Generation of Neutrophil Mediators During an Experimental Infection with Rhinovirus-16 in Asthmatic Patients.
Sunday, March 4, 2018
South Hall A2 (Convention Center)
Robert A. Sullivan, MD, Evan Rajadhyaksha, BSc, Patricia Jorge, M.D, Holliday T. Carper, BS, Deborah D. Murphy, RN, Thomas A.E. Platts-Mills, MD PhD FAAAAI, Peter W. Heymann, MD
RATIONALE: Rhinovirus (RV) infections frequently cause asthma exacerbations in children and young adults. RV infections are also known to stimulate recruitment of neutrophils into the airways. We speculate that neutrophil mediators will be increased in nasal washes (NW’s) from asthmatics compared to non-asthmatic controls during an experimental infection with RV-16.

METHODS: Sixteen subjects (ages 19-33) were inoculated with RV-16 (dose=300 TCID50). They included 9 allergic-asthmatics (total IgE levels 596-1989 IU/mL), and 7 controls (total IgE levels 5-42 IU/mL). Neutrophil mediators, neutrophil elastase (NE) and myeloperoxidase (MPO), were measured by ELISA in NW’s obtained before and during (Days 1, 2, 3, 4, 7, 14, 21) the infection. The results were compared to symptom scores.

RESULTS: Both NE and MPO levels peaked in NW’s on Day 3 of the infection, paralleling the development of peak cold symptoms in both asthmatics and controls. Compared to baseline values before inoculation, mediator values by Day 3 increased 7 and 5-fold for NE and MPO among asthmatics, respectively, and 5 and 3-fold among the controls. Cumulative values (summed over days 1-3 following RV inoculation) trended higher in asthmatics compared to controls (e.g., geometric means for NE=3775ng/mL and 2167ng/mL, respectively, p=0.45; MPO=1375ng/mL and 917.3ng/mL, p=0.66), but this trend was not apparent during resolution of the infection (days 14 and 21).

CONCLUSIONS: During the early (innate) phase of the infection, a consistent trend in higher levels of neutrophil mediators was observed in nasal washes from asthmatic subjects compared to controls. This increase was no longer seen during resolution of the infection.