Immunity to human cytomegalovirus measured and compared by complement fixation, indirect fluorescent-antibody, indirect hemagglutination, and enzyme-linked immunosorbent assays

Comparison of two enzyme immunoassays and two latex agglutination assays for detection of cytomegalovirus antibody

Two commercially available enzyme immunoassays for cytomegalovirus (CMV) immunoglobulin G (IgG), Vidas and Diamedix, and two latex agglutination tests that detect both CMV IgG and IgM, CMV-Scan and CMV-Gen, were evaluated using 165 human serum specimens. Among these, 46.7% contained CMV-reactive antibody. The first three assays had sensitivities of 100%; the sensitivity of the CMV-Gen procedure was 98.7%. The specificities of the four tests were 100, 97.7, 97.3, and 93.2%, respectively.

Viral reactivation as a cause of unexplained fever in patients with progressive metastatic breast cancer

Patients suffering from metastatic breast cancer and recurrent fever were investigated for viral reactivation or new viral infection as a possible cause of these febrile episodes. Three groups of patients were included in the study: (a) patients under adjuvant chemotherapy with cyclophosphamide, methotrexate and fluoruracil, (b) patients with stable metastatic disease treated with cyclophosphamide, fluoruracil and Adriamycin or mitoxantrone and (c) patients with progressive metastatic disease who also received the latter treatment. During the time of observation, patients under adjuvant chemotherapy did not present with fever or asymptomatic viral reactivation or bacterial infections at all. Out of 7 patients with stable disease, 2 had bacterial infections that coincided with the leukocyte nadir, and 1 presented with asymptomatic reactivation of cytomegalovirus. In contrast, fever in 9 of 11 patients with progressive disease was associated with a reactivation of herpes simplex virus (HSV) and in 3 of them with a consecutive reactivation of varicella zoster virus (VZV). The increase in complement-fixing anti-HSV or anti-VZV antibodies occurred in close association with a rise of the respective preexisting antibodies of the IgG class. In addition, HSV-infected cells were recovered from the urine of 7 patients with progressive disease further corroborating the serological data. Incidentally, natural killer cell activity, which has been postulated to be connected with the defense against viral infections, was found to be significantly lower in the group of patients with progressive disease, as compared to the group of patients under adjuvant chemotherapy (P less than 0.05) or to the group of patients with stable disease (P less than 0.05). We conclude that unexplained fever in patients with progressive metastatic breast cancer may result from viral reactivation.

Evaluation of four methods for cytomegalovirus antibody detection for use by a bone marrow transplantation service

Four methods, latex agglutination, indirect fluorescent antibody, enzyme immunoassay, and complement fixation, were compared for cytomegalovirus antibody screening and for pre- and posttransplant determinations on bone marrow transplant recipients. Latex agglutination was most sensitive (98%) and specific (97%) for screening and pretransplant determinations and was quickest and easiest to perform. In posttransplant sera from allogeneic bone marrow transplant recipients, all methods except complement fixation detected cytomegalovirus antibody from therapeutically administered globulin preparations; this made it difficult to determine the significance of changes in cytomegalovirus antibody titer.

Latex agglutination and enzyme-linked immunosorbent assays for cytomegalovirus serologic screening of transplant donors and recipients

The effectiveness of three serologic assays (two enzyme-linked immunosorbent assays [ELISAs] and latex agglutination) for cytomegalovirus (CMV) serologic matching of donors and recipients was assessed over a 2-year period in a major organ transplant program. Sera with equivocal test results were investigated by repeat testing of serum samples and additional specimens from the individuals involved and monitoring of CMV infection in recipients. An in-house ELISA identified all CMV-infective donors as seropositive. Of 63 ELISA-positive donors, 5 were negative by latex agglutination; recipients from 3 of these donors developed primary CMV infection posttransplant. The in-house ELISA and a commercial ELISA (Abbott enzyme immunoassay; Abbott Laboratories, North Chicago, Ill.) had a 93% concordance of results; follow-up testing indicated that the Abbott assay was sensitive but had a false-positive rate of about 11%. One recipient with a false-positive result developed symptomatic primary CMV infection after receiving a seropositive organ. Thus, performance characteristics of currently used screening assays affect recipient outcome.

