Hello. This is the second part of my talk on
anti-nuclear antibody and related antibody testing.
In the first part, we briefly reviewed the history of autoantibody testing,
some of the changes that have occurred in the explosion of
autoantibodies in systemic lupus and related diseases,
the challenges that are being faced in terms of
ANA interpretation of the indirect immunofluorescence assay.
I now want to address the changing bandwidth of ANA testing,
talk about the gold standard of ANA testing,
and then the future of ANA testing in the context of precision health.
First of all, speaking to the changing bandwidth of ANA and autoantibody testing,
dating back to the 1950s in the history of
the ANA tests that I reviewed earlier, all the way to the present in 2019.
You can see the technologies as they changed over time,
starting with the LE cell,
moving to double immunodiffusion, indirect immunofluorescence,
ELISA, line immunoassays, addressable laser bead
immunoassays and multi-analyte arrays in the 2019 era.
Over the years along with the technology creep,
the bandwidth is not only changed in terms of the technologies that are being used,
but also in the diseases that anti-nuclear antibody testing has used them.
That is shown near the top of the slide with the arrow shaded in yellow,
where initially the anti-nuclear antibody test was used
as a diagnostic approach for systemic lupus or SLE.
Over the years, this has changed to include Sjögren's syndrome,
mixed connective tissue disease, sub-acute cutaneous lupus,
systemic sclerosis, overlap syndrome,
anti-phospholipid syndrome, inflammatory myopathies,
autoimmune liver disease and so on.
The point is, in addition to the technology changing bandwidth
of diseases that we now use anti-nuclear antibody testing in,
has also dramatically expanded.
Along with that, as I've already reviewed with you,
there's been a change in the different autoantibody targets that we now can identify
and only a few of those are shown in the dark box as starting in the early 60s and 70s,
SNP and histone, DNA,
to a broadening array of auto-antibodies such as Sm or RNP to cardiolipin,
chromatin, topo 1, centromere,
RNAP and so on.
Along with the changing profile of diseases that are seen,
the clinicians who ordered the ANA test is also
dramatically widened as shown in the box as well.
Initially, the anti-nuclear antibody tests
were primarily used by rheumatologists and immunologists.
Today, as shown in the far right,
that is now markedly expanded to include primary care, hematology,
oncology, obstetrics, cardiology, neurology,
psychiatry, and respiratory or pulmonary medicine.
The bandwidth of autoantibody testing has changed in a number of dimensions,
which includes the technologies used,
the diseases that are addressed by anti-nuclear antibody testing,
the different targets that have been described,
but also in the clinical setting in which these autoantibodies are tested and
the clinicians who see these patients with this wide range of ANA tests related diseases.