Immune modulation after total hip surgery. A prospective ex vivo study.
BACKGROUND
Major trauma affects the immune system, and immunosuppression may render the patients susceptible to septic complications. The purpose of this study was to investigate lipopolysaccharide (LPS)-induced releases of tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) in whole blood in patients undergoing total hip replacement.


METHODS
Seven patients (6 females) who underwent elective total hip replacement were included. Ex vivo LPS-induced releases of TNF-alpha and IL-6 were measured in a whole blood assay at days 1, 6, 9 and 12 postoperatively, using low- and high-dose LPS incubation. At the same time, white blood cell counts were analyzed.


RESULTS
The amount of TNF-alpha release was significantly reduced at days 6 and 12. Compared to monocyte counts, TNF-alpha release was significantly decreased also at day 9 in low- and high-dose LPS stimulation. IL-6 in plasma was significantly increased at day 1 and normalized thereafter. There were no differences in LPS-induced IL-6 levels compared to the levels before surgery.


CONCLUSIONS
This in vivo/ex vivo study shows a reduced capacity of whole blood to release LPS-induced TNF-alpha at day 6 through to day 12 after major orthopedic surgery. Attenuated TNF-alpha release may contribute to an increased postoperative susceptibility to gram-negative sepsis.
Bastian
D
D
Department of Orthopaedics, Rikshospitalet Radiumhospitalet Medical Center, University of Oslo, Oslo, Norway.
Sun
J
J
Danckert Krohn
C
C
Reikerås
O
O
D000328:Adult; D000368:Aged; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects*; D005260:Female; D006801:Humans; D007111:Immunity, Cellular / Q000502:physiology*; D015850:Interleukin-6 / Q000097:blood*; D007958:Leukocyte Count; D008070:Lipopolysaccharides; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000097:blood*; D014409:Tumor Necrosis Factor-alpha / Q000097:blood*
D015850:Interleukin-6; D008070:Lipopolysaccharides; D014409:Tumor Necrosis Factor-alpha