P430 Mesalazine dose modification based on fecal calprotectin levels in ulcerative colitis patients in clinical remission

Piñero, G.S.(1,2,3)*;Mañosa , M.(1,3);Cañete, F.(1,3);Calafat, M.(1,3);González, L.(1,3);Ruffinengo, O.(2);Domènech, E.(1,3);

(1)Hospital Universitari Germans Trias i Pujol, Gastroenterology, Badalona, Spain;(2)Hospital Provincial del Centenario, Gastroenterology, Rosario, Argentina;(3)CiberEHD, Gastroenterology, Madrid, Spain;


Mesalazine is the most widely used maintenance therapy for ulcerative colitis (UC). The lowest effective dose recommended is 2g/day, although higher doses are often prescribed. Fecal calprotectin (FC) is a monitoring biomarker that correlates well with endoscopic remission and predicts clinical relapse. Our aim was to evaluate the suitability of mesalazine dose modification based on FC levels in asymptomatic UC patients.


Retrospective study in asymptomatic UC patients treated with oral mesalazine therapy which dose was modified in clinical practice according to FC levels between 2016-2022. Sustained clinical remission, clinical relapse and treatment escalation (increase in dose or introduction of rescue therapy) after dose change were assessed during follow-up. 


Mesalazine dose was reduced in 47 patients because of persistent low FC (mean 36ug/g; IQR 22-85); 51% extensive UC, median age of 55 years (IQR 43-63), median duration of clinical remission before dose-reduction 17 months (IQR 8-32) and mean baseline dose 3.2g/day (IQR 2-4). Mesalazine was reduced to 2g/day (IQR 0-2.4). A FC value >250 ug/g was observed at least once in 10% of subjects during follow-up. The cumulative probability of maintaining clinical remission after dose reduction was 90% and 82% at 12 and 24 months, respectively. Rescue therapy was used in 27%, 17% being corticosteroids. 
In 17 patients, mesalazine dose was increased due to high FC levels (mean 524ug/g; IQR 393-739); 47% extensive UC, median age 54 years (IQR 39-72), median duration of clinical remission before dose increase 16 months (IQR 11-33) and mean baseline dose 2.4g/day (IQR 1.5 -2.4). Dose was increased to 3.2g/day (IQR 3-4.4) and 58% presented FC <250 ug/g at least once during the follow-up. The cumulative probability of clinical recurrence after dose escalation was 14% and 28% at 12 and 24 months, respectively, and 29% needed rescue therapy (6% steroids).


Mesalazine dose modification based on CF levels in asymptomatic patients with UC appears to be a safe strategy and is followed by a low probability of clinical recurrence in the mid-term.