High levels of antipeptidoglycan antibodies in psoriatic and other seronegative arthritides.

Bacterial cell wall peptidoglycan, the arthritogenic factor in adjuvant induced arthritis, may also be involved in the etiology of some human rheumatic diseases. Patients with some seronegative rheumatic diseases like ankylosing spondylitis and Reiter's syndrome have elevated antibody titers to peptidoglycan. Using an ELISA with soluble peptidoglycan, we examined the sera of 110 patients with psoriatic arthritis, psoriasis without arthritis and a variety of other joint diseases. Antibody titers were significantly higher (p less than 0.001) among the 22 patients with psoriatic arthritis than the 16 patients with psoriasis without arthritis. Patients with other seronegative arthritides also had higher levels of antipeptidoglycan antibodies than patients with rheumatoid (seropositive) arthritis, osteoarthritis and crystal induced arthritis. Our results furnish additional support for the suggestion for a bacterial role in the pathogenesis of psoriatic and some other seronegative arthritides.