Alterations in the levels and lipid composition of plasma lipoproteins (VLDL, LDL and HDL) in Brazilian patients with hepatosplenic schistosomiasis mansoni.

1. The plasma concentrations of low- and high-density lipoproteins (LDL and HDL) were significantly reduced in Brazilian patients with compensated hepatosplenic schistosomiasis mansoni (SM) when compared with healthy individuals, but very low-density lipoprotein (VLDL) levels were unchanged. 2. All three classes of lipoproteins isolated from SM plasma had an increased content of triacylglycerol and unesterified cholesterol and decreased cholesteryl ester and phospholipid. 3. The individual phospholipid composition of patient VLDL, LDL, HDL was also altered; the amount of phosphatidylcholine was increased and that of lysophosphatidylcholine decreased. 4. The saturated and monounsaturated fatty acyl content of cholesteryl esters in patient lipoproteins was also significantly increased, and diunsaturated and polyunsaturated fatty acyl content was decreased. 5. When isolated lipoproteins were examined as negatively stained preparations by electron microscopy, the morphology of SM patient LDL was normal but the HDL fraction was abnormal and showed marked heterogeneity of size with the presence of occasional discoidal particles which resembled "nascent" HDL.