[Using PCR method to study the EB virus DNA in NPC].

Objective: To study the EB virus DNA distribution in paraffin-embedded tissue, peripheral blood leukocyte and serum in nasopharyngeal carcinoma patients (NPC).

Method: PCR method, in paraffin-embedded tissue of 39 patients with NPC (NPC group-1) and 20 patients with chronic nasopharyngitis (control group-1), in peripheral blood leukocyte and serum of 24 patients with NPC (NPC group-2) and 10 patients with other head and neck carcinoma (control group-2) and 10 patients with chronic nasopharyngitis (control group-3) were used to test the presence of Epstein-Barr virus DNA. At the same time, we also measured serum EB virus VCA-IgA antibodies with enzyme-immunoassay in NPC group-2, control group-2 and control group-3.

Result: The results showed that 28 of 39 nasopharyngeal carcinoma patients (71.8%) (NPC group-1) and 3 of 20 chronic nasopharyngitis (15%) (control group-1) were EB virus DNA positive in paraffin-embedded tissues. The difference between NPC group-1 and control group-1 was statistically significant. Ten of 24 NPC group-2 (41.67%) and 1 of 10 control group-2 (10%) were EB virus DNA positive in peripheral blood leukocyte. Control group-3 EB virus DNA was negative in peripheral blood leukocyte. The difference between NPC group-2 and control group-3 was statistically significant (P < 0.05). All of the patients' EB virus DNA were negative in serum. The difference between NPC group-2 and control group-2; 2 was statistically significant in VCA-IgA titer respectively (Ridit Test P < 0.01).

Conclusion: EB virus DNA positive in paraffin-embedded tissues is higher than that in peripheral blood leukocyte in nasopharyngeal carcinoma patients. In serum EB virus DNA is negative. The results suggest that EB virus DNA positive from paraffin-embedded tissues to peripheral blood leukocyte to serum is decrease gradually. There must be some relationship between VCA-IgA in serum and EB virus DNA in peripheral blood leukocyte.