DNA ploidy, S-phase, and Ki-67 antigen expression in the evaluation of cell content of pleural effusions

Abstract

Cells from pleural effusions (28 malignant and 14 nonmalignant with reactive mesothelial cells) were examined in parallel by means of conventional cytology and multiparametric flow cytometry. The latter included the evaluation of DNA ploidy, the calculation of DNA index (DI), the determination of S phase fraction (SPF), and cell proliferation associated with Ki-67 antigen expression. Propidium iodide was used for the DNA staining, and fluorescein-conjugated monoclonal mouse antibodies were applied to the human Ki-67 antigen staining. The specimens were analyzed by the Becton Dickinson (BD) FACScan apparatus. 10(4) events were collected, and thereafter the obtained data were analyzed by the software Lysis II and CellFit (BD) for DNA and Ki-67 data analysis, respectively. Out of the 28 cases examined, 18 (64%) of the malignant effusions were aneuploid. All of the benign effusions were typically diploid. The average SPF of benign, malignant diploid, and malignant aneuploid cases was 6, 6, and 30 respectively. The comparison between SPF and DI in malignant cases showed a significant correlation (p < 0.001). The average of Ki-67-positive cells that were benign, malignant diploid, and malignant aneuploid were 11, 19, and 35, respectively. There was a significant correlation between Ki-67 expression, SPF (p < 0.05), and the percent of the aneuploid cell population (p = 0.01). The sensitivity of conventional cytology, the determination of DNA ploidy and of Ki-67 expression, was 80, 64, and 92%, respectively; specificity was 100% for cytology and DNA ploidy and 46% for Ki-67 expression. These data show that Ki-67 antigen expression is a potentially useful adjunct to cytometric DNA content analysis, determination of SPF, and conventional cytology in the diagnosis of malignant pleural effusions.

Correlation between DNA Content, Expression of Ki-67 Antigen of Tumor Cells and Immunophenotype of Lymphocytes from Malignant Pleural Effusions

“…Percentage values of Ki-67 determination were dichotomized on subgroups showing !20% and 120% of positive cells. This cut-off resulted from our previous studies [13]. We found there that in nonmalignant pleural effusions the proportion of Ki-67-positive cells did not exceed 20% (corresponding to a specificity of 100%).…”

“…An example of immunologically active cells being in direct contact with a tumor are cells from malignant pleural effusions. In the previous study we have evaluated DNA ploidy, S phase fraction, Ki-67 antigen expression [13] and AgNORs number [14] in the cells of pleural effusions. We concluded that the cells of malignant and benign pleural effusions show differences concerning these parameters.…”

Ribonucleotide Reductase Immunoreactivity in Adenocarcinoma Cells and Malignant or Reactive Mesothelial Cells in Serous Effusions

“…[9][10][11] Saleh et al 9 studied Ki-67 (MIB1) immunostaining with microwave antigen retrieval on cell block sections of serous effusions and reported a significant difference in the mean Ki-67 value between malignant (28%) and benign (9%) effusions. Sikora et al 10 studied Ki-67 expression in serous effusions with flow cytometry using fluorescein-conjugated antibody.…”

“…8 Only a few of these antibodies have been investigated in effusion cytology. [9][10][11] RNR is a key enzyme in the synthesis of deoxyribonucleotide from ribonucleotides. 12 This enzyme is composed of two nonidentical subunits, R1 and R2, which are differentially regulated during the cell cycle.…”

“…[2][3][4] Recently, several antigens that are associated with cell proliferation have been recognized, [5][6][7][8] but only a few studies regarding immunostaining for these antigens in effusion cytology have been published. [9][10][11] Ribonucleotide reductase (RNR) is a cytoplasmic enzyme that catalyzes the direct reduction of four ribonucleotides to the corresponding deoxyribonucleotides needed for DNA synthesis. 12 It consists of two dissimilar subunits, R1 and R2 (or M1 and M2, respectively), which are both essential for the enzyme activity.…”