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[CD15 focus score for diagnostics of periprosthetic joint infections : Neutrophilic granulocytes quantification mode
B Kölbel1, S Wienert, J Dimitriadis
1Zentrum für Histologie, Zytologie und Molekulare Diagnostik, Max-Planck-Str. 5, 54296, Trier, Deutschland.
Background:
The aim of this project was to devise a quantification method for neutrophils within a single focal point through the development of a CD15 focus score which enables bacterial infections in synovial-like interface membranes (SLIM) to be diagnosed.
Methods:
In this study a histopathological classification of 91 SLIM removed during revision surgery from the hips (n = 59) and knees (n = 32) was performed. Neutrophils were identified immunohistochemically by means of a CD15-specific monoclonal antibody. The quantitative evaluation of CD15-positive neutrophils (CD15Ne) used the principle of maximum focal infiltration (focus) together with an assessment of a single focal point (0.3 mm(2)). This immunohistochemical approach made it possible to develop the CD15 quantifier software, which automatically quantifies CD15Ne.
Results:
The SLIM cases with positive microbiological findings (n = 47) had significantly (p < 0.001, Mann-Whitney U-test) more CD15Ne/focal point than cases with negative microbiological findings (n = 44). A count of 50 CD15Ne/focal point was identified as the optimum threshold when diagnosing periprosthetic joint infections (PJI) using the CD15 focus score. If the microbiological findings are used as a gold standard, the diagnostic sensitivity is 0.83, and the specificity is 0.864 with a positive predictive value (PPV) of 0.87, a negative predictive value (NPV) of 0.83, an accuracy of 0.846 and an area under the curve (AUC) of 0.878. The evaluation of findings for the preparations using the CD15 quantifier software (n = 31) deviated by an average of 12 cells from the histopathological evaluation findings (CD15 focus score). Above a cell count of 62, the CD15-quantifier needs on average 32 s less than the pathologist.
Conclusion:
The immunohistochemical CD15 focus score has a high diagnostic value and allowed the development of the CD15 quantifier software. This provides an automated procedure, which shortens the mentally tiring and time-consuming process of microscopic cell counting and thus makes a contribution towards the standardization of tools for diagnosing PJI.
Insights
A new CD15 focus score method accurately quantifies neutrophils in synovial-like interface membranes (SLIM) for diagnosing bacterial infections. This approach led to CD15 quantifier software, improving periprosthetic joint infection (PJI) diagnosis efficiency.
Area of Science:
- Orthopedics
- Pathology
- Biomedical Engineering
Background:
- Synovial-like interface membranes (SLIM) are crucial in diagnosing periprosthetic joint infections (PJI).
- Accurate quantification of neutrophils in SLIM is essential for diagnosing bacterial infections.
- Current diagnostic methods for PJI can be time-consuming and subjective.
Purpose of the Study:
- To develop a quantitative method for neutrophil assessment in SLIM.
- To create a CD15 focus score for diagnosing bacterial infections in SLIM.
- To develop automated software for neutrophil quantification in SLIM.
Main Methods:
- Histopathological classification of 91 SLIM samples from hip and knee revision surgeries.
- Immunohistochemical identification of CD15-positive neutrophils (CD15Ne) using a CD15-specific monoclonal antibody.
- Quantitative evaluation of CD15Ne using maximum focal infiltration and assessment of a single focal point (0.3 mm²).
- Development of CD15 quantifier software for automated CD15Ne quantification.
Main Results:
- SLIM cases with positive microbiological findings showed significantly higher CD15Ne/focal point counts (p < 0.001).
- A threshold of 50 CD15Ne/focal point was optimal for diagnosing PJI, yielding high sensitivity (0.83) and specificity (0.864).
- The CD15 quantifier software demonstrated high accuracy, with an average deviation of 12 cells from manual histopathological evaluation and reduced processing time.
Conclusions:
- The immunohistochemical CD15 focus score possesses high diagnostic value for PJI.
- The developed CD15 quantifier software offers an automated, efficient, and standardized method for neutrophil counting.
- This automated approach reduces the time and cognitive load associated with microscopic cell counting, aiding in PJI diagnosis standardization.
