Objective: Subclinical gut inflammation has been described in patients with ankylosing spondylitis (AS) or psoriatic arthritis (PsA). Joint involvement has also been reported related to celiac disease. We investigated IgA antibodies to bovine tissue tranglutaminase (tTg) and IgA and IgG antibodies to human tTg and to Saccharomyces cerevisiae (ASCA) in patients with AS and PsA.
Methods: We evaluated the frequency of IgA antibodies to bovine tTg, and of IgA and IgG antibodies to human tTg and to ASCA in 43 patients with AS and 75 with PsA. As control groups we considered 79 patients with rheumatoid arthritis (RA) and 78 healthy blood donors.
Results: We detected antibodies as follows: IgA antibodies to bovine tTg in 1/43 patients with AS, 3/75 with PsA, 1/79 with RA, and in 9/78 healthy controls; IgA antibodies to human tTg in 1/43 patients with AS, 1/75 with PsA, 1/79 with RA, and in 3/78 healthy controls; IgG antibodies to human tTg in 1/43 patients with AS, 4/75 with PsA, 5/79 with RA, and in 7/78 healthy controls. IgA ASCA were confirmed in 10/43 patients with AS, 7/75 with PsA, 14/79 with RA, and in 7/78 healthy controls; IgG ASCA were present in 5/43 patients with AS, 4/75 with PsA, 8/79 with RA, and in 8/78 healthy controls. No statistically significant difference was observed in the prevalence of IgA or IgG antibodies to bovine and human tTg and in the frequency and in mean level of IgA or IgG ASCA between the studied groups or between each group and healthy controls.
Conclusion: Our data fail to show an increased prevalence of autoantibodies associated with celiac and Crohn's disease in patients with AS and PsA.