Amyloidosis Support Group
Primary amyloidosis occurs when the body's antibody-producing cells do not function properly and produce abnormal protein fibers made of antibody fragments. Some people with primary amyloidosis have a condition called multiple myeloma. The antibody fragments come together to form amyloid deposits in different organs, including the kidneys, where they cause serious damage.
The common treatment for primary amyloidosis is chemotherapy. Even though I have secondary, they are seeking to kick it's butt, so so speak, and therefore are giving me chemotherapy for six months to see if we can get the amyloidosis to step down. It can slow the progression while you are looking for the underlying cause. If I were you, I'd learn more about autoimmune diseases, since they are among the most common inflammatory diseases out there. There aren't many, and most of them are very manageable. Let me know what England says, I will be keeping you all in my thoughts.
As for what causes AA amyloidosis, it is supposed to be from infections such as tuberculosis, leprosy, bronchiectasis, chronic osteomyelitis, and chronic pyelonephritis, or inflammations such as rheumatoid, reactive ,or psoriatic arthritis; inflammatory bowel disease; or Behcet syndrome (not usual in the U.S.). It can be associated with lupus, polymyositis, and polymyalgia rheumatica., and even gout, pseudogout, and noninflammatory sarcoidosis. I've read it can also be associated with ankylosing spondylitis (causes inflammation and spontaneous fusion of vertebrae to adjacent vertebrae) which is in turn associated with the HLA B-27 haplotype - an inherited protein on the surface of white blood cells.
If your husband has been having any back or neck problems suggestive of ankylosing spondylitis, your doctor might consider checking his blood for the HLA B-27 antigen.
The AA type can also go along with certain cancers such as Hodgkins disease and renal (kidney) cell carcinoma. And it can go along with FMF and other fever syndromes. It can also go along with Castleman's Disease. It can even go along with subcutaneous drug abuse (past usage included).
I would suggest making a list of these things at take it to a good internal medicine specialist and ask him to work to rule out or confirm each. So many possibilities makes it a tough nut to crack. I hope you find out which thing it is!