Abstract
Three hundred and fifty-five kidney specimens obtained from diabetic patients were studied to elucidate the role of mesangiolysis on the process of diabetic nodule formation. Mesangiolyses were found in 56 specimens. These were characterized by focal and segmental dissociation of mesangial matrix, and classified into three phases; “tornoff phase”, “structureless phase” and “re-constructive phase”. Mesangiolyses initially appeared as dissociation of the pivotal structure of the mesangium, and then consecutively transformed into the diabetic nodular lesions through the above three phases. As the grade of the diffuse lesion and of arteriolosclerosis advanced, the prevalence of mesangiolyses and nodular lesions became significantly higher. The grades of diffuse lesions in the specimens with both mesangiolyses and nodular lesions were significantly higher than those in the specimens with mesangiolyses but without nodular lesions. On the other hand, the grades of arterioloscleroses were equally high both in the specimens with mesangiolyses and nodular lesions and in the specimens with mesangiolyses but without nodular lesions. Based on these results, we conclude that 1) the mesangiolysis consecutively transformed into the nodular lesion, 2) presence of moderate to severe diffuse lesion was essential for transformation of the mesangiolysis to the nodular lesion and 3) the mesangiolysis might be a consequence of glomerular ischemia caused by arteriolosclerosis.