Palivizumab Exposure and the Risk of Atopic Dermatitis, Asthma and Allergic Rhinoconjunctivitis: A Cross-National, Population-Based Cohort Study

BACKGROUND: Palivizumab is a humanized monoclonal antibody designed to provide passive immunity against respiratory syncytial virus. It is prescribed to children at high risk for severe infection with respiratory syncytial virus. However, little is known about the risk of the immune-mediated diseases atopic dermatitis, asthma, and allergic rhinoconjunctivitis after palivizumab exposure.

AIM: Our objective was to investigate whether exposure to palivizumab was associated with atopic dermatitis, asthma, or allergic rhinoconjunctivitis in childhood.

METHODS: This was a cross-national population-based cohort study including data from 769,523 Danish children born 1 January 1999-31 December 2010 and 581,742 Swedish children born 1 July 2005-31 December 2010. Since palivizumab is only indicated for children at the highest risk, sub-cohorts of preterm children, children with bronchopulmonary dysplasia, and children with hemodynamic significant heart disease were defined.

RESULTS: Of the 1,351,265 children included, 1192 (0.09%) were exposed to palivizumab. An increased risk of asthma after palivizumab exposure was observed in the total birth cohort (hazard ratio [HR] 1.49; 95% confidence interval [CI] 1.32-1.68) and in the sub-cohort of preterm children (HR 1.24; 95% CI 1.07-1.44). However, post hoc analyses using the propensity score to balance confounding factors found no increased risk of asthma in preterm children (HR 0.91; 95% CI 0.56-1.48). No increased risks of atopic dermatitis (HR 1.18; 95% CI 0.94-1.48) or allergic rhinoconjunctivitis (HR 1.14; 95% CI 0.92-1.42) were observed.

CONCLUSION: Exposure to palivizumab neither increased the risk of atopic disease nor protected against asthma.