Table 4.
Clinicopathological findings for chickens infected with NDV-DR499-31/08
| Tissue and staining methoda | Result on day postinoculationb |
||
|---|---|---|---|
| 2 | 3 | 4 | |
| Eyelid | |||
| HE | + | + | ++ |
| IHC | ++ | +++ | ++++ |
| Spleen | |||
| HE | + | ++ | ++++ |
| IHC | + | ++ | +++ |
| Thymus | |||
| HE | − | ++ | +++ |
| IHC | + | +++ | ++++ |
| Bursa | |||
| HE | − | ++ | +++ |
| IHC | − | ++ | ++++ |
| Harderian gland | |||
| HE | − | − | − |
| IHC | − | − | + |
| Proventriculus | |||
| HE | + | ++ | ++ |
| IHC | − | ++++ | ++ |
| Pancreas | |||
| HE | + | ++ | |
| IHC | − | ++ | ++ |
| Small intestine | |||
| HE | − | + | + |
| IHC | − | + | ++ |
| Mekel's diverticulum | |||
| HE | + | − | +++ |
| IHC | + | − | ++ |
| Cecal tonsils | |||
| HE | + | ++ | +++ |
| IHC | ++ | ++ | + |
| Large intestine | |||
| HE | − | + | + |
| IHC | + | + | ++ |
| Air sac | |||
| HE | − | − | − |
| IHC | − | − | − |
| Trachea | |||
| HE | − | − | − |
| IHC | − | − | + |
| Lung | |||
| HE | − | + | + |
| IHC | − | + | + |
| Heart | |||
| HE | − | + | ++ |
| IHC | − | − | ++ |
| Esophagus | |||
| HE | − | − | − |
| IHC | − | + | + |
| Tongue | |||
| HE | − | − | − |
| IHC | − | − | − |
| Pharynx | |||
| HE | + | − | + |
| IHC | − | + | +++ |
| Crop | |||
| HE | − | − | − |
| IHC | − | − | ++ |
| Brain | |||
| HE | − | − | +/− |
| IHC | − | − | − |
| Liver | |||
| HE | − | − | + |
| IHC | − | − | ++ |
| Kidney | |||
| HE | − | + | + |
| IHC | − | + | ++ |
| Comb | |||
| HE | − | − | − |
| IHC | − | − | − |
| Femur | |||
| HE | − | + | ++ |
| IHC | − | − | ++ |
| Turbinates | |||
| HE | − | − | − |
| IHC | − | − | − |
HE, hematoxylin and eosin staining; IHC, immunohistochemistry staining for the NDV nucleoprotein.
For HE staining, the results are scored by tissue as follows: (i) for the spleen, + is moderate hyperplasia, ++ is mild (<20%) lymphocytic depletion, +++ is moderate (20 to 50%) lymphocyte depletion with macrophage accumulation and multifocal necrosis, and ++++ is severe (>50%) lymphocytic depletion, macrophage accumulation, and necrosis; (ii) for the thymus, cecal tonsil, gut-associated lymphoid tissue, and bursa, + is mild (<20%) lymphocytic depletion, ++ is moderate (20 to 50%) lymphocytic depletion with necrosis and macrophage accumulation, and +++ is severe (>50%) lymphocytic depletion, macrophage accumulation, and necrosis; (iii) for bone marrow, + is mild (<20%) bone marrow necrosis, ++ is moderate (20 to 50%) bone marrow necrosis, and +++ is severe (>50%) bone marrow necrosis; (iv) for the pancreas, + is mild (<3 areas) vacuolation and degeneration and ++ is moderate (>3 areas) vacuolation and degeneration; (v) for the brain, + is vascular reactivity, ++ is vascular reactivity and perivascular cuffing, and +++ is vascular reactivity, perivascular cuffing, and gliosis; and (vi) for other tissues, + is mild (<20%) necrosis, ++ is moderate (20 to 50%) necrosis, and +++ is severe (>50%) necrosis. For IHC staining, the results are scored as follows: −, no IHC signal present; +/−, very rare positive-signal cells observed; +, rare cells in the section are positive upon IHC staining; ++, positive-signal cells seen in <50% of all high-power fields; +++, positive-signal cells seen in 50 to 75% of high-power fields; ++++, abundant positive-signal cells in more than 75% of high-power fields.