Table 5.
Histopathologic Examination and Scoring of Microscopic Observations in Challenged Female Rabbits That Died or Were Euthanized in Phase 1 of the Prelicensure Study, by Antitoxin Type
| Tissue | Observation | Animals Scored per Group/Average Severitya | ||
|---|---|---|---|---|
| AIGIV (6 Examined) | Raxibacumab (2 Examined) | Placebo (8 Examined) | ||
| Brain | Bacteria | 6/1.7 | 2/1.0 | 8/1.6 |
| Fibrin | 2/2.0 | 2/1.5 | 0/0.0 | |
| Hemorrhage | 3/2.0 | 2/1.5 | 3/1.7 | |
| Inflammation | 2/2.5 | 2/3.5 | 1/1.0 | |
| Necrosis | 2/2.5 | 2/1.5 | 0/0.0 | |
| Vasculitis | 2/1.5 | 2/1.0 | 0/0.0 | |
| Liver | Bacteria | 3/1.0 | 1/1.0 | 6/1.3 |
| Degeneration/necrosis | 6/1.5 | 0/0.0 | 5/1.4 | |
| Hemorrhage | 0/0.0 | 0/0.0 | 1/1.0 | |
| Inflammation | 3/1.0 | 0/0.0 | 2/1.0 | |
| Leukocytosis | 6/1.0 | 2/1.0 | 7/1.0 | |
| Lungs | Bacteria | 4/1.8 | 0/0.0 | 8/2.0 |
| Edema | 4/1.0 | 0/0.0 | 3/1.7 | |
| Fibrin | 4/1.0 | 2/2.0 | 5/1.6 | |
| Hemorrhage | 1/1.0 | 1/3.0 | 1/2.0 | |
| Inflammation | 6/1.5 | 2/2.5 | 7/1.3 | |
| Vasculitis | 0/0.0 | 0/0.0 | 0/0.0 | |
| Thrombosis | 2/1.0 | 2/1.0 | 2/1.0 | |
| Lymph nodes/mediastinal | Bacteria | 5/2.2 | 0/0.0 | 8/3.9 |
| Fibrin | 5/1.8 | 2/3.0 | 8/2.5 | |
| Hemorrhage | 3/2.0 | 2/1.5 | 8/2.1 | |
| Inflammation | 2/1.5 | 1/1.0 | 7/1.3 | |
| Necrosis | 6/2.0 | 2/3.0 | 8/3.3 | |
| Spleen | Bacteria | 6/1.3 | 1/1.0 | 8/2.8 |
| Fibrin | 5/1.6 | 2/1.0 | 6/2.0 | |
| Hemorrhage | 4/1.5 | 1/1.0 | 6/1.3 | |
| Necrosis | 6/1.7 | 2/2.0 | 8/2.4 | |
| Pigment | 4/1.5 | 4/1.5 | 5/1.2 | |
Abbreviation: AIGIV, anthrax immunoglobulin intravenous.
a
Severity score: 1, minimal (least detectable lesion); 2, mild (easily discernable lesion); 3, moderate (change affecting a large area); 4, marked (lesion that approached maximal).