Rapid Diagnosis of Cytomegalovirus Infections by Direct Immunoperoxidase Staining with Human Monoclonal Antibody against an Immediate‐Early Antigen

Abstract

Direct immunoperoxidase technique using a horseradish peroxidase (HRP)-conjugated Fab' fragment of human monoclonal antibody (humab C7), designated HRP-C7, was evaluated as a rapid diagnosis of cytomegalovirus (CMV) infection. A total of 138 clinical specimens consisting of 124 urine samples and 14 oral swabs were examined for CMV by the direct HRP-C7 staining in comparison with conventional virus isolation. The number of CMV-positive samples by each method was 40 (29.0%) for the former and 37 (26.8%) for the latter, respectively. By HRP-C7 staining, CMV was identifiable within 24 hr after inoculation. By conventional isolation method, an average of 10.3 days had passed before cytopathic effect characteristic of CMV appeared in the cell culture. Some false-positive and false-negative cases were discussed in relation to toxicity of urine samples, storage of the samples, and amount of CMV in the sample. The sensitivity and specificity of HRP-C7 method against conventional isolation method were 89.2% and 93.1%, respectively. Thus, HRP-C7 staining is useful for a rapid diagnosis of CMV infections, Human cytomegalovirus (CMV) is an important pathogen not only for fetuses, but also for immunocompromised hosts such as patients with organ transplantation, acquired immunodeficiency syndrome (AIDS), or neoplastic diseases. Those patients are at high risk for active CMV infection, with CMV pneumonitis being critical event (18). In addition, through its own immunosuppressive effect, active CMV infection itself predisposes the patients to secondary infections by bacteria, fungi or protozoa (3). Therefore, the rapid confirmation of active CMV infections in those patients is essential for early initiation of anti-CMV treatments (21). The most reliable diagnosis of active CMV infections is virus isolation. However, CMV grows so slowly in cell culture that detection of CMV by its typical cytopathic effect (CPE) requires a long incubation for weeks.CMV produces a number of early antigens (EA) in the infected cells before viral 1015

Usefulness of quantitative real-time PCR assay for early detection of cytomegalovirus infection in patients with ulcerative colitis refractory to immunosuppressive therapies

“…Several methods are used to diagnose CMV infection, including histologic examination, CMV antigenemia, and PCR assay. [7][8][9] Among them, CMV antigenemia and PCR assay using whole blood potentially reflect the reactivation of CMV in the whole body, but does not necessarily indicate CMV infection in the colonic mucosa. Indeed, there are several reports of reactivation of CMV in the plasma of patients with collagen disease and AIDS without gastrointestinal involvement of CMV infection.…”

“…[7][8][9] For diagnosis of CMV infection in the gastrointestinal tract, combined CMV antigenemia assay and detection of CMV inclusion bodies in biopsy specimens from the gastrointestinal mucosa by either hematoxylin and eosin (H&E) staining or immunohistochemistry (IHC) using anti-CMV monoclonal antibodies has been proposed. 1 It is often difficult, however, to accurately diagnose CMV infection in patients with UC, 10 even when using this combined diagnostic method.…”

Fatal adult case of severe lymphocytopenia associated with reactivation of human herpesvirus 6

“…A chest roentgenogram showed that there were marked bilateral interstitial in®ltrates on February 26. Because CMV antigenemia was identi®ed (by HRP-C7 method [Eizuru et al, 1991]) in addition to the clinical features, ganciclovir treatment was started from March 3. No other pathogen was isolated from his sputum specimens by bacterial and fungal cultures.…”

The Absence of Large Ulcer Predicts Latent Cytomegalovirus Infection in Ulcerative Colitis with Positive Mucosal Viral Assay

“…The diagnosis of UC was made by clinical, endoscopic, and histological findings based on standard criteria (16,17).…”