Molecular imaging of lymphoid organs and immune activation by positron emission tomography with a new [18F]-labeled 2′-deoxycytidine analog

Noninvasively monitoring immune function by positron emission tomography could affect the diagnosis and treatment evaluation of immunological disorders. Progress, however, has been hampered by the lack of probes with distinct biodistribution patterns. Radu et al. exploit the fact that many immune cells utilize a salvage pathway for nucleotide generation during DNA synthesis to develop [18F]FAC (1-(2′-deoxy-2′[18F]fluoroarabinofuranosyl) cytosine), a new probe with increased accumulation in proliferating T cells. Studies in mice show it has advantages over commonly used probes and may be clinically useful.