Abstract
Comparisons were made between 151 sera from 131 donors with Burkitt's lymphoma, nasopharyngeal carcinoma and other tumors of the head and neck area, from patients having had infectious mononucleosis and from healthy controls, in three EBV‐associated serological tests: intracellular immunofluorescence on fixed smears of EBV‐carrying lymphoblastoid cell lines (“anti‐EBV‐reaction”), blocking of membrane fluorescence on similar lines and immunoprecipitation against the soluble antigen extracted from the EBV‐carrying P3J culture line. Anti‐EBV and membrane blocking antibody levels showed concordant patterns in 122 sera (81%) and discordant in 29 (19%), in agreement with previous results. If the anti‐EBV and the precipitin tests are compared, 81.5% of the sera gave concordant and 18.5 discordant results. Blocking of membrane reactivity gave concordant results with the precipitin test in 71.5% of the sera whereas 28.5% were discordant. All three tests gave concordant results in 67% of the serum material; this figure fits expectations if it is assumed that the probability of an association between the anti‐EBV titer and the membrane blocking antibody level is independent of the probability of an association between the anti‐EBV titer and the antibody detected by the precipitin test. Analysis of the serological patterns in relation to disease categories shows that the sera of patients with head and neck tumors other than carcinoma of the post‐nasal space or Burkitt's lymphoma fell mainly within the low reactive categories. Sera from nasopharyngeal carcinoma and African Burkitt lymphoma patients showed the opposite behavior, with a majority of highly reactive sera according to all three tests. Most control sera were negative or low in all three tests. In one Burkitt patient, the serological findings could be related to the clinical course of the disease; high membrane reactive antibody levels were seen in the course of tumor regression, but fell to low levels before and immediately after recurrence. Precipitating antibodies showed the opposite pattern, being absent during regression and highly positive after recurrence.