P062 Chromoendoscopy With Magnification Colonoscopy: Analysis of Mucosa of Colon And Ileum In Patients With Gastrointestinal Symptoms Without IBD
Authors: Izquierdo Viviana Parra , Florez Cristian , Molano Wilson Bautista , Beltran Adriana , Jaimes Diego , De Avila Juliette , Casallas Alejandro Ramos , Bello Juan , Gutierrez Jaiber , Philippe Chalem , Romero-Sanchez Consuelo 
Published: December 2021

BACKGROUND:
Digital chromoendoscopy (Narrow Band Imaging By Olympus) or BLI (Blue Light Imaging By Fujifilm), with the magnification endoscope, allows a detailed evaluation of the mucosal surface and its vascular network, which facilitates the diagnosis and monitoring of early lesions. This technique has demonstrated a better detection, which allows optical diagnosis during a colonoscopy examination. Patients with SpA with nonspecific gastrointestinal symptoms, subclinical intestinal inflammation are defined as endoscopic and histologically. The aim was to detect early structural inflammatory changes by chromoendoscopy and magnification colonoscopy in colonic/ileum digestive mucosa, and establish its association with clinical variables in SpA and gastrointestinal symptoms. Study approved by Institutional Ethics Committee, code HMC 2017-023.

METHODS:
Clinical evaluation by rheumatologist in SpA patients (ASAS/criteria), fecal calprotectin levels, and HLA-B*27 were evaluated. In patients with ≥2 gastrointestinal symptoms, clinical evaluation by gastroenterologist, digital chromoendoscopy (NBI) or (BLI), magnification colonoscopy, and histological analysis were performed. The association between clinical and colonoscopy variables were established using the Chi-square or Fisher's exact test.

RESULTS:
In total, 62 SpA patients were included, with mean age of 45.1 ± 11.3 years, axial SpA (77.4%) peripheral SpA (12.9%), biological treatment (69.4%), ASDAS-CRP>2,1 (67.7%), presence of HLA-B*27 (41.9%). Patients with ≥2 gastrointestinal symptoms were found in 67.7%. The most important symptoms were abdominal pain (66.1%), abdominal distension (64.5%), and food intolerance (59.7%). 22.6% of patients showed high level of calprotectin. In those patients with gastrointestinal symptoms, chromoendoscopy and magnification colonoscopy were performed. The mean age of those patients was 45.4 ± 10.5, 57.6% were male, BMI>25 in 69.7%, presence of HLA-B*27 in 39.4%, 33.3% were former smokers, axial SpA in 84.8% and ASDAS-CRP>21 in 78.8%. In total, 27.27% of the patients presented high levels of calprotectin, of which 66.0% had more than two gastrointestinal symptoms (p = 0.015). 77.8% presented alterations in ileal mucosa (p=0.060). The most frequent alteration was the loss of vascular pattern (p = 0.002). By histological analysis, 5 patients had acute inflammation in the ileum, of which 4 had increased levels of fecal calprotectin (p = 0.013). 30.8% of patients positive for HLAB*27:05:02 had ulcers in ileum (p = 0.017) and 61.5% had chronic inflammatory patterns (p=0.020).

CONCLUSION:
Chromoendoscopy provided an enhanced, detailed contrast of the gastrointestinal mucosa surface, mainly in the loss of vascular pattern in ileum. The active search for symptoms, signs, and biomarkers of gastrointestinal involvement in addition to an objective endoscopic and histological evaluation may offer new perspectives at the evaluation of SpA patients and may provide guidance for specific clinical and therapeutic management.