How I treat autoimmune neutropenia in adults

Autoimmune neutropenia (AiN) in adults is rare when compared to children. It occurs predominantly in female patients and in individuals with other autoimmune conditions. Anti‑neutrophil antibodies are detected in ~50% of patients with AiN, and it is not clear whether this reflects testing limitations or cell-mediated (rather than antibody-mediated) mechanisms of neutrophil destruction. Unlike the commonly self‑limited pediatric disease, adult AiN is generally chronic. The degree of neutropenia and the clinical severity is highly variable, and most patients remain asymptomatic and free of infection despite absolute neutrophil counts (ANC) persistently lower than 500 /uL. As most patients do well despite their neutropenia, observation and supportive care are generally preferred over active treatment. Where necessary, empiric treatment recommendations have stemmed from small numbers of cases. Therapy focuses on boosting endogenous neutrophil production, reducing immune-mediated destruction, or eliminating pathogenic autoantibodies. Clinical response is highly variable, and second-line therapies, including T‑cell-directed approaches, can be effective, supporting a role for cell-mediated mechanisms of neutrophil destruction in a subset of patients. Emerging strategies, such as plasma cell-targeted therapies, modulation of cytokine signaling pathways, and complement blockade also show promise. Collaboration and discussion around this rare condition is critical to enhance treatment algorithms.