Monoclonal Gammopathy, Arthralgias, and Recurrent Fever Syndrome: A New Autoinflammatory Syndrome?

International audienceObjective. To describe a new autoinflammatory syndrome with recurrent fever and monoclonal gammopathy that differs from Schnitzler syndrome. Methods. We conducted a retrospective study of patients with monoclonal gammopathy and recurrent fever of unknown origin. Results. Five patients were studied; median age at onset of symptoms was 44 years. Median frequency of fever attacks was 6 episodes per year. In the absence of treatment, the median duration of fevers was 3 days. Conclusion. This new autoinflammatory syndrome is defined by an association among monoclonal gammopathy, arthralgias, and recurrent fever

Antiplatelet Antibodies Do Not Predict the Response to Intravenous Immunoglobulins during Immune Thrombocytopenia

Immune thrombocytopenia (ITP) is a rare autoimmune disease due to autoantibodies targeting platelet glycoproteins (GP). The mechanism of platelet destruction could differ depending on the specificity of antiplatelet antibodies: anti-GPIIb/IIIa antibodies lead to phagocytosis by splenic macrophages, in a Fcγ receptor (FcγR)-dependent manner while anti-GPIb/IX antibodies induce platelet desialylation leading to their destruction by hepatocytes after binding to the Ashwell–Morell receptor, in a FcγR-independent manner. Considering the FcγR-dependent mechanism of action of intravenous immunoglobulins (IVIg), we assumed that the response to IVIg could be less efficient in the presence of anti-GPIb/IX antibodies. We conducted a multicentric, retrospective study including all adult ITP patients treated with IVIg who had antiplatelet antibodies detected between January 2013 and October 2017. Among the 609 identified, 69 patients were included: 17 had anti-GPIb/IX antibodies and 33 had anti-GPIIb/IIIa antibodies. The response to IVIg was not different between the patients with or without anti-GPIb/IX (88.2% vs. 73.1%). The response to IVIg was better in the case of newly diagnosed ITP (odds ratio (OR) = 5.4 (1.2–24.7)) and in presence of anti-GPIIb/IIIa (OR = 4.82 (1.08–21.5)), while secondary ITP had a poor response (OR = 0.1 (0.02–0.64)). In clinical practice, the determination of antiplatelet antibodies is therefore of little value to predict the response to IVIg