Infectious outcomes of a standardized subcutaneous immunoglobulin dose reduction strategy in primary immune deficiencies amid global shortage

• Published in: Frontiers in immunology 2025-01, Vol.15
• Main Authors: Moral Moral, Pedro, Cabanero-Navalon, Marta Dafne, López-León, Paula Teresa, Balastegui-Martín, Héctor, Martínez Mercader, Sandra, Mir, Amparo, Garcia-Bustos, Victor
• Format: Article
• Language: English
• Subjects: cost-effectiveness; humoral primary immune deficiencies; immunoglobulin replacement therapy; infections; resource shortage; subcutaneous immunoglobulin
• ISSN: 1664-3224; 1664-3224
• DOI: 10.3389/fimmu.2024.1527514

IntroductionImmunoglobulin replacement therapy (IgRT), either intravenous (IVIg) or subcutaneous (SCIg), is crucial for managing primary immune deficiencies (PIDs) with hypogammaglobulinemia by reducing infection rates and mortality. During the COVID-19 pandemic, a global shortage of SCIg prompted our unit to reduce SCIg doses or maintain the same dose intravenously. This study evaluates the impact of a standardized SCIg dose reduction on infection rates and clinical outcomes in patients with humoral PID and with a low burden of infections.MethodsAdult PID patients on SCIg for at least 6 months, with IgG trough levels ≥ 700 mg/dL (or ≥ 900 mg/dL under specific conditions), and no significant infections in the past 6 months were eligible. A dose reduction of 15 mg/kg/week (60 mg/kg/month) for every 150 mg/dL above 700 mg/dL (or 900 mg/dL) was proposed. Clinical and laboratory data, and infectious events at 6- and 12-month follow-ups, were analyzed.ResultsThirty-one patients with PID were included: common variable immunodeficiency (54.83%), IgG subclass deficiency (9.67%), and other PIDs (35.48%). The average SCIg dose was initially reduced from 7.82 g/week to 5.72 g/week and adjusted to 6.94 g/week at 12 months. There was no significant change in severe or mild infections before and at 6- and 12-months post-dose adjustment. The dose reduction saved an average of 5,550 euros per patient annually, totaling 172,050 euros annually for our cohort.DiscussionOptimizing SCIg doses in selected well-controlled humoral PIDs is feasible without increasing infection rates, conserving this plasma-derived product during shortages. Larger prospective studies are needed to confirm this strategy's utility and its application to other Ig formulations.