Evaluation of Two Enzyme Immunoassays for Detection of Immunoglobulin G Antibodies to Mumps Virus

Abstract

To determine suitability for national serosurveys, we compared two commercial enzyme-linked immunosorbent assays (ELISAs) for mumps antibody, Enzygnost Anti-Parotitis-Virus/IgG (which uses a whole-virus antigen) and Microimmune Mumps IgG Screen ELISA (which uses a recombinant nucleoprotein antigen), by testing 1,915 opportunistically collected sera submitted to diagnostic laboratories across Australia in 1997 to 1998. The proportion of positive results increased with age in both ELISAs but was significantly higher with the Microimmune than with the Enzygnost ELISA overall (88% versus 63%; P < 0.01) and in all age groups. However, the proportion of equivocal results was significantly higher with the Enzygnost than with the Microimmune ELISA (9% versus 4%; P < 0.01). Of the 572 sera with discrepant or equivocal results, 508 had sufficient sample remaining to perform the neutralization test (NT). A proportion with concordant results in both ELISAs were also tested by the NT. For sera with discrepant results, there was significantly better agreement between the NT and Microimmune than between the NT and Enzygnost (310/444 [70%] versus 135/348 [39%]; P < 0.01). Of 64 sera with equivocal Microimmune results, 45 (70%) were positive in the NT compared with 140 of 160 (88%) equivocal Enzygnost results (P < 0.01). Compared with the NT, the Microimmune ELISA is more sensitive (96% versus 80%) but apparently less specific (36% versus 85%) than the Enzygnost ELISA. However, this is likely to be due to the generally lower sensitivity of the NT, since the Microimmune results reflect expected seroprevalence, based on vaccine uptake in the age groups studied. We conclude that the Microimmune ELISA is a more appropriate assay than the Enzygnost ELISA for estimation of mumps seroprevalence.Assessing population-based mumps seroprevalence is difficult. There is no international reference serum, and correlation between different assays differs according to the virus strain used and the type of antibodies detected (14). The lack of standardization is a major obstacle to international comparisons of mumps serosurvey results and evaluation of the impact of different mumps vaccination schedules.The neutralizing antibody test (NT) is considered the most specific indicator of protective mumps antibodies, but it is labor-intensive and difficult to perform (4, 10). Enzyme-linked immunosorbent assays (ELISAs) are simple, rapid, and suitable for automation and so ideally suited to large-scale mumps serosurveys (17). Generally they are reported to be more sensitive than the NT (2, 5, 9, 13, 15, 16). However, the NT can detect functional antibody of any class and has been shown to detect low levels of specific measles antibody below the level of detection of immunoglobulin G (IgG) binding antibody assays, such as ELISAs (3). It is plausible that the same could apply to mumps antibody.In this study we compared the performance of two commercial ELISAs (Enzygnost Anti-Parotitis-Virus/IgG [Dade Behring, Marburg, Germany] and Mumps IgG Screen ELISA [...

Estimates of Mumps Seroprevalence May Be Influenced by Antibody Specificity and Serologic Method

“…Several reports have indicated that mumps-neutralizing antibody does not correlate particularly well with mumps IgG ELISA measurements (25)(26)(27)(28)(29)(30)(31)(32)(33). An explanation for these observations is that mumps antibodies predominantly measured by ELISAs which use whole-virus antigen differ from those measured by plaque neutralization tests.…”

“…Although neutralizing antibody is thought to be essential for protection (40) and PRN titration is generally considered to be the gold standard for mumps serology, previous attempts to determine a reliable threshold for protective PRN titers have been unsuccessful (20). To add further ambiguity, there have been several reports of poor correlations between mumps PRN titration and various other serologic methods, such as ELISA and immunofluorescent assays (IFA) (25)(26)(27)(28)(29)(30)(31)(32)(33)(34). These studies indicated that mumps serologic data must be interpreted with caution.…”

“…As a result, it has been widely replaced by the faster and more convenient ELISA. Interestingly, however, numerous reports (25)(26)(27)(28)(29)(30)(31)(32)(33)(34) indicate that the correlations between mumps PRN titers and IgG ELISAs, which use whole virus as the target antigen, range from poor (32) to significant but imperfect (31). Here, we report the development of mumps NP-and HN-specific ELISA methods that facilitate the analysis of sera with higher degrees of resolution than whole-virus ELISA methods.…”

Human Leukocyte Antigen and Cytokine Receptor Gene Polymorphisms Associated With Heterogeneous Immune Responses to Mumps Viral Vaccine

“…19,22 The limit of detection of the test was Ͻ230 of mumps IgG antibody titer. The cellular immune status to mumps vaccine was assessed by using an in vitro [ 3 H]thymidine incorporation assay as previously described.…”

Development of a Luciferase Immunoprecipitation System Assay To Detect IgG Antibodies against Human Respiratory Syncytial Virus Nucleoprotein

“…Nucleoprotein antigen has been used to develop serological assays for a variety of paramyxoviruses and pneumoviruses; anti-N responses are routinely used to assess exposure to measles virus in epidemiological studies (12,(23)(24)(25)(26)(27). A side-by-side comparison of a human immunoglobulin RSV Lot 1 using the LIPS-N RSV and PRN tests over a wide range of IgG concentrations suggests that the LIPS-N RSV assay may also be more sensitive than the PRN assay in detecting RSV antibodies.…”