Oral graft vs host disease: An immune system disorder in hematopoietic cell transplantation

Table 1 Histological grading of oral mucosa and salivary glands according to Horn et al[14]

Grade	Definition
Grade I	Mucosa: Vacuolization of basal cells, moderate lymphocytic infiltrate, moderate epithelial exocytosis Salivary glands: Mild interstitial inflammation
Grade II	Mucosa: Epithelial cells with basal vacuolization and dyskeratotic, necrotic keratinocytes with satellitosis, moderate to heavy lymphocytic infiltrate in the submucosa and moderate epithelial exocytosis Salivary glands: Mild acinar destruction, ductal dilation, squamous metaplasia, mucous pooling, mild fibrosis, duct cell proliferation, periductal lymphocytic infiltrate
Grade III	Mucosa: Focal cleavage between the epithelium and connective tissue, intense lymphocytic infiltrate in the connective tissue, dyskeratotic epithelial cells, lymphocyte exocytosis Salivary glands: Marked interstitial lymphocytic infiltrate. Diffuse destruction of ducts and acini
Grade IV	Mucosa: Separation of epithelium and the connective tissue Salivary glands: Nearly complete loss of acini, dilated ducts, interstitial fibrosis with or without inflammation