title: Adequacy of mucosal biopsies for evaluation of intestinal cytokine-specific mRNA. Comparative study of RT-PCR in biopsies and isolated cells from normal and inflamed intestine.
abstract: Endoscopic biopsies are being increasingly utilized to investigate cytokine profiles in normal and diseased intestine. To evaluate the adequacy of mucosal biopsies as a source of cytokine-specific mRNA, we measured their content of interleukin-1 beta (IL-1 beta) and interleukin-2 (IL-2) mRNA by reverse transcription-polymerase chain reaction and compared it to that of autologous lamina propria mononuclear cells in control and inflammatory bowel disease-involved specimens. High-quality total RNA was recovered more consistently from cell isolates than from biopsies. Interleukin-1 beta mRNA was reliably detected in both cell and biopsy samples, whereas IL-2 mRNA was measurable in all lamina propria cells but not always in biopsies. Compared to controls, levels of IL-1 beta were significantly elevated in Crohn's disease and ulcerative colitis cells and biopsies, and a weak but significant correlation existed between values derived from the two sources. In contrast, only ulcerative colitis cell isolates but not biopsies contained significantly reduced concentrations of IL-2 mRNA compared to those of control and Crohn's disease samples, and no correlation was found between cell and biopsy contents. Widely different levels of cytokine-specific mRNA were present in closely adjacent biopsies, particularly for IL-2. These results suggest that mucosal biopsies are suitable to assess some but not all cytokine-specific mRNA due to variation in RNA recovery, intrinsic level of cytokine gene expression, and substantial variability of cytokine transcripts.
authors.affiliation: Division of Gastroenterology, Case Western Reserve University School of Medicine, Cleveland, Ohio 44106-4952, USA.
authors.forename: K
authors.initials: K
authors.lastname: Fukushima
authors.forename: G
authors.initials: G
authors.lastname: West
authors.forename: C
authors.initials: C
authors.lastname: Fiocchi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001706:Biopsy; D003092:Colitis / Q000473:pathology; D016207:Cytokines / Q000235:genetics*; D005260:Female; D006801:Humans; D007375:Interleukin-1 / Q000235:genetics; D007376:Interleukin-2 / Q000235:genetics; D007413:Intestinal Mucosa / Q000737:chemistry* / Q000166:cytology*; D008297:Male; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000032:analysis*; D012194:RNA-Directed DNA Polymerase
chemical_list: D016207:Cytokines; D007375:Interleukin-1; D007376:Interleukin-2; D012333:RNA, Messenger; D012194:RNA-Directed DNA Polymerase