Sorry Lab, I somehow missed this thread >_<.
I wonder if it is worth exploring the complement deficiency further. I must admit, I had never heard of it before until you mentioned your low complement levels in another post. I'm also wondering why your GI thinks you don't have lupus.
On the other hand it could just be a Remicade reaction. There was a guy on the UC board who got into remission on Remicade but had body pains so severe he was on Tramadol for two years. He had every test under the sun but no cause was found. Eventually he stopped the Remicade and went gluten-free. He doesn't post any more, but last I heard he was still in remission and the pains were much better (though not fully gone).
It properly sucks when a medication works but the side-effects are almost as bad as the original disease itself.
As for what caused my bone loss, I don't know exactly but a combination of taking steroids for a long time and active Crohn's seems by far and away the safest bet. I didn't wear braces when I was younger either and wish I had done now :-/ I blame my parents for putting me off the idea - wish I hadn't listened to them either and gone ahead with a brace while I was a teenager and it would have been 100% free. Now my teeth are an utter mess, which I have to try keep going for the rest of my life 'cos I certainly don't want false teeth.
Dx Crohn's in June 2000. (Yay )
Tried: 5-ASAs, azathioprine, 6MP, Remicade, methotrexate, Humira, diets.
1st surgery 20/2/13 - subtotal colectomy with end ileostomy.
2nd surgery 10/7/15 - ileorectal anastomosis. Stoma reversed and ileum connected to the rectum.
Current status: Chronic flare. Do I have any other kind?
Current meds: 50mg 6MP; Entyvio (started 3/11/16)