Artikel
CD15 Focus Score: A histopathological score for the stratification into low-virulence and high-virulence microbial pathogens in periprosthetic joint infections
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Autoren
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Vincent Krenn
- Sigmund Freud PrivatUniversität Wien, Wien, Austria
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Martin Liebisch
- Sigmund Freud PrivatUniversität Wien, Wien, Austria
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Veit Krenn
- MVZ-ZHZMD Trier, Trier, Germany
| Veröffentlicht: | 6. November 2018 |
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Gliederung
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Objectives: The aim of this work is to validate the CD15 Focus Score for the clinical infection pathology of periprosthetic joint infections (PJI). By the means of a large sample analyses this study allows a valid stratification into low- and high-virulent microbial pathogens using a quantification system for the detection of CD15 positive neutrophil granulocytes (NG).
Methods: 275 histopathological tissue samples (synovia) were taken intraoperatively during revision procedures (n = 127 hip; n = 141 knee; n = 2; shoulder; n = 5 ankle) and were classified according to the SLIM consensus classification.
The samples were stained with haematoxylin and eosin (HE) and a periodic acid-Schiff (PAS) staining was additionally performed. For immunhistochemical staining an anti-CD15 antibody was used for identification of CD15.
The NG cell count was evaluated using the CD15 Focus Score, which follows the principle of focal maximum infiltration (0.3 mm²). Comparing the values with the microbiological diagnosis lead to a stratification into low- and high-virulent microbial pathogens (Figure A).
Results and conclusion: Patients with positive microbial findings (n = 160) had a significantly higher (p < 0.001, Mann-Whitney U test) CD15 Focus Score in comparison to patients with negative findings (n = 115). The cut-off being 39 NG per high power field (HPF). If the microbiological findings are used as a gold standard the diagnostic sensitivity and specificity were .91 and .92 (PPV = 0.94; NPV = 0.88; accuracy: 0.92; AUC = 0.95), respectively. The CD15 Focus Score values of low-virulence microbial pathogens (n = 94) were significantly lower (p < 0.001, Mann-Whitney U test) than the values of high-virulence microbial pathogens (n = 55). The cut-off value being 106 cells per HPF. The diagnostic sensitivity was .70 with a specificity of .77 (PPV = 0.63; NPV = 0.81; accuracy = 0.74; AUC = 0.74).
The high diagnostic quality of the CD15 Focus Score guarantees a valid diagnosis of PJI. This histopathologic procedure provides an additional criterion for diagnosis due to a valid stratification into low- and high-virulent microbial pathogens, which provides further assistance for a pathogen specific antibiotic therapy upon unclear clinical findings.
