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Analysis of Microglia and Monocyte-derived Macrophages from the Central Nervous System by Flow Cytometry
Published on: June 22, 2017
Detection of monocyte/macrophage cell populations in effusions: a comparative study using flow cytometric
B Risberg1, B Davidson, S Nielsen
1Division of Cytology, Department of Pathology, Norwegian Radium Hospital, Oslo, Norway. brisberg@ulrik.uio.no
Insights
Flow cytometry (FCM) and immunocytochemistry (ICC) effectively detect macrophages in effusions. Both methods aid in identifying cell populations, crucial for diagnosing benign and malignant conditions.
Area of Science:
- Cytopathology
- Immunology
- Flow Cytometry
Background:
- Macrophages are significant cell populations in serous effusions.
- Their size and morphology can lead to confusion with malignant cells.
- Accurate identification of cell types in effusions is critical for diagnosis.
Purpose of the Study:
- To compare the diagnostic efficiency of flow cytometry (FCM) and immunocytochemistry (ICC) for macrophage detection in serous effusions.
- To evaluate the association of macrophage presence with clinical and cytological parameters.
Main Methods:
- Analyzed 90 serous effusions using FCM and ICC for CD14 (monocyte/macrophage marker).
- Identified epithelial (Ber-EP4), lymphoid (CD45), and mesothelial (N-cadherin) cells.
- Correlated findings with clinical data and cytological diagnoses.
Main Results:
- CD14-positive cells were detected in 94% of effusions by FCM and 100% by ICC.
- Both methods showed good agreement (P < 0.001) in detecting CD14+ cells.
- Macrophage presence correlated with female gender (P = 0.002 for FCM, P = 0.011 for ICC), not other parameters.
Conclusions:
- Both FCM and ICC are effective tools for identifying macrophages in effusions.
- Accurate identification of macrophages aids in differentiating benign from malignant effusions.
- These immunophenotyping techniques enhance diagnostic accuracy in effusion analysis.
Abstract:
The objective of the present study was to compare the efficiency of immunophenotyping using flow cytometry (FCM) and immunocytochemistry (ICC) in the detection of macrophages in serous effusions. Cytoblock sections from 90 effusions were stained for the monocyte/macrophage marker CD14, using ICC. Fresh-frozen samples of all cases were analyzed for CD14 expression, using FCM. Epithelial, lymphoid, and mesothelial cell populations were identified using antibodies against Ber-EP4, CD45, and N-cadherin, respectively. Results were compared with clinical parameters and morphological diagnosis. Thirty-nine specimens were cytologically diagnosed as malignant, containing tumor cells of nonhematologic origin, whereas 46 were interpreted as benign. Two additional specimens were diagnosed as indeterminate or suspicious for malignancy, and 3 specimens contained lymphoma cells. CD14-positive cells were detected in 85/90 (94%) of effusions using FCM, and in all 90 specimens using ICC. The percentage of CD14-positive cells was highly variable, but in some specimens was as high as 76% using FCM and 85% using ICC. A good association was observed between the two methods in the detection of CD14-positive cells (P < 0.001). The presence of macrophages in effusions showed an association with female gender, using both FCM (P = 0.002) and ICC (P = 0.011), but none with effusion site, patient age, clinical and cytological diagnosis, or presence of Ber-EP4-positive cells (P > 0.05). The presence of Ber-EP4-positive cells showed a strong association with the cytological diagnosis of malignancy (P < 0.001). In conclusion, macrophages are a significant cell population in effusions, of both benign and malignant etiology, due to both their size and their possible confusion with cancer cells. Both FCM and ICC aid in the recognition of these cells, and thus provide an effective tool for the identification of different cell populations in effusions.
