Quality and Safety Intervention: Improving Care of Patients Undergoing B Cell-Targeted Therapies.

B cell-targeted therapies (BCTT) are increasingly being used with excellent efficacy across a range of conditions and specialties, including autoimmune diseases and hematologic malignancies. However, with these BCTT, there is the potential for hypogammaglobulinemia and increased risk for infections. It is critical for clinicians to understand and manage secondary immune deficiency to ensure patient safety and optimize therapeutic outcomes. Increased monitoring including evaluating immunoglobulin levels and B-cell flow cytometry before the initiation of therapy and periodically afterward can assist in tailored management of these patients, with potential consideration of prophylactic antimicrobials and/or immunoglobulin replacement to improve outcomes through reduction of morbidity and mortality. Conversely, because inborn errors of immunity are more frequent in patients receiving BCTT, clinicians should be alert to clinical and immunologic red flags suggestive of an underlying inborn errors of immunity. Two illustrative cases are used to present important considerations in the diagnosis, evaluation, and management of patients receiving BCTT.