INTERLEUKIN-8 AND INDUCIBLE NITRIC-OXIDE SYNTHASE MESSENGER-RNA LEVELS IN INFLAMMATORY BOWEL-DISEASE AT FIRST PRESENTATION

Interleukin-8 (IL-8) and nitric oxide (NO) may be important mediators in the pathogenesis of chronic idiopathic inflammatory bowel disease ( CIID), but their roles in disease activity in ulcerative colitis (UC) and Crohn's disease (CD) are uncertain, The aim of this study was to m easure mRNA for IL-8 and inducible NO synthase (iNOS) in small mucosal biopsies from untreated patients at first presentation and to relate these measurements to the histological levels of polymorph infiltratio n graded on a ten-point scale, For this purpose, a sensitive enzyme-li nked oligonucleotide chemiluminescent assay (ELOCA) was developed to q uantitate reverse transcription-polgmerase chain reaction (RT-PCR) pro ducts amplified from RNA from paired biopsy samples, The levels of IL- 8 and iNOS mRNAs were calculated as ratios of the RT-PCR products to g lyceraldehyde-3-phosphate dehydrogenase (GAPDH) RT-PCR product, In UC patients, median values of IL-8/GAPDH and INOS/GAPDH were significantl y elevated compared with controls and CD, However, in both UC and CD, the IL-8/GAPDH and iNOS/GAPDH ratios correlated significantly with pol ymorph infiltration, ELOCA enabled quantitation of multiple mRNAs in s mall mucosal biopsies from untreated patients with CIIBD and supported a role for IL-8 and iNOS in acute inflammation in both UC and CD.