Abstract
Background/Aims: The presence of both small and large bowel inflammation in patients with axial spondyloarthritis (axSpA) is well documented. Numerous studies employing ileocolonoscopy suggest a prevalence of 40-65%. Gut lesions also correspond with non-invasive markers, including elevated CRP and faecal calprotectin, but symptomatic Inflammatory bowel disease is present in only ∼ 8% of patients with axSpA, the remainder said to have silent, asymptomatic or subclinical bowel inflammation. We considered that this gut inflammation was unlikely to be asymptomatic. Previously we validated a questionnaire for assessing bowel symptoms in axSpA, the Dudley Inflammatory Bowel Symptoms Questionnaire (DISQ-axSpA modification). In this study we aimed to assess the frequency and severity of bowel symptoms in a large cohort with axSpA and assess the correlation between bowel symptoms and non-invasive indicators of gut inflammation disease activity and quality of life.
Methods: AxSpA patients fulfilling the ASAS criteria (n = 370) were recruited across six New Zealand centres. All participants completed the DISQ-axSpA modification (scored 0-60 with scores > 11 indicating significant symptoms impacting quality of life). Faecal samples were collected for calprotectin (n = 205) [<50μg/g ‘normal’] and CRP in all participants. The Ankylosing Spondylitis Disease Activity Score (ASDAS-CRP) was completed in all patients and Pearson’s correlations were performed. Medications were recorded. DISQ scores and ASDAS-CRP were correlated with the AS quality of life score (ASQoL) using Pearson’s correlations.
Results: Mean DISQ scores were 13.5 (SD 9.5). Mean ASDAS-CRP score was 2.74 (SD 1.31) and mean CRP 10.41 (SD 14.45). Medications: 9.5% were taking TNFis, 61.9% NSAIDs, 13.8% both medications. 14.9% were on no treatment. Mean faecal calprotectin was 109.1 (SD 147.9). Faecal calprotectin showed a positive correlation with DISQ scores (r(1)=0.146 p = 0.04). The DISQ correlated positively with ASQoL (r(1) = 0.285, p < 0.001) and with ASDAS CRP (r(1) = 0.199, p < 0.001). Categorising patients according to clinically relevant subsets, 28% had a DISQ score between 11 and 19 (highly symptomatic), 27.84% >19 (scores comparable with patients who have active IBD) and 32.16% <7.6 (normal to low).
The ASQoL score varied significantly with DISQ (one-way ANOVA p < 0.001, n = 322). Patients with DISQ ≤7.6 (32% of patients) had significantly lower mean ASQoL scores than both patients with DISQ scores ≥11 and ≤19 (28% of patients, Tukey’s p < 0.001) and with DISQ ≥19 (28% of patients, Tukey’s p < 0.001). There was no significant difference in DISQ score between patients taking no medications, NSAIDs only, TNFis only, or NSAIDs and TNFis together (one-way ANOVA, p = 0.756).
Conclusion: Clinically relevant bowel symptoms are highly prevalent in patients with axSpA and correlate with higher faecal calprotectin and disease activity measures. There is a strong correlation between worse quality of life and bowel symptoms, but no association with medications.
Poster presentation.