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The treatment of SAPHO syndrome is empirical and has recently been reviewed.1–3 Non-steroidal anti-inflammatory drugs (NSAIDs) are the first choice but have limited efficacy. Second line drugs have been tried with mixed results. Positive effects with pamidronate, which partly works by blocking tumour necrosis factor α, have been reported.3,4 Recently, Maksymowych et al suggested that pamidronate is also effective in spondarthritis, which shares manifestations and clinical associations with the SAPHO syndrome.5,6 Infliximab, a chimeric anti-tumour necrosis factor α monoclonal IgG1 antibody, has recently been proved to be effective in the treatment of ankylosing spondylitis7,8 and psoriatic arthritis.7,9
In view of this information we treated two patients affected by refractory SAPHO syndrome with infliximab. Both patients had chest pain limiting normal activity despite adequate treatment with NSAIDs and second line treatment was unsuccessful. Both patients received three intravenous infusions of infliximab (5 mg/kg) at weeks 0, 2, and 6 and were evaluated at baseline, on days 3, 7, and 14, and then every two weeks.
The first patient was a 35 year old man who had had severe acne and painful osteitis of the left clavicle for 17 years. His family history showed that his mother had psoriasis and his brother had had one episode of acute anterior uveitis. Locus B HLA typing of the patient disclosed the B18 antigen. His disease had been treated with NSAIDs for 12 years. In 1996 he was given cyclosporin at a dose of 3 mg/kg/day, with some benefits for the chest pain only. The drug was stopped after two years owing to a loss of efficacy. In the following months long term antibiotic treatment with azithromycin, which has been suggested to be efficacious in SAPHO syndrome,10 was tried without any results.
When we decided to start infliximab treatment the patient had had severe pain of his left clavicle for three months despite treatment with nimesulide, the best alternative NSAID for our patient, at a dose of 400 mg/day. The left clavicle was swollen, warm, and tender and florid acne was present on his face and posterior chest wall. Laboratory evaluation was normal except for a C reactive protein (CRP) of 13.5 mg/l (normal <5). Three days after the first infusion the chest wall pain disappeared and the patient was able to stop NSAID treatment. Swelling and tenderness on the left clavicle remitted and the CRP returned to normal. Severe acne dramatically improved in one week. Chest wall pain, swelling and tenderness, and acne reappeared two months after the third infusion when we decided to proceed with a fourth infusion. The CRP was normal. Again a complete remission of the symptoms was seen in three days. The disease has remained in remission so far, two and a half months after the fourth infusion. Infliximab treatment was well tolerated, with no side effects.
The second patient was a 52 year old man with SAPHO syndrome affecting the sternum, the sternoclavicular joints, the clavicles, and the first two ribs. He had no family history of SAPHO syndrome or spondarthritis. Locus B HLA typing was positive for B35 and B52. His disease began at the age of 42 with palmoplantar pustolosis, which disappeared after six months. Five years later a severe chest wall pain appeared, which was treated with various NSAIDs for 10 years. In 1996 and 1997 he was given sulfasalazine, methotrexate, and cyclosporin A at different times, with no improvement. In the six months before the start of infliximab treatment the patient took 150 mg/day diclofenac, with little result.
On the day on which the first infusion was given a physical examination showed tenderness and swelling on the manubrium sterni and both sternoclavicular joints. The only aspect of laboratory evaluation worthy of note was a CRP of 24 mg/l (normal <5). The day after the first infusion the chest wall pain disappeared and NSAIDs were discontinued. At the first visit, on day 3, a physical examination and CRP were normal. The disease remained in remission for two and a half months after the third infusion. Pain, swelling, and tenderness on the manubrium sterni and both sternoclavicular joints again disappeared in three days after the fourth infusion and have not reappeared so far, two months after the fourth infusion. No side effects of infliximab treatment were seen.
Our study suggests that infliximab is an effective drug in SAPHO syndrome. A larger, controlled, double blind study is required, which should also establish whether improvement of bone scan or magnetic resonance imaging parallels the clinical remission.
Supported by the Government of Basilicata (Lucania) Region.
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