Immunoassay with cyromegalovirus early antigens from gene products p52 and CM2 (UL44 and UL57) detect active infection in patients with chronic fatigue syndrome

Abstract

Aims: The purpose of this study is to demonstrate that the use of recombinant early antigens for detection of antibodies to cytomegalovirus (HCMV) gene products CM2 (UL44, UL57) and p52 (UL44) is specific in the diagnosis and differentiation of active HCMV infection in a subset of patients with chronic fatigue syndrome (CFS) which is often missed by the current ELISA assay that uses crude viral lysate antigen. Methods: At a single clinic from 1999 – 2001 a total of 4,774 serologic tests were performed in 1135 CFS patients using two immunoassays; Copalis immunoassay and ELISA immunoassay. The Copalis immunoassay utilized HCMV Early gene products of UL44 and UL57 recombinant antigens for detection of HCMV IgM antibody, and viral capsid antigen for detection of HCMV IgG antibody. The ELISA immunoassay utilized viral crude lysate as antigen for detection of both HCMV IgG and IgM. Results: Of the total, 1135 CFS patients, 517 patients (45.6%) were positive for HCMV IgG by both HCMV IgG by both assays. Of these, twelve CFS patients (2.2%) were positive for HCMV(V) IgM serum antibody by HCMV ELISA assay, and 61 CFS patients (11.8%) were positive for IgM HCMV serum antibody by Copalis assays. The Copalis assay that uses HCMV early recombinant gene products CM2 (UL44, UL57) and p52 (UL44) in comparison with ELISA was 98% specific. Conclusions: Immunoassays that use Early Antigen recombinant HCMV CM2 and p52 are five times more sensitive than HCMV ELISA assay using viral lysate and are specific in the detection and differentiation of active HCMV infection in a subset of CFS patients.