Centrifugal separation of cells in sputum specimens from patients with undifferentiated carcinoma

A New Method for the Sputum Cytology Test Without Direct Contact to Specimens During COVID-19 Pandemic

Background

Coronavirus disease 2019 (COVID-19) pandemic continues to spread across the world. Specimens of blood, body fluids and excreta received in the department of pathology undoubtedly increased the risk of infection, especially in some hospitals that are short of professional protection capability. Here we provided a new simple way for the sputum cytology test during the COVID-19 pandemic.

Methods

Sputum samples from 30 patients with lung cancer were collected and divided into two groups, including the control group and the experimental group. Samples of the control group were processed in the biological safety cabinet, while the experimental group was put into the sealed specimen bag directly and pretreated with 75% medical alcohol. Then the cell morphology and tumor cell identification were analyzed by cell smears and liquid-based cell staining. The expression of cell antigens was determined by immunohistochemical staining.

Result

Our result showed that both sputum samples in two groups exhibited complete cell structure and clear morphology according to the cell smear and liquid-based cell staining. In addition, the immunohistochemical result showed that cell antigens, including cytokeratin (CK), leukocyte common antigen (LCA), and thyroid transcription factor-1 (TTF1), were specifically expressed in the cell membrane, cytoplasm, and nucleus, respectively. The tumor cells were distributed diffusely, and cell antigens were located accurately after pretreatment with 75% medical alcohol and were consistent with that of the control group.

Conclusion

Using 75% medical alcohol to pretreat sputum specimens has no obvious impact on cell morphology and antigens expression. Our study provided a new method for the sputum cytology test with no direct contact so as to protect medical staff against the virus during COVID-19 outbreak.

Magnetic enrichment of bronchial epithelial cells from sputum for lung cancer diagnosis

BACKGROUND

Sputum is an easily accessible diagnostic material for lung cancer early detection by cytologic and molecular genetic analysis of exfoliated airway epithelial cells. However, the use of sputum is limited by its cellular heterogeneity, which includes >95% macrophages and neutrophils and only about 1% bronchial epithelial cells. We propose to obtain concentrated and purified bronchial epithelial cells to improve early detection of lung cancer in sputum samples.

METHODS

Sputum was collected from patients with stage I nonsmall-cell lung cancer, cancer-free smokers, and healthy nonsmokers. Magnetic-assisted cell sorting (MACS) with anti-CD14 and anti-CD16 antibody beads were used to enrich bronchial epithelial cells by depleting macrophages and neutrophils from sputum. Fluorescence in situ hybridization (FISH) analysis for detection of FHIT deletion and cytology were evaluated in the enriched specimens.

RESULTS

The bronchial epithelial cells were concentrated to 40% purity from 1.1% of the starting population, yielding an average of 36-fold enrichment and at least 2.3 x 10(5) cells per sample. Detecting FHIT deletions for lung cancer diagnosis produced 58% sensitivity in the enriched sputum, whereas there was 42% sensitivity in the unenriched samples (P = .02). Cytologic examination of the enriched sputum resulted in 53% sensitivity, as compared with 39% sensitivity in unenriched sputum (P = .03). Furthermore, only 2 cytocentrifuge slides of the unenriched sputum were needed for the analyses, as compared with up to 10 cytocentrifuge slides required from the unprocessed specimens.

CONCLUSIONS

The enrichment of bronchial epithelial cells could improve the diagnostic value of sputum and the efficiency of genetic and cytologic analysis of lung cancer.

Exfoliative cytologic evaluation of primary cultured lung carcinomas

This paper describes a tissue culture and exfoliative cell culture system that enables one to (1) evaluate the adequacy of primary lung carcinoma cultures for cytogenetic analysis, and (2) predict the likelihood of viable cells and type of differentiation present in the primary lung tumor cultures used for cytogenetics. Primary lung carcinomas were established from explant outgrowths and maintained in serum supplemented or serum free media on plastic or basement membrane associated protein coated dishes in order to obtain cells for karyotypic analysis (Miura et al., 1990). The media from these cultures that would ordinarily have been discarded was aspirated at each media change and used to prepare cytocentrifuge cytology preparations. Papanicolaou stained cells from the preparations were evaluated by cytotechnologists in order to assess (1) the cellularity and presence of cancer cells in the sample, (2) cytology preparations of cell and explant outgrowth cultures from primary lung tumors are reliable method for screening and evaluating the suitability of primary lung carcinoma cultures for cytogenetic analysis.

Centrifugal separation of carcinoma or atypical cells in voided urine

A simple density gradient method was used to separate atypical and cancer cells from non-cancer cells in voided urine from patients with transitional cell atypia (moderate and grave atypia) and bladder cancer (squamous cell carcinoma and transitional cell carcinoma). Prior to cell separation, the Saccomanno preserved cells were dispersed by homogenization. After cell separation (5 min x 1400 rpm), atypical and cancer cells were enriched up to 20-fold. Also, most of the leucocytes (68-98%) and squamous cells (47-82%) were absent from density gradient specimen fractions containing the largest percentages of atypical and cancer cells. Peak purity ranges of atypical or cancer cells from different sample classes showed a large degree of overlap. This permitted the pooling of density gradient fractions enriched for atypical or cancer cells, thus increasing the efficiency of the method. Also, following centrifugation, the Papanicolaou-stained specimen fractions showed less background staining than the unprocessed controls, and the cells retained diagnostic morphologic features. We infer that this method may be a useful, low-cost approach for the morphologic study of developing cancers, not only from the urinary bladder, but also from the respiratory tract.