B cell depletion in immune thrombocytopenia reveals splenic long-lived plasma cells.

International audiencePrimary immune thrombocytopenia (ITP) is a disorder caused by autoantibody-mediated platelet destruction and decreased platelet production. Rituximab, a B cell-depleting agent, has become the first-line treatment for ITP; however, patients with refractory disease usually require splenectomy. We identified antibody-secreting cells as the major splenic B cell population that is resistant to rituximab. The phenotype, antibody specificity, and gene expression profile of these cells were characterized and compared to those of antibody-secreting cells from untreated ITP spleens and from healthy tissues. Antiplatelet-specific plasma cells (PC) were detected in the spleens of patients with ITP up to 6 months after rituximab treatment, and the PC population displayed a long-lived program similar to the one of bone marrow PC, thus explaining for most of these patients the absence of response to rituximab and the response to splenectomy. When analyzed by multiplex PCR at the single-cell level, normal splenic PC showed a markedly different gene expression profile, with an intermediate signature, including genes characteristic of both long-lived PC and proliferating plasmablasts. Surprisingly, long-lived PC were not detected in untreated ITP spleens. These results suggest that the milieu generated by B cell depletion promotes the differentiation and settlement of long-lived PC in the spleen

Br J Haematol

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Mémoire immunitaire contre le SARS-CoV-2: Des anticorps contre l’infection initiale et des lymphocytes B à mémoire contre les infections futures

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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

Clinical severity in adult warm autoimmune hemolytic anemia and its relationship to antibody specificity

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Bortezomib and dexamethasone, an original approach for treating multi‐refractory warm autoimmune haemolytic anaemia

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Antigenic targets in anti-SRP immune-mediated necrotizing myopathy

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