Presentation: Elevated Airway CD45RO Memory Cells in Wheezing Children with Lower Respiratory Infection ( World Allergy Congress)

Wednesday, 14 October 2015

Hall D1 Foyer (Floor 3) (Coex Convention Center)

Jungi Choi, MD , Asthma Allergy Center, Sanggye Paik Hospital, Seoul, South Korea

Yusok Han, MD , Asthma Allergy Center, Sanggye Paik Hospital, Seoul, South Korea

Jin-Sung Park, MD , Asthma Allergy Center, Sanggye Paik Hospital, Seoul, South Korea

Eunmi Kwon, CRN , Asthma Allergy Center, Sanggye Paik Hospital, Seoul, South Korea

Chang-Keun Kim, MD, PhD , Asthma and Allergy Center, Inje University Sanggye Paik Hospital, Seoul, South Korea

Introduction: No data on airway T cell subsets in “wheezing” children (WC) is available. CD25, found on activated T cells and CD45RO “memory”cells, associated with T cell development, T cell activation and IgE synthesis, were analyzed in BAL from WC and normals.

Methods: We evaluated 18 WC with a minimum of 2 episodes of wheezing or prolonged wheezing ≥2 months in a 6 month period with BAL. WC were further sub-divided into children with history of RSV (WC+RSV)(n=10, median age 17.0 months) or without RSV (WC-RSV)(n=8, median age 9.3 months). Comparisons were made with normal controls (Control)(n=5, median age 19.5 mos). BAL cell counts and differentials were determined, and 10⁶ cells were fixed in acetone and embedded in glycol methacrylate resin. Cell blocks were cut and immunohistochemically stained for the following T cell surface markers: CD3, CD4, CD8, CD25, and CD45RO. Co-expression of CD25 or CD45RO on CD3, CD4, and CD8 T cells was evaluated by an image analysis program on sequential sections. Comparisons between all the groups were first made using the Kruskal-Wallis test. In case of significant difference, individual groups were compared by using the Mann-Whitney U test.

Results: The total number of CD3 cells was significantly elevated in the WC+RSV compared with the Control (p=0.008). WC+RSV had significant (p=0.003) elevations in # of CD45RO cells/1000 cells compared to Control and the total number of CD45RO was significantly elevated in the WC+RSV compared with the WC-RSV (p=0.033) and the Control (p=0.001). Although the % of CD4 T cells expressing CD45RO was greater in WC+RSV than WC-RSV, the elevation was only statistically significant compared to Control (p=0.005).

Conclusions: These findings suggest that specific T cell profiles exist in WC+RSV which differ from WC-RSV and Control. Furthermore CD45RO cells may play a role in the immune processes of WC+RSV.

1150 Elevated Airway CD45RO Memory Cells in Wheezing Children with Lower Respiratory Infection