Background CRMO is an autoinflammatory disease characterized by relapsing and remitting episodes of pain related to the presence of foci of sterile bone inflammation . TNFα levels are elevated in the serum of patients affected by CRMO and in bone-biopsy specimens . NSAIDs and steroid afford symptomatic relief of pain and swelling in approximately 80% of patients . Some recent reports have shown that anti-TNFα agents lead to clinical and radiological improvement in refractory cases of CRMO.
Objectives We provide a review of the literature concerning the efficacy and safety of anti-TNFα in CRMO.
Methods We searched the MEDLINE database and selected articles published in the English language with the headings “CRMO” and “anti-TNFα”. We only included unambiguous CRMO cases. We added a patient from our cohort.
Results A total of 13 patients met our inclusion criteria (see Table 1). Etanercept (ETN) was the anti-TNFα most commonly used (7 pts). In 6 cases ETN was used at a dosage of 0.8 mg/kg/week. In 5 cases the dosage was modified after 6 months to 0.8 mg/kg every 2 weeks. In 1 case the drug was used at a dosage of 0.4 mg/kg twice a week. In 2 cases MTX was added to ETN. Infliximab (IFX) was used in 4 pts. It was administered at a dose of 5 mg/kg in 3 pts. In 2 cases a loading dose similar to the one recommended for the treatment of RA was used. In our case, due to the recurrence of bone pain after 4 years with IFX 5 mg/kg every 8 weeks, we reduced the administration interval to 6 weeks. In another patient with worsening bone pain after an initial administration of IFX at a dosage of 5 mg/kg every 8 weeks, a loading dose of 6.7 mg/kg was used for three times every 2 weeks. The patient was then treated with an IFX 6.7 mg/kg every 4 weeks. In 1 pt, an initial regimen of IFX every 4 weeks was modified after 1 year to an 8-weeks regimen. 1 pt was instead treated with IFX at a dosage of 3 mg/kg every 8 weeks. IFX was used as a monotherapy in all cases. Adalimumab (ADA) was used in 2 pts. No data about ADA dose or administration interval were recorded in the published article. Of note, all patients underwent remission after starting an anti-TNFα therapy. In 3 cases a disease flare occurred during the anti-TNFα treatment. In 1 case the flare occurred after increasing the administration interval of ETA from one to two weeks. In the 2 remaining cases the disease flare occurred without any previous therapy modification. In all cases increasing the anti-TNFα agent dosage allowed to achieve remission of CRMO. No adverse events were recorded during the anti-TNFα therapy. No pt required a switch to a different anti-TNFα agent. Attempts to discontinue etanercept therapy were performed in 4 pts, but were followed by disease relapses within a month in 3 cases; in the remaining case, ETA was successfully discontinued after 4.5 years of treatment.
Conclusions Our experience and the review of the literature indicate that anti-TNFα agents represent an effective and possibly safe option in the treatment of refractory CRMO.
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Disclosure of Interest None declared