英文原文
(已適當過濾和修正口語表達):
Okay okay, as a quick recap, the model that’s generally thought to be what leads to the symptoms of lupus starts with some environmental trigger, which damages cells, and causes apoptosis and the release of nuclear antigens. At this point, the genetic components come in, and the person likely has certain genes that make them not so good at clearing these apoptotic bodies and nuclear antigens, so you end up with a lot of nuclear antigens floating around. In combination, they probably also have genes that cause their immune cells to recognize these nuclear antigens as foreign, which initiates an immune response, creates antinuclear antibodies that bind to the antigens and then float around and deposit in various tissues, which causes inflammation. These deposits and inflammation seem to be the cause of most of the symptoms of lupus, which remember is a type III hypersensitivity reaction. Many patients, though, also develop antibodies targeting other cells, like red and white blood cells, and molecules like various phospholipids, which can mark them for phagocytosis and destruction, leading to additional symptoms. And this is considered a type II hypersensitivity reaction, although it isn’t fully understood why some of these antibodies targeting specific cells and molecules develop.
So the classic presentation of lupus is fever, joint pain, and a rash in a woman of childbearing age, but the actual diagnosis is difficult because it can affect a variety of people of different genders and ages, and there’re also a wide variety of symptoms. There are general symptoms like fever and weight loss, as well as specific symptoms depending on the specific organ system being affected and damaged. In fact, it’s so unpredictable that a diagnosis is given only when 4 or more out of eleven diagnostic criteria are met.
The first few have to do with the skin and often happen to sun-exposed areas. The first is a Malar rash, meaning a rash over the cheeks that spares the nasolabial folds, sometimes just called a 「butterfly rash」, and this appears after sun exposure.
Second is a discoid rash, which are chronic rash in sun-exposed areas that are plaque-like or forms a sort of patchy redness and can scar.
Finally, a general photosensitivity of the skin—essentially a catch-all category for other rashes that happen to sun-exposed areas—typically only lasting a couple of days. Another type of tissue that can be damaged is the mucosa, which is the inner membrane of various tissues,so the fourth criteria is ulcers in the mucus membrane of the mouth or the nose.
Along with the mucosa, lupus can also affect the serosa, which is like the outer membrane of an organ or tissue, so if it gets inflamed, people get serositis, which could manifest as something like pleuritis, which is inflammation of the lining around the lungs and the chest cavity, or as pericarditis, inflammation of the lining of the heart. Although this isn’t strictly a criteria, it’s worth noting that lupus can affect any layer of the heart—meaning in addition to inflammation of the pericardium, they might also have inflammation of the endocardium and myocardium, leading to endocarditis and myocarditis, of which the former presents as Libman-Sacks endocarditis, where vegetations form, which are essentially clumps of fibrin, a blood-clotting protein and immune cells, around the mitral valve.