Familial lupus. Family studies of HLA and serologic findings.

HLA profiles in 103 members of 4 separate kindred with multiple occurrence of SLE were compatible with the presence of a disease susceptibility factor linked to HLA or a direct effect of antigens B8, A11, and B35 on disease expression. Serum ANA was found in 52.9% of consanguineous, 56.5% of nonconsanguineous relatives of SLE probands, and 5% of controls, a finding that suggests the presence of a transmissible agent in the families. By contrast, lymphocytotoxic antibodies were not increased in relatives compared to controls.