Rubella Virus-specific Antibodies Research Articles

Seroprevalence of Rubella Virus-specific Antibodies in Women and the Diagnostic Efficacy of Enzyme-linked Immunoassay and Rapid Immunochromatographic Tests.

IntroductionRubella is an infectious disease caused by the Rubella virus. The disease was previously called German measles and is transmitted through respiratory aerosols. Rubella causes both clinical and subclinical infections in children and young adults. Rubella virus has teratogenic capabilities and may cause severe complications in the fetuses of women who acquire Rubella viral infection during their pregnancy. The present study aims to evaluate the seroprevalence of anti-Rubella virus immunoglobulin (Ig) G and IgM antibodies in both pregnant and non-pregnant women and assess the diagnostic efficacy of enzyme-linked immunosorbent assay (ELISA) and rapid immunochromatographic tests.MethodsThe study included 240 females in the age range of 16-45 years. The study subjects included both pregnant women and non-pregnant women. After informed consent, 5 milliliters of blood was collected from each participant, and serum was separated and tested for the presence of antibodies (IgG and IgM) against the Rubella virus using both the traditional ELISA (Delta Biologicals, Pvt. Ltd., China) and a rapid ELISA-immunochromatographic test (ICT) (Span Biotech. Ltd., China). The data collected were systematically entered into Microsoft Excel sheets (Microsoft Corporation, Redmond, Washington) and were analyzed using SPSS Statistics for Windows, Version 17.0, 2008 (SPSS Inc., Chicago, Illinois).ResultsThe study revealed an overall seroprevalence of 31.66% for Rubella-specific IgG and IgM antibodies. Out of the 125 pregnant women included in the study, 49 (39.20%) were seropositive for Rubella IgG antibodies, and among the 115 non-pregnant women tested, 24 (20.86%) were positive for Rubella IgG antibodies. Four (5.26%) of the 76 seropositive women revealed IgM antibodies. The sensitivities of both the ELISA (40.61%) and rapid immunochromatographic (39.20%) tests were observed to be low and the specificities of both methods were similar (79.13%).ConclusionThe seroprevalence of Rubella-specific IgG antibodies was observed to be low as compared to the other regions of India. The low seroprevalence may predispose pregnant women to Rubella viral infection and may lead to increased incidences of congenital Rubella syndrome (CRS). Both the ELISA and immunochromatographic tests showed low sensitivity and similar specificities.

Seroprevalence of rubella virus antibodies among pregnant women in the Center and South-West regions of Cameroon.

Rubella infection in early pregnancy can lead to miscarriages, fetal death, or birth of an infant with congenital rubella syndrome (CRS). In Cameroon, like in many developing countries, rubella surveillance is not well-established. The aim of this study was to determine the prevalence of rubella virus specific antibodies among pregnant Cameroonians. We conducted a cross-sectional study for rubella infection among pregnant women attending antenatal clinics in the Center and South-West regions of Cameroon. Demographic data and blood were collected and tested for rubella specific antibodies (IgG and IgM), and for the IgM positive cases, IgG avidity and real time PCR was done. From December 2015 to July 2017, 522 serum samples were collected and tested from pregnant women. The seroprevalence of rubella specific IgG was 94.4%, presumably due to immunity induced by wild-type rubella virus. The seroprevalence of rubella specific IgM was 5.0%, possibly indicating rubella infection. However, IgG avidity testing of the IgM positive cases detected high avidity IgGs, ranging from 52.37% to 87.70%, indicating past rubella infection. 5.6% (29/522) of the participants had negative results for IgG to rubella virus, indicating susceptibility to rubella infection. None of the participants had received a rubella containing vaccine (RCV), but 51% (266/522) of the pregnant women lived in a house with a child with records of at least one dose of RCV. Rubella virus RNA was not detected in the urine of any IgM positive case. Findings from this study show that rubella infection is significant in Cameroon. Some pregnant women are still susceptible to rubella infection. For a better management of rubella infection in pregnancy in Cameroon, consideration should be taken to investigate for IgG-avidity test in cases with positive rubella IgM result to distinguish between recent from past rubella infection.

Characterization of rubella-specific humoral immunity following two doses of MMR vaccine using proteome microarray technology.

Introduction//BackgroundThe lack of standardization of the currently used commercial anti-rubella IgG antibody assays leads to frequent misinterpretation of results for samples with low/equivocal antibody concentration. The use of alternative approaches in rubella serology could add new information leading to a fuller understanding of rubella protective immunity and neutralizing antibody response after vaccination.MethodsWe applied microarray technology to measure antibodies to all rubella virus proteins in 75 high and 75 low rubella virus-specific antibody responders after two MMR vaccine doses. These data were used in multivariate penalized logistic regression modeling of rubella-specific neutralizing antibody response after vaccination.ResultsWe measured antibodies to all rubella virus structural proteins (i.e., the glycoproteins E1 and E2 and the capsid C protein) and to the non-structural protein P150. Antibody levels to each of these proteins were: correlated with the neutralizing antibody titer (p<0.006); demonstrated differences between the high and the low antibody responder groups (p<0.008); and were components of the model associated with/predictive of vaccine-induced rubella virus-specific neutralizing antibody titers (misclassification error = 0.2).ConclusionOur study supports the use of this new technology, as well as the use of antibody profiles/patterns (rather than single antibody measures) as biomarkers of neutralizing antibody response and correlates of protective immunity in rubella virus serology.

