Critical illness causes disturbances in lipid metabolism. Here, we investigated the levels of
apolipoprotein A-IV (apoA-IV), a regulator of triglyceride and cholesterol metabolism, in human sepsis.
ApoA-IV (analyzed in 156 patients with systemic inflammatory response syndrome (SIRS)/sepsis)
and cholesteryl ester (CE) (analyzed in 121 of these patients) were lower in patients compared to
43 healthy controls. In contrast, triglyceride (TG) levels were elevated in patients. ApoA-IV levels
in plasma of the patients did not correlate with these lipids. Patients with SIRS, sepsis or septic
shock had comparable apoA-IV, TG, CE and free cholesterol (FC) levels. Patients on dialysis had
significantly lower CE levels, whereas apoA-IV levels did not change much. CE levels were elevated
in patients with viral sepsis due to SARS-CoV-2 infection in comparison to SIRS/sepsis patients not
infected by this virus. CE levels correlated negatively with procalcitonin, interleukin-6 and bilirubin,
while TGs were positively associated with bilirubin and C-reactive protein. ApoA-IV, TG, CE and FC
levels were not associated with bacterial infection or survival. In conclusion, this analysis suggests
that CE levels decline in sepsis-related renal failure and also shows that plasma apoA-IV and CE
levels are early biomarkers of sepsis.