Myositis- but no increased Creatine Kinase?

[1Livi]

Hello everybody,
I am a little bit confused about my diagnostical results so far and maybe anyone has an idea about it!
The doctors say I might have Myositis because of my symptoms (weak arms and legs, pain in my arms, legs and skin, muscle and skin atrophy in my arms for years).  They have already made several tests (EMG, ENG, MRI scan, CT scan) which all turned out to be negative with no sign of myositis. My Creatine Kinase, which has been tested several times, has never been increased. They only found myositis- specific antibodies (TIF 1 gamma and PL- 7) in my blood, which are slightly increased. They now want to do a biopsy but I am really not sure if it makes any sense due to all the negative results.
Does anyone has an idea of how significant these myositis- specific antibodies really are for diagnosing myositis when all the other tests are negative?

[Baz993]

I don't know whether this will still be of use to you, after all of this time, but I had a similar situation. Since I hadn't had any success with doctors I wound up doing all of my own research into my condition and it payed off. My own condition was caused by acute respiratory failure, which went undiagnosed for years, and it's that oxygen deficiency which results in our situation. Extreme CK losses only occasionally occurred in myself, and it often results from the combination of muscle damage and genetic predisposition. There are two genes which result in massive losses of CK and Mexican researchers were able to link one of them to myositis. I can't tell you the reason for your lack of oxygen supply to your muscles but I can explain. PL-7 antibodies are produced in order to destroy threonyl tRNA-synthetase, an enzyme produced by hypoxic cells. That enzyme triggers angiogenesis, the proliferation of blood vessels in an attempt to increase oxygen supply. This is also called cancer. My rheumatologist was recommending immune suppression to me until I pointed that out to her. While I can't find any research which indicates exactly what TIF-1 gamma actually does inside the body researchers are aware that it is linked to cancer formation. The TIF-1 antibodies are probably a similar effort by the body to prevent the formation of the cancer. I don't yet share those antibodies with you, only testing positive for PL-7. After seven years my MRI's are demonstrating mild muscle inflammation but the physicians are too scared of infection to be prepared to do the biopsy on me now.

[Jmc2835]

Hello. Did you ever find an answer to this?