Background: Patients with an IgG subclass deficiency (IgSD) ± specific polysaccharide antibody deficiency (SPAD) often present with recurrent infections. Previous retrospective studies have shown that prophylactic antibiotics (PA) and immunoglobulin replacement therapy (IRT) can both be effective in preventing these infections; however, this has not been confirmed in a prospective study. Objective: To compare the efficacy of PA and IRT in a randomized crossover trial. Methods: A total of 64 patients (55 adults and 9 children) were randomized (2:2) between two treatment arms. Treatment arm A began with 12 months of PA, and treatment arm B began with 12 months of IRT. After a 3-month bridging period with cotrimoxazole, the treatment was switched to 12 months of IRT and PA, respectively. The efficacy (measured by the incidence of infections) and proportion of related adverse events in the two arms were compared. Results: The overall efficacy of the two regimens did not differ (p = 0.58, two-sided Wilcoxon signed-rank test). A smaller proportion of patients suffered a related adverse event while using PA (26.8% vs. 60.3%, p < 0.0003, chi-squared test). Patients with persistent infections while using PA suffered fewer infections per year after switching to IRT (2.63 vs. 0.64, p < 0.01). Conclusion: We found comparable efficacy of IRT and PA in patients with IgSD ± SPAD. Patients with persistent infections during treatment with PA had less infections after switching to IRT. Clinical Implication: Given the costs and associated side-effects of IRT, it should be reserved for patients with persistent infections despite treatment with PA.
Bibliographical noteFunding Information:
This study was sponsored by the Sanquin Plasma Products, Amsterdam, the Netherlands.
We wish to acknowledge the assistance provided by R. Albers-Strik, J. van Esch, and M. van Aartrijk in patient recruitment and data collection, which was greatly appreciated. Moreover, we would like to thank G. Rijkers for measuring the specific polysaccharide antibodies and Prof. P.J.J. Hooykaas and M. van der Burg for measuring the B cell subsets in the blood samples of our patients. We thank Sanquin Home Service for making it possible for patients to have IVIG infusions at home and for collecting blood samples.
© 2020, The Author(s).