scholarly journals Immune complexes containing factor V in a patient with an acquired neutralizing antibody

Blood ◽  
1985 ◽  
Vol 65 (4) ◽  
pp. 810-818
Author(s):  
HC Chiu ◽  
AK Rao ◽  
C Beckett ◽  
RW Colman

An 82-year-old woman presented with extensive hematomas and melena associated with markedly decreased plasma factor V coagulant activity (FV:C). Using a competitive enzyme-linked immunosorbent assay developed in our laboratory, we made serial measurements of factor V antigen (FV:Ag) in plasma and found it to be normal or elevated. The patient's plasma was demonstrated to contain an IgG antibody that could neutralize FV:C in normal plasma. The antibody was of restricted heterogeneity (IgG1, IgG2,kappa). Circulating immune complexes containing antibody to factor V and FV:Ag were demonstrated directly in the plasma by immunoelectrophoresis with polyclonal monospecific antibody and with a monoclonal antibody using an enzyme-linked immunosorbent assay. Presence of neutralizing antibody could be demonstrated in vitro even at times when FV:C was within normal limits by heat inactivation of FV:C. Treatment with plasma and platelet transfusions as well as plasmapheresis induced definite but transient elevation of FV:C. Steroid therapy lowered the neutralizing antibody concentration and produced a rapid and persistent elevation of FV:C during two separate hospitalizations. This report describes a patient in whom levels of FV:Ag have been serially measured, and the presence of circulating immune complexes consisting of factor V and a neutralizing antibody have been directly demonstrated.

Blood ◽  
1985 ◽  
Vol 65 (4) ◽  
pp. 810-818 ◽  
Author(s):  
HC Chiu ◽  
AK Rao ◽  
C Beckett ◽  
RW Colman

Abstract An 82-year-old woman presented with extensive hematomas and melena associated with markedly decreased plasma factor V coagulant activity (FV:C). Using a competitive enzyme-linked immunosorbent assay developed in our laboratory, we made serial measurements of factor V antigen (FV:Ag) in plasma and found it to be normal or elevated. The patient's plasma was demonstrated to contain an IgG antibody that could neutralize FV:C in normal plasma. The antibody was of restricted heterogeneity (IgG1, IgG2,kappa). Circulating immune complexes containing antibody to factor V and FV:Ag were demonstrated directly in the plasma by immunoelectrophoresis with polyclonal monospecific antibody and with a monoclonal antibody using an enzyme-linked immunosorbent assay. Presence of neutralizing antibody could be demonstrated in vitro even at times when FV:C was within normal limits by heat inactivation of FV:C. Treatment with plasma and platelet transfusions as well as plasmapheresis induced definite but transient elevation of FV:C. Steroid therapy lowered the neutralizing antibody concentration and produced a rapid and persistent elevation of FV:C during two separate hospitalizations. This report describes a patient in whom levels of FV:Ag have been serially measured, and the presence of circulating immune complexes consisting of factor V and a neutralizing antibody have been directly demonstrated.


1986 ◽  
Vol 60 (3) ◽  
pp. 239-243 ◽  
Author(s):  
K. Matsumura ◽  
Y. Kazuta ◽  
R. Endo ◽  
K. Tanaka ◽  
T. Inoue

AbstractThe presence of circulating immune complexes (CIC) in the sera of dogs infected with Dirofilaria immitis was detected by using a Clq-binding enzyme-linked immunosorbent assay. Specificity of this assay with different concentrations of heat-aggravated canine IgG (ACG) was observed, i.e., the ELISA readings, expressed as ug equivalents ACG/ml, increased with increasing amounts of ACG. The intra-assay variability was below 10%. The CIC levels of infected and uninfected dogs were 177–0± 104–7 ug/ml and 22–8±45–8 ng/ml (mean±SD), respectively. The highest level was observed in 12 dogs with amicrofilaraemic infection. Age distribution of CIC levels in the 23 infected dogs also showed a significant positive correlation. These findings suggested that the CIC are present in the sera of dogs with dirofilariasis and may relate to canine glomerulonephritis.


