Sera-reactivity in inflammatory bowel disease: frequency of recognition of Crohn's disease tissue primed nude mouse lymphoid tissue in an interinstitutional blinded study.

We used a double-blinded interinstitutional study with an indirect immunofluorescence assay to evaluate the immunoreactivity of Crohn's disease (CD) sera against hyperplastic and malignant lymph nodes from nude mice primed with CD tissue filtrates. We assessed the reactivity for potential usefulness as a serodiagnostic test by using sera from different clinical subgroups of patients with inflammatory bowel disease. The immunoreactivity of 86 coded sera from ambulatory patients treated at the Mount Sinai Medical Center were examined-29 from patients with CD, 25 from patients with ulcerative colitis (UC), 21 from disease controls, and 11 from normal controls. Each serum was tested at the Albert Einstein College of Medicine against lymph nodes from at least two of six nude mice inoculated with CD tissue filtrates or CD filtrate-induced lymphoma. There was positive immunofluorescent staining in 11 of 29 (38%) CD patients, 4 of 25 (16%) UC patients, 1 of 21 (4.8%) disease controls, and 0 of 11 normal volunteers. Statistically significant differences in immunoreactivity were seen between CD patients compared to non-inflammatory-bowel-disease controls (p = 0.007) and to normals (p = 0.02).