Most of the commercially available
(ELISA) systems are based on the detection
of immunoglobulin G (IgG) antibodies
against whole-cell preparations of H.pylori (9
). Such preparations include antigens crossreacting
with other bacterial species, resulting
in a specificity that rarely exceeds 90%, even
with a second-generation ELISA system
employing highly purified, presumably noncross-
reactive components of the outer
membrane of H.pylori as antigens(10 ).
However, if the decision to treat a
patient for H.pylori infection is based solely
on the result of serological tests ; there is a
definite need for tests offering a higher
specificity (11 ). Western blotting may be a
useful tool in this respect because it allows
the direct visualization of antibody binding to
antigens highly specific for H.pylori , help to
recognize infections caused by CagAexpressing
H.pylori strains which is highly
immunogenic and usually stimulates an IgG
immune response against the corresponding
antibody of 118 to 136 kDa , and differentiate
between type land II infection (12).
Since it is less than 2% of H.pylori
infected patients fail to seroconvert, an
optimally sensitive Western blotting system
should be able to detect approximately 98%
of active infections( 13 ). |
