MIKROGEN recomLine Toxoplasma IgG [Avidity] recomLine ...

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Toxoplasma gondii
MIKROGEN
molekularbiologische Entwicklungs-GmbH
C 0483
Line Assay
recomLine Toxoplasma IgG [Avidity]
recomLine Toxoplasma IgM
recomLine Toxoplasma IgA
Strip-Immunoassay with antigens produced by recombinant techniques for the detection
of IgG, IgM and IgA antibodies against Toxoplasma gondii.
Toxoplasma gondii shows the highest incidence of any human pathogenic parasite in
central Europe. As a rule, the course of the infection is asymptomatic or mild and
confers lifelong immunity on immunocompetent persons. Initial contact with the pathogen
during pregnancy can result of transmission of the pathogens to the foetus, resulting
in severe damage to it.
The main task of routine diagnostics is thus within the framework of preventive
examinations during pregnancy. Due to the asymptomatic genesis of a toxoplasmosis
in most cases, diagnostic detection is in most cases serological. It is very important to
differentiate acute infections from long past infections. A problem is presented in this
respect by the tendency of the Toxoplasma-specific IgM antibodies to persist for months
and even years after initial contact, so that detection of IgM is not a sufficient criterion
for an acute toxoplasmosis infection. The most important differential characteristic is
thus the avidity of the Toxoplasma-specific IgG antibodies.
The recomLine Toxoplasma is designed as a confirmation test on the basis of antigens
sprayed onto nitrocellulose strips. The line assay technique facilitates detection and
identification in a single test charge and at a single glance of IgG, IgM or IgA antibodies
against highly specific genetically engineered Toxoplasma antigens. In addition, the
avidity of the IgG antibodies to each of the respective antigens can also be determined.
React. Contr.
Conjugate Contr.
IgG
IgA
IgM
Cut-off Contr.
ROP1
MAG1
SAG1
GRA7
GRA8
n Product advantages
• Recombinant antigens, therefore:
➣ High sensitivity and specificity
➣ Easy and clear interpretation due to easy to read bands
• Easy test procedure; automation possible
• Test procedure is identical to other MIKROGEN strip tests
• Safe evaluation due to strip specific controls (cut-off and conjugate control)
• Separate detection of IgG, IgM and IgA antibodies possible
• Easy and reliable determination of avidity possible
• C label: The recomLine Toxoplasma tests meet the high standard of the EC directive 98/79/EC on
in vitro diagnostic medical devices
• Most accurate determination of stage of infection
n Related recombinant Toxoplasma antigens
Antigen
A bbreviation
Molecular weight [kDa]
Rhoptry
antigen
ROP1
66
Matrix
antigen
MAG1
65
Surface
antigen
SAG1
30
Granular
antigen
GRA7
29
Granular
antigen
GRA8
35

n Testprinciple and Procedure
1 st Incubation: A test strip loaded with Toxoplasma antigens is incubated
with diluted serum or plasma in a dish for 60 min.
wash 3 times
E
E
E
2 nd Incubation: Peroxidase conjugated anti-human antibodies (IgG, IgM or
IgA specific) are added. Incubate for 45 min.
wash 3 times
3 rd Incubation: 5 - 10 minutes after addition of the coloring solution, insoluble
colored bands develop at the sites on the test strips occupied
by antibodies.
n Data
Course 1
4 w
12 w
CutOff
ROP1
IgG
MAG1
SAG1
GRA7
GRA8
Avid.
Avid.
CutOff
ROP1
IgM
MAG1
SAG1
GRA7
GRA8
IgG antibody titer
GRA7
MAG1
SAG1
40 w
Avid.
low
Avidity
high
Course 2
3 w
4 w
12 w
w = weeks. Displayed are the assumed time intervals after infection.
Avid.
Avid.
Avid.
Course of two Toxoplasma infections.
Course 1 covers a period of approx. 40 weeks. Course 2 covers a
period of approx. 11 weeks. The time of infection is estimated in both
cases. The early increase in antibodies to GRA7 and GRA8 and the
approx. 4-week delay before the antibodies to MAG1 and SAG1 then
increase as well are characteristic. The early phase of the infection is
also characterized by low-avidity IgG antibodies (apparent in the
"flushed-off" bands). In the advanced phase of the infection, the avidity
of the IgG antibodies to first GRA7 and later SAG1, MAG1 normally
rises.
Time after infection
Phase I Phase II Phase III Phase IV
3-4 Weeks 2 Months > 1 Year
Model course of maturation of IgG antibodies to
Toxoplasma gondii antigens.
In most Toxoplasma gondi infections, antibodies to the granular
antigens GRA7 and/or GRA8 are produced at first. Antibodies
to MAG1 and/or SAG1 usually do not occur until four weeks
later. The titre of SAG1 antibodies usually does not rise as
sharply as that of the antibodies to GRA7, GRA8 and MAG1.
An important parameter in evaluation of infection status is the
avidity of the IgG antibodies (shown as increasing line width).
Remember, only the avidity of the IgG antibodies to SAG1,
MAG1 and GRA7 remains constantly high. The avidity of IgG
antibodies to other Toxoplasma gondii antigens are of no use
for the determination of the infection status.
Phases of infection: The switch from phase I to phase II is
approximately marked by MAG1 antibodies with intermediate
avidity - MAG1 antibodies with high avidity can exclude an
infection within the last three months. The avidity of SAG1
antibodies is then often still low. The phase III is definetily
reached when SAG1 antibodies display high avidity. Phase IV
is marked by the absence of IgM antibodies against Toxoplasma
gondii antigens.
n Storage and Shelf life
At 4 °C, 18 months from the time of production
n Commercial Product Article No. 5972 recomLine Toxoplasma IgG [Avidity]*
Reagents for 25 determinations
* [ ] optional available
as additional reagent
Article No. 5973
Article No. 5971
Article No. 11010
recomLine Toxoplasma IgM
Reagents for 25 determinations
recomLine Toxoplasma IgA
Reagents for 25 determinations
Blot, Line - avidity reagent
Reagent for 25 avidity determinations
MIKROGEN GmbH
Floriansbogen 2-4 · D-82061 Neuried · Germany · Tel.: +49 (0)89 54801-0 · Fax: +49 (0)89 54801-100
Internet: www.mikrogen.de · eMail: mikrogen@mikrogen.de
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