Imaging Cell Death with Radiolabeled Annexin V in an Experimental Model of Rheumatoid Arthritis
Anneke M. Post, BS1,
Peter D. Katsikis, MD, PhD2,
Jonathan F. Tait, MD, PhD3,
Sharon M. Geaghan, MD4,
H. William Strauss, MD5 and
Francis G. Blankenberg, MD6
1 Division of Nuclear Medicine, Department of Radiology, Stanford University, Stanford, California
2 Department of Microbiology and Immunology, MCP Hahnemann University, Philadelphia, Pennsylvania
3 Department of Laboratory Medicine, University of Washington, Seattle, Washington
4 Department of Pathology, Stanford University, Stanford, California
5 Division of Nuclear Medicine, Department of Radiology, Memorial Sloan-Kettering Hospital, New York, New York
6 Division of Pediatric Radiology, Department of Radiology, Lucile Salter Packard Children’s Hospital, Stanford, California
View larger version (23K):
[in a new window]
|
FIGURE 1. Diagrammatic schema of experiments. First, DBA/1 mice are inoculated with emulsion of killed Mycobacterium tuberculosis and bovine type II collagen dissolved in incomplete Freund’s adjuvant. Autoimmune response results in polyarticular rheumatoid arthritis in 3–4 wk. Second, 99mTc-annexin V is injected, and autoradiographic images are obtained from frozen coronal sections of paw. Third, ROIs are drawn over each digit, paw pad, and Achilles tendon sheath and are used to analyze counts.
|
|
View larger version (48K):
[in a new window]
|
FIGURE 2. Front pad thickness after collagen injection. Bars represent average values of front pad thickness, expressed in millimeters, of each group of mice immediately before and after collagen injection. Error bars represent ±1 SD from mean value. N.S. = no significant difference from baseline measurements; TX = treatment. **Highly significant difference (P < 0.004) from baseline measurements.
|
|
View larger version (37K):
[in a new window]
|
FIGURE 3. Rear pad thickness after collagen injection. Bars represent average values of rear pad thickness, expressed in millimeters, of each group of mice immediately before and after collagen injection. Error bars represent ±1 SD from mean value. N.S. = no significant difference from baseline measurements; TX = treatment. *Significant (P < 0.05) difference from baseline measurements. **Highly significant difference (P < 0.01) from baseline measurements.
|
|
View larger version (39K):
[in a new window]
|
FIGURE 4. Autoradiographic study of representative coronal histologic sections of front paws of 3 individual mice: 1 control (A), 1 with untreated arthritis at day 26 (B), and 1 with steroid-treated arthritis (C). Mice were sacrificed 1 h after tail vein injection of 37–55 MBq (1–1.5 mCi) of 99mTc-annexin V. Frozen sections (50 µm) were obtained and exposed overnight on tritium phosphor screen. Screens were then read out with resolution of 50 µm.
|
|
View larger version (85K):
[in a new window]
|
FIGURE 5. Representative time course of 99mTc-annexin V uptake in hind paws of representative mice: 1 with untreated arthritis at week 2 (A), 1 with untreated arthritis at week 3 (B), 1 with untreated arthritis at week 4 (C), 1 control (D), and 1 with steroid-treated arthritis (E). Mice were sacrificed 1 h after tail vein injection of 37–55 MBq (1–1.5 mCi) of 99mTc-annexin V. Frozen sections (50 µm) were obtained and exposed overnight on tritium phosphor screen. Screens were then read out with resolution of 50 µm.
|
|
View larger version (27K):
[in a new window]
|
FIGURE 6. Graph of time course of 99mTc-annexin V uptake as seen by ROI analysis after collagen injection. Number of mice sacrificed at each time point is shown in parentheses. *Significantly increased (P < 0.002) 99mTc-annexin V uptake compared with age-matched control mice. #Significantly increased 99mTc-annexin V uptake (P < 0.02) compared with untreated arthritic mice at 25 or 26 d.
|
|
View larger version (62K):
[in a new window]
|
FIGURE 7. 99mTc-annexin V uptake (A) vs. nonspecific 125I-BSA uptake (B) within representative rear paws of arthritic and age-matched control mice. Mice were sacrificed 1 h after tail vein injection of 37–55 MBq (1–1.5 mCi) of 99mTc-annexin V. Frozen sections (50 µm) were obtained and exposed overnight on tritium phosphor screen. Screens were then read out with resolution of 50 µm. Five days later, after complete decay of 99mTc activity, same sections were placed on fresh tritium phosphor screen for 1 wk to determine 125I activity. Screens were then read out with resolution of 50 µm.
|
|
View larger version (119K):
[in a new window]
|
FIGURE 8. Representative 5-µm hematoxylin- and eosin-stained histologic sections of arthritic footpad 25 or 26 d after collagen injection. Scattered mononuclear cells (arrows) are seen within dermis and subdermal tissues.
|
|
Copyright © 2002 by the Society of Nuclear Medicine.
