Immunoglobulin G avidity testing in serum and cerebrospinal fluid for analysis of measles virus infection

Abstract

We studied a variety of patients with measles virus infection by using avidity testing for measles virusspecific immunoglobulin G (IgG) in serum and cerebrospinal fluid samples. For the avidity testing, an Enzygnost measles IgG enzyme-linked immunosorbent assay kit was used with an 8 M urea denaturing method. With this method, low-avidity IgG (acute primary infection, avidity of <30% within 15 days of the onset of rash) and high-avidity IgG (subacute sclerosing panencephalitis, avidity of >75%) could be clearly distinguished by using serum samples. One patient, who developed a typical course of measles despite a previous vaccination, showed a positive IgM response with an initial low titer of measles virus-specific IgG of low avidity, but a later sample revealed a high titer of IgG of intermediate (40%) avidity, suggesting previous immunological priming. Two patients with breakthrough infection (secondary vaccine failure), both having central nervous system involvement, showed a positive IgM response with initial high titers of serum IgG of high avidity. In addition, one of the patients had a detectable level of measles-specific IgG in cerebrospinal fluid. In this patient, the avidity of both serum and cerebrospinal fluid IgG decreased during the short follow-up period. This phenomenon has never before been reported. In subacute sclerosing panencephalitis patients, the avidity of cerebrospinal fluid IgG was consistently lower than that of serum IgG. The difference in avidity between cerebrospinal fluid and serum IgG may be used as a direct indicator of intrathecal production of IgG. In conclusion, the avidity testing is simple to perform, reliable, and highly informative in the analysis of measles virus infection.

Reconstitution of Humoral Immunity During Pregnancy

“…The other is that the mechanism does not necessarily favor high-affinity antibody-secreting B-cell clones. This is because in the one case in which a sample taken before pregnancy could be tested, the avidity was somewhat lower during pregnancy, and also because some of the samples from mothers and pregnant women showed a low avidity category (B 30% for measles 15 and 5 31% for mumps 16 ), which suggests ''primary infection'' in a nonpregnant population. The latter finding may have a significant implication in interpreting avidity results, specifically for rubellavirus IgG because of the fact that a low IgG avidity for rubella virus is a risk factor for developing congenital rubella syndrome.…”

“…Avidity testing was performed using an Enzygnost Anti-Measles or Anti-Parotitis Virus IgG ELISA kit (Dade-Behring, Marburg, Germany), as described. 15,16 Briefly, two pairs of each sample were placed in the antigen and control wells of the plate and the procedures were carried out according to the manufacturer's instructions with the modification of 8M-urea (measles) or 6M-urea (mumps) washing added to one of the pairs. The percentage of avidity was calculated as (urea-treated OD} untreated OD)× 100.…”

“…3,5,10 -14 An exception was an experimental observation of a transient positive correlation between avidity and concentration (r= 0.50, P B0.01) in a rabbit model system. 2 We have used a single-dilution, urea-denaturation methodology to determine avidity in the analyses of measles 15 and mumps 16 virus infections. During our study on the effect of avidity on the placental transport of maternal antibodies, we found a closely positive, highly significant correlation (r=0.75, P B 0.001, n=30) between avidity and concentration (i.e., enzyme-linked immunosorbent assay [ELISA] titers) of measles virus-specific immunoglobulin G (IgG) in cord serum samples (unpublished observation).…”

Detection of Toxoplasma gondii soluble antigen, SAG-1(p30), antibody and immune complex in the cerebrospinal fluid of HIV positive or negative individuals

“…Although intrathecal antibody production may establish a specific indicator of toxoplasmic encephalitis, approximately 50% of the patients will not present a detection of antibody in the CSF samples 34,40 . Important differences related to the avidity of the IgG antibody can be detected when it was compared paired samples of the CSF/serum and constitute in a direct indicator of the IgG intrathecal production 32 . The presence of anti-T. gondii IgG antibodies of low avidity in serum samples of patients presenting recent primary infection was described in the literature 18 .…”

Evaluation of the Kinetic Change of the Immunogenicity of Dengue-2 DNA Vaccine in Mice Administered by Different Administration Routes

“…Antibody avidity measurements were performed by comparing antibody binding to antigens in the presence and absence of 6 M urea in a standard ELISA [37,38]. Briefly, sera were diluted so as to obtain a standard ELISA absorbance of between 0.8 and 1.5.…”