I'm not qualified and I'm just putting together my theories of what might cause lupus. Please read with caution!
I believe that white blood cells are critically changed and modified in the liver, although their origins come from being produced in the lungs where oxygen is integrated into the blood and therefore changing calcium proteins which have come from sorted food in the stomach. When the new white cells reach the liver they are changed either into enzymes or more mature proteins. The enzymes affect the mature proteins in a similar way in lupus patients, infections are critical since the immune system is blinded and impaired. As a result, the enzymes make the white blood cells full of dying cell properties such as an abundance of carbon dioxide which makes the lungs work harder to reoxygenate the white blood cells. Unless the lupus person does a lot of exercise the lungs could become less efficient so it's important to do exercise. But critically unless the heart is strong enough to support the exercise and regenerate the lungs by working the body, then this could affect not only general health but the liver will produce more dying cells rather than produce mature proteins which rehydrate and rejuvinate the body. Therefore organs such as the kidneys will be affected because they cannot cope with the sorting of water because the heart uses water, and more water will be needed when the heart has to work harder. The solution would be not to treat the heart, lungs, kidney but to treat the liver which seems to be the key problematic organ affecting lupus which seems to trigger problems in other organs as a result of the liver producing more enzymes than it needs to. Now, I think the underlying reason for this is at some stage the body has had to conserve white blood cells more than it should for example exposure to bright lights, going from one extreme to another eg. stressful social environments, too much confused communication, unsteady personalities around you, thinking too much. This is because I believe somehow the brain goes into overdrive mode and is trying to rejuvinate the body in terms of poisioning it - making the liver produce too many enzymes (dying white cells) rather than concerntrating on positive or balanced cells production, producing more mature proteins which fight infection by feeding the infected bacteria with hormones such as insulin which digest the proteins and convert to muscle, fat, blood, organs whatever is needed. In lupus patients the body is less rejuvinated because the type of white cells is different to normal and so the sorting out and distributing of healthy white blood cells which transport digested proteins is doing this differently and so therefore can't fight infection because it does not 'feed' bacteria properly. If only we could change the habits and physical structure of the white cell so we could somehow get it to behave more normally and stop misbehaving and allowing infection to provail!
We need to find a way of temporarily changing the DNA of white blood cells so that somehow we can help lupus people fight infection better and maintain the replenishment of healthy skin, organs, cells, blood better so they have more energy and feel less drained. You could change the DNA cells by somehow finding a medication that does not allow the white cells to become a different shape or chemical structure, perhaps by not allowing the cells to become deoxygenated and die in the first place or even find a chemical that absorbs oxygen better. Either way I so hope a solution is round the corner so we can find a cure for lupus.