[Lupus erythematosus and hereditary lack of complement. Review of about one case of C2 deficit (author's transl)].
A 22 year old woman having disseminated discoid L.E. with alopecia, photosensitivity and normal renal function is presented. Speckled FANA type R.N.P. was found; L.E. cells and anti-DNA were not present. Direct IF of involved skin revealed deposits of IgG and C3 forming a band at the dermo-epidermal junction. In normal skin there was speckled epidermal nuclear staining with IgG. The study of the patient's complement revealed a selective defect of the C2 component (0 p.100) with a drop in total complement (6 p. 100). The father probably has a heterozygote deficit of C2 (55 p. 100); the mother, however, is within the normal range (119 p. 100). The HLA investigation of the patient and her immediate family did not demonstrate haplotype A10, B18, DW2 as is frequently seen in cases of L.E. associated with a C2 deficiency. The patient is A1, B18, DW--/A10 (W26), BW15, DW--.