General immunological status of nasopharyngeal carcinoma patients in Singapore.

Newly diagnosed NPC patients were found to have impaired general T-cell functions, as determined in vivo by the Mantoux test and in vitro by the PHA response assay. Treated remission patients were as hyporesponsiveness as newly diagnosed patients. PHA hyporesponsiveness was associated with the HLA profile of A2-B Sin 2 and with high antibody titres to EBV-related antigens, in particular to the early antigen. Impaired responses in the Mantoux or PHA tests were associated with poor survival. The impaired response could be partially or totally restored by in vitro treatment of the hyporesponsive lymphocytes with levamisole.