Name: 狼瘡とは何か？ (What Exactly is Lupus?)
Uploaded: 2021-01-14T10:34:40.000Z
Duration: 4 min 51 s
Description: VoiceTubeの動画で発音を聞きながら英語表現を覚えよう！学べる英語：

Our immune system is an incredible thing.

It's a complex, disease-fighting machine, capable of fending off attacks from bacteria and viruses.

But what happens when that same incredible system stops fighting diseases, and starts attacking you?

Lupus has been around for a very long time.

Symptoms were first described back in the nineteenth century,

specifically a butterfly rash that appears on the face.

It was later discovered that lupus causes many, seemingly unrelated symptoms.

But although we've known about the disease for years, there's still much about lupus we don't fully understand.

I'm Ali Duarte, I'm a physician and researcher.

I'm also the co-director of the Lupus Program here at Mayo Clinic in Rochester.

so this means that your immune system that is in charge of defending you against microbes sort of bacteria starts to attack itself.

For example, when you have a dog that protects you against all the bad guys and then this dog starts to bite you.

Autoimmune diseases aren't uncommon, and there are many different types.

But for now, we'll be focusing on this type, systemic lupus.

When people talk about lupus they're usually referring to systemic lupus the type of lupus that affects the internal organs.

So, what would cause the immune system, or the body's guard dog, to turn against its owner?

Which, is kind of the story behind lupus.

But, thanks to specialists like Dr. Duarte, we know a lot more than we used to.

So what do we know right now is or what we think is that there is a genetic component and an environmental component.

In order to begin to show the symptoms of lupus, two things need to happen.

First, since lupus isn't contagious, you have to have a genetic predisposition to the disease.

The genetic factor that causes lupus is currently unknown,

but doctors do know that certain demographics are more at risk than others.

So Lupus is a disease typically of young women.

It affects a women 10 times more frequently than males.

And you usually see the disease between the ages of 20 and 50.

Because of the much higher rates of female patients,

researchers suspect that the disease is associated with the number of X-chromosomes one has,

since women have 2 x-chromosomes and men usually have only one.

But simply having the genetic predisposition is only the first part of the puzzle.

And then if you were born with this a very active immune system and you are exposed to the right stimuli,

which can be maybe a drug or can be the UV light or something that we have any identified yet it starts and perpetuates the disease.

So what happens to your body when it encounters a trigger?

Well, in lupus, what happens is that something like UV light may trigger cell death.

So these cells start to die and they'd release DNA.

And the DNA then is taken by one of the cells of the immune system called dendritic cells.

And then these cells take the DNA and expose it and activate other cells called lymphocytes, so the T cells or the B cells.

Normally, immune cells would just get rid of a dead cell and move on.

But in lupus patients, these cells are slow at clearing the death cells and start to create an antibody against the cell's DNA.

Which is a big problem, because there are a lot of healthy cells in your body that have that same DNA,

which these immune cells now want to destroy.

This results in chronic inflammation and potentially damage to internal organs like the kidneys or brain.

And can even lead to  organ failure and death.

So even though we haven't we haven't had a significant drug break through discoveries in the last 60 years,

we have learned how to manage the disease better.

Just over half-a-century ago, patients were expected to live a few years.

Of course, there are still many unanswered genetic questions.

Lupus affects African Americans 3 to 4 times more than caucasians, for example.

And there is no identifiable genetic reason why this should be the case.

And while there is strong evidence that environmental factors could be the culprit,

the environmental triggers aren't fully understood.

So, while outcomes for patients diagnosed with lupus are much better than they have ever been in the past,

when it comes to exactly how the disease works, the answer is still usually...

So, while more women are at risk of developing lupus than men, men tend to have worse outcomes.

Like other aspects of the disease, this is another unknown, but there are some theories...

Maybe one of the components is just that males take longer to go to the doctor,

and they may just delay going for looking for care, so that may change the prognosis of the disease.

So, maybe get a checkup every now and then?