IgG In Serum Samples Research Articles

Insights From LGI1 and CASPR2 Potassium Channel Complex Autoantibody Subtyping

To determine, in patients identified as seropositive for neuronal voltage-gated potassium channel (VGKC) complex autoantibodies, the spectrum of clinical presentations and frequency of leucine-rich glioma-inactivated protein 1 (LGI1) and contactin-associated protein-like 2 (CASPR2) as defined antigenic neuronal targets in the VGKC macromolecular complex. Retrospective cohort study. Clinical practice, Mayo Clinic Neuroimmunology Laboratory and Department of Neurology. A total of 54 853 patients were evaluated, of whom 1992 were found to be VGKC complex IgG positive. From June 1, 2008, to June 30, 2010, comprehensive service serologic evaluation performed on 54853 patients with unexplained neurologic symptoms identified 1992 patients (4%) who were positive for VGKC complex IgG (values ≥ 0.03 nmol/L). Among 316 seropositive patients evaluated clinically at our institution, 82 (26%) were seropositive for LGI1 IgG and/or CASPR2 IgG. Of these 82 patients, 27% had low (0.03-0.09 nmol/L), 51% had medium (0.10-0.99 nmol/L), and 22% had high (≥ 1.00 nmol/L) VGKC complex IgG values. Leucine-rich glioma-inactivated protein 1 IgG positivity was associated with higher VGKC complex IgG values (P< .001) and cortical presentations (P< .001); CASPR2 IgG was associated with peripheral motor excitability (P= .009). However, neither autoantibody was pathognomonic for a specific neurologic presentation or correlated significantly with cancer. Neurologic phenotypes were diverse. Cerebrocortical manifestations (including cognitive impairment and seizures) were recorded in 76% of patients with LGI1 IgG alone (n=46) and 29% with CASPR2 IgG alone (n=28). Peripheral motor hyperexcitability was found in 21% of patients with CASPR2 IgG alone and 6.5% of patients with LGI1 IgG alone. The study emphasizes diverse and overlapping neurologic phenotypes across a range of VGKC complex IgG values and varying LGI1 IgG and CASPR2 IgG specificities. The frequent occurrence of LGI1 IgG and CASPR2 IgG in serum samples with low and medium VGKC complex IgG values supports the clinical significance of low values in clinical evaluation. Additional antigenic components of VGKC macromolecular complexes remain to be defined.

P3-S1.35 Systemic and mucosal IgG and IgA antibody responses in genital Chlamydia trachomatis infection

BackgroundChlamydia trachomatis (CT) is the most common sexually transmitted infection in the UK. Screening and treatment programmes do not appear to have reduced the population levels of Chlamydia. Ideally a...

Research on Dynamics of Colostral Antibodies in Vaccinated Females Coming from her on 7 Days of Service

Evaluation of immunity acquired from her coming from females in pet can help in understanding the immunological reactions a long specific infections and may contribute to the development of effective vaccines . The period immediately after birth is critical to the health and development of animals, whereas throughout this period the susceptibility to infectious diseases is high. To a ssess the dynamics of antibodies to colostral her mother coming from vaccinated at 7 days after s ervice, were examined a total of 68 newborn puppies of different breeds of 15 nesting. At 24, 48, 72 hours and weekly for 6 weeks after birth, all the animals were examined cl inically and have been taken: from samples of milk and colostrum/ from chicken blood samples (without tubes anticoagulated) and nasal discharge. Concentrations of IgG, IgA and IgM in se rum and milk, nasal secretion have been measured with commercially available ELISA kits. In the first three days of life the dominant nasal secretion isotype of identified puppies was I gG, which is on the first day by 1.4 times, on the second day of 1.7 times and on the third day of 1.6 times larger than IgA. In the weeks 1, 2 and 3 of life the dominant isotype was IgA, Ig G and IgA ratio: 0,3, 0,4 respectively. After the fourth week of life became the dominant isotype IgG. Concentrations of IgG in serum samples collected from cloves in the first six week s of life declined gradually after the first day of colostrum level, up to the age of 5 weeks, a fter which it was found growing in the last two tests at 35 and 42 days. Concentrations of IgA in serum samples collected from cloves in the first six weeks of life have equal value in the first month of life, after which it was found to increase their value to an average of 17.1 ± 1,6 mg/ml were observed variations between concentrations of Ig highlights from one nest to an other, and every chicken in the same nest both in samples of nasal discharge and serum This s uggests existence numerous individual factors that influence the dynamics of titers serum antibody and the lining of the nose to the puppies.