Seroprevalence of rubella antibodies in The Netherlands after 32 years of high vaccination coverage

Here we present rubella virus specific antibody levels in a large cross-sectional population-based serosurveillance study performed in The Netherlands in 2006/2007.In the nationwide sample, seroprevalence was high (95%). Higher levels of rubella specific antibodies were observed in the naturally infected cohorts compared with the vaccinated cohorts. After both vaccinations, the geometric mean concentration of rubella specific antibodies remained well above the protective level. However, antibody concentrations decreased faster after one than after two vaccinations. Infants too young to be vaccinated were a risk group in the nationwide sample. In the orthodox protestant group, individuals younger than 6 years of age were at risk for an infection with rubella, consistent with a small local outbreak that recently occurred at an orthodox protestant primary school.The general Dutch population is well protected against an infection with rubella virus. However, monitoring the rubella specific seroprevalence remains an important surveillance tool to assess possible groups at risk.

Preparation of immunoblot test stripes from a Rubella virus-like particles dye crystal complex as antigen

Stably transfected Chinese hamster ovary (CHO24S) cells were the source for Rubella virus-like particles (RVLP) containing all structural proteins (E1, E2, C and their dimers). RVLP are secreted from the CHO24S cells into the medium and the time-point for collecting the medium with the highest yield of >100 kDa proteins (with 17 mg protein from 10 ml cell culture supernatant) was after 2 days of incubation. Different methods for RVLP isolation from the cell culture supernatants were assessed by SDS-PAGE and Western blotting (using sera positive or negative for Rubella virus (RV)-specific antibodies or an anti-E1 monoclonal antibody). A combination of membrane filtration with a rapid, novel gradient ultracentrifugation step (using Coomassie brilliant blue G crystals as adsorbens for RVLP that facilitated virus isolation) was the most suitable technique. 132 RV-positive human sera (RV IgG > 20 IU/ml by commercial ELISA) were tested by our "self made" immunoblot test stripes (using RVLP adsorbed to dye crystals as antigen) for the presence or absence of antibodies specific for RV structural proteins. 57.6% of these sera had antibodies against E1, E2 and C, 31% against E1 and C, and 1.5% against E1 only, whereas 3.8% had no RV specific antibodies and only 6.0% were equivocal which demonstrated that these "self made" test stripes can reliably differentiate RV antibody specificities.

Single-serum radial hemolysis to detect recent rubella virus infection.

In the radial hemolysis test for rubella virus-specific antibodies, sera obtained shortly after primary rubella produce a characteristically altered hemolysis zone, termed soft hemolysis. The occurrence of soft hemolysis was analyzed statistically in 6,723 sera. The specificity of soft hemolysis for infection with rubella virus was 99.0%. Its sensitivity in primary infections was 97.3%, and the predictive value for rubella serodiagnosis (increase in IgG level or detectable IgM) was 91.2%. The temporal association of soft hemolysis with rubella was determined with sera obtained from 129 persons during late convalescence (70-310 days after onset of symptoms). Soft hemolysis disappeared by 190 days after the onset of symptoms and the presence of ordinary hemolysis ruled out primary rubella in the preceding 70-100 days. Soft hemolysis was caused by IgG antibody to rubella virus, and thus represents a new serodiagnostic principle. This technique, together with an Igm assay, allows rapid diagnosis of recent rubella from a single serum sample.

Subclass distribution of rubella virus-specific immunoglobulin G.

An enzyme-linked immunosorbent assay was used to study the subclass distribution of rubella virus-specific immunoglobulin G (IgG) in 97 serum samples from healthy donors and from patients with recent or remote rubella infections. Plastic beads coated with rubella antigen were incubated with test serum and then with monoclonal antibodies to the four human subclass of IgG. Rubella virus-specific IgG1 was present in all serum samples containing rubella virus-specific IgG antibodies. Rubella virus-specific IgG2 was present in 1 of 35 samples from healthy donors that also contained specific IgG1. Rubella virus-specific IgG3 was found in serum samples from patients with recent rubella infections but had disappeared by 6 months after the onset of symptoms. Rubella virus-specific IgG4 was found in low amounts in 7 of 35 samples from healthy immune donors. Of 20 serum samples that were negative by other serological techniques, 8 gave absorbances above cutoff levels in the assays for rubella virus-specific total IgG and IgG1. In 1 of 20 serum samples, the assays for total IgG and IgG2 were positive. High absorbance in the assay for rubella virus-specific IgG4 was found in one serum. This serum was negative in all other assays for rubella virus-specific antibodies.

Progressive rubella virus panencephalitis: Synthesis of oligoclonal virus-specific IgG antibodies and homogeneous free light chains in the central nervous system

The occurrence of oligoclonal IgG and homogeneous free lambda light chains in the cerebrospinal fluid (CSF) of a patient with progressive rubella virus panencephalitis is reported. Fractions of oligoclonal IgG corresponding to those of the CSF occurred also in the serum. Evidence is presented that the oligoclonal IgG of serum and CSF represent rubella virus-specific antibodies. Different populations of oligoclonal IgG appear to be associated with antibody specificities to different antigenic components of the virus.