P435 The mean corpuscular volume flow – prognostic value for inflammatory bowel disease under thiopurine treatment
Roseira J.*1, Tavares de Sousa H.1, Marreiros A.2, Queiros P.1, Vaz A.M.1, Gago T.1, Contente L.1, Guerreiro H.1
1Algarve Hospital Centre, Gastroenterology, Algarve, Portugal 2Universidade do Algarve, Biomedical Science, Algarve, Portugal
The difficult access to thiopurine metabolites therapeutic drug monitoring led to the search for accessible markers to estimate thiopurine's efficacy. The difference in mean corpuscular volume (ΔMCV) ≥7fL at week 26 of azathioprine monotherapy (Aza) or combined with infliximab (AzaI) was shown to be associated with favourable outcomes in Inflammatory Bowel Disease (IBD). Objective: To confirm the association of ΔMCV ≥7 at week 26–28 with favourable outcomes in IBD in a Portuguese population.
Retrospective assessment of patients with IBD under Aza or AzaI at time-point: Week 26–28 of treatment. Demographic characterization and severity of pre-treatment disease was evaluated (location, previous surgery status, Mayo score and Crohn's disease activity index [CDAI]). Quantification of ΔMCV and association with time-point outcomes: Steroid-free clinical remission (Rem-sf, CDAI <150, Mayo <2); mucosal healing (MH); C-reactive protein (CRP) normalization <5. Patients with vitamin B12 deficiency were not included. Statistic: Chi-square test or Fisher exact test.
A total of 122 patients with IBD were evaluated [(71 Crohn's disease, 28% operated); 57.4% women; mean age 40±15.6 years] at week 26–28 of treatment with Aza (86.9%) or AzaI (13.1%).
In both treatment groups the mean ΔMCV was ≥7 (Aza 7.9 vs. AzaI 8.1) and this was achieved in the same proportion of patients (66 vs. 62.5%). There was a strong association between ΔMCV ≥7 and remission outcomes (Rem-sf: p<0.05; CDAI <150/Mayo<2: p<0.001) and MH (p<0.05), but not with CRP normalization. However, CRP ≤10 was related to remission outcomes (Rem-sC: p<0.05; CDAI <150/Mayo <2: p<0.001) and MH (p=0.004).
This work confirmed the prognostic importance of ΔMCV ≥7 in our population. The correlation of ΔMCV ≥7 with clinical remission and mucosal healing outcomes occurred in Crohn's disease and Ulcerative Colitis and was independent of the anti-TNF association.