Molecular Imaging of Acute Graft-Versus-Host Disease

Abstract

Noninvasive molecular imaging of acute graft-versus-host disease (GvHD) after allogeneic hematopoietic stem cell transplantation has great potential to detect GvHD at the early stages, aid in grading of the disease, monitor treatment response, and guide therapeutic decisions. Although the specificity of currently available tracers appears insufficient for clinical GvHD diagnosis, recently, several preclinical studies have identified promising new imaging agents targeting one or more biologic processes involved in GvHD pathogenesis, ranging from T-cell activation to tissue damage. In this review, we summarize the different approaches reported to date for noninvasive detection of GvHD using molecular imaging with a specific focus on the use of PET. We discuss possible applications of molecular imaging for the detection of GvHD in the clinical setting, as well as some of the predictable challenges that are faced during clinical translation of these approaches.

Keywords: PET/CT; clinical; graft-versus-host disease; hematology; molecular imaging; preclinical.

FIGURE 1.

Summary of preclinical (mouse icon) or clinical (human icon) studies to image different phases of acute GvHD pathogenesis. VHH = variable fragments of heavy chain antibody.

FIGURE 2.

Examples of preclinical and clinical PET-imaging approaches to imaging acute GvHD. In Cherk et al. (4), patients received [¹⁸F]FDG (3 MBq/kg) and were imaged 60–80 min later. In Van Elssen et al. (11), mice were given 1.85 MBq (∼5 μg) of [⁶⁴Cu]Cu-DOTA-OX40mAb and were imaged 2 h after injection. In Xiao et al. (16), mice received 1.85 MBq (∼7 μg) of [⁸⁹Zr]Zr-DFO-ICOSmAb and were imaged 48 h later. VHH = variable fragments of heavy chain antibody. (Reprinted from (4,11,16).)