Positron emission tomography in the prediction of inflammation in children with human immunodeficiency virus related bronchiectasis.

There is a lack of objective tools to reliably diagnose exacerbations in bronchiectasis. The primary aim of this study was to assess the ability of fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) to detect sites of active inflammation in children with human immunodeficiency virus (HIV)-related bronchiectasis with or without exacerbations. The secondary aim was to assess whether ¹⁸F-FDG-PET/CT results are in agreement with local and systemic inflammatory markers and markers of HIV disease activity. Forty-one children with HIV-related bronchiectasis underwent ¹⁸F-FDG PET/CT. Data on the presence of a clinical exacerbation were recorded. Serum was collected for CD4 count, HIV viral load, C-reactive protein (CRP) and cytokines IL-8, INF-γ and TNF-α. Induced sputum samples were processed for microbiological culture and for IL-8, INF-γ and TNF-α.Mean age of all children was 8.2 ± 2.2 years. Twelve subjects showed F-FDG lung uptake while six of them had an exacerbation. There was no difference in the ¹⁸F-FDG uptake in participants with or without an exacerbation (P=0.613). Fluorine- 18-FDG-PET had a good correlation with the presence of consolidation (P=0.01, OR=6.67). The mean CRP was higher in the subjects with (18)F-FDG uptake when compared to those without uptake (51.96 ± 95.12 vs. 13.26 ± 19.87), although this difference was not significant (P=0.09). In conclusion, the ¹⁸F-FDG-PET lung uptake technique could not reliably predict the presence of an exacerbation in children with HIV and bronchiectasis, and its diagnostic value was limited to identifying disease activity on the scan in acute pneumonia cases. Fluorine-18-FDG-PET had no significant correlation with CRP or with other inflammatory biomarkers and markers of HIV disease activity.