Development and evaluation of a capture ELISA for IgM antibody to the human cytomegalovirus major DNA binding protein.
A new capture ELISA (ELAb) for determination of the IgM antibody response to the human cytomegalovirus major DNA binding protein (p52) was developed by using a p52-specific monoclonal antibody. As a reference test, a capture ELISA using in parallel viral- and cell-control labeled antigens (ELA) was employed. General specificity, which was determined on 180 unselected IgM-negative sera from an adult population was 100%; stringent specificity, which was evaluated on 108 potentially interfering sera from patients with Epstein-Barr virus infectious mononucleosis, autoimmune diseases, rheumatoid factor or treated with radioimmunotherapy, was 96.3%; finally, clinical specificity, determined on 79 IgM-negative sera drawn prior to onset of primary HCMV infection, was 100%. Thus, the overall specificity was 98.9% (363/367 IgM negative tested sera). Sensitivity assayed on 277 IgM-positive sera was 100%. The study of the kinetics of the IgM antibody response in sequential blood samples from 9 immunocompetent and 9 heart transplanted patients showed that, while in the immunocompetent p52-specific IgM titer fell sharply 2-3 months after onset and was virtually undetectable 12 months after onset, in the immunocompromised the IgM response persisted for longer than a year. Recurrent HCMV infections were associated with a high titer IgM response in 6 (30%), and with a low IgM response in another 6 (30%) heart transplanted patients within a group of 20 patients sequentially examined. Finally, IgM antibodies were detected in all 4 infants with congenital infection and in 5 of 6 infants with neonatal infection. The results show that the HCMV p52-specific IgM antibody response parallels that obtained by ELA, thus representing a major component of it. ELAb is highly sensitive, specific and reproducible. It represents a major advance among capture ELISA techniques, allowing detection of IgM antibody reactive to a specific viral protein.
Grazia Revello
M
M
Virus Laboratory, University of Pavia, Italy.
Percivalle
E
E
Zannino
M
M
Rossi
V
V
Gerna
G
G
D000911:Antibodies, Monoclonal; D000914:Antibodies, Viral / Q000276:immunology*; D001327:Autoimmune Diseases / Q000276:immunology; D003587:Cytomegalovirus / Q000276:immunology*; D003586:Cytomegalovirus Infections / Q000276:immunology*; D004268:DNA-Binding Proteins / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D006801:Humans; D016867:Immunocompromised Host / Q000276:immunology; D007074:Immunoglobulin G / Q000276:immunology; D007075:Immunoglobulin M / Q000276:immunology*; D007244:Infectious Mononucleosis / Q000276:immunology; D007700:Kinetics; D016499:Radioimmunotherapy; D012008:Recurrence; D012217:Rheumatoid Factor / Q000276:immunology; D012680:Sensitivity and Specificity; D014764:Viral Proteins / Q000276:immunology*
D000911:Antibodies, Monoclonal; D000914:Antibodies, Viral; D004268:DNA-Binding Proteins; C072217:ICP36 protein, Cytomegalovirus; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D014764:Viral Proteins; D012217:Rheumatoid Factor