Baseline demographic and clinical characteristics of the study population
| Normal gut histology (n=35) | Acute inflammation (n=11) | Chronic inflammation (n=16) | |
|---|---|---|---|
| Age, years* | 36.4±9.0 | 32.8±8.3 | 28.9±7.0 |
| Symptom duration, years† | 7.6±7.5 | 2.6±3.7 | 4.1±4.5 |
| Male gender | 19 (54.3) | 4 (36.4) | 7 (43.8) |
| HLA-B27 (+) | 28 (80.0) | 10 (90.9) | 11 (68.8) |
| ModNY AS | 11 (31.4) | 3 (27.3) | 7 (43.8) |
| CRP, mg/dL | 0.4 (0.0–2.4) | 0.5 (0.0–5.4) | 0.6 (0–2.2) |
| BASDAI, numeric rating scale‡ | 3.7 (0.4–7.1) | 6.0 (2.4–9.6) | 5.3 (0.4–6.6) |
| ASDAS | 2.3 (0.4–3.9) | 3.0 (1.2–5.4) | 2.8 (1.0–4.2) |
In case of numeric variables, results are given as mean with SD or as median and range; dichotomous parameters are presented as frequencies with percentage.
*Patients with chronic gut inflammation were significantly younger compared with patients with normal gut histology (one-way ANOVA—independent samples t test).
†Patients with acute gut inflammation had a significant shorter symptom duration compared with patients with normal gut histology (Kruskal–Wallis and Mann–Whitney U test). These differences reflect the conclusion of our recently published prediction model for microscopic gut inflammation.2
‡Although patients with normal gut histology had numerically lower values for BASDAI compared with patients with either acute or chronic gut lesions, this difference did not reach statistical significance (p=0.068).
ASDAS, Ankylosing Spondylitis Disease Activity Score; BASDAI, Bath Ankylosing Spondylitis Disease Activity Index; CRP, C-reactive protein; HLA, human leucocyte antigen; ModNY AS, ankylosing spondylitis according to modified New York criteria.