The concept that gut inflammation is implicated in the pathogenesis of spondyloarthropathies (SpA) has long been considered. Subclinical intestinal inflammation has been reported in adult patients with SpA by histological examination of intestinal biopsies. We assessed the presence of gut inflammation by abdominal 99mTc-hexamethyl propylene amine oxime (99mTc-HMPAO) labeled leukocyte scintigraphy in a group of children and adolescents with HLA-B27 positive SpA without gastrointestinal (GI) symptoms, and correlated the scintigraphic results to disease activity.
Abdominal scintigraphy with 99mTc-HMPAO labeled leukocytes was performed in 27 HLA-B27 positive children and adolescents with SpA without GI symptoms. Patients were divided into 2 groups according to the presence of active or inactive joint disease: Group A, 17 patients with active disease, and Group B, 10 patients with inactive disease. Patients with positive abdominal scintigraphy underwent complete bowel investigation by means of small bowel barium follow-through, abdominal ultrasound scan, and ileocolonoscopy with mucosal biopsies.
Thirteen of 27 patients (48%) had scintigraphy indicating the presence of bowel inflammation. All patients with abnormal scan had active joint disease, whereas no patient with inactive disease had a positive intestinal uptake of labeled leukocytes. Bowel investigation revealed the presence of aspecific mucosal inflammatory changes in the majority of patients with positive scintigraphy.
The presence of intestinal leukocyte uptake only in patients with active joint disease, even if intestinal inflammatory changes were minimal and clinical gut manifestations were absent, supports the role of gut inflammation in the pathogenesis of joint disease in HLA-B27 positive patients with SpA.