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

Abstract

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 18F-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 18F-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 technique could not reliably predict the presence of an exacerbation in children with HIV, 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.