Published in:
01-05-2009 | Original Article
Time-dependent appearance of intrathrombus neutrophils and macrophages in a stasis-induced deep vein thrombosis model and its application to thrombus age determination
Authors:
Mizuho Nosaka, Yuko Ishida, Akihiko Kimura, Toshikazu Kondo
Published in:
International Journal of Legal Medicine
|
Issue 3/2009
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Abstract
We immunohistochemically examined neutrophils and macrophages in venous thrombi, which developed in the ligation of the inferior vena cava (IVC). Myeloperoxidase (MPO)-positive neutrophils and F4/80-positive macrophages were detected in the whole course of thrombi after IVC ligation. Morphometrically, the number of neutrophils was greatest at 1 day after IVC ligation and, thereafter, gradually decreased with an increase of the post-ligation interval. In contrast, the number of macrophages peaked at 7 days after ligation. The number of intrathrombus neutrophils was significantly higher than that of intrathrombus macrophages at 1 and 3 days, and the average ratios of neutrophils to macrophages (N/M ratios) were 6.8 ± 1.1 (4.8–9.0) and 2.5 ± 0.4 (1.7–4.2) at 1 and 3 days, respectively. After more than 5 days, all samples had N/M ratios of <2.0 (0.2–1.4). These observations suggest that an N/M ratio of >2.0 indicates a thrombus age of 1–3 days. To differentiate between 1- and 3-day-old thrombi, an N/M ratio markedly exceeding 5.0 strongly indicates an age of 1 day. Furthermore, an N/M ratio of 1.0 or less probably indicates an age of more than 5 days. The present study demonstrated that the immunohistochemical detection of intrathrombus neutrophils and macrophages was suitable to determine the age of venous thrombi.