Is the clinical picture of Schnitzler syndrome always Schnitzler syndrome?

Here we present two cases, a female and a male patient with Schnitzler-like syndrome. Both patients had two major (monoclonal gammopathy and chronic urticaria) and almost all minor symptoms (e.g. arthralgia, bone pain, fever, etc.) of Schnitzler syndrome. It is considered that interleukine (IL)-1 has important influence on immunopathogenesis of Schnitzler syndrome. However, when looked at the immune response in our two patients, we found significant differences between them. In the sera of the female patient, IL-1beta was increased. However, the highest increase was found for granulocyte- colony stimulating factor (G-CSF), IL-32 alpha and IL-17E (IL-25). The male patient had a significant increase in the percentage of NK-cells, a decrease in CD4+ helper cells and no increase in cytokine levels. In both patients an increase in CD40L (CD154) was found. Our statement is that, besides clinical symptoms and signs, additional immune parameters should be tested before diagnosis of Schnitzler syndrome is established.