title: Early Changes by (18)Fluorodeoxyglucose positron emission tomography coregistered with computed tomography predict outcome after Mycobacterium tuberculosis infection in cynomolgus macaques.
abstract: Cynomolgus macaques infected with low-dose Mycobacterium tuberculosis develop both active tuberculosis and latent infection similar to those of humans, providing an opportunity to study the clinically silent early events in infection. (18)Fluorodeoxyglucose radiotracer with positron emission tomography coregistered with computed tomography (FDG PET/CT) provides a noninvasive method to measure disease progression. We sought to determine temporal patterns of granuloma evolution that distinguished active-disease and latent outcomes. Macaques (n = 10) were infected with low-dose M. tuberculosis with FDG PET/CT performed during infection. At 24 weeks postinfection, animals were classified as having active disease (n = 3) or latent infection (n = 6), with one "percolator" monkey. Imaging characteristics (e.g., lesion number, metabolic activity, size, mineralization, and distribution of lesions) were compared among active and latent groups. As early as 3 weeks postinfection, more pulmonary granulomas were observed in animals that would later develop active disease than in those that would develop latent infection. Over time, new lesions developed in active-disease animals but not in latent animals. Granulomas and mediastinal lymph nodes from active-disease but not latent animals consistently increased in metabolic activity at early time points. The presence of fewer lesions at 3 weeks and the lack of new lesion development in animals with latent infection suggest that innate and rapid adaptive responses are critical to preventing active tuberculosis. A greater emphasis on innate responses and/or rapid recruitment of adaptive responses, especially in the airway, should be emphasized in newer vaccine strategies.
authors.affiliation: Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh Pennsylvania, USA.
authors.forename: M Teresa
authors.initials: MT
authors.lastname: Coleman
authors.forename: Pauline
authors.initials: P
authors.lastname: Maiello
authors.forename: Jaime
authors.initials: J
authors.lastname: Tomko
authors.forename: Lonnie James
authors.initials: LJ
authors.lastname: Frye
authors.forename: Daniel
authors.initials: D
authors.lastname: Fillmore
authors.forename: Christopher
authors.initials: C
authors.lastname: Janssen
authors.forename: Edwin
authors.initials: E
authors.lastname: Klein
authors.forename: Philana Ling
authors.initials: PL
authors.lastname: Lin
mesh_terms: D000818:Animals; D018450:Disease Progression; D019788:Fluorodeoxyglucose F18; D008252:Macaca fascicularis; D008992:Monkey Diseases / Q000175:diagnosis* / Q000473:pathology; D009169:Mycobacterium tuberculosis; D049268:Positron-Emission Tomography / Q000379:methods*; D011237:Predictive Value of Tests; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014376:Tuberculosis / Q000175:diagnosis* / Q000473:pathology
chemical_list: D019788:Fluorodeoxyglucose F18