A B S T R A C T 61 biopsies of normal skin from the deltoid area and lesional skin from various sites from 48 patients with systemic lupus erythematosus (SLE) were studied for the presence of properdin, C3, C4, and immunoglobulins (IgG, IgM, and IgA) in the dermalepidermal junction (DEJ) using direct and indirect immunofluorescence. Properdin was present in 50% of normal and 40% of lesional skins. Properdin was present without C4 in only 2 of 38 nonlesional skin biopsies and in only 2 of 20 lesions. There was no significant difference in incidence of deposition of any of the six proteins studied between nonlesional and lesional skin.The frequency of deposition of each of the proteins correlated with clinical disease activity. The presence of proteins in the DEJ did not correlate with the presence of active renal disease at the time of biopsy nor with previously documented active nephritis. In addition, no other single clinical manifestation correlated with the presence of DEJ deposition of any protein studied. IgA was not demonstrated in the DEJ of nonlesional skin of 16 patients in remission and was present in 7 of 23 patients with active disease (P < 0.05). Deposition of properdin in lesional skin correlated with the presence of extracutaneous disease activity (P < 0.05).Analysis of serologic studies on serum obtained at the time of biopsy revealed a statistically significant correlation between C4 and C3 (r = 0.67). This correlation was stronger than that between properdin and C3 (r = 0.49) which in turn was stronger than that be-

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Normal complement in early poststreptococcal glomerulonephritis Patients with acute poststreptococcal glomerulonephritis are usually found to have reduced serum concentrations of the third component of complement (C3), properdin, and total haemolytic complement (CH50).' We report here a unique variation of this pattern. Case report A previously healthy 72-year-old boy was admitted to hospital after one day of macroscopic haematuria. Blood pressure was 110/80 mm Hg.

To assess the relative roles of the classic and alternative pathways of complement activation in chronic discoid lupus erythematosus (CDLE), serum levels of properdin, C3, and C4, and deposition of these proteins in the dermal-epidermal junction (DFJ) of 20 CDLE patients were compared to the findings in patients with clinicajly active and inactive SLE. Properdin was demonstrated in the DEJ of 10 of 14 (71%) histologically typical skin lesions from patients with CDLE, usually in association with deposits of immunoglobulin, C3, and C4. Properdin levels in CDLE patients were significantly increased (137 f 34%) ( P < 0.05) when compared to normal controls (101 f 18%) or to patients with clinically active SLE (89 f 32%). C3, C4, DNA-binding, and antinuclear antibody tests in CDLE were indistinguishable from those in normals, but significantly different from patients with active SLE ( P < 0.05). The complement profiles of patients with ______