Comparison of six methods for the detection of antibody to cytomegalovirus

Five commercial assays were compared to a standardized complement fixation (CF) test for the detection of antibody to cytomegalovirus. Two hundred and thirty serum specimens were analyzed. In addition, nine pairs of acute- and convalescent-phase sera were tested by two of the commercial assays. The assays were compared as to sensitivity, specificity, and positive and negative predictive value, as well as incidence of false-positive and -negative results. Samples which did not agree in all the assays were retested and tested with an indirect fluorescent-antibody assay. Of 228 specimens, 103 (45.2%) were positive by CF. Of the 230 samples, 2 (0.9%) were inconclusive by CF and readable in the other assays. Of the 230 specimens, 97 (42.2%) were positive by an enzyme immunoassay (EIA; Litton Bionetics), 100 (43.5%) were positive by a second EIA (Abbott Laboratories), 104 (45.2%) were positive by a third EIA (M. A. Bioproducts). One hundred and eight (47.0%) were positive by indirect hemagglutination (IHA; Cetus Corporation), and 110 (47.8%) were positive by latex agglutination (LA; Hynson, Westcott and Dunning). Sensitivity and specificity were similar with all the assays (93 to 100%). The greater numbers of positive results by IHA and LA were confirmed by repeat CF testing at less than 1:8 dilution, and by indirect fluorescent-antibody assay. Acute- and convalescent-phase serum pairs showed a significant rise in antibody titer when tested by anticomplement immunofluorescence, IHA, and LA. There was good agreement among the assays, with LA having the highest sensitivity.

Cytomegalovirus antigenic heterogeneity can cause false-negative results in indirect hemagglutination and complement fixation antibody assays

Cord sera and antepartum maternal sera from three congenitally cytomegalovirus (CMV)-infected infants and their mothers were CMV seronegative (titer, less than 8) in a complement fixation (CF) assay with a glycine-extracted CMV AD169 antigen; sera from two of the infants and mothers were also seronegative in a commercial indirect hemagglutination (IHA) assay with AD169 antigen. In tests with their own CMV isolates propagated and made into glycine-extracted CF antigen, all were seropositive. When 108 random cord sera were assayed for CF antibody with AD169, Davis, and A antigens (A is a locally derived antigen from one of the above infants), 44 were seropositive and 54 were seronegative for all three antigens. Of the remaining 10 sera, 4 were positive for A only, 3 were positive for A and Davis only, 2 were positive for Davis and AD169 only, and 1 was positive for AD169 only. All 10 were positive when a mixture of all three antigens was used. The IHA assay with AD169 antigen was positive with only 4 of these 10 sera. These results suggest that up to 6% of sera may be misclassified as seronegative in the CF and IHA assays if only a single antigen is used.

Screening tests for antibodies to cytomegalovirus: an evaluation of five commercial products

Four hundred and ninety two samples of serum from blood donors were screened for the presence of antibodies specific to cytomegalovirus using radioimmunoassay, a modified complement fixation test, and five commercially available tests: the Cetus CMV IHA, Abbott CMV total AB EIA, Cytomegalisa Stat EIA, Enzygnost EIA, and Virenz G-CMV EIA. A wide variation in results was found, with only 53.5% of the sera giving total concordance by all methods. Rates of seropositivity in the different tests ranged from 34.9% to 59.3%, with sensitivities ranging from 75.2% to 99.1% compared with the radioimmunoassay. Of 211 sera which gave positive results with four or more of the tests, none was negative by the radioimmunoassay and Abbott EIA, three were negative in Cetus IHA and Enzygnost EIA, and 11 were negative in the modified complement fixation test. Virenz G and Cytomegalisa Stat EIAs, however, gave 40 (19%) and 49 (23.2%), respectively, as negative. The results confirmed the reliability of the radioimmunoassay for the detection of the antibody status to CMV, but this test is too elaborate for a screening procedure. The Abbott EIA and Cetus IHA were found to be the most suitable for this purpose in spite of high false positive rates.

Comparison of a latex agglutination test with five other methods for determining the presence of antibody against cytomegalovirus

A latex agglutination test for determination of antibody against cytomegalovirus was compared with five other methods: a solid-phase fluorescent immunoassay, an indirect hemagglutination test, two solid-phase enzyme immunoassays, and an indirect fluorescent-antibody method, with sera collected from 210 random blood donors. Of the sera tested, 28% were positive for anti-cytomegalovirus by concordance of four or more methods. The latex agglutination test performed well, with a sensitivity of 100%, a specificity of 99%, and positive and negative predictive values of 97 and 100%, respectively. The methods were also evaluated for the number of sera requiring repeat testing, equivocal results after retesting, ease of performance, turnaround time, and technical demands. The tests which best met the requirements for a screening test were the solid-phase fluorescent immunoassay, the indirect hemagglutination test, and the latex agglutination test. The latex agglutination test is a valuable screening tool for detecting total anti-cytomegalovirus which has high sensitivity, high negative predictive value, and rare equivocal results and also has the added advantages of ease of performance and rapid turnaround time.