Immunoglobulin for PID Requires Education, Caution, and Finesse

IN A VIRTUAL symposium held in conjunction with the Asembia Specialty Pharmacy Summit, 2 speakers discussed the common primary immunodeficiency disorders (PIDs) and their effects on patients’ quality of life (QOL). This was an important symposium because the dosing, the unique characteristics, and the appropriate use of subcutaneous and intravenous immunoglobulins (SCIGs, IVIGs) for PID are complex. Pharmacists are ideally positioned to work with the rest of the health care team to optimize treatment for those with PID.

Luigi Brunetti, PharmD, MPH, BCPS, BCGP, used a case study to explore ways that the clinical treatment team can be involved in care management. He explained that about 250,000 Americans have PID, with Caucasians twice as likely to be affected as African Americans and Hispanics. Often inherited, PID is an adaptive and/or innate immunity disorder. Patients with PID have an increased susceptibility to infection because of a deficient immune system.

PID exists in over 200 permutations, with agammaglobulinemia, common variable immunodeficiency, severe combined immunodeficiency disorder, selective IgA deficiency, Wiskott-Aldrich syndrome, and chronic granulomatous disease the most common. Brunetti discussed immune deficiency patterns, presentation, and place in therapy of immunoglobulin for each.

Brunetti compared the available immunoglobulin formulations and highlighted key differences including osmolarity, IgA content, pH, and stabilizers. For this reason, organizations need institutional protocols to guide treatment initiation, adjustment, and monitoring.

Over the past several years, SCIG has emerged as a new treatment route and offered increased independence for patients with PID. Some studies suggest that home-based SCIG replacement improves health-related QOL or satisfaction and may be preferable to hospitalbased IVIG or even home-based IVIG infusion.

Jonathan Ogurchak, PharmD, CSP, then took over and covered the specialty pharmacist’s role in coordinating care for patients with PID. He discussed 8 areas in which pharmacists need to be involved based on the American Academy of Asthma, Allergy & Immunology’s guidance. IV and SC administration have comparable efficacy, and results of recent studies indicate that initiating treatment with SC dosing is acceptable. Of note, patients who receive reduced doses of SCIG have 30% higher rates of hospitalization.

Ogurchak noted that SC administration is most appropriate in patients with poor venous access, younger patients, patients with low-volume tolerance, and patients who have low trough levels when they receive IVIG. The transition from IVIG to SCIG should be done carefully using a conversion factor, which can be found in the labeling for each product.

Ogurchak added that adverse effects (AEs) vary between the IV and SC route of administration. For IVIG, systemic reactions are more common, whereas local reactions predominate with SCIG treatment. He discussed strategies to minimize and manage AEs should they occur.

In addition, Ogurchak emphasized that central lines can increase infection and blood clot risk. He also urged pharmacists to consider increasing doses during periods of infection as well as administering prophylactic antibiotics. He reminded attendees that live vaccines are contraindicated for both the affected individuals and for family members and caregivers.

Ogurchak concluded the presentation by highlighting clinical pearls that pharmacists can employ in caring for patients with PID. He emphasized that the selection of the optimal treatment approach is highly individualized and should be centered on patient characteristics and preference.