Determinants of Serum- and Plasma Sphingosine-1-Phosphate Concentrations in a Healthy Study Group
Günter Daum,
Martin Winkler,
Eileen Moritz,
Tina Müller,
Maria Geffken,
Mirjam von Lucadou,
Munif Haddad,
Sven Peine,
Rainer H. Böger,
Axel Larena-Avellaneda,
Eike Sebastian Debus,
Markus Gräler,
Edzard Schwedhelm
Affiliations
Günter Daum
Clinic and Polyclinic for Vascular Medicine, University Heart and Vascular Center, Hamburg, Germany
Martin Winkler
Department of Anesthesiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
Eileen Moritz
German Center for Cardiovascular Research (DZHK), Partner Site Hamburg/Kiel/Lübeck (GD, ES, MvL) and Greifswald (EM), Berlin, Germany
Tina Müller
Department of Anesthesiology and Intensive Care Medicine, Center for Sepsis Control and Care (CSCC), and the Center for Molecular Biomedicine (CMB), Jena University Hospital, Jena, Germany
Maria Geffken
Institute for Transfusion Medicine, University Medical Center Hamburg, Eppendorf, Germany
Mirjam von Lucadou
German Center for Cardiovascular Research (DZHK), Partner Site Hamburg/Kiel/Lübeck (GD, ES, MvL) and Greifswald (EM), Berlin, Germany
Munif Haddad
Institute for Clinical Chemistry, University Medical Center Hamburg, Eppendorf, Germany
Sven Peine
Institute for Transfusion Medicine, University Medical Center Hamburg, Eppendorf, Germany
Rainer H. Böger
Institute for Clinical Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
Axel Larena-Avellaneda
Clinic and Polyclinic for Vascular Medicine, University Heart and Vascular Center, Hamburg, Germany
Eike Sebastian Debus
Clinic and Polyclinic for Vascular Medicine, University Heart and Vascular Center, Hamburg, Germany
Markus Gräler
Department of Anesthesiology and Intensive Care Medicine, Center for Sepsis Control and Care (CSCC), and the Center for Molecular Biomedicine (CMB), Jena University Hospital, Jena, Germany
Edzard Schwedhelm
German Center for Cardiovascular Research (DZHK), Partner Site Hamburg/Kiel/Lübeck (GD, ES, MvL) and Greifswald (EM), Berlin, Germany
Introduction To correctly interpret plasma- or serum-sphingosine-1-phosphate (S1P) concentrations measured in clinical studies it is critical to understand all major determinants in healthy controls. Methods Serum- and plasma-S1P from 174 healthy blood donors was measured by liquid chromatography-tandem mass spectrometry and correlated to clinical laboratory data. Selected plasma samples, 10 with high and 10 with low S1P concentrations, were fractionated into very low-density lipoprotein (VLDL)-, low density lipoprotein (LDL)-, high density lipoprotein (HDL)-, and lipoprotein-free fractions. S1P was then measured in each fraction to determine its distribution. Results The mean S1P concentration in serum (1.04 ± 0.24 nmol/mL) was found 39% higher compared with plasma (0.75 ± 0.16 nmol/mL) and overall was not different between men and women. Only when stratified for age and gender, older women were found to exhibit higher circulatory S1P levels than men. In plasma, S1P levels correlate to red blood cell (RBC) counts but not to platelet counts. Conversely, serum-S1P correlates to platelet counts but not to RBC counts. In addition, eosinophil counts are strongly associated with serum-S1P concentrations. Both serum- and plasma-S1P correlate to total cholesterol but not to HDL-C. The distribution of S1P between VLDL-, LDL-, HDL-, and lipoprotein-free fractions is independent of total plasma-S1P concentrations. S1P concentrations in HDL but not in LDL are highly variable. Conclusion These data indicate S1P concentrations in plasma and serum to be differentially associated with cell counts and S1P carrier proteins. Besides platelets, eosinophil counts are identified as a novel determinant for serum-S1P concentrations further suggesting a role for S1P in eosinophil pathologies.
