Localization of apolipoprotein(a) and B-100 in various renal diseases

Recently it has become clear that abnormalities of lipid metabolism play a large role in the progression of renal diseases. To investigate the relationship between lipids and kidney tissue, we employed an immunofluorescent technique to determine the localization pattern of apolipoprotein(a) [apo(a)], apoB-100, and low-density lipoprotein receptor in the glomeruli, and analyzed the relationship between their presence and the clinical and histological findings of a total 92 patients with glomerular diseases. Immunostaining showed co-localization of apo(a) and apoB-100 in glomeruli. The patients were divided into three groups, as follows: both apo(a) and apoB-100 positive (Group 1; 38 cases), apo(a) positive only (Group 2; 19 cases) and apo(a) negative (Group 3; 35 cases). Group 1 had more severe proteinuria, higher levels of lipoprotein(a) [Lp(a)], and lower total protein levels than Group 3. Group 1 had a higher prevalence of glomerulosclerosis and interstitial changes than Group 3. Group 2 had more severe proteinuria and a higher prevalence of glomerulosclerosis than Group 3. Although apo(a) and apoB-100 are almost absent in normal controls, these apoproteins [and presumably lipoproteins Lp(a)] are present in the glomeruli of patients with glomerular diseases. The data support the view that these apoproteins play a significant role in progressive renal diseases.