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Leukocyte Esterase as a Biomarker in the Diagnosis of Periprosthetic Joint Infection

View Article: PubMed Central - PubMed

ABSTRACT

Background: Total joint arthroplasty (TJA) has been one of the most rewarding interventions for treating patients suffering from joint disorders. However, periprosthetic joint infection (PJI) is a serious complication that frequently accompanies TJA. Our study aimed to investigate the application of the leukocyte esterase (LE) strip in the diagnosis of PJI.

Material/methods: From October 2014 to July 2015, 72 patients who had undergone joint puncture after arthroplasty in our hospital were enrolled in this trial. One drop of synovial fluid from each available patient was applied to the LE strip, and the results were observed after 1–3 min. If the color turned to dark purple, we recognized this as a positive result, while other colors were regarded as negative results. Centrifugation was used when the synovial fluid was mixed with blood. The Musculoskeletal Infection Society (MSIS) definition was used as the standard reference to identify whether PJI was found in patients or not. The results of diagnosis and LE strips test were compared, and indicators reflecting diagnostic value were calculated. Correlation of the LE data with erythrocyte sedimentation rate (ESR), elevated C-reactive protein (CRP), synovial white blood cell (WBC) counts, and polymorphonuclear neutrophil (PMN) percentage was calculated.

Results: By MSIS criteria, 38 patients were diagnosed with PJI and 34 patients were not infected. Two types of LE strip presented the same results with sensitivity of 84.21% (95% confidence interval [CI]: 68.75~93.98%), specificity of 97.06% (95% CI: 84.67~99.93%), positive predictive value (PPV) of 96.97% (95% CI: 84.24~99.92%), and negative predictive value (NPV) of 84.62% (95% CI: 69.47~94.14%). There were one false-positive case and six false-negative cases in this trial. There is a strong correlation between LE strip and synovial fluid PMN percentage.

Conclusions: The sensitivity and specificity of the LE strip in the diagnosis of PJI are quite high, which means the LE strip might be used as an alternative to diagnose PJI in clinical practice.

No MeSH data available.


LE strip test of synovial fluid with two different strips. Synovial fluid from four different patients was dropped on two strips. (A, B) Showed that the LE strip tests were negative. (C, D) Showed that LE strip tests were positive. In (A, C) Combur10 TestM Roche strips were used, while in (B, D), AUTION Sticks 10PA Arkray strips were used.
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f1-medscimonit-23-353: LE strip test of synovial fluid with two different strips. Synovial fluid from four different patients was dropped on two strips. (A, B) Showed that the LE strip tests were negative. (C, D) Showed that LE strip tests were positive. In (A, C) Combur10 TestM Roche strips were used, while in (B, D), AUTION Sticks 10PA Arkray strips were used.

Mentions: Immediately following aspiration, one drop of synovial fluid was applied to the leukocyte test pad of two standard chemical test strips (Combur10 TestM Roche, Germany, and AUTION Sticks 10PA Arkray) to detect the presence of LE. Results were recorded after 60 to 180 seconds [9–11]. Two LE strips were used per aspiration to ensure the reliability of the strip result. The changing color of the test strip was interpreted as negative (white), trace (slightly purple), + (light purple), or ++ (dark purple). Only dark purple was considered as a positive result; otherwise, the result was negative (Figure 1). All strips were read and interpreted by three different trained orthopedic research fellows, and a conclusion was made based on the major result if there is a disparity. Samples contaminated with blood were centrifuged [12] and supernatant was applied to the strip (5000 r/min, 3 min). In addition, there were 9 patients whose synovial fluid was insufficient for LE strip test but who could be diagnosed through using the MSIS criteria. These patients were regarded as false-negative.


Leukocyte Esterase as a Biomarker in the Diagnosis of Periprosthetic Joint Infection
LE strip test of synovial fluid with two different strips. Synovial fluid from four different patients was dropped on two strips. (A, B) Showed that the LE strip tests were negative. (C, D) Showed that LE strip tests were positive. In (A, C) Combur10 TestM Roche strips were used, while in (B, D), AUTION Sticks 10PA Arkray strips were used.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC5382836&req=5

f1-medscimonit-23-353: LE strip test of synovial fluid with two different strips. Synovial fluid from four different patients was dropped on two strips. (A, B) Showed that the LE strip tests were negative. (C, D) Showed that LE strip tests were positive. In (A, C) Combur10 TestM Roche strips were used, while in (B, D), AUTION Sticks 10PA Arkray strips were used.
Mentions: Immediately following aspiration, one drop of synovial fluid was applied to the leukocyte test pad of two standard chemical test strips (Combur10 TestM Roche, Germany, and AUTION Sticks 10PA Arkray) to detect the presence of LE. Results were recorded after 60 to 180 seconds [9–11]. Two LE strips were used per aspiration to ensure the reliability of the strip result. The changing color of the test strip was interpreted as negative (white), trace (slightly purple), + (light purple), or ++ (dark purple). Only dark purple was considered as a positive result; otherwise, the result was negative (Figure 1). All strips were read and interpreted by three different trained orthopedic research fellows, and a conclusion was made based on the major result if there is a disparity. Samples contaminated with blood were centrifuged [12] and supernatant was applied to the strip (5000 r/min, 3 min). In addition, there were 9 patients whose synovial fluid was insufficient for LE strip test but who could be diagnosed through using the MSIS criteria. These patients were regarded as false-negative.

View Article: PubMed Central - PubMed

ABSTRACT

Background: Total joint arthroplasty (TJA) has been one of the most rewarding interventions for treating patients suffering from joint disorders. However, periprosthetic joint infection (PJI) is a serious complication that frequently accompanies TJA. Our study aimed to investigate the application of the leukocyte esterase (LE) strip in the diagnosis of PJI.

Material/methods: From October 2014 to July 2015, 72 patients who had undergone joint puncture after arthroplasty in our hospital were enrolled in this trial. One drop of synovial fluid from each available patient was applied to the LE strip, and the results were observed after 1–3 min. If the color turned to dark purple, we recognized this as a positive result, while other colors were regarded as negative results. Centrifugation was used when the synovial fluid was mixed with blood. The Musculoskeletal Infection Society (MSIS) definition was used as the standard reference to identify whether PJI was found in patients or not. The results of diagnosis and LE strips test were compared, and indicators reflecting diagnostic value were calculated. Correlation of the LE data with erythrocyte sedimentation rate (ESR), elevated C-reactive protein (CRP), synovial white blood cell (WBC) counts, and polymorphonuclear neutrophil (PMN) percentage was calculated.

Results: By MSIS criteria, 38 patients were diagnosed with PJI and 34 patients were not infected. Two types of LE strip presented the same results with sensitivity of 84.21% (95% confidence interval [CI]: 68.75~93.98%), specificity of 97.06% (95% CI: 84.67~99.93%), positive predictive value (PPV) of 96.97% (95% CI: 84.24~99.92%), and negative predictive value (NPV) of 84.62% (95% CI: 69.47~94.14%). There were one false-positive case and six false-negative cases in this trial. There is a strong correlation between LE strip and synovial fluid PMN percentage.

Conclusions: The sensitivity and specificity of the LE strip in the diagnosis of PJI are quite high, which means the LE strip might be used as an alternative to diagnose PJI in clinical practice.

No MeSH data available.