The Role of Immunotherapy in the Treatment of Asthma
Abstract
Objectives. To evaluate the efficacy and safety of subcutaneous immunotherapy (SCIT) and sublingual immunotherapy (SLIT) in the treatment of allergic asthma.
Data Sources. We searched PubMed, Embase, and CENTRAL through May 8, 2017.
Methods. Two reviewers independently selected randomized controlled trials (RCTs) of the efficacy of SCIT and SLIT and RCTs, observational studies, and case series or case reports on safety. Two reviewers independently assessed the risk of bias for each study and together graded the strength of the evidence.
Results. We identified 54 RCTs on efficacy: 31 assessed SCIT and 18 assessed SLIT and 5 on SCIT versus SLIT. We included 80 studies on safety: 26 RCTs and 18 non-RCTs for SCIT, 20 RCTs and 10 non-RCTs for SLIT and one non-RCT on SCIT versus SLIT.
SCIT reduces the use of long-term control medications [moderate strength of evidence (SOE)]. SCIT may improve quality of life, reduce the use of quick-relief medications (short-acting bronchodilators), reduce the need for systemic corticosteroids, and improve FEV1 (low SOE). There was insufficient evidence regarding the effect of SCIT on asthma symptoms and health care utilization. Local and systemic allergic reactions were frequent but infrequently required a change in treatment. We are unable to draw conclusions about whether SCIT increased risk of anaphylaxis, primarily because anaphylaxis was not directly measured (insufficient SOE). There was one case report of a death determined possibly to be caused by SCIT.
SLIT improves asthma symptoms (high SOE); decreases use of long-term control medication and improves FEV1 (moderate SOE). SLIT may decrease quick-relief medication use, and may improve quality of life (low SOE). There was insufficient evidence about the effect of SLIT on systemic corticosteroid use and health care utilization. Local and systemic allergic reactions were common but infrequently required changes in treatment. Life-threatening reactions were not commonly reported, with three case reports of anaphylaxis (insufficient SOE) and no deaths (moderate SOE) reported.
There was insufficient evidence to draw conclusions about the comparative effects of SCIT versus SLIT or for differential effects of immunotherapy based on patient age, setting of administration, or type of allergen.
Conclusions. Overall, SLIT and SCIT were beneficial for the majority of asthma-related outcomes assessed in this report. Local and systemic allergic reactions were common but infrequently required changes in treatment. Life-threatening events (such as anaphylaxis) were reported rarely.
RPR Commentary
This systematic review found that immunotherapy is realtively safe and effective in patients with asthma.