Treatment of polyarteritis nodosa with tocilizumab: a new therapeutic approach?

We describe the effect of interleukin 6 (IL-6) blockade using tocilizumab (TCZ) for inducing and maintaining remission of refractory polyarteritis nodosa (PAN). Three patients with refractory PAN defined according to the American College of Rheumatology criteria were treated with TCZ infusions (8 mg/kg) on a monthly basis. All of them had severe cutaneous and articular involvement with elevated biological inflammatory markers. One suffered from a neuritis multiplex and one from renal and digestive damage. All three patients were dependent on high doses of glucocorticoids (above 0.5 mg/kg) and two of them were resistant to immunosuppressive drugs. All patients achieved and maintained clinical response and normalisation of the inflammation acute-phase proteins after a few weeks of treatment with TCZ. Prednisolone could be reduced by an average of 41–13 mg/day. These first case reports suggest that IL-6 blockade using TCZ could be a therapeutic alternative to induce remission in patients with polyarteritis nodosa resistant or intolerant to the reference treatment.