HLA-antigen b27 in cases with joint affections in an outbreak of salmonellosis.

An outbreak of infection with Salmonella typhi murium occurred in southern Sweden in the summer of 1974. About 330 persons were infected; 91 were hospitalized. 13 of the 91 patients (9 men and 4 women) had symptoms of aseptical polyarthritis. The 13 patients with arthritis were HLA typed with a standard microlymphocytotoxicity test. 13 salmonellosis patients from the same epidemic but without arthritis and 446 healthy blood donors served as controls. Nine (69%) of the 13 patients with arthritis had HLA-B27 compared to 1 (8%) of the control patients and 44 (10%) of the blood donors. The observed association between HLA antigen B27 and reactive arthropathy following salmonella infection could be due to a function of a disease predisposing gene closely linked to HLA-B27.