Fig. 4

Possible changes of sphingosine 1-phosphate (S1P) sources in blood during sepsis. In healthy controls, S1P is almost equally distributed between serum albumin (SA) and high-density lipoproteins (HDL). In trauma patients with low SOFA score, the total plasma S1P remains constant. However, S1P is shifted from SA to HDL as carrier. In sepsis patients, total plasma S1P levels decrease with higher severity. The significant decrease is explained mainly by the loss of HDL-S1P. The contribution of SA-S1P is insignificant