Re: Using IGeneX Urine Tests

a_weisman_at_yahoo.com
Date: 02/23/05 

Date: 23 Feb 2005 15:58:50 -0800

Archived

Susan wrote:
> x-no-archive: yes
>
> Phyllis, this smacks of blatant advertising, as a surrogate for a
> commercial interest.
>
> Readers should be aware that these tests have not been independently
> validated and/or replicated by those with no financial interest in
the
> outcome.
>
> Susan
>
>
> pmerv@direcway.com wrote:
> > Urine Antigen
> >
> > The bladder has been reported as a prime site for culturing
borrelia.
> > This suggests that urine would be a logical place to look for
antigen.
> > Some people have asked about the differences between IGeneX's
> > previous urine antigen test, the LUAT and the current test urine
> > antigen test, LDA (Lyme Dot Assay). According to IGeneX's
President,
> > Dr. Nick Harris, while both assays measure antigen, the technology
is
> > different.
> >
> > 1. LUAT was a quantitative test whereas LDA is qualitative.
> > 2. The LUAT used labeled purified anti-B. burgdorferi specially
> > labeled antibodies. Unfortunately, IGeneX ran out of these labeled
> > antibodies. The Lyme Dot does not require specially labeled
antibodies.
> > 3. The LUAT assay was an ELISA assay in which bound and free
antigen
> > competed for antibody binding. The signal was read in a
fluorometer.
> > Although it was very sensitive, it was a complicated assay, almost
an
> > art; and very difficult to reproduce. Thus, some assay runs had to
be
> > repeated several times. The new LDA assay is not an art and is
highly
> > reproducible. It is easy to read. In LDA, the antigen present in
the
> > urine sample is bound to the membrane. If B. burgdorferi antigens
are
> > present in the urine sample, a blue dot is visible on the membrane.
> >
> > The LDA assay has a sensitivity of 21%. The specificity of the LDA
is
> > about 89%. Therefore, IGeneX recommends confirmation by Reverse
> > Western Blot (RWB) assay. Thus, the urine antigen tests can pick
up
> > about 15-18% of the Lyme Disease positive patients. The LDA may
also
> > be present in patients positive by Lyme IgM Western Blot only.
Urine
> > testing can pick up about 5%-8% of patients that are negative for
WB
> > and blood, serum and urine PCR, which is important to the patients
in
> > that group.
> >
> > Urine PCR
> >
> > Bergmann et al report that by taking specific steps to optimize the
> > urine PCR technique, B. burgdorferi infection can be diagnosed by
using
> > urine samples from EM patients with sensitivity (85%),
substantially
> > better than that of serological methods (50%). IGeneX urine PCR has
> > passed reviews by both New York and California. The PCR is
sensitive,
> > specific and reproducible because: (1) IGeneX recommends that urine
be
> > collected in special preservative tubes. (2) A special method is
used
> > to purify and concentrate Borrelia specific DNA from a patient's
> > urine sample.
> >
> > In summary, advantages of the urine tests are:
> >
> > 1. These tests are direct tests, unlike antibody tests that
are
> > indirect.
> >
> > 2. These tests can detect false negatives of the serologic
tests.
> >
> > 3. The test methods are non-invasive, thus suitable for all
ages
> > (including infants).
> > 4. Unlike antibody tests, these tests can detect antigen within
few
> > days of infection.
> >
> > You can find out more at the IGeneX website.
> >
> > Phyllis Mervine, President
> > California Lyme Disease Association
> > Affiliate of the Lyme Disease Association, Inc.
> > PO Box 1423
> > Ukiah, CA 95482
> >
> >
> > Visit our websites
> > calda.intranets.com
> > www.lymedisease.org
> > www.lymetimes.org
> > Join our online discussion and support group at
> > http://health.groups.yahoo.com/group/CaliforniaLyme/
> >

Relevant Pages

  • Re: Using IGeneX Urine Tests
    ... If the "labelled antibodies" ran out, ... If the LDA assay is more standardized and reproducible, ... > Urine Antigen ... If B. burgdorferi antigens ...
    (sci.med.diseases.lyme)
  • Re: Using IGeneX Urine Tests
    ... > This suggests that urine would be a logical place to look for antigen. ... LUAT was a quantitative test whereas LDA is qualitative. ... The LUAT assay was an ELISA assay in which bound and free antigen ... If B. burgdorferi antigens are ...
    (sci.med.diseases.lyme)
  • Using IGeneX Urine Tests
    ... This suggests that urine would be a logical place to look for antigen. ... LUAT was a quantitative test whereas LDA is qualitative. ... The LUAT assay was an ELISA assay in which bound and free antigen ... If B. burgdorferi antigens are ...
    (sci.med.diseases.lyme)