Lipopolysaccharide-binding protein: a valuable biomarker in the differentiation between periprosthetic joint infection and aseptic loosening?
OBJECTIVE
The pre-operative differentiation between periprosthetic joint infection (PJI) and aseptic loosening after total hip (THA) or knee (TKA) arthroplasty is essential for successful therapy and relies in part on the use of molecular markers. The objective of this study was to assess serum levels of lipopolysaccharide-binding protein (LBP) as a diagnostic tool for PJI and to compare its accuracy with standard tests.


METHODS
One hundred and twenty patients presenting with a painful TKA or TKA with indication for surgical revision were included in this prospective, controlled, clinical trial at a single centre. Pre-operative blood and serum samples were collected and analysed for white blood cell (WBC) count, C-reactive protein (CRP) and LBP. The definite diagnosis of periprosthetic joint infection was determined on the basis of clinical, microbiological and histopathological examination.


RESULTS
LBP showed significantly higher values in PJI compared with aseptic loosening (p < 0.001) and control (p < 0.001), with a specificity of 66% and a sensitivity of 71% at a cutoff value of >7 ng/ml. In combination with CRP, the positive predictive value for PJI was at 0.67; negative predictive value with both negative was at 0.77.


CONCLUSIONS
Patients with PJI have elevated serum levels of LBP when compared with patients with aseptic loosening. The use of LBP in serum appears not to be a more accurate marker than CRP level in serum for detecting PJI. On the basis of these results, we cannot recommend the sole use of LBP for differentiating PJI and aseptic loosening following THA and TKA.
Department of Orthopedics and Trauma Surgery, University Clinic of Bonn, Sigmund Freud Str. 25, 53105, Bonn, Germany, max.friedrich@ukb.uni-bonn.de.
Max J
MJ
Friedrich
Thomas M
TM
Randau
Matthias D
MD
Wimmer
Ben
B
Reichert
Dominik
D
Kuberra
Birgit
B
Stoffel-Wagner
Dieter C
DC
Wirtz
Sascha
S
Gravius
D000209:Acute-Phase Proteins; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects*; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects*; D015415:Biomarkers / Q000032:analysis / Q000097:blood*; D002097:C-Reactive Protein / Q000032:analysis; D002352:Carrier Proteins / Q000097:blood*; D005260:Female; D006801:Humans; D007958:Leukocyte Count; D008297:Male; D008562:Membrane Glycoproteins / Q000097:blood*; D008875:Middle Aged; D011446:Prospective Studies; D011475:Prosthesis Failure / Q000209:etiology*; D016459:Prosthesis-Related Infections / Q000097:blood / Q000175:diagnosis*; D012086:Reoperation; D012680:Sensitivity and Specificity; D000099231:Lipopolysaccharide-Binding Protein
D000209:Acute-Phase Proteins; D015415:Biomarkers; D002097:C-Reactive Protein; D002352:Carrier Proteins; D008562:Membrane Glycoproteins; D000099231:Lipopolysaccharide-Binding Protein