Feng M, et al. - Researchers determined the link between clinical outcomes and functional responses of allergen-specific IgG4 (sIgG4) and specific IgE (sIgE) during Dermatophagoides pteronyssinus s.c. allergen immunotherapy (SCIT) in allergic rhinitis and/or asthma patients. During the updosing (week 0, 4, 12, and 16) and maintenance (week 52, 104, and 156) phase of SCIT, evaluation of combined symptom medication scores (SMS), D. pteronyssinus–sIgG4 levels, D. pteronyssinus–sIgE levels, and the serum inhibitory capacity against D. pteronyssinus–sIgE facilitated allergen binding to B cells (IgE-FAB) was carried out. D. pteronyssinus–sIgG4 level and D. pteronyssinus IgE-FAB were found to be related to clinical efficacy in the maintenance phase rather than the updosing phase of SCIT. When maintenance phase was achieved, immunologic tolerance could be induced with SCIT.