We sought to determine the effect of treatment with topical tacrolimus on B- and T-cell immunity including the primary antibody response to pneumococcal polysaccharide vaccine in children with atopic dermatitis.

In this open-label, noncomparative study, 23 children aged 2 to 12 years with moderate to severe atopic dermatitis were treated with tacrolimus 0.03% ointment twice daily for 7 weeks, immunized with a 23-valent pneumococcal polysaccharide vaccine after 3 weeks of treatment, and had their antibody response measured (for 12 pneumococcal serotype antigens present in the vaccine) before and 4 weeks after vaccination. None had received pneumococcal vaccine before the study. Patient antibody and cellular immune responses were assessed at each study visit (baseline, week 3, and week 7).

No significant changes in complete blood cell count, lymphocyte subsets, CD4/CD8 ratio, immunoglobulin levels, antibody titers to tetanus and Haemophilus influenzae, or lymphoproliferative responses were noted during the tacrolimus ointment treatment period. Tacrolimus blood levels were 1 ng/mL or less in all 23 children. Protective pneumococcal titers to all 12 serotypes were observed in 2 of 23 (9%) children prevaccination and in 16 of 23 (70%) children postvaccination. All 6 children who had protective titers to 0 to 5 of the 12 serotypes developed protective titers to an additional 5 to 11 serotypes. Of the patients, 91% had a greater than 4-fold increase in titer for at least 4 of 12 pneumococcal serotypes.

Topical application of tacrolimus ointment does not affect the serologic response to pneumococcal vaccine or interfere with preexisting T- and B-cell immune responses.