Cytomegalovirus (CMV) Total Antibody EIA
The Immucor Capture-CMV is an in vitro qualitative solid phase red cell adherence test system for the detection of antibodies (IgG plus IgM) to cytomegalovirus (CMV) in human serum or plasma. Capture-CMV is intended to be used in screening of donors or patients for serological evidence of previous infection by CMV.
Cytomegalovirus (CMV) is a common human viral pathogen which belongs to the family of herpes viruses. The presence of CMV antibodies in an individual indicates prior infection by the virus. The possibility exists that viral reactivation can occur in such individuals. CMV infection is usually asymptomatic, and can persist as a latent or chronic infection.1 Viral transmission may occur through transfusion of blood or transplantation of organs from seropositive donors.2
Immunocompromised patients, such as premature neonates, organ transplant patients, and oncology patients, are at greater risk of developing more severe manifestations of CMV infections which can be a major direct or indirect cause of mortality in such patients.2 Congenitally infected newborns are especially prone to developing severe cytomegalic inclusion disease (CID).3 The severe form of CID may be fatal or may cause permanent neurological sequelae, such as mental retardation, deafness, microcephaly, and motor dysfunction. A CMV mononucleosis-type syndrome can result from the transfusion of CMV-infected blood products or the transplantation of CMV-infected donor organs in a seronegative immunocompromised patient.1 Low birth weight neonates are also at high risk to CMV mononucleosis
through transfusion of CMV-infected blood products.
One method of preventing or reducing CMV infection in seronegative immunocompromised patients is to select CMV seronegative blood donors or organ donors that have been tested by serological screening test for antibodies to CMV. Capture-CMV is a solid phase red cell adherence antibody detection system based on procedures of Plapp et al.4 This procedure is a modification of the mixed agglutination tests for antigen and antibody detection of Coombs et al5 and Hogman6 employing anti-IgG and IgG-coated red cells as the indicator system. Capture assays for the detection of antibodies to red cells or platelets use anti-IgG-coated red cells as the indicator.7 Capture-CMV uses anti-IgG plus anti-IgM-coated indicator red cells.
The CMV antigen utilized in this test is obtained from the cytomegalovirus strain AD 169 grown in human foreskin (HF) fibroblast cells. The inactivated virus is coated onto microtitration wells. The wells are dried and supplied to users along with necessary reagents and controls.
The assay procedure is a two step solid phase red cell adherence test carried out in microtitration wells coated with inactivated CMV virus. Serum or plasma samples are added to the viral-coated wells. The samples are incubated for five minutes, during which antibodies specific for CMV proteins bind to immobilized viral proteins. Unbound immunoglobulins are washed from the wells and replaced with a suspension of anti-IgG- plus anti-IgM-coated indicator red cells. Centrifugation brings the indicator red cells in contact with antibodies bound to the immobilized viral proteins. In the case of a positive test, the migration of the indicator red cells to the bottom of the well is impeded as the anti-IgG and anti-IgM bridges are formed between the indicator red cells and the viral-bound antibodies. As a consequence, the indicator red cells adhere over the surface of the microtitration well. In contrast, in the absence of viral antigen-antibody interactions (ie, a negative test) the indicator red cells are not impeded during their migration, and pellet to the bottom of the well as a packed, well-defined cell button. Test performed by VRL Eurofins, 6933 S. Revere Parkway, Centennial, CO 80112. This test has been cleared or approved for diagnostic use by the U.S. Food and Drug Administration. See package insert for more information.