IgG-detection devices for the Tus-Ter-lock immuno-PCR diagnostic platform

The number of new Immuno-PCR technologies and applications is steadily growing as a result of a general need for more sensitive immunoassays for early detection of diseases. Although Immuno-PCR has been demonstrated to be superior to its immunoassay counterpart, it is still regarded as a challenging technology due to various problems arising from its increased detection power, such as high background noise as well as substantial batch-to-batch reproducibility issues. Current efforts have intensified to produce homogeneous universal protein-DNA conjugates to simplify this technology and render it more robust. We have recently developed a new quantitative Immuno-PCR (qIPCR) technology using the Tus-Ter-lock (TT-lock) interaction to produce homogeneous protein-DNA conjugates that can detect very small numbers of disease-related antibodies. We now report the further development of the TT-lock Immuno-PCR platform for the quasi universal quantitative detection of antigens and mammalian IgG. For this, Tus was fused to various IgG-binding proteins--i.e. protein G, protein L and their LG chimera--and self-assembled to the TT-lock-T template. These detection devices were then evaluated and applied in various direct and indirect Immuno-PCR formats. The direct TT-lock qIPCR could detect goat anti-GFP IgG at concentrations as low as 0.3 pM and total human IgG in serum samples with great sensitivity. Further indirect TT-lock qIPCR systems were developed that could detect 1 pM of GFP and 10 pM of measles nucleoprotein. In all cases, the superiority of the TT-lock Immuno-PCR was demonstrated in terms of sensitivity over an analogous Protein G-Peroxidase ELISA.

Highly sensitive electrochemical immunoassay for human IgG using double-encoded magnetic redox-active nanoparticles

A new sandwich-type electrochemical immunoassay was developed for the detection of human IgG using doubly-encoded and magnetic redox-active nanoparticles as recognition elements on the surface of a glassy carbon electrode modified with anti-IgG on nanogold particles. The recognition elements were synthesized by coating magnetic Fe3O4 nanoparticles with Prussian blue nanoparticles and then covered with peroxidase-labeled anti-IgG antibodies (POx-anti-IgG) on Prussian blue nanoparticles. The immunoelectrode displays very good electrochemical properties towards detection of IgG via using double-encoded magnetic redox-active nanoparticles as trace and hydrogen peroxide as enzyme substrate. Its limit of detection (10 pmol·L−1) is 10-fold better than that of using plain POx-anti-IgG secondary antibodies. The method was applied to the detection of IgG in serum samples, and an excellent correspondence with the reference values was found.

Identification and sequence analysis of E gene of Dengue virus type 2 strain isolated from patient serum in Shenzhen

To isolate and identify the pathogen of Dengue fever from Shenzhen city in 2005 - 2006, and to analyze the molecular characteristics of the isolated Dengue virus strain as well as to explore its possible origin. IgM and IgG of serum samples taken from 60 suspected Dengue fever patients were detected by ELISA and immunochromatography, and 9 specimens were positive. Nine samples from patients with early stage Dengue fever were used to isolate virus with C6/36 cell line and the positive cell cultures were identified by MGB fluorescent PCR. The type of isolated virus strain was determined by RT-semi-nested-PCR and fluorescent PCR. E gene of isolated virus strain was amplified by RT-PCR and sequenced. Homology and phylogenetic tree of E gene of Shenzhen Dengue virus with the strains isolated from other areas were constructed. Of nine antibody-positive serum samples, one strain of Dengue virus was successfully isolated. The isolated virus strain was confirmed as Dengue virus type 2 and designated as DEN2-SZ0521. The homology of nucleotide sequence and the deduced amino acid sequence of E gene of SZ0521 with standard type 2 Dengue virus NGC strain was 94.2% and 98.2%, but the homology with standard Dengue virus 1, 3, 4 in the same fragment were 59.1%, 57.2%, 58.5% and 68.1%, 66.7%, 63.2%, respectively. The phylogenetic tree indicated that SZ0521 had the greatest similarity with the Malay0412a/Tw strain and they lied in the same branch of the phylogenetic tree. The corresponding homology of nucleotide sequence and amino acid sequence was 99.8% and 100%, respectively. The isolated Dengue virus type 2 belonged to genotype IV with Indonesia-76, Somalia-84 and Sri Lanka-90. Dengue virus was isolated from Shenzhen for the first time, and it was classified as type 2. It was confirmed that the type 2 Dengue virus may come from the epidemic area in Malaysia.

