%0 Journal Article %A Vanessa Algar %A Grace Choi %A Konstantinos Douros %A Mark Everard %T Neutrophil count trends in BAL samples from children being investigated for chronic cough %D 2012 %J European Respiratory Journal %P P4113 %V 40 %N Suppl 56 %X Introduction: Investigating probable persistent bacterial bronchitis (PBB) with a bronchoscopy allows the identification of infectious agents and quantification of cellular responses in the paediatric population who rarely expectorate sputum under the age of 10. Methods: Bronchoscopies in children carried out 2010-11 were identified and a retrospective case notes analysis done to identify those performed because of chronic cough or proven/probable PBB. Bronchoalveolar lavage (BAL) samples were analysed for standard bacterial culture, viral PCR and neutrophil count (%). Results: 70 bronchoscopy BALs were analysed: 18.6% positive for bacterial and viral culture (B pos/V pos); 35.7% positive for bacteria but negative for viruses (B pos/V neg); 21.4% negative for bacteria but positive for viruses (B neg/V pos); 24.3% negative for both (B neg/V neg). Analysis of the BAL neutrophil count (%) was performed with one-way ANOVA and Cuzick's test for trend. For the reasons of analysis the 4 groups were ordered as follows: group 1: B pos/V pos• group 2: B pos/V neg• group 3: B neg/ V pos• group 4 B neg/Vneg. The 4 groups differ significantly (means±sd:45.7±30.7, 18.6±21.4, 20.4±22.9, 11.6±15.2, for groups 1, 2, 3, and 4, respectively, p=0.001). Furthermore, a significant trend was found across the 4 ordered groups (p=0.003). Conclusion: The presence of bacteria and viruses is associated with a significantly more neutrophils and thus a greater degree of inflammation than that induced by bacteria alone and could explain why recurrent viral infections are a feature of PBB. %U https://erj.ersjournals.com/content/erj/40/Suppl_56/P4113.full.pdf