52 Clinical characteristics and diagnosis of NTM infection in children with cystic fibrosis (CF) in the North East of England

Objective Non-tuberculous mycobacterial (NTM) infection is an emerging clinical problem in people with CF but the threshold for treatment is uncertain. American Thoracic Society (ATS) criteria exist for the diagnosis of NTM infection but are not CF specific and their usefulness in children is uncertain. We audited whether NTM affected patients in our service met these criteria relative to decisions regarding treatment. Methods Clinical, radiographic and microbiological data were collected on all NTM affected patients. The ATS diagnostic criteria are a.presence of pulmonary symptoms; b.nodular or cavitary opacities on CXR OR multifocal bronchiectasis plus nodules on HRCT; and c.positive cultures from 2 or more sputum samples. Results Ten children (7 male, median age 13.5 years, 6 × DF508/ DF508) isolated Mycobacterium abscessus between 1 and 18 times (median 5.5). Median % predicted FEV1 pre-NTM isolation was 82.5% and post was 82.0% (p=NS). Median weight-for-age Z score pre-isolation was 0.18 and post-isolation was –0.25 (Kruskal–Wallis p=0.056). Four of ten patients fulfilled clinical, radiographic and microbiological criteria at isolation of NTM. Five patients were treated for NTM infection; of these three met the ATS criteria at the time of commencing treatment. Conclusion Acquiring NTM was not associated in a decline in lung function in children in our service. ATS criteria were of limited clinical utility in our clinic but the recent publication of consensus guidelines will help to improve this situation.