Quality control of immunocytochemical staining of effusions using a standardized method of cell processing

Our plain-English summary of Quality control of immunocytochemical staining of effusions using a standardized method of cell processing, by V. Kuenen-Boumeester, P. van Loenen, E.M. de Bruijn, et al (Acta Cytologica, 1996).

The study

• Authors: V. Kuenen-Boumeester, P. van Loenen, E.M. de Bruijn, S.C. Henzen-Logmans
• Journal: Acta Cytologica
• Published: 1996;40(3):475-9
• Cited by: 34 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Objective: To improve the quality and reproducibility of immunocytochemical staining of effusions by using a standardized method of cell processing.

Study Design: The study included the specimens of 108 effusions (44 benign, 56 adenocarcinoma metastases and 8 mesotheliomas). Hemorrhagic effusions were lysed using isotonic ammonium chloride. All pellets were fixed in 1% paraformaldehyde dissolved in phosphate-buffered saline (PBS), pH 7.4, and washed in PBS. A Burker counting chamber was used to adjust the pellets to a standard cell concentration. The panel of monoclonal antibodies (MAbs) included MOC-31, Ber-EP4 and anticarcinoembryonic antigen (anti-CEA). The alkaline phosphatase/anti-alkaline phosphatase technique was applied.

Results: Standardized material processing resulted in reproducible specimens with good preservation of cell morphology, reduction of nonspecific interaction and good immunostain intensity. MAbs MOC-31 and Ber-EP4 gave similar results: both were positive in all adenocarcinomas. Anti-CEA was positive in 73%. Benign effusions showed no expression. In contrast to the literature, seven mesotheliomas showed variable membranous expression of MOC-31 and Ber-EP4.

Conclusion: High-quality immunostaining results were obtained by using a standardized method of cell processing. MAbs MOC-31 and Ber-EP4 cannot be used as differentiation markers between mesotheliomas and adenocarcinomas. Discrepancies in immunocytochemical staining results may be caused partly by differences in cell preparation.

In plain English

This laboratory study, by authors at a cancer center in Rotterdam, the Netherlands, tested a standardized way of preparing cells from ascitic and pleural fluid before staining them with antibodies. The authors used fluid from 108 patients: 44 with benign effusions, 8 with malignant mesothelioma and 56 with metastatic adenocarcinoma. Three antibodies were tested: MOC-31, Ber-EP4 and anti-CEA. The article does not discuss asbestos exposure. Anti-CEA staining was negative in all benign effusions and all 8 mesotheliomas, and positive in 73% of the adenocarcinoma effusions. MOC-31 and Ber-EP4 stained all 56 adenocarcinomas. They also stained cells in 7 of the 8 mesotheliomas, mostly at the cell membrane. One mesothelioma was negative for both. In 11 of 44 benign samples, an occasional reactive mesothelial cell stained with MOC-31 and Ber-EP4. The authors reported that the method gave a consistent proportion of cells per slide. The authors concluded that neither MOC-31 nor Ber-EP4 can separate adenocarcinomas from mesotheliomas on staining grounds alone. They also concluded that differences in cell processing may explain some disagreements between published studies.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Laboratory study of a standardized cell-processing and immunostaining method applied to effusion specimens with known diagnoses
• Who was studied: Ascitic and pleural fluid from 108 patients: 44 benign effusions, 8 malignant mesotheliomas and 56 adenocarcinoma metastases (25 breast, 10 ovary, 3 endometrium, 3 pulmonary, 1 prostate, 1 kidney, 6 digestive tract, 7 unknown primary). Diagnoses were confirmed by clinical and/or histologic follow-up. The authors' department was in Rotterdam, the Netherlands. The collection period is not stated.
• Exposure: No asbestos or other environmental exposure was studied. The test variables were a standardized cell-preparation method (red-cell lysis, 1% paraformaldehyde fixation, standard cell concentration) and three monoclonal antibodies: MOC-31, Ber-EP4 and anti-CEA.
• Main results:
  • Benign effusions: all 44 were negative for anti-CEA, although cross-reactivity with polymorphonuclear leukocytes was seen.
  • Benign effusions: in 11 of the 44 samples (25%), an occasional reactive mesothelial cell showed positive membranous staining for MOC-31 and Ber-EP4. No malignancy was shown in follow-up.
  • Malignant mesotheliomas: all 8 were negative for anti-CEA.
  • Malignant mesotheliomas: 7 of 8 showed varying numbers of weakly to intensely stained cells with MOC-31 or Ber-EP4, mostly membranous. Only 1 was negative for both antibodies.
  • Metastatic adenocarcinomas: 73% of effusions were positive for anti-CEA, and all 56 expressed MOC-31 and Ber-EP4.
  • In two effusions regarded as negative for cancer cells on cytologic grounds, immunostaining was positive. Malignancy was confirmed in follow-up.
  • Processing: lysing red cells made individual cells easier to identify, and the standard cell concentration gave a consistent percentage of cells on the slides.
• The authors' conclusion: The authors concluded that neither MOC-31 nor Ber-EP4 can be used, on immunocytochemical grounds alone, to discriminate between adenocarcinomas and mesotheliomas. They concluded that differences in cell processing may explain some discrepancies in published immunostaining results. They reported that their standardized method improved the quality and reproducibility of their immunostaining.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Pleural plaques and thickening.

Medical terms in this study, explained in our Lexicon: Adenocarcinoma, Mesothelioma, Monoclonal, MOC-31, Ber-EP4.

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