Soluble haemoglobin scavenger receptor (sCD163): a marker associated with bacteraemia
© BioMed Central Ltd 2005
Published: 7 March 2005
Soluble haemoglobin scavenger receptor (sCD163) is a macrophage-specific marker, and elevated levels have been observed in patients with pneumonia and sepsis. The objective of our study was to evaluate sCD163 as a diagnostic and prognostic marker in patients with community acquired sepsis.
A prospective observational study.
One hundred and ninety-four adult patients admitted to a Department of Internal Medicine at a tertiary hospital with suspected community acquired infections. Daily blood sampling for sCD163 analysis was performed for up to 5 days. Laboratory analyses were performed with a sandwich ELISA using polyclonal rabbit anti-CD163 as the catching antibody and monoclonal anti-CD163 as the secondary antibody. The patients were classified according to SIRS criteria. The patients were divided in the following groups: patients with no proven infection (n = 67, control group), patients with possible infection (n = 21, not included in analysis), patients with proven infection without SIRS (n = 25), patients with sepsis (n = 52), patients with severe sepsis (n = 29). Only one patient had septic shock. Twelve patients had bacteraemia. Demographic data, comorbidity, microbiological aetiology, biochemical parameters, focus of infection, severity score and mortality on day 28 were recorded.
The median age was 68 years (range 18–92). The male–female ratio was 0.84. The mortality rate among infected patients on day 28 was 3.8%. sCD163 concentrations are presented as medians and range: 2.9 mg/l (1.22–12.65) in patients with no proven infection, 3.75 mg/l (1.59–74.04) (P = 0.04) in patients with infection without SIRS, 3.02 mg/l (0.54–22.51) (not significant) in patients with sepsis, 4.05 mg/l (1.71–28.4) (P < 0.01) in patients with severe sepsis, 4.92 mg/l (2.66–28.4) (P < 0.01) in patients with bacteraemia.
Elevated levels of sCD163 were observed in patients with infection without SIRS, in patients with severe sepsis and in patients with bacteraemia. The sepsis group had sCD163 levels comparable with the noninfected control group. The highest levels of sCD163 were associated with the presence of bacteraemia. Further studies are needed to unravel the role of sCD163 in severe infections.