Of Mice and Men

Abstract

Over the past 10 years, Kiron Das and his associates have developed an animal model for the study of a putative Crohn's disease (CD)-specific antigen. Athymic T-cell deficient nu/nu mice inoculated with intestinal and lymph node tissue filtrates from patients with CD sometimes develop lymphomas and/or lymph node plasma cell hyperplasia. Patients with CD often have an antibody that reacts with an antigen contained in these murine lymphomas and hyperplastic lymph nodes. This antibody is found in the sera of about one-third to one-half of CD patients, but it is rarely found in ulcerative colitis (UC) patients and almost never in other controls. This issue of the Journal of Clinical Gastro-enterology contains Das's most recent clinical study on the subject, indicating that this serum antibody was present in 11 of 29 CD patients (38%), in only 4 of 25 UC patients (16%), and in almost no disease controls or normal subjects. Das's immunofluorescent assay is not yet sufficiently sensitive, specific, or convenient to be widely applicable as a routine serodiagnostic tool in clinical practice, but it could be enormously important if it proved in fact to be a marker for a CD-specific antigen. Other laboratories, however, have sharply questioned the specificity of this antigen, whose pathogenetic significance therefore remains controversial.