IgA monoclonal gammopathy associated with refractory IgA vasculitis successfully treated with clone-targeted therapy

IgA vasculitis with underlying monoclonal IgA gammopathy: innovative therapeutic approach targeting plasma cells. A case series

OBJECTIVE

There is currently no evidence of the possible benefit of plasma cell-targeting therapies (PCTT) in immunoglobulin A (IgA) monoclonal gammopathy (MG) associated with IgA vasculitis (IgAV). We report the outcome of different PCTT regimens in a cohort of MG-IgAV.

METHODS

We used a French network to retrospectively describe the outcome of MG-IgAV patients treated with PCTT.

RESULTS

Five patients were included (mean age 65 years). All patients had severe baseline presentation including extensive necrotic purpura (n = 5), gastrointestinal involvement (n = 2), peripheral neuropathies (n = 2), and glomerulonephritis (n = 1). Two patients had IgA indolent multiple myeloma and three had IgA "MG of undetermined significance." Monotypic IgA deposition in the skin vessels wall was highlighted using an immunofluorescence assay. Cases of vasculitis in three patients (n = 3) were refractory to multiple line therapies, including cyclophosphamide (n = 3) or rituximab. Finally, PCTT including bortezomib plus cyclophosphamide and dexamethasone, bortezomib plus melphalan and prednisone, or bortezomib plus lenalidomide and dexamethasone were proposed, allowing complete remission in 4/5 patients without major adverse drug events.

CONCLUSION

This study suggests that the MG-IgAV phenotype might be distinctive of usual IgAV (severe and refractory to conventional immunosuppressive regimens) and supports the benefit of PCTT. This study sheds new light on the overall biology of IgAV, strengthening the pathogenic role of the monoclonal IgA component in IgAV.

Bortezomib in autoimmune hemolytic anemia and beyond

Bortezomib is a first-in-class, potent, selective and reversible proteasome inhibitor approved for the treatment of multiple myeloma (MM) and relapsed/refractory mantle cell lymphoma. In these diseases, bortezomib targets plasma cells and lymphocytes reducing tumor burden. Recently, preclinical evidence highlighted its efficacy in reducing long-lived plasma cells responsible of autoantibodies production in several models of autoimmune conditions. These findings paved the way to a number of experiences of bortezomib use in patients with various autoimmune conditions, including autoimmune hemolytic anemia (AIHA). The latter is a nice model of autoimmunity in hematology and is caused by the production of autoantibodies against erythrocytes resulting in various degrees of hemolytic anemia. AIHA is classified in warm and cold forms according to the thermal characteristics of the autoantibody, and first-line treatment mainly relies on steroids for warm cases and the anti-CD20 rituximab for cold ones. Relapsed/refractory cases are still an unmet need, and bortezomib has been proposed in this setting with intriguing efficacy. In this review, we collected available literature on bortezomib use in AIHA and in other immune-mediated hematologic and non-hematologic diseases. Overall, most experiences highlight bortezomib efficacy even in multi-relapsed/refractory patients and suggest to consider its use in AIHA after rituximab failure.