Defective germinal center selection results in persistence of self-reactive B cells from the primary to the secondary repertoire in Primary Antiphospholipid Syndrome.

Primary antiphospholipid syndrome (PAPS) is a life-threatening clotting disorder mediated by pathogenic autoantibodies. Here we dissect the origin of self-reactive B cells in human PAPS using peripheral blood and bone marrow of patients with triple-positive PAPS via combined single-cell RNA sequencing, B cell receptors (BCR) repertoire profiling, CITEseq analysis and single cell immortalization. We find that antiphospholipid (aPL)-specific B cells are present in the naive compartment, polyreactive, and derived from the natural repertoire.

CAR-T cells for treating systemic lupus erythematosus: A promising emerging therapy.

Chimeric Antigen Receptor T-cell therapy (CAR-T), currently employed routinely for treating B-cell malignancies, has emerged as a groundbreaking approach in addressing severe autoimmune diseases, especially for systemic lupus erythematosus (SLE). The immunological rationale for targeting B lymphocytes in autoimmune diseases is well-established, demonstrating success in numerous autoantibody-mediated autoimmune conditions through targeted therapies over several years. However, this approach has often proven ineffective in the context of systemic lupus erythematosus.

Case Report: Acquired Disseminated BCG in the Context of a Delayed Immune Reconstitution After Hematological Malignancy.

Context: Disseminated infections due to Bacillus Calmette-Guérin (BCG) are unusual and occur mostly in patients with inborn error of immunity (IEI) or acquired immunodeficiency. However, cases of secondary BCGosis due to intravesical BCG instillation have been described. Herein, we present a case of severe BCGosis occurring in an unusual situation.