Morphometric analysis of small intestinal mucosa

Summary

With the aid of computerised image-analysis, morphometric techniques were used to measure the volumes of crypt epithelium, with reference to a constant test area (10⁴ µm²) of muscularis mucosae, in untreated and treated celiac sprue mucosae in comparison with four other groups of control jejunal specimens. Crypt epithelial lymphocyte populations were also analyzed in terms of absolute numbers (N), mean nuclear ($\bar D$ _N) and cytoplasmic ($\bar D$ _CYT) diameters, and mean nuclear ($\bar V$ _N) and cell ($\bar V$ _CELL) volumes.

Untreated celiac sprue crypts, despite a 3–5 fold increase in volume over control mucosae, contained a markedly expanded population of lymphocytes which was localised predominantly to the upper crypt regions and comprised approximately 6% large lymphocytes ($\bar D$ _N>6 µm:$\bar D$ _CYT>9 µm). These changes were entirely reversed by dietary treatment and hence were considered to be gluten-driven.

The infiltrate might reflect the expression of gluten receptors on maturing upper crypt enterocytes: but why these lymphocytes do not cause any apparent injury to crypt epithelium (unlike surface epithelium) or influence its well-known compensatory response, remains unclear.