SeroMP™ Recombinant IgG

Intended Use
SeroMP™ Recombinant IgG kit is a semi-quantitative
Enzyme Linked Immunosorbent assay (ELISA) for the
determination of species specific IgG antibodies to
Mycoplasma pneumoniae in human serum.
The Savyon ® SeroMPTM Recombinant IgG is used as an aid
in the diagnosis of Mycoplasma pneumoniae infection. The
test also enables the diagnosis of current infection by
determining the rise of IgG antibodies in paired sera taken
2-4 weeks apart.
For In Vitro Diagnostic Use.
Introduction
M. pneumoniae is a common cause of community-acquired
pneumonia, often characterized by gradual onset of
headache, fever, malaise and, most typically, dry cough. M.
pneumoniae is common in all age groups, however, it is
most common in the first two decades of life and is rare in
children under the age of four. It has been reported as the
cause of up to 30% of all pneumonia cases (2).
M. pneumoniae has also been associated with non
respiratory diseases as meningitis, encephalitis, pancreatitis,
sensorineural hearing loss, and acute brainstem syndrome
(5).
Due to its common occurrence, one should consider M.
pneumoniae in all cases of pneumonia, but being the same
symptoms for different agents, additional diagnostic tools,
such as serological tests, are required (3).
The ELISA technique is sensitive, specific and enables a
differential determination of specific IgG, IgA and IgM
antibodies (6).
In respect to diagnosis and treatment, the most prominent
structural feature of MP is the lack of a cell wall. It has been
shown that surface-exposed polypeptides elicit an
immunogenic response, in particular those that are involved
in the attachment organelle of MP. This attachment
organelle is composed of a complex of polypeptides, in
which P1 Cytadhesin Protein has a major role. (1; 4; 10) Due
to its high immunogenicity P1 is a paradigm for utilizing a
definitive antigen in serology-based diagnostic systems,
attempting to improve various parameters of assay
performance. A common way to improve test performances
by using highly immunogenic polypeptides like the P1 is
incorporating these polypeptides in the tests as recombinant
antigens. Indeed, several polypeptides have been identified
in the literature as good candidates for this purpose. (9)
M. pneumoniae specific IgM antibodies rise early after onset
of the disease, reach peak levels in one to four weeks, then
decline to diagnostically insignificant levels within a few
months (7). Due to the early appearance and relatively short
lifetime of IgM antibodies, their detection allows the
diagnosis of acute infection using a single serum sample.
Young patients tend to have higher IgM levels than adults
(8). IgG levels rise slower than IgM, but remain elevated
much longer, so a significant increase in two consecutive
samples taken at least 2 weeks apart, may indicate current
infection or re-infection even in the absence of IgM. IgA
antibodies are seen at higher levels in elderly patients (7)
and may be more useful than IgM for the diagnosis of
current infection in adults (8).
Savyon® Diagnostics Ltd. has developed semi-quantitative
kits utilising recombinant antigens in IgG, IgA ELISA tests
and a qualitative kit utilising mixture of recombinant and
native antigen in the IgM ELISA test which enable to follow
the change of antibody levels in human sera.
The SeroMP™ Recombinant IgG, IgA and IgM tests enable
early and accurate detection of M. pneumoniae infection.
Principle of the Test
SeroMP™ Recombinant microtiter plates are coated
with M. pneumoniae recombinant antigens.
The serum to be tested is diluted and incubated in the
SeroMP™ Recombinant plate. In this step, M.
pneumoniae specific antibodies are bound to the
immobilized antigens.
Non-specific antibodies are removed by washing.
Anti-human IgG conjugated to horseradish peroxidase
(HRP) is added. In this step the HRP-conjugate is bound
to the prebound antigen-antibody complex.
Unbound conjugate is removed by washing.
Upon the addition of TMB-substrate, the substrate is
hydrolyzed by the peroxidase, yielding a blue solution of
the reduced Substrate.
Upon the addition of the stop solution, the blue color
turns yellow and should be read by an ELISA reader at
a wavelength of 450/620nm.
The absorbance is proportional to the levels of the
specific antibodies that are bound to the coated
antigens