Vitamin D – An Environmental Factor
Guest: Dr. Diane Kamen - Rheumatology & Immunology
Host: Dr. Linda Austin – Psychiatry
Linda Austin: I’m Dr. Linda Austin. I’m interviewing Dr. Diane Kamen who is
Assistant Professor in the Department of Medicine, Division of Rheumatology,
and here at the Medical University of South Carolina. Dr. Kamen, you have been interested in lupus
since you were a medical student.
Diane Kamen: Yeah, or even before that
actually. When I was in college, my
roommate had lupus, and then when I graduated from college, at Northwestern, my
first job was as a study coordinator in lupus research studies.
Linda Austin: Really? So, you went to medical school wanting to
become a doctor taking care of lupus patients?
Diane Kamen: Absolutely. I knew then that’s what I wanted to do. I worked with rheumatologists there.
Linda Austin: What was it about lupus
that captured your energy?
Diane Kamen: It’s an autoimmune
disease. It’s like the prototype of
autoimmune diseases. And we really feel
like if we could understand lupus, we could understand a lot of autoimmune
Linda Austin: Autoimmune is a word that
is very familiar to you, but not everybody knows that word. What does that mean?
Diane Kamen: It means the immune system,
which normally protects us against bacteria, infections, foreign things, our
immune system, when we have autoimmunity, has turned against our own body, our
own proteins. Our immune system can make
these antibodies that actually attack our own cells. And, in lupus, those antibodies can be
against anything head-to-toe in the body.
So, patients with lupus can get rashes, brain involvement, heart involvement,
lung involvement, kidney involvement, really, you name it.
think about lupus as being a prototype in a way because if we can understand
that breakdown in immune tolerance in lupus, we’d feel like we’ve come a long
way in understanding all different autoimmune diseases and that we’d be getting
at what it is that triggers the immune system to go haywire, so to speak.
Linda Austin: Now, you began a very
fascinating research project here as a resident. Tell us about that.
Diane Kamen: When I was here training
for internal medicine, I knew that I wanted to do rheumatology. Actually, I knew I wanted to do lupus
research. Gary Gilkeson is one of the
rheumatologists here who is world renowned for his lupus research, both basic
science and translational research in lupus.
So, I requested to work with him during my residency and had this
wonderful opportunity. The timing was
just right, where clinical and research in lupus was really taking off. He had some wonderful ideas about studies we could
do looking to see why it is that African-Americans are more predisposed to
getting lupus. Not only do they get
lupus more often, but they also tend to be affected with more severe lupus and
more kidney involvement.
wanted to get at the root of that and went into the community here on the
African-American sea island, Gullah, community and see if we could not only
find out the prevalence of lupus and learn more about lupus here, but then see
if there were environmental of genetic reasons that lupus is more
predominant. There’s a disproportionate
number of African-Americans affected by it.
Linda Austin: So, what are your ideas
about that, Dr. Kamen?
Diane Kamen: We started writing the
initial thoughts and hypotheses about what environmental triggers there could
be. And one of the things that came up
was the fact that we don’t see that much lupus in Africa,
yet Africans living elsewhere in the world, further away from the equator, tend
to get more lupus and more severe lupus.
One of the
things that can be affected by lack of sun exposure and lack of UV light
exposure is vitamin D. And we know
vitamin D has immune effects as well. We
know a lot more about it now than we did when we were first starting with these
initial thoughts and hypotheses. And,
fortunately, we were in the right place at the right time. MUSC was one of the
centers doing a lot of early vitamin D research. We had Norman Bell here, who’s now
retired. Bruce Hollis and Carol Wagner,
here at MUSC, were doing some of the leading research in vitamin D, really
exciting stuff, and getting at the cause of seeing rickets again in babies born
with vitamin D deficiency and finding out that pregnant women and newborns were
often vitamin D deficient.
were able to actually get in on some of this early vitamin D work and look at
it in lupus. We already were entering
members of the sea island African-American community in a database. It was an observational study we were doing
to look at the progression of autoimmunity among family members of lupus
patients. And we did screening for
vitamin D deficiency among the community members and found 95 percent of them
were deficient. And a large number were
severely deficient in vitamin D, some of the lowest levels that had been seen.
Linda Austin: Now, explain that and the
question it raises. Is that more common
in African-Americans versus Africans living in Africa?
Diane Kamen: Yeah. It has a lot to do with how far you are from
the equator, how much time you spend in the sun. And, as we know, lifestyles here in the United States
are much different. We spend a lot of
time working inside and staying inside.
Then, also, skin pigment, the melanin in the skin is one of the best
blockers of vitamin D conversion. So,
the darker your skin, the less likely you are to convert enough vitamin D in
the skin. Most people would normally get
vitamin D from sunlight exposure. But
what we’re finding is that people, at least at that time, were not taking
supplements and were not getting that sun exposure, so we were seeing very
severe deficiency of vitamin D.
Linda Austin: Do you believe that it is
related to lupus?
Diane Kamen: Since that time we’ve done
several studies and now we’ve even completed our first interventional trial of
vitamin D in lupus, all based on the knowledge that vitamin D does play an
important role in the immune system. And
it may be that this breakdown of immune tolerance to your own body happens very
early on, and by the time you’ve actually developed full-blown lupus, it might
be too late. But what we have seen is
that vitamin D is, of course, well-tolerated, and we do see a correlation with
disease activity using some of our measures of how active the lupus is in the
when we give that vitamin D and get people up to the normal levels, we see a
reduction in some of the disease activity.
That was just a small pilot study.
Now we’re doing a randomized control trial on a larger scale at multiple
centers. And we’ve gotten funding from
the NIH to proceed along those same lines of research.
collaboration with Gary Gilkeson, here, and some groups across the United States,
at other research centers, we’ve learned just how complex lupus is and how
difficult it’s going to be to get at the root cause. It’s probably not going to be one cause of
lupus in everybody. But we do think
vitamin D, as one of those environmental factors, will prove to be important. We know it’s important for bone health and
immune health. We’re learning more and
more, it seems, everyday. It’s exciting.
Linda Austin: Dr. Kamen, thank you so
Diane Kamen: Thank you.
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