Assessment of serologic markers for Epstein-Barr virus

Epstein-Barr virus specific marker molecules for early diagnosis of infectious mononucleosis

The molecular specificity of the antibody response against Epstein-Barr Virus (EBV) is studied in patients with acute primary EBV-infection, i.e. infectious mononucleosis syndrome. Using the immunoblot technique both IgM and IgG antibody responses are studied in sera obtained serially until week 20 after onset of symptoms. Healthy seropositive blood donors are used as control. Antigens are prepared from virus producer cell lines B95-8, P3HR1 and HH514-c16 (a superinducible derivative of P3HR1), induced for the expression of early antigens (EA) or viral capsid antigens (VCA) and from the EBV-negative cell lines BJAB and RAMOS. The 'WC'-serum, described by Edson et al. (J. Immunol. 130, 1983) is used to characterize EA- and VCA-specific polypeptides and to define their subcellular location. The immunoblot studies reveal an enormous diversity in EBV-specific polypeptides recognised by different individual patients, both for IgM and IgG. In addition, these patterns were markedly different from those found with control blood donor sera. The latter predominantly recognised bands at 72 kDa (EBNA) and 41 and 18 kDa respectively (both VCA components). Despite the great individual variation observed, EA-specific polypeptides at 138 kDa and at 45-52 kDa were recognised by both IgM and IgG antibodies in first serum samples of all patients tested.

Development of an antibody-capture IgM-enzyme-linked immunosorbent assay for diagnosis of acute Epstein-Barr virus infections

An anti-EBV IgM-ELISA was developed using the antibody-capture principle, to be used for the diagnosis of acute infectious mononucleosis (IM). The test was based on anti-human IgM-coated microtiter plates; nuclei of EBV producer cells were used for antigen; conjugate was prepared by labeling sheep anti-EBV IgG with horseradish peroxidase. The specificity of the anti-EBV IgM-ELISA was studied with a panel of sera from acute infections with hepatitis A virus, rubella virus, Toxoplasma gondii and cytomegalovirus, and sera positive for rheumatoid factors, positive for antinuclear antibodies, as well as with sera from normal blood donors and pregnant women. Specificity in these panels was 98.4%. In a clinical study with 449 sera from patients with IM-like symptoms, 109 of 109 confirmed patients were detected by the anti-EBV IgM-ELISA. Specificity of the anti-EBV IgM-ELISA in this clinical study was 99.7%. The anti-EBV IgM-ELISA detected several acute EBV patients who had negative heterophile antibody titers.