Comparison of FITC-labelled vedolizumab and Alexa fluor- labelled adalimumab staining detected by CLE in inflamed and non-inflamed mucosa.

Comparison of FITC-labelled vedolizumab and Alexa fluor- labelled adalimumab staining detected by CLE in inflamed and non-inflamed mucosa.</p

S2 Fig -

Absolute counts of T cells (panel A), B cells (panel B) and NK cells (panel D) as determined by flow cytometry in responders (R) and non-responders (NR) to vedolizumab at week 0 (W0) and week 22 (W22). The monocyte blood count (panel C) was measured using the Sysmex XS-800i analyzer. There was no difference of absolute counts of the different cells between responders and non-responders to vedolizumab. In responder patients, the absolute count of monocytes (panel C) decreased significantly between week 0 and 22 and monocytes were also significantly fewer at week 22 in responders compared to non-responders. α4β7 expression was analyzed by flow cytometry using a FITC-conjugated vedolizumab antibody in T cells (panel E), B cells (panel F), NK cells, monocytes (panel G) and NK cells (panel H). There was no difference between responders and non-responders to vedolizumab at week 0 before the initiation of the treatment. At week 22, the number of vedolizumab positive B cells decreased significantly in both responders and non-responders (panel F). (TIF)</p

Adalimumab staining of colonic biopsies detected by CLE and response to adalimumab at week 30.

Adalimumab staining of colonic biopsies detected by CLE and response to adalimumab at week 30.</p

Fig 2 -

Representative CLE pictures obtained from the same colonic biopsy after staining with vedolizumab-FITC (panel A, green) and adalimumab-Alexa fluor (panel B, red). Arrows identified positive vedolizumab -FITC positive cells and solid arrows, adalimumab-Alexa fluor positive cells in each panel. CLE images were merged (panel C) and showed an overlay of 80%.</p

B cell subpopulations analysis for α4β7 expression by flow cytometry using a FITC-conjugated vedolizumab antibody in responders (R) and non-responders (NR) patients at weeks 0 (W0) and 22 (W22).

Plasmablasts and switch B cells decreased between inclusion and week 22 in both groups and the difference was only significant in responder patients. (TIF)</p

Adalimumab staining of colonic biopsies detected by CLE at inclusion and response to vedolizumab at week 22.

Adalimumab staining of colonic biopsies detected by CLE at inclusion and response to vedolizumab at week 22.</p

Vedolizumab staining of colonic biopsies detected by CLE at inclusion and response to vedolizumab at week 22.

Vedolizumab staining of colonic biopsies detected by CLE at inclusion and response to vedolizumab at week 22.</p

DETECT study flow chart.

A total of 23 patients were screened for eligibility and 19 were enrolled in the study and received at least one dose of vedolizumab. Three patients did not meet the inclusion criteria and one patient declined its participation. All patients received vedolizumab at day 0 and week 2, 6 and 14 and were evaluated at week 22. One patient who discontinued vedolizumab between day 0 and week 22 and, who received prematurely adalimumab was considered as a failure of vedolizumab and was analyzed at week 30.</p

Vedolizumab staining of colonic biopsies detected by CLE at inclusion and response to vedolizumab at week 22.

The median of areas ≥ 70 μm2 stained by the FITC-conjugated vedolizumab detected by CLE in inflamed colonic biopsies per patient with UC is plotted, with each dot representing one patient. As overlay, a box plot is shown, with the ends of the box representing the first and third quartiles and the middle line the median. Data for clinical remission after vedolizumab at week 22 with the confusion matrix are shown in panel A and endoscopic improvement, defined by a Mayo endoscopic sub-score or 0 or 1, with the confusion matrix in panel B.</p

TREND statement checklist.

AimsIn patients with ulcerative colitis (UC), no biomarker is available to help the physician to choose the most suitable biotherapy. The primary objective of this pilot study was to assess the feasibility of identification of α4β7- and TNF-expressing cells, to predict the response to vedolizumab using confocal laser endoscopy (CLE).MethodsPatients with moderate-to-severe UC, naïve of biotherapy, received vedolizumab. Clinical evaluation was performed at each infusion. Endoscopic evaluation was performed before inclusion and at week 22. Fresh colonic biopsies were stained using FITC-labelled vedolizumab and Alexa fluor-labelled adalimumab and ex vivo dual-band CLE images were acquired. Blood samples were collected to measure trough concentrations of vedolizumab and to determine absolute counts of T and B cells subpopulations, NK cells and monocytes.ResultsNineteen patients were enrolled in the study and received at least one dose of vedolizumab. Clinical remission and endoscopic improvement were observed in 58% of whom 5 patients (45%) had an endoscopic subscore of 0. In terms of clinical response and remission, endoscopic improvement and histologic response, FITC-conjugated vedolizumab staining tended to be higher in responder patients compared to non-responders at week 22. A threshold value of 6 positive FITC-vedolizumab staining areas detected by CLE seemed informative to discriminate the responders and non-responders. The results were similar in terms of clinical remission and endoscopic improvement with a sensitivity of 78% and a specificity of 85% (p = 0.05). Trough concentrations and blood immune cells were not associated with responses to vedolizumab.ConclusionThis pilot study demonstrate that dual-band CLE is feasible to detect α4β7- and TNF-expressing cells. Positive α4β7 staining seems to be associated with clinical and endoscopic remission in UC patients treated by anti-α4β7-integrin, subject to validation by larger-scale studies.Clinical-trial.gov: NCT02878083</div