased cell number. Sclerosis of juxtaglomerular bodies o ccurred independently of glomerular sclerosis. The highest percentage of glomeruli with expanded juxtaglomerular bodies and high cell count was present in specimens of Study IDDS with the most abnormal levels o f microalbuminuria. T lymphocytes, noted within juxtaglomerular bodies , were present in specimens of 62% of the 52 Study and Non-Study IDDS. Abnormalities of the juxtaglomerular body are distinctive features of renal pathology in IDDS. T lymphocytes in the endocrine juxtaglomerul ar body suggest the presence of an autoimmune process. Confirmatory st udies are necessary.