The effect of warfarin sodium on excretion of calcium, phosphorus, and 4-carboxy-L-glutamic acid (Gla) was studied in 5 patients with ectopic calcification (2 with scleroderma, 1 with dermatomyositis, and 2 with myositis ossificans progressiva). Warfarin reduced urinary excretion of Gila in all patients, but no changes in calcium and phosphorus excretion or in objective parameters of calcinosis were observed during 6-36 months of treatment. Two patients experienced hemorrhagic complications during therapy, emphasizing a hazard of long-term anticoagulation treatment. Since ectopic calcium deposits contain Gla-rich protein, suppression of Gla synthesis by warfarin sodium over a longer ]period may prevent deposition and allow removal of existing calcinosis deposits. jEctopic calcification is an occasional complication of certain connective tissue diseases. It occurs rarely in systemic lupus erythematosus patients (l), in approximately 9% of patients with scleroderma (Z), and in 20% of adults and 40% of children with dermatomyositis (3). Muscle calcification also occurs in myositis ossificans (4), a relatively rare condition of unknown origin.

Synovial tissue samples from 6 patients with rheumatoid arthritis were cultured, and the IgG antibodies isolated from the synovial culture supernatants were used to immunize rabbits to make 6 antiidiotypic (anti-Id) antibody preparations. After extensive adsorption, the rabbit anti-Id were tested in a solid-phase enzyme-linked immunosorbent assay (ELISA). Each anti-Id reacted predominantly with the immunizing synovial IgG and showed almost no reactivity with either pooled normal human serum IgG or with IgG from 50 normal donors. When identical amounts of matched rheumatoid arthritis serum IgC and synovial culture supernatant IgG were probed simultaneously with the corresponding rabbit anti-Id in an ELISA, 3 of 6 pairs demonstrated an increased concentration of specific idiotypes in the synovial culture supernatant IgG. Furthermore, when these 6 matched samples were subsequently analyzed by isoelectric focusing, individual IgG antibodies in 5 of 6 synovial IgG samples revealed enhanced reactivity with the corresponding rabbit antiId preparations, when compared with matched serum IgG. This increased synovial concentration of specific idiotypes detected by both the ELISA and isoelectric focusing was compatible with enhanced synovial tissue synthesis of the antibodies involved. These specific Id/