Urinary high density lipoprotein in minimal change glomerular disease and chronic glomerulopathies

Serum lipids and lipoproteins and urinary apolipoprotein A (Apo A) were determined in two groups of patients. One group consisted of 11 children (ages ranging from 4 to 14 years) with minimal change glomerular disease. The other group consisted of 13 patients, eight less than 19 years old five adults, with different types of chronic glomerulopathy. Elimination of urinary lysozyme was a feature of chronic glomerulopathies, and creatinine clearances were also significantly lower in this group. Patients with chronic glomerulopathies had significantly lower HDL cholesterol and Apo A concentrations in their sera. In contrast, urinary Apo A concentrations were significantly higher in patients with chronic glomerulopathies, who also showed significantly lower urinary protein selectivities. Lipoprotein electrophoresis of urines containing Apo A showed distinct high-density lipoprotein (HDL) fractions, suggesting that HDL is eliminated in the urine as a result of increased glomerular permeability. This is also supported by a correlation coefficient of 0.77 between the selectivity indices and the ratio of urinary Apo A to total proteinuria. The determination of urinary Apo A appears to give valuable diagnostic information in patients with glomerular disease. According to our results the absence of urinary Apo A is very suggestive of minimal change glomerular disease.