Determination of Anti- Anisakis Simplex Antibodies and Relationship with αβ and γδ Lymphocyte Subpopulations in Patients with Crohn’s Disease

Background The etiology of Crohn’s disease (CD) is still unknown although new theories are based on defects in innate immunity. We have previously shown a decrease in γδ T cells in CD patients. Previous studies have shown a high prevalence of anti- A. simplex immunoglobulins in CD patients. The diminution of γδ T cells in the peripheral blood and intestinal mucosa of CD patients may create a state of immunosuppression that would facilitate A. simplex infection. Aims To study the antibody responses to Anisakis antigens in Crohn’s disease patients and its relationship with αβ and γδ T cell subsets. Methods We recruited 81 CD patients and 81 healthy controls. αβ and γδ T cell subsets and anti- A. simplex antibodies were measured. Results Levels of anti- A. simplex IgG and IgM were significantly increased in CD patients. Almost 20% of CD patients were positive for IgG and IgM anti- A. simplex versus only 3.7 and 2.5%, respectively, in normal subjects. However, lower specific IgA levels were observed in the group of CD patients versus healthy subjects. We found an association between CD3 + CD8 + γδ subset and IgM anti- A. simplex levels. In ileal cases and stricturing behavior of CD, we observed the highest levels of specific antibodies with the exception of anti- A. simplex IgA. Conclusions The relationship of specific antibodies with a γδ T cell deficiency makes these cell candidates to play a role in the immune response against Anisakis . In addition, anti- Anisakis antibodies could be considered as markers of risk of progression in CD.