Long-term response after 6-year treatment with anakinra and onset of focal bone erosion in neonatal-onset multisystem inflammatory disease (NOMID/CINCA).

The exact elucidation of skeletal and cartilagineous involvement in neonatal-onset multisystem inflammatory disease (NOMID) is still poorly known, and there are few data providing the long-term response to treatment with the available interleukin-1 inhibitors. We present here a 13-year-old boy with NOMID treated with anakinra and low-dose methylprednisolone since he was 7 years old for an overall period of 6 years. Every clinical manifestation was highly responsive to interleukin-1 blockade, with the exception of his bone abnormalities. At the comparison of radiography and magnetic resonance imaging of his knees made respectively at 7 and 13 years, we noticed a bone erosion on the posterior surface of the patella combined with the progression of distal femoral overgrowth and endosteal thinning of both meta-epiphyses. This report must encourage clinicians in a precocious institution of interleukin-1 antagonists to thwart the occurrence of irreversible bone changes.