Cancer Diagnosis Program | Biorepositories and Biospecimen Research Branch

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Quantitation of the cellular content of saliva and buccal swab samples.

Author(s): Theda C, Hwang SH, Czajko A, Loke YJ, Leong P, Craig JM

Publication: Sci Rep, 2018, Vol. 8, Page 6944

PubMed ID: 29720614 PubMed Review Paper? No

Purpose of Paper

Conclusion of Paper

Studies

1. Study Purpose

   This study compared proportions of epithelial cells and white cells in buccal swab and saliva specimens from adults and children. The effects of gingivitis on the proportion of white cells in buccal swab and saliva specimens from children was also examined. Specimens were collected from 20 children (mean age 6.7 years, 6.4-7.1 years old) and 12 adults (mean age 36.3 years, 20–59 years old). Unstimulated saliva was obtained by passive drool for 3-5 min from participants that were asked to consume nothing but water for 30 min before collection and to rinse their mouths with water 10 min prior to collection. One hundred mL of saliva were applied to a microscope slide, smeared, immediately fixed with 95% ethanol for 10 min, and left to dry at room temperature. After saliva collection, buccal specimens were collected with two Copan Swabs by rubbing up and down against the inside of each check 20 times and then in the maxillary and mandibular buccal sulcus for 10 seconds per side. Each buccal swab was wiped along the length of a standard size microscope slide and fixed as described above for saliva. Slides were stained with Papanicolaou (Pap) stain and analyzed simultaneously by two observers using dual microscopy who counted epithelial cells (differentiated as cells with blue, orange, or pink cytoplasm) and leukocytes (differentiated into segmented cells, lymphocytes, or other mononuclear cells) until at least 50 epithelial cells and a minimum of 100 white cells from at least two fields of view had been counted. Slides with insufficient total cell numbers to perform the microscopic analysis were excluded. Participants underwent oral examinations with a trained dental examiner to determine presence of gingivitis (inflammation, infections, oral lesions, or evidence of tooth decay).

   Summary of Findings:

   Buccal swab slides had sufficient numbers of cells for analysis from all 20 children and from 11/12 adults while saliva slides were analyzable from only 16/20 children and 8/12 adults. The mean proportion of cells was higher in buccal swab specimens than in saliva from children (90.3% versus 70.3%, P=0.012) and adults (83.4% versus 47.3%, P=0.001). While children had a higher average number of epithelial cells in both buccal swab and saliva specimens compared to adults, the difference was significant only for saliva (P=0.022). Analysis of epithelial cell type found significantly more non-keratinous superficial squamous cells than keratinous superficial squamous cells or intermediate squamous cells in both buccal swab and saliva specimens from children and adults (P>0.05, all). White cell counts revealed significantly more segmented cells than lymphocytes or other mononuclear cells in both specimen types (P>0.05, all). While there were no differences in the proportion of white cells in buccal swabs between children with gingivitis and those without (11.0% versus 8.9%, P=0.638), the number of white cells in saliva was significantly higher in children with gingivitis compared to those without (63.6% versus 14.9% of all cells, P=7.2 × 10^-6).

   Biospecimens

   • Cell - Saliva
   • Cell - Buccal

   Preservative Types

   • None (Fresh)

   Diagnoses:

   • Normal

   Platform:

   Analyte	Technology Platform
   Cell count/volume	Light microscopy

   Pre-analytical Factors:

   Classification	Pre-analytical Factor	Value(s)
   Preaquisition	Diagnosis/ patient condition	Gingivitis present Gingivitis not present
   Biospecimen Acquisition	Method of cell acquisition	Saliva Buccal swab
   Preaquisition	Patient age	Children (mean age 6.7 years, 6.4-7.1 years old) Adults (mean age 36.3 years, 20–59 years old)

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