HLA antigens were examined in 118 unrelated patients of whom 49 had definite severe systemic lupus erythematosus (SLE). HLA A1 was found in 45 % of the 49 SLE patients and in 20 % of the controls, which consisted of 900 blood donors. HLA B8 was found in 47 % of the patients and in 20 % of the controls (relative risk = 3.5, P = 0.000017), while HLA B7 was found in 22 % of the patients and in 24 % of the controls.
Of the 118 patients 69 had chronic biologically false-positive (CBFP) seroreactions for syphilis. In 32 of these 69 patients definite or probable SLE was diagnosed during the observation time, which varied from 3 to 16 years. HLA B7 was found in 38 % of these 32 patients, while HLA B8 was found in 25 %. When the occurrence of these antigens was correlated to the length of the observation time it was found that 53 ~o of the patients in whom the disease manifested first after 10 years follow-up were carriers of HLA B7 (P = 0.0005) and only 12% had HLA B8 (relative risk = 0.5). In patients with a faster development of the disease both of these antigens were found in about the same frequency as in severe SLE patients. In 37 of the 69 patients no definite diagnosis could be established even it 19 of them had clinical and serological manifestations compatible with SLE. HLA B7 was found in 46% and HLA B8 in 14% of these patients. Moreover it was found that 72 ~o of the 18 patients who had only antilipoidal antibodies in their serum were carriers of HLA B7, while 21% of the 19 patients with other circulating auto-antibodies had HLA B7. D-locus antigens were examined in 35 patients. HLA D w3 was found in 54 ~ of the patients and in 24 % of the controls. Twelve of the patients with D w3 had severe SLE and nine of them had also HLA BS.