IGM and IGG Response to 29–35-kDa Toxoplasma gondii Protein Fractions in Experimentally Infected Goats

The evolution of the humoral responses of IgG and IgM against 29-35-kDa Toxoplasma gondii fractions from experimentally infected goats were studied and compared by ELISA with the use of whole T. gondii soluble extracts and 29-35-kDa electroeluted proteins as antigens. The IgM response to electroeluted proteins was detected from wk 1 to wk 3 postinfection, showing a similar evolution to that observed when T. gondii crude extracts were used as antigens. These results suggest that this group of proteins could be used for a more specific detection of anti-T. gondii IgM. In the same way, the IgG response was equivalent in both cases, although when 29-35-kDa T. gondii fractions were used as antigens, the level of specific IgGs reached a peak 2 wk before than when T. gondii crude extract was used. The detection by ELISA of anti-T. gondii IgM in goats does not seem to be affected by the presence of specific IgG in serum samples when 29-35-kDa protein fractions were used as antigens.

The optimisation of a novel iodide microassay and its application in an immunoassay for human antibody levels in serum

Radioactive iodine has been used as an antibody label in many immunoassays. The feasibility of using non-radioactive iodine as a label was investigated. A microassay for iodide based on the Sandell-Kolthoff reaction was optimised. It was used to detect iodine-labelled antibody and successfully applied to the detection of human IgG in serum samples. The performance of this assay system compared with enzyme-linked immunosorbent assay using HRP was evaluated.

Incidence of anti-mouse IgG in normal subjects and patients with autoimmune thyroid disease.

Serum antibodies to mouse IgG occasionally interfere with two-site immunometric assays in which mouse monoclonal antibodies are used. We examined the titers of antibodies to mouse IgG in serum samples from normal subjects and patients with autoimmune thyroid disease (AITD) using an enzyme-linked immunosorbent assay. Anti-mouse IgG antibodies were positive in 7/119 patients with Graves' disease (5.9%) and 3/60 patients with Hashimoto's thyroiditis (5.0%). One of the 15 patients with a thyroid neoplasm (6.7%) also had antibodies to mouse IgG, as did 5/60 healthy subjects (8.3%). These antibodies were either of the IgG or IgM class. There was no significant difference in the incidence of positive anti-mouse IgG antibody between normal subjects and patients with AITD. It is important to note this high incidence of antibodies to mouse IgG due to the potential of interference with immunometric assays employing mouse monoclonal antibodies.

Immune complex transfer enzyme immunoassay for (anti-human t-cell leukemia virus type i) igg in serum using a synthetic peptide,env gp46(188–209), as antigen

An immune complex transfer enzyme immunoassay for (anti-human T-cell leukemia virus type I) IgG (anti-HTLV-I IgG) in serum using a chemically and safely synthesized peptide, env gp46(188-209), is described. Anti-HTLV-I IgG in test serum, which had been incubated with excess of inactive beta-D-galactosidase to eliminate interference by anti-beta-D-galactosidase antibodies, was reacted simultaneously with dinitrophenyl bovine serum albumin-env gp46(188-209) conjugate and env gp46(188-209)-beta-D-galactosidase conjugate. The complex formed of the three components was trapped onto polystyrene balls coated with affinity-purified (anti-dinitrophenyl group) IgG. After washing to eliminate nonspecific IgG in the test serum and excess of the beta-D-galactosidase conjugate, the complex was eluted from the polystyrene balls with dinitrophenyl-L-lysine and transferred to polystyrene balls coated with affinity-purified (anti-human IgG gamma-chain) IgG. beta-D-Galactosidase activity bound to the (anti-human IgG gamma-chain) IgG-coated polystyrene balls was assayed by fluorometry. This assay was sensitive and detected anti-HTLV-I IgG in serum samples which were negative by the conventional enzyme immunoassay and Western blotting. And the specificity of this assay was confirmed by preincubation of test serum with excess of env gp46(188-209). However, some disadvantages were also noted.

Immunoglobulin class of anti nPNP antibody and its clinical evaluation

Nuclear ribonucleoprotein (nRNP) was prepared from rabbit thymus extract by the ultracentrifugation and ammonium sulfate precipitation. Immunoglobulin class of anti nRNP antibody was measured by the enzyme linked immunosorbent assay (ELISA). In the measurement of IgA anti nRNP antibody, IgG of serum samples was removed by absorption with Sepharose 4B conjugated with goat anti human IgG antibody. Both IgG and IgA anti nRNP antibody levels were markedly reduced by the massive corticosteroid therapy and gradually recovered in accordance with tapering of corticosteroid dose. Highly elevated levels of IgA anti nRNP antibody were demonstrated in patients with sicca complexes, suggesting IgA anti nRNP antibody might be related with exocrine disturbances presnted in Sjogren's syndrome. IgM anti nRNP antibody was not detected in any case of patients in present study.