Nodular-like glomerular lesion after long-standing chronic renal infection in a patient with medullary sponge kidney and mild hyperglycemia

[摘要] A 63-year-old Japanese woman was admitted to our institute for the evaluation of proteinuria. The patient was diagnosedwith medullary sponge kidney, distal type renal tubular acidosis, and renal infection at the age of 37. Thereafter, thepatient had repeated renal infections. Urinary proteinuria appeared at around the age of 61 and gradually increased upto 1.0 g daily. In the same period, glycated hemoglobin (HbA1c) increased to 7.0%. On kidney biopsy, light microscopyshowed a nodular glomerular lesion and capsular drop. Linear staining for immunoglobulin G along the glomerularbasement membrane was observed by immunofluorescence. Electron microscopy showed thickening of the glomerularbasement membrane to a width of 800–900 nm. A class III glomerular lesion was diagnosed according to the Tervaertclassification. This case indicates that mild but prolonged hyperglycemia for more than 10 years may also contribute tothe formation of nodular lesions, although long-standing repeated chronic renal infection and chronic acidosis may havebeen a precipitating factor in the formation of diabetic nephropathy, including nodular glomerular lesions. This hypothesisis of interest because nodular lesions specific to diabetes are currently considered to be associated with long-term severehyperglycemia.

[学科分类] 血液学