Low density lipoproteins inhibit endotoxin activation of monocytes.

Human serum and low density lipoproteins (LDLs) were shown to inactivate endotoxin (lipopolysaccharide [LPS]) by testing the effect of LPS interactions with serum or LDL on the activation of human monocytes. Sera and LDL preparations from four patients with familial hypercholesterolemia were used to demonstrate the inhibition of LPS from inducing interleukin-1 release. Before LDL removal by immunoapheresis, the patients' sera were able to inactive approximately fivefold more LPS than after LDL removal. The LPS-inactivating capacity lost during apheresis could essentially be retrieved in the LDL-rich eluate from the immunoadsorption columns. Because patients were treated frequently with immunoapheresis, their LDL levels before LDL removal were not markedly elevated. These patients' sera before LDL removal were shown to inactivate amounts of LPS comparable to those inactivated by the sera from three healthy volunteers. LDL prepared by ultracentrifugation showed similar LPS inactivation as LDL prepared by immunoapheresis. We conclude that the inhibition of LPS-induced monocyte activation by human serum is dependent to a large extent on the LDL fraction. LDLs were demonstrated to inhibit LPS from inducing interleukin-1 release by human monocytes.

[Rheologic studies before and after therapeutic cytapheresis and plasma exchange treatment]. / Rheologische Untersuchungen vor und nach therapeutischen Zytapheresen und Plasmaaustauschbehandlungen.

Changes in rheological properties of human blood before and after platelet pheresis were measured in patients with myeloproliferative diseases as well as in a control group of platelet donors. Although the subjective feeling of the patients during measurement did improve, a better rheological situation could not be demonstrated by the rheological parameters used. A reduction of platelets does not influence the viscosity of whole blood or of plasma. On the other hand, the viscosities of whole blood and plasma differed significantly before and after plasma-pheresis in patients with monoclonal gammopathies. The control group comprised patients without hyperviscosity syndrome and did not show any change in rheological parameters.

[Therapeutic thrombocytapheresis in patients with myeloproliferative diseases with the cell separators Fresenius AS 104 and Cobe Spectra: biocompatibility and safety]. / Therapeutische Thrombozytapheresen an Patienten mit myeloproliferativen Erkrankungen mit den Zellseparatoren Fresenius AS 104 und Cobe Spectra: Biokompatibilität und Sicherheit.

We studied biocompatibility, safety and efficiency of the two cell separators AS 104 (Fresenius) and Spectra (Cobe) during therapeutic thrombocytaphereses. Although some patients have very high platelet levels and coagulation as well as circulatory equilibrium is easily disturbed, no important activation of coagulation or complement was observed. In respect to patient's safety both cell separators performed very well.