Table 3.

Classification of acute uterine rejection in endocervical biopsy samples in baboon (71).

Grade	Rejection	Biopsy findings
0	No	Normal morphology
1	Mild	Mild diffuse mixed inflammatory cell infiltrate (mainly lymphocytes). Occasional epithelial apoptotic bodies, focal distribution. Surface epithelium intact. No necrosis
2	Moderate	Moderate, diffuse mixed inflammatory cell infiltrate (mainly lymphocytes). Increased amount of epithelial apoptotic bodies: Reduced thickness surface epithelium, possible focal erosion. No necrosis
3	Severe	Significant, diffuse and aggregate, mixed inflammatory cell infiltrate (mainly lymphocytes; neutrophils and eosinophils may be present). Frequent apoptotic bodies. Epithelial erosions, focal to total. Focal necrosis
4	Total necrosis	Necrotic tissue only