Manifestation and prognostic value of EBV serology in nasal/nasopharyngeal T and NK-cell lymphomas.

Background: Extranodal nasal type T and NK-cell lymphoma is highly associated with the Epstein-Barr virus (EBV) infection which is usually found in tumor cells, but the serum manifestation of EBV and its prognostic value remains unclear.

Methods: 151 patients with nasal/nasopharyngeal T and NK-cell lymphomas were reviewed, the diagnoses of which were confirmed by histology and immunohistochemistry from Jan, 1992 to Nov, 2004. In 40 patients, which included 30 males and 10 females and aged 24 to 73(median 46) years old, analyses were performed of serum titers of antibodies against virus-capsid antigen (VCA-IgA) and early antigen (EA-IgA) with immunoenzyme assay, and antibody against EBV DNAase (EDAb), with immunoradiological method. Positive criteria were identified as VCA-IgA > 1: 10, EA-IgA> 1: 10, and EDAb > 30%. Clinically, 87.5% of the 40 patients were staged as Ann Arbor I and II diseases. Most patients underwent combined chemo and radiotherapy.

 Results: Median follow-up time for survived patients was 17(6-136) months. Median survival time for the overall patients were 12 months. Highest serum VCA-IgA, EA-IgA, and EDAb levels were 1: 1280, 1: 40, and 86% respectively. Positive rates of the three parameters were 60%, 15%, and 50% respectively. 30 patients(75%) had at least one positive parameter. Positve EA-IgA was negatively correlated with survival (p=0.0245) in Kaplan-Meier analysis, neither positive VCA-IgA or elevated EDAb level showed significant correlation with survival (p=0.134 and 0.405 ).

Conclusions: Most patients with nasal/nasopharyngeal T and NK-cell lymphomas showed serum evidences of EBV infection, higher EA-IgA level can be a poor prognostic factor for survival. The importance of EBV serology in patients with nasal/nasopharyngeal T and NK-cell Lymphoma deserves further investigation.