AANEM News Express

AANEM News Express

Science News: Muscular and Extramuscular Clinical Features of Patients with Anti-PM/Scl Autoantibodies

9/18/2018
 
Submitted by Leigh Maria K. Ramos-Platt, MD, News Science Editorial Board
Edited by Benn E. Smith, MD, News Science Editorial Board
 
DeLorenzo, R. et al. Muscular and extramuscular clinical features of patients with anti-PM/Scl autoantibodies. Neurology. 2018 Jun 5;90(23):e2068-e2076. doi: 10.1212/WNL.0000000000005638. Epub 2018 May 4.
 
In this study, DeLorenzo et al asked the question whether there were features which set anti-PM/Scl autoantibody positive myositis patients apart from those patients with the 3 most common myositis (Dermatomyositis – DM, Antisynthetase Syndrome – AS, and Immune Mediated Necrotizing Myopathy – IMNM). Using data from the John Hopkins Myositis Center Longitudinal Cohort collected between 2002 and 2016, various clinical and diagnostic study parameters found that there were differences which set anti-PM/Scl autoantibody myositis patients apart. 
 
This study stemmed from the observation that myositis overlaps with other connective tissue disorders. Systemic sclerosis is the most common (40%). Out of 949 patients identified as myositis patients in the Myositis Cohort study, 178 had DM, 132 has AS, 185 had IMNM, and 41 were positive for anti-PM/Scl. 
 
Key Features that Set Anti-PM/Scl Patients Apart  
1. Muscle weakness was not as prominent early in the course but became more prominent with time 
2. Unlike the 3 most common myositis types, the deltoid was more affected than the hip flexors. In DM, AS, and IMNM, the hip flexors were more affected. 
3. 23% of patients with anti-PM/Scl positive myositis had distal weakness despite the majority not having clinical generalized scleroderma. 
4. Of the 21/41 patients with available muscle biopsy results, 17 had perivascular inflammation.  
5. Perifascicular atrophy was twice as common in DM and AS (56% and 52% respectively) compared to 24% in patients with anti-PM/Scl positive myositis patients’ muscle biopsies. 
6. Thigh muscle edema seen on MRI was more common in DM, AS, and IMNM, compared to anti-PM/Scl patients (71%, 76%, and 90% respectively vs 39%). 
7. Anti-PM/Scl positive patients were more likely to develop pulmonary hypertension (12%) compared to 3% or less in the other 3 disorders. 
8. Patients with anti-PM/Scl were more likely to have or develop skin features such as Gottron rashes, mechanic’s hands, sclerodactyly, Raynaud phenomenon, and telangiectasias.  
9. Patients with anti-PM/Scl antibody positive myositis tended to respond to immunosuppressive therapies quite well. 
 
Comment: The findings of this study suggest that there are multiple features which set anti-PM/Scl antibody positive myositis apart from DM, AS, and IMNM. This distinction is important when determining overall treatment strategies.  


View Related News Stories:

  EducationScience News


Recent AANEM News

Science News: Role of Ultrasonography in Severe Distal Median Nerve Neuropathy

Received a Solicitation for EDX Services? Send it to AANEM

Science News: Shared Polygenic Risk and Causal Inferences in Amyotrophic Lateral Sclerosis

Exciting Workshops Coming to 2019 AANEM Annual Meeting

AANEM Announces 2019 Achievement Award Winners





Advertisement

ABEM

Advertisement

TPP

Advertisement

CSL Behring