Quantification of eosinophil densities in the oesophagus, stomach and small bowel of adults: A review of endoscopic and surgical specimens with normal histology, Free State Province, South Africa.

Aim: Studies defining eosinophil densities in the gastrointestinal tract (GIT) are limited. To assess whether eosinophils are pathologically infiltrating the GIT, it is important to evaluate eosinophil densities for specific populations.

Methods: A retrospective, quantitative, comparative study was conducted to determine the number of eosinophils in the oesophagus, stomach and small bowel of patients in central South Africa and to investigate whether a statistically significant difference occurred between ethnic and gender groups.

Results: In total, 309 histological sections from the oesophagus, gastric corpus, gastric antrum and small intestine were sampled from male and female, African and Caucasian patients. Histology reports and review of the slides confirmed the absence of histological abnormality. The number of eosinophils in the epithelium and lamina propria were manually quantified. The eosinophil values across gender, ethnicity and location were 0-2.0/mm² for the oesophagus, 0-53.0/mm² for the gastric corpus and 7.1-115.3/mm² for the small intestine. Regarding the gastric antrum, African and Caucasian females had eosinophil values of 1.0-35.7/mm² and 0-22.4/mm², respectively. Males had an eosinophil density of 0-31.6/mm² in the gastric antrum. The eosinophil values in the oesophagus, gastric corpus and small bowel were not significantly different between genders and ethnic groups. The only site where ethnicity influenced the number of eosinophils was the gastric antrum, a discrepancy that cannot be explained.

Conclusion: To the authors' knowledge, this is the first report on the eosinophil densities in the oesophagus, stomach and small bowel of adults in South Africa.