Purpose: Intravenous immunoglobulin (IVIG) is used to replenish immunoglobulins in hypogammaglobulinemia (HG) caused by hematologic malignancies (HM) or their treatment (autologous stem-cell transplantation [ASCT] and chimeric antigen receptor T-cell therapy [CAR-T]), in an effort to reduce the risk of infections. However, there is limited evidence to support this use, and IVIG supplies are limited and shortages are common.
Methods: An IVIG stewardship program (ISP) was implemented with the following requirements for IVIG administration: immunoglobulin G (IgG) level < 400 mg/dL (corrected for paraprotein) for post-ASCT and post-CAR-T patients, or IgG < 400 mg/dL with a history of a bacterial infection within the preceding 3 months for those with HM. Comparisons of the amount of IVIG administered, the incidence of infections, and the use of antimicrobials were performed between the 3 months before ISP and the 3 months after ISP.
Results: IVIG administered for HG decreased from 4,902 g in 86 patients before ISP to 1,777 g in 55 patients after ISP, a cost savings of $44,700. Adherence to ISP guidelines was 80%. Compared with before ISP, patients who stopped receiving IVIG after ISP had lower nadir IgG, fewer infections/patient-months, less antimicrobial usage, and a lower hospitalization rate for infection; no deaths occurred. Compared with before ISP, patients receiving IVIG after ISP had lower predose IgG and fewer infections/patient-months; the antibiotic usage, hospitalization rate for infection, and deaths from infection remained stable.
Conclusion: To our knowledge, this is the first ISP to lead to a dramatic decrease in IVIG usage with high adherence, primarily by selecting out patients at low risk of infection after IVIG discontinuation. Such an ISP is replicable and warrants adoption.