A method for isolation and culture of lymphocytes from endoscopic biopsies.

Human small and large intestinal lamina propria lymphocytes have been successfully prepared from endoscopic biopsies by a combined enzymatic and mechanical method which gives higher yields of viable mucosal lymphocytes than previously reported, despite the small size of the biopsy samples. Viability of the cells was demonstrated by dye exclusion and they could be satisfactorily maintained in short-term culture. Phytohaemagglutinin-P (PHA-P) transformation characteristics of intestinal lymphoid cells and those of peripheral blood were studied in 20 patients with Crohn's disease and 10 control subjects. Peripheral blood lymphocytes were separated according to this technique, no decrease in viability being observed when compared to a standard Ficoll-Hypaque gradient technique. Endoscopically abnormal (EA) and endoscopically normal (EN) Crohn's tissue showed significantly different responses to PHA-P (P less than 0.001), EA tissue lymphocytes giving lower blastogenic responses.