The Study Of Myositis Autoantibody And Muscle Magnetic Resonance Imaging In Polymyositis And Dermatomyositis

Background1. The polymyositis and dermatomyositis (PM / DM) is a kind of connective tissue disease (CTD), which is easy to violations of multi-organ, multi-system. It is difficult to achieve early diagnosis and treatment because of the complexity of clinical manifestations.In recent years it is be found that there is a series of auto-antibodies in the serum of PM/DM patients. They are myositis-specific autoantibodies (MSAs) and myositis associated autoantibodies (MAAs). MSAs can be divided into three categories: anti-synthetase(ARS) antibodies, anti-SRP antibody and anti-Mi-2 antibody. The anti-synthetase(ARS) antibodies include anti-Jo-1 antibody, anti-PL-7 antibody and anti-PL-12 antibodies, such as. MAAs include anti-Ku-72 antibody, anti-Ku-86 antibody and anti-PM-Scl antibody and so on. The Study abroad reported that MSAs and the clinical symptoms and prognosis are closely related. Less coverage of domestic parties, there are good prospects for clinical application.2. The magnetic resonance imaging(MRI) contribute to PM / DM diagnosis. Magnetic resonance imaging (MRI) has the high sensitivity of soft tissue, and can inspecte repeatly and observate dynamicly.At present, MRI has been used abroad diagnosis to muscle disease. We has not been enough attention.ObjectiveThrough the detection of myositis autoantibody spectru of PM/DM patients to explore its PM / DM diagnosis value; Through the examination of MRI, we discuss the diagnosis value for PM/DM of MRI.Methods1.Myositis myositis autoantibody testing:â‘ The study object: There were 260 serum specimens which come from 56 PM/DM, 163 connective tissue diseases(CTD), 41 spondyloarthropathies(SpA)patients and 30 healthies.â‘¡Detected their myositis-specific autoantibodies (MSAs) and myositis-associated auto-antibodies (MAAs) by Myositis antibody repertoire. Detected their 7 kinds of antibody in which anti Jo-1, anti PL-7, anti-PL-12, anti-Mi-2 antibody were MSAs and anti- Ku-72, anti- Ku-86, anti-PM-Scl antibody were MAAs by Myositis antibody repertoire with Western blotting.2. The muscle MRI examination: â‘ The study object: PM / DM patients with a total of 35 cases, of which PM11 cases, DM24 cases; healthy control group: 10 cases.â‘¡instruments and methods: The use of GE Vectra 1.5T superconductive MRI scanners,the ptional body coil coronal scan. Conventional spin echo (SE), including T1-weighted image (T1WI) and T2-weighted image (T2WI) and short time inversion recovery (STIR) check. Scan parts: buttocks and lower limbs.Results1. The spectrum myositis autoantibody test results:â‘ The 7 myositis autoantibodies sensitive species are as follows: anti-Jo-1 antibody (23.2%), anti-PL-7 antibody (8.9%), anti-PL-12 antibodies (10.7%), anti-Mi-2 antibody (8.9%), anti-Ku-72 antibody (10.7%) , anti-Ku-86 antibody (14.3%), anti-PM-Scl antibody (5.4%);Specificity respectively: Anti-Jo-1 antibody (99.0%), anti-PL-7 antibody (98.5%), anti-PL-12 antibodies (99.5%), anti-Mi-2 antibody (99.0%), anti-Ku-72 antibody (78.9%), anti-Ku-86 antibody (82.8%), anti-PM-Scl antibodies (92.2%).â‘¡The sensitivity of anti-synthetase antibody jointted detection of the PM/DM was significantly higher than a separate detection of anti-Jo-1 antibody (P <0.05), no significant decline in specificity.â‘¢anti-synthetase antibodies associated with clinical symptoms:the major clinical manifestations of anti-synthetase-positive patients are myalgia, myasthenia gravis, arthritis, interstitial lung disease, fever and Raynaud's phenomenon. The positive rate is higher than the negative control group.2. The muscle MRI Results:â‘ control group: the signal for the muscle tissue between cortical bone and subcutaneous fat between the moderate- intensity and more even signal.â‘¡PM/DM group: the 7 cases of PM and DM for the 12 cases of pure muscle edema, 4 cases of PM and DM for the seven cases is fatty infiltration of muscle edema combined (duration> 1 year). Muscle edema was slightly lower in T1WI sequence to signal, T2WI and STIR sequence showed multiple patchy distribution of small high-signal; fatty infiltration in both T1WI and T2WI showed high signal, and STIR sequences, such as low signal . Conclusions1. The MSAs for PM/DM has high specificity. A number of MSAs increased the joint detection so sensitive and help to raise the PM / DM patients with the diagnosis.2. The muscle MRI examination can be used in muscle lesions of suspicious PM/DM patients. It will help improve the diagnosis rate of the DM/PM patients.