Treatment of Schnitzler's syndrome with anakinra: report of three cases and review of the literature

Schnitzler's syndrome is characterized by chronic urticarial rash, a monoclonal immunoglobulin (Ig)M gammopathy, and increased levels of markers of systemic inflammation. The response to immunosuppressive therapy is usually disappointing, but recent reports on the favourable effect of interleukin (IL)-1 receptor antagonists are promising. We report here three patients who obtained prompt and lasting complete remission when treated with the IL-1 receptor antagonist anakinra. Including the present three cases, a literature review disclosed 26 cases of Schnitzler's syndrome who responded favourably to treatment with anakinra. The male-to-female ratio was 1.4, and in more than 50% of cases the disease duration prior to administration of anakinra exceeded 5 years. Cessation of treatment was unanimously followed by recurrence of disease, but reinstitution of anakinra resulted in remission. Monoclonal gammopathy was documented in 21 out of 23 cases (IgM in 18 and IgG in three cases), but no definite effects of anakinra upon monoclonality were observed. Based on this report and previous observations, we tentatively suggest that IL-1 receptor antagonists should be considered early in the course of Schnitzler's syndrome.