Increased serum soluble CD14, ICAM-1 and E-selectin correlate with disease activity and prognosis in systemic lupus erythematosus

To improve monitoring of immunological and disease activity, we determined soluble markers of activity of the monocyte/macrophage system (sCD14) and the vascular endothelium (sE-selectin, sICAM-1) in patients with systemic lupus erythematosus (SLE) and primary Sjögren's syndrome (pSS) in comparison to patients with infections or sepsis. Concentrations of sCD14, sICAM-1 and sE-selectin (soluble CD14, ICAM-1 and E-selectin, respectively) were measured in serum samples from patients with SLE and pSS, patients with sepsis, different infectious diseases and healthy controls using ELISA systems. Elevated levels of sE-selectin and sICAM-1 were detected in patients with SLE as well as sepsis, in contrast to patients with a localized infection (SLE and sepsis, respectively, versus infection P<0.001; Kruskal-Wallis test). Levels of sCD14 were persistently elevated in sera from patients with SLE, whereas these values decreased rapidly after effective therapy in patients with sepsis or infection. A continuous elevation of all of these three parameters was associated with a fatal outcome in patients with sepsis as well as in patients with SLE. Combined elevation of sCD14, sICAM-1 and sE-selectin correlates with the prognosis in patients with active SLE and indicates a remarkable immune activation involving the monocyte/macrophage system and the endothelium comparable to an activation found only in patients with sepsis.