title: Immunologic study on nasopharyngeal carcinoma patients: correlation of in vivo and in vitro reactivity to phytohemagglutinin.
abstract: The skin response to 5 micrograms of purified phytohemagglutinin (PHA) was studied in 125 subjects, including 32 normal controls, 31 patients with head and neck cancer other than nasopharyngeal carcinoma (NPC), and 62 NPC patients. In vitro lymphocyte transformation to PHA (M form) was tested simultaneously to examine its correlation to the PHA skin test. A positive reaction of skin test was observed 24 hours after injection in 29 (90.6%) of 32 normal controls, 16 (51.6%) of 31 patients with head and neck cancer other than NPC, and 51 (82.3%) of 62 NPC patients respectively. Histological examination of the area of erythema revealed the same as those found in the delayed hypersensitivity with perivascular mononuclear cell infiltration. The PHA skin test was repeated 3 times over a period of 9 weeks in 10 normal controls, and no significant change in their skin reactivity was detected. In vitro reactivity to PHA-M was hyporesponsive in NPC patients than in normal controls in three measurements i.e. net counts of incorporated tritiated thymidine, stimulation index, or differences of square roots of counts between the well with PHA and without PHA. Net counts proved to be the most sensitive criterion to differentiate the lymphocyte response to PHA between NPC and normal controls. It is suggested that the general hyporesponsiveness to PHA stimulation in NPC is due to intrinsic T-cell dysfunction. The suboptimal dose of PHA for lymphocyte transformation in NPC was 2.5 microliters per 1.5 X 10(5) cells. Quantitatively, the correlation between in vivo and in vitro reactivity to PHA was not found in normal controls, yet it proved to have a good correlation in some NPC patients--in stage III r = 0.63, p greater than 0.05; in stage IV r = 0.71, p less than 0.01; in stage V r = 0.95, p less than 0.001. Qualitatively (delta cpm greater than or equal to 20,000; erythema greater than or equal to 20 mm), a correlation was found between in vivo and in vitro reactivity to PHA in 27 (84.4%) of 32 normal controls (p less than 0.001), and 39 (62.9%) of 62 NPC patients (p less than 0.01). It is concluded that if in vitro testing of PHA stimulation can not be done, the PHA skin test can be used as an alternative to screen the T-cell functions of NPC patients.
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D006258:Head and Neck Neoplasms / Q000276:immunology; D006801:Humans; D008213:Lymphocyte Activation; D008875:Middle Aged; D009303:Nasopharyngeal Neoplasms / Q000276:immunology*; D010835:Phytohemagglutinins / Q000494:pharmacology*; D012882:Skin Tests
chemical_list: D010835:Phytohemagglutinins