To determine the significance of anti-laminin antibodies in patients with collagen vascular diseases using a large control population of normal individuals.
Anti-laminin antibodies of IgG isotypes were determined using an ELISA assay in a population consisting of 73 patients with systemic sclerosis, 10 with urticarial vasculitis, five with leukocytoclastic vasculitis, 13 with giant cell arteritis, and eight with dermatomyositis. Sera from 134 healthy individuals served as controls.
Only eight sera in the systemic sclerosis group, one in the leukocytoclastic group and one in the giant cell arteritis group were abnormal. No other sera were abnormal.
These data contradict previous studies using smaller numbers of controls. The necessity for an adequate control population to define abnormal when comparing immune responses among groups is frequently under-emphasised in rheumatological studies.