Demonstration of β1h globulin together with c3 in the dermal‐epidermal junction of patients with systemic lupus erythematosus

Skin lesions and clinically normal skin from 10 patients with systemic lupus erythematosus (SLE) were examined by immunofluorescence for the presence of C3 and its control protein, β1H globulin. β1H was always found in association with deposited C3; in the instance where C3 deposits were not found β1H was also not found. Granular deposits of C3 and β1H were found in the dermal‐epidermal junction (DEJ) in all of the 5 nonlesional skins studied. In the lesional skin, C3 was found in 4 of 5; in 2 of these 4, β1H was also found. As previously demonstrated for in vitro systems, β1H also binds in vivo to fragments of C3, presumably C3b, generated during activation of the complement system.