Radiotracers for fungal infection imaging.
Invasive fungal infections are recognized as an important cause of morbidity and mortality in the immunocompromised host. Rapid initiation of adequate antifungal treatment is often hampered by the limitations of current diagnostic methods. This review encompasses the promises and limitations of newer tracers (believed to target the infectious agents), i.e., radiolabeled antimicrobial peptides, antifungals and chitin-specific agents, for fungal infection imaging by scintigraphy. In mice (99m)Tc-labeled peptides derived from human ubiquicidin (UBI29-41) and lactoferrin (hLF1-11) distinguished local Candida albicans and Aspergillus fumigatus infections from sterile inflammatory processes, but not from bacterial infections. Clinical trials showed that (99m)Tc-UBI29-41 can distinguish infections from inflammatory lesions with 80% specificity and 100% sensitivity. (99m)Tc-hLF1-11 was able to monitor the antifungal effects of fluconazole on C. albicans infections. Moreover, (99m)Tc-fluconazole proved to be an excellent tracer for C. albicans infections as it did not accumulate in bacterial infections and inflammatory processes. However this tracer poorly detected A. fumigatus infections. Furthermore, (123)I-chitinase and (99m)Tc-HYNIC-CBP21 accumulated in both C. albicans and A. fumigatus infections in mice at later time points. In conclusion, despite the recent advances in radiolabeled imaging techniques for invasive fungal infections, the search for better tracers for fungal infection imaging should be continued.
Lupetti
Antonella
A
Dipartimento di Patologia Sperimentale, Biotecnologie Mediche, Infettivologia ed Epidemiologia, Università di Pisa,Via San Zeno 35-39, Pisa, Italy. alupetti@biomed.unipi.it
de Boer
Mark G J
MG
Erba
Paola
P
Campa
Mario
M
Nibbering
Peter H
PH
D000818:Animals; D000935:Antifungal Agents / Q000378:metabolism; D001228:Aspergillosis / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000382:microbiology; D001232:Aspergillus fumigatus / Q000378:metabolism* / Q000472:pathogenicity; D002176:Candida albicans / Q000378:metabolism* / Q000472:pathogenicity; D002177:Candidiasis / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000382:microbiology; D002686:Chitin / Q000378:metabolism; D003937:Diagnosis, Differential; D015725:Fluconazole / Q000378:metabolism; D006801:Humans; D007781:Lactoferrin; D051379:Mice; D010446:Peptide Fragments; D011849:Radioactive Tracers; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D012680:Sensitivity and Specificity; D013667:Technetium
D000935:Antifungal Agents; D010446:Peptide Fragments; D011849:Radioactive Tracers; D019275:Radiopharmaceuticals; C466658:lactoferrin (1-11), human; D002686:Chitin; D013667:Technetium; D015725:Fluconazole; D007781:Lactoferrin