Mucosal concentrations of N-acetyl-5-aminosalicylic acid related to endoscopic activity in ulcerative colitis patients with mesalamine

  • J Gastroenterol Hepatol. 2020 Nov;35(11):1878-1885. doi: 10.1111/jgh.15059.
Tomohiro Fukuda  1 Makoto Naganuma  1 Kaoru Takabayashi  2 Yuya Hagihara  1 Shun Tanemoto  1 Ena Nomura  1 Yusuke Yoshimatsu  1 Shinya Sugimoto  1 Kosaku Nanki  1 Shinta Mizuno  1 Yohei Mikami  1 Kayoko Fukuhara  3 Tomohisa Sujino  1 Makoto Mutaguchi  2 Nagamu Inoue  3 Haruhiko Ogata  2 Yasushi Iwao  3 Takayuki Abe  4 Takanori Kanai  1
Affiliations
  • 1. Division of Gastroenterology and Hepatology, Department of Internal Medicine, Keio University School of Medicine, Tokyo, Japan.
  • 2. Center for Diagnostic and Therapeutic Endoscopy, Keio University School of Medicine, Tokyo, Japan.
  • 3. Center for Preventive Medicine, Keio University School of Medicine, Tokyo, Japan.
  • 4. School of Data Science, Yokohama City University, Yokohama, Japan.
Abstract

Background and aim: 5-Aminosalicylic acid (5-ASA) is a fundamental treatment for mild-to-moderate ulcerative colitis (UC). 5-ASA is taken up into the colonic mucosa and metabolized to N-acetyl-5-ASA (Ac-5-ASA). Few studies have assessed whether mucosal 5-ASA and Ac-5-ASA concentrations are associated with endoscopic remission. This study aimed to investigate differences in 5-ASA and Ac-5-ASA concentrations according to endoscopic activity.

Methods: This single-center, prospective, cross-sectional study was conducted between March 2018 and February 2019. UC patients who were administered with 5-ASA medication for at least 8 weeks before sigmoidoscopy were enrolled. Mucosal 5-ASA and Ac-5-ASA concentrations were measured using liquid chromatography with tandem mass spectrometry. The primary endpoint was defined as the difference in mucosal concentrations of 5-ASA and Ac-5-ASA, according to the Mayo endoscopic subscore (MES).

Results: Mucosal concentrations were analyzed in 50 patients. In the sigmoid colon, the median 5-ASA concentration in patients with MES of 0 (17.3 ng/mg) was significantly higher than MES ≥ 1 (6.4 ng/mg) (P = 0.019). The median 5-ASA concentrations in patients with Ulcerative Colitis Endoscopic Index of Severity ≤ 1 (16.4 ng/mg) were also significantly higher than in patients with Ulcerative Colitis Endoscopic Index of Severity ≥ 2 (4.63 ng/mg) (P = 0.047). In the sigmoid colon, the concentration of Ac-5-ASA was higher in patients with MES of 0 (21.2 ng/mg) than in patients with MES ≥ 1 (5.81 ng/mg) (P = 0.022).

Conclusions: The present study showed that mucosal Ac-5-ASA concentrations, as well as 5-ASA concentrations, are higher in UC patients with endoscopic remission. Ac-5-ASA may be useful for a biomarker of 5-ASA efficacy.

Keywords
5-Aminosalicylic acid; Mucosal concentration; Ulcerative colitis.
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