The function, composition, and particle size of high-density lipoprotein were severely impaired in an oliguric phase of hemorrhagic fever with renal syndrome patients

Background:Patients suffering from hemorrhagic fever with renal syndrome (HFRS) often showed strikingly reduced high-density lipoprotein (HDL)-cholesterol levels during the oliguric phase, indicating severe alterations in lipoprotein metabolism.Objective:To compare changes in the functions and composition of HDL, lipoprotein metabolism parameters were analyzed in the sera of HFRS patients in the oliguric phase and after recovery.Methods:The serum cholesterol, triglyceride (TG), and lipoprotein/apolipoprotein profiles of HFRS patients in the oliguric and recovery phases were compared with those of normal reference sera. The activities of HDL-associated enzymes, lecithin:cholesterol acyltransferase (LCAT), and paraoxonase (PON) were also assessed.Results:In the oliguric phase, serum cholesterol was substantially decreased and serum TG was increased. As observed by electron microscopy, the sizes of the HDL particles from the HFRS patients were smaller than those seen in the reference sera, with more heterogeneous distribution. Serum amyloid A (SAA) and apolipoprotein (apo) C-III were overexpressed in the oliguric phase, particularly in the HDL fraction. However, in immunodetection, the levels of apoA-I in the HDL2 and HDL3 of the HFRS patients were lower than those of the reference HDL. Serum LCAT and PON activities were reduced significantly in the oliguric phase, which is associated with a reduction in HDL-cholesterol levels and HDL particle size.Conclusion:Overexpression of both apoC-III and apoSAA in HDL and attenuated serum LCAT and PON activity were observed during the oliguric phase in HFRS patients. These results demonstrate that structural, functional, and compositional changes of HDL occurred to a substantial degree in the oliguric phase.