Clinical implications of autoantibody screening in patients with autoimmune myositis.

Abstract

OBJECTIVE:

To evaluate the clinical usefulness of serum autoantibody profiling in patients with autoimmune myositis.

METHODS:

We retrospectively studied 74 consecutive patients: 68 had definite or probable myositis according to Bohan-Peter criteria, six suffered from antisynthetase syndrome with subclinical myopathy. Myositis specific antibodies (MSA) (anti-ARS, -SRP, -Mi-2) were determined by RNA immunoprecipitation or immunoblot, myositis associated antibodies (MAA) (anti-RoRNP, -U1RNP, -PM/Scl, -Ku) by immunoblot.

RESULTS:

Forty-three patients (58%) were positive for MSA: anti-Jo-1 in 15/27 polymyositis (PM) (55%), 4/33 dermatomyositis (DM) (12%), 1/8 overlap (12%) and 2/6 antisynthetase syndrome (33%); anti-ARS non-Jo-1 in 1/27 PM (4%), 2/33 DM (6%) and 4/6 antisynthetase syndrome (67%); anti-Mi-2 in 1/27 PM (4%) and 11/33 DM (33%); anti-SRP in 3/27 PM (11%) and 1/33 DM (3%). One patient was anti-Jo-1/Mi-2 positive, one anti-Jo-1/SRP positive. Moreover, 27 patients (36%) were positive for MAA: anti-Ro/SSA in 8/27 PM (30%), 7/33 DM (21%), 1/8 overlap (12%), and 3/6 antisynthetase syndrome (50%); anti-U1RNP in 1/27 PM (3.7%), 1/33 DM (3%), and 2/8 overlap (25%); anti-PM/Scl in 2/8 overlap (25%), anti-Ku in 2/8 overlap (25%). Anti-Jo-1 was predominantly associated with PM, anti-Mi-2 was almost exclusively found in DM patients. Anti-ARS antibodies were closely associated with interstitial lung disease and polyarthritis; notably, anti-ARS non-Jo-1 was more frequent in patients without overt muscle alterations. Anti-Ro/SSA antibody was not associated with any disease subset, but significantly more frequent in antisynthetase syndrome.

CONCLUSIONS:

Searching for MSA and MAA in patients with autoimmmune myositis is recommended because of its diagnostic and clinical value. Anti-ARS non-Jo-1 antibodies seem to preferentially target patients with pulmonary fibrosis without overt myopathy.

• Authors: A Ghirardello, S Zampieri, E Tarricone, L Iaccarino, R Bendo, C Briani, R Rondinone, P Sarzi-Puttini, S Todesco, A Doria
• Journal: Autoimmunity (Autoimmunity) Vol. 39 Issue 3 Pg. 217-21 (May 2006) ISSN: 0891-6934 [Print] England
• PMID: 16769655 (Publication Type: Journal Article)

Chemical References

• Antibodies, Antinuclear
• Autoantibodies

Topics

• Adolescent
• Adult
• Aged
• Aged, 80 and over
• Antibodies, Antinuclear (blood)
• Autoantibodies (blood)
• Autoimmune Diseases (diagnosis, immunology)
• Cohort Studies
• Female
• Humans
• Male
• Middle Aged
• Myositis (diagnosis, immunology)
• Retrospective Studies