2021 ◽  
Vol 26 (4) ◽  
pp. 138-143
Author(s):  
S.V. Zakharov  ◽  
V.K. Zakharov

The objective of this work is to study nonspecific protective factors in patients with latent early syphilis. The results of the study are based on the data of a comprehensive examination before treatment of 142 patients with early latent syphilis and 20 patients of the comparison group. Methods of investigation: serological methods for the diagnosis of syphilis complex of serological reactions, enzyme-linked immunosorbent assay (IgM, IgG), Indirect immunofluorescence reaction (RIF) RIF-200, RIF-abs; determination of cytokines IL-2, IL-6, IL-10, TNFα and INFγ in blood serum by enzyme-linked immunosorbent assay; determination of the phenotype of lymphocytes (CD-receptors), the concentration of circulating immune complexes, phagocytic number, phagocytic index, Nitroblue tetrazolium test. In the blood serum of patients the concentration of IL-2, IL-6, IL-10 and TNFα, INFγ was significantly increased. The concentration of IL-10 and IL-6 was also significantly increased in patients with more than 1 year of infection. The most significant disorders of the parameters of the metabolic activity of neutrophils were found in patients with an infection of more than 1 year; an imbalance in the circulating immune complexes concentration was also established. Under the increasing duration of the infection, the concentration of CD16+ in the blood serum progressively decreases. The content of pro-inflammatory and anti-inflammatory cytokines in the blood serum of patients with early latent syphilis was significantly increased and depended on the timing of infection. This relationship was most pronounced for IL-6 and IL-10. In patients with early latent syphilis there is also an imbalance between CD25+ and late activation factor HLA-DR against the background of a progressive decrease in the number of CD16+ lymphocytes. A direct relationship was established between the time of infection and the number of NK-cells. The revealed disorders may be the consequence of significant disorders on the part of neutrophils and may be one of the factors of the latent course of syphilitic infection.


mSphere ◽  
2018 ◽  
Vol 3 (4) ◽  
pp. e00128-18 ◽  
Author(s):  
Danka Pavliakova ◽  
Peter C. Giardina ◽  
Soraya Moghazeh ◽  
Shite Sebastian ◽  
Maya Koster ◽  
...  

ABSTRACT A Luminex-based direct immunoassay (dLIA) platform has been developed to replace the standardized pneumococcal enzyme-linked immunosorbent assay platform. The multiplex dLIA simultaneously measures the concentration of serum immunoglobulin G (IgG) antibodies specific for pneumococcal capsular polysaccharide (PnPS) serotypes 1, 3, 4, 5, 6A, 6B, 7F, 9V, 14, 18C, 19A, 19F, and 23F. The assay uses poly-l-lysine (PLL)-conjugated PnPS, chemically coupled to spectrally distinct Luminex microspheres. Assay validation experiments were performed using residual human serum samples obtained from 13-valent pneumococcal conjugate vaccine (13vPnC) clinical studies. Assay results are expressed as IgG antibody concentrations in micrograms per milliliter using the international reference serum, 007sp. The lower limit of quantitation (LLOQ) for all serotypes covered in the 13-plex dLIA fell within the range of 0.002 to 0.038 µg/ml serum IgG. The difference between the lower limit and upper limit of the assay range was >500-fold for all serotypes, and assay variability was <20% relative standard deviation (RSD) for all serotypes. IgG antibody measurements were shown to be serotype-specific (some cross-reactivity was observed only between the structurally related serotypes 6A and 6B as well as 19A and 19F), and no interference was observed between the serotypes when the assay was performed in the 13-plex format compared to the singleplex assays. The 13-plex dLIA platform developed by Pfizer Inc. generates up to 143 test results in a single 96-well plate and is a suitable replacement of the enzyme-linked immunosorbent assay (ELISA) platform for evaluating vaccine clinical trials. IMPORTANCE The pneumococcal enzyme-linked immunosorbent assay (ELISA) measures IgG antibodies in human serum, and it is an important assay that supports licensure of pneumococcal vaccines. The immune correlate of protection, 0.35 µg/ml of IgG antibodies, was determined by the ELISA method. Pfizer has developed a new Luminex-based assay platform to replace the ELISA. These papers describe the important work of (i) validating the Luminex-based assay and (ii) bridging the immune correlate of protection (0.35 µg/ml IgG) to equivalent values reported by the Luminex platform.


1988 ◽  
Vol 101 (2) ◽  
pp. 405-410 ◽  
Author(s):  
R. C. H Lau

SUMMARYEnzyme-linked immunosorbent assay (ELISA) tests were used to measure IgG antibody levels in 2638 New Zealand children who had been immunized with the triple vaccine DTP. The percentage of children immune to diphtheria decreased with age. The percentage of children immune to tetanus varied from 67.1 to 55.0%. The percentage of children with measurable antibody to pertussis increased with age. The mean percentages of children with measurable antibody or immunity to one or more DTP components were 34.2% (with 3 components), 34.4% (2 components), and 78.1% (1 component). It appears the immunization strategy for diphtheria and tetanus is satisfactory for herd immunity in New Zealand children. However, the current pertussis strategy may not be providing adequate immunity to 5-year-olds in this country.


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