Brian Weinshenker:
What is happening when a patient starts having symptoms, say for example in their eye, actually typically with optic neuritis, although it’s variable, it’s usually the center part of the vision that patients, they’ll say, “I see like a donut with a hole in the center that I can’t see through.” There’s usually some eye pain. It hurts when they move their eye, especially, and if it gets very severe, they may see nothing through that eye. Usually, there’s nothing for us to see when we look in the eye, but when we flash a flashlight, we can tell it’s a problem with the optic nerve rather than, let’s say, the front of the eye or the cornea or anything like that, plus the exam is normal.
Brian Weinshenker:
In the case of neuromyelitis optica, we would imagine that some of the capillaries are abnormally dilated and allowing antibodies to leak in and in neuromyelitis optica, it’s the astrocytes which have little what we call foot processes that come up against the blood vessels and line the blood vessels and it’s right on these foot processes where the aquaporin for protein is concentrated. So, as soon as those antibodies get across, the first thing they see on those astrocytic end feet are the aquaporin four molecules. And they would then activate this protein compliment, which compliment is like a cascade, it’s like a chain reaction as it were. And then bits of the compliment break off and pull in cells called eosinophils. And we see a lot of them in the NMO lesions, they got these red granules and they’re very characteristic in neuromyelitis optica and they would punch holes, that’s what compliment does. It makes little holes in the cells and allow them to swell and die.