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Published on: April 9, 2010
Preservation of biomarkers immunoreactivity on cytospins protected with polyethylene glycol
Irena Srebotnik Kirbis1, Maria José Praça2, Ruben Rodrigues Roque2
1Institute of Pathology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia.
Insights
Polyethylene glycol (PEG) protection preserves biomarker immunoreactivity on cytospins stored at room temperature for at least 12 months for most markers. This method offers a reliable approach for long-term storage of cytological samples.
Area of Science:
- Cytopathology
- Biomarker analysis
- Immunohistochemistry
Background:
- Biomarker immunoreactivity is crucial for cytological diagnosis.
- Standard cytospins have limited storage stability.
- Preservation methods are needed for retrospective analysis and biobanking.
Purpose of the Study:
- To evaluate the preservation of biomarker immunoreactivity on cytospins protected with polyethylene glycol (PEG).
- To assess the impact of room temperature (RT) storage duration on biomarker stability.
- To compare PEG-protected cytospins with baseline samples.
Main Methods:
- Retrospective evaluation of immunocytochemical reactions on methanol-fixed and PEG-protected cytospins.
- Comparison with corresponding baseline methanol-fixed cytospins.
- Semi-quantitative assessment of immunoreactivity scores (0-3) over time.
Main Results:
- Immunoreactivity for the majority of 40 biomarkers (78%) remained unchanged for up to 12 months on PEG-protected cytospins stored at RT.
- Specific biomarkers like GFAP, p40, and hepatocyte antigen showed stability for 1, 8, and 7 months, respectively.
- Minor losses or changes in immunoreactivity were observed for a few markers (e.g., Ki67, p63) within 12 months.
Conclusions:
- Polyethylene glycol (PEG) protection effectively preserves biomarker immunoreactivity on cytospins stored at room temperature (RT) for at least 12 months for most biomarkers.
- This finding supports the utility of PEG-protected cytospins for long-term storage and future diagnostic or research purposes.
- The study highlights the stability of numerous biomarkers, facilitating retrospective studies and biobanking efforts.
Introduction:
The aim of this retrospective study was to evaluate the preservation of biomarkers immunoreactivity on cytospins protected with polyethylene glycol (PEG).
Methods:
In two independent cytopathology laboratories, immunocytochemical reactions were retrospectively evaluated on methanol-fixed and PEG-protected cytospins stored at room temperature (RT) for different time periods and compared with immunocytochemical reactions on corresponding baseline methanol-fixed cytospins. Semi-quantitatively assessed immunoreactivity, using scores from 0 to 3, was considered reduced if two sequential scores were lowered by at least one point.
Results:
Immunocytochemical reactions for 40 biomarkers with membrane (10), cytoplasmic (22) and nuclear (8) localisation were performed on 921 slides prepared from 183 cytological samples. For the majority of biomarkers (29/37, 78%), immunoreactivity on PEG-protected cytospins stored at RT remained unchanged in the first 12 months. Immunoreactivity for GFAP, p40 and hepatocyte antigen was monitored and remained unchanged for 1, 8 and 7 months, respectively. Partial or complete loss of immunoreactivity on PEG-protected cytospins stored for less than 12 months was found on a single sample out of the total evaluated for CD3 (1/7), CD30 (1/4), CD45 (1/10), CK5/6 (1/7), MelanA (1/7) and vimentin (1/7), while more frequent changes of immunoreactivity were found for Ki67 (4/7) and p63 (2/7).
Conclusion:
Immunoreactivity on cytospins protected with PEG and stored at RT is well-preserved for at least 12 months for the majority of biomarkers.
