Source: Phlebology  |  Posted 9 years ago

Quantitative measurement of mucosal interleukin-8 messenger RNA in patients with ulcerative colitis may be a reliable and reproducible way of predicting their response to granulocytapheresis (GCAP).

Researchers in Tokyo Women's Medical University, in Tokyo, and National Yokohama Hospital, in Yokohama, Japan, found significantly increased interleukin (IL) 8 messenger RNA in the inflamed mucosa of patients with ulcerative colitis being treated with prednisolone. These patients also were found to have a good response to GCAP.

The researchers obtained colonoscopic biopsies of inflamed colonic mucosa from 16 patients with ulcerative colitis (21 cases) and of uninflamed colonic mucosa from 25 patients (33 cases). They extracted messenger RNA and used real-time polymerase chain reaction to measure levels of IL-12, interferon-gamma, tumour necrosis factor-alpha (TNF-a), IL-4, IL-8 and IL-18.

Seven patients with high disease activity despite treatment with prednisolone at doses higher than 20 mg/day received one course of GCAP. Their cytokine profiles were determined before and after treatment.

In patients with inflamed colonic mucosa, the researchers observed three cytokine profiles. Those who were not treated with prednisolone and who had low disease activity, the researchers found a high expression of interferon-gamma, TNF-a, and IL-4, but low expression of IL-8. Patients with high disease activity and those on high-dose prednisolone had high expression of IL-8 messenger RNA and low expression of other messenger RNAs.

Interleukin-8 messenger RNA was significantly higher in inflamed than in uninflamed samples of ulcerative colitis.

Five of seven (71.4 percent) patients who were resistant to prednisolone also showed good response to GCAP.

IL-8 was the only cytokine that correlated with good response to GCAP.

Patients who responded to GCAP had significantly higher IL-8 messenger RNA before GCAP than non-responders. They showed marked reduction of IL-8 after GCAP.

The researchers conclude that IL-8 mRNA expression in colonic mucosa in patients treated with prednisolone is a marker of response to GCAP.