Introduction

Lymphoma is a common hematological malignancy. Relationship with the Epstein-Barr virus (EBV) was indicated [₁]. Young and Rickinson said that EBV was found to be widespread in all human populations and to persist in the vast majority of individuals as a lifelong, asymptomatic infection of the B-lymphocyte poo [₁]. They noted that despite such ubiquity, the link between EBV and endemic lymphoma proved consistent and became the first of an unexpectedly wide range of associations discovered between this virus and tumors [₁]. Concerning the correlation between tumor and EBV, Busson et al recently said that tumor development appeared to require the expression of a small subset of transforming viral RNAs [₂]. They also noted that Impairment of the interactions of viral proteins with cellular partners or disruption of viral latency might prove to be useful for novel therapeutic strategies [₂].

Anti-EBV serology, immunoligcal test for detection of EBV infection is applied for screening and detection of many EBV – related cancers including lymphoma [₃]. However, the detection of Anti-EBV IgG is not useful in some specific area such as the tropical Southeast Asia where most of the populations usually have positive titer for this antibody [₄]. Therefore, new more specific Anti-EBV tests are required. Of several tests, IgA antibody to viral capsid antigens of EBV (VCA-lgA antibody) has been mentioned as a valuable test for screening for and early detection of lymphoma [₅,₆, ₇]. Here, the author performs an appraisal on the prevalence of serum VCA-lgA antibody among Thai patients with lymphoma comparing with healthy control subjects. Risk analysis was performed. The author hypothesized that the serum VCA-lgA antibody might be an effective screening test for lymphoma among the Thais.

Materials and Methods

Literature review

Metanalysis

Results

According to the literature review, 2 reports [₆, ₇] were recruited for further metanalysis (Table 1). According to the metanalysis, 39 cases and 252 healthy subjects were investigated for serum VCA-lgA antibody. The overall antibody positive rate in the patients and healthy subjects are 35.9 % (14/39) and 2.4 % (6/252), respectively. The odds ratio is 22.96 (95 % confidence interval = 8.1 – 65.0)(Table 2).

Figure 1

Table 1: Reports on serum VCA-lgA antibody in Thai patients with lymphoma and healthy subjects.

Figure 2

Table 2: Case-control analysis for the correlation between serum VCA-lgA antibody and lymphoma

Discussion

EBV as a member of the herpesvirus family persists lifelong in the human body and causes diseases associated with virus replication (infectious mononucleosis, oral hairy leukoplakia) as well as neoplastic conditions such as nasopharyngeal carcinoma, B-cell lymphoma, Hodgkin's disease associated with viral latency [₈]. In many tropical countries including Thailand, the reported prevalence of EBV infection is very high. There are some comments on the correlation between EBV and lymphoma in those countries [₆, ₇]. According to this study, there are some efforts to use EBV serological markers for lymphoma in Thailand [₆,₇].

Here, the author tried to summarize the previous reported on the prevalence of serum VCA-lgA antibody among Thai patients with lymphoma comparing with healthy control subjects. According to this study, it could be seen that having serum VCA-lgA antibody positive is a very high risk for lymphoma. Of interest, although the lymphoma is high prevalent in Thailand there is no specific recommendation in screening for this disease in high risk population. According to this study, the results suggested that the EBV-specific serum IgA antibodies might be a useful screening test for the cancer in people of high risk.