SAPHO syndrome treated with pamidronate: an open-label study of 10 patients

In recent years the SAPHO syndrome (synovitis, acne, pustulosis, hyperostosis and osteitis) has been encountered more frequently. However, clinical evidence indicating superiority of a specific therapeutic modality is still absent. Pamidronate, a second-generation bisphosphonate, has a pronounced effect on bone metabolism by suppressing bone resorption. We report our clinical experience with intravenous pamidronate in SAPHO syndrome.

Between the years 1999 and 2003 we treated 10 patients with the SAPHO syndrome who did not respond to NSAIDs, oral corticosteroids, colchicine, methotrexate, sulphasalazine or infliximab. All patients were treated with 60 mg pamidronate, given intravenously within an hour. In cases of no response a subsequent dose was given within a month and if there was a partial response an additional infusion was given after 4 months. The primary endpoint was the disappearance of recurrent bouts of bone pain, osteitis or hyperostosis, or recurrent synovitis. Reduction of the frequency of attacks by 50% was regarded as a partial response.

Seven of the patients were females and three were males. The age at diagnosis ranged from 26 to 68 yr. All patients had axial or peripheral arthritis and cutaneous involvement; three had severe acne, eight had pustulosis and two had concomitant psoriasis vulgaris. Hyperostosis of the anterior chest wall involving either sternocostal or sternoclavicular joints, as seen on technetium 99 bone scintigraphy, was detected in all patients. Complete remission was observed following therapy in six patients, three others partially responded and only one patient had no response. Two patients needed four cycles of pamidronate infusion, one patient needed three, six needed two infusions and one patient remitted following a single pamidronate infusion. In all but one patient pamidronate was effective in preventing recurrent bouts of pustulosis.

Pamidronate seems to be a very effective mode of therapy for patients with the SAPHO syndrome, by promoting remission in all components of the disorder, such as bone, joint and skin involvement, and ceases the bouts that characterize this disorder.