Surrogate markers that accurately detect mucosal healing [MH] in patients with ulcerative colitis [UC] are urgently needed. Several stool neutrophil-related proteins are currently used as biomarkers for MH. However, the sensitivity and specificity are not sufficient to avoid unnecessary endoscopic evaluations.
Novel serum neutrophil-related markers (neutrophil gelatinase B-associated lipocalin and matrix metalloproteinase-9 [NGAL-MMP-9 complex], cathelicidin LL-37 and chitinase 3-like 1 [CHI3L1]), together with C-reactive protein [CRP] and neutrophil counts were studied. Serum samples were obtained from 176 anti-tumour necrosis factor [anti-TNF]-treated UC patients (145 infliximab [IFX] and 31 adalimumab [ADM]) at baseline and after a median of 9.5 weeks. All patients had active disease prior to treatment (Mayo endoscopic subscore [MES] ≥ 2), and MH was defined as MES ≤ 1. Serum was also obtained from 75 healthy controls. Binary logistic regression analysis was used to generate the Ulcerative Colitis Response Index [UCRI]. The performance of individual markers and UCRI was tested with receiver operating characteristic analysis.
All neutrophil-related markers were significantly higher in active UC patients compared to healthy controls. In the IFX cohort, CRP, NGAL-MMP-9, CHI3L1 and neutrophil count decreased significantly after treatment and all marker levels were significantly lower in healers compared to non-healers following IFX. In the ADM cohort, CRP, NGAL-MMP-9, CHI3L1 and neutrophil count decreased significantly only in healers. UCRI [including CRP, CHI3L1, neutrophil count and LL-37] accurately detected MH in both IFX-treated (area under the curve [AUC] = 0.83) and ADM-treated [AUC = 0.79] patients.
The new UCRI index accurately detects MH after treatment with IFX and ADM. This panel is useful for monitoring MH in UC patients under anti-TNF treatment.
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