EBV specific secretory IgA in saliva of NPC patients. Presence of secretory piece in epithelial malignant cells.

Saliva samples from 59 patients with nasopharyngeal carcinoma (NPC) and from 20 normal individuals were studied to determine the nature and origin of the EBV-specific IgA in NPC saliva. About 50% of NPC saliva samples contained secretory IgA specific for EBV. The corresponding tumor IgA(alpha) was found in plasma cells surrounding the epithelial tumor cells and the secretory piece at the surface of epithelial cells. A slightly higher proportion of NPC saliva samples containing IgA was found in patients from Tunis than in samples from Hong Kong. Attention is drawn to the clinical value of the salivary IgA in diagnosis and monitoring of treatment of NPC.