An effective algorithm for the serological diagnosis of idiopathic inflammatory myopathies: The key role of anti-Ro52 antibodies.
Clin Chim Acta
; 475: 15-19, 2017 Dec.
Article
in En
| MEDLINE
| ID: mdl-28986052
ABSTRACT
BACKGROUND:
Patients with suspected idiopathic inflammatory myopathies (IIM) are commonly tested for the presence of anti-nuclear antibodies (ANA) by indirect immunofluorescence (IIF) on HEp-2 cell substrates. However, ANA-IIF false negative tests may occur in IIM because some antigens, such as Jo1 and Ro52, may be scarcely expressed on HEp-2 cells. In addition, cytoplasmic staining is often not appropriately investigated by a specific antibody assay, leading to decreased clinical sensitivity of the ANA test. We evaluated the diagnostic impact of different strategies using different combination of myositis-related autoantibody tests.METHODS:
Sera from 51 patients with an established diagnosis of IIM were tested for ANA by IIF on HEp-2 cells and for myositis-specific antibodies (MSA) and myositis-associated antibodies (MAA) by lineblot methods.RESULTS:
Forty-four/51 (86.3%) samples tested positive with at least one of the three methods and seven were negative with all methods. Of the 44 positive samples, 9 (20.5%) tested negative for the ANA-IIF test and positive for MAA/MSA. Anti-Ro52 were the most prevalent autoantibodies in IIM patients (21/51; 41%), frequently associated with anti-Jo1 antibodies (13/21; 62%). 13 (16%) anti-Ro52 and anti-Jo1 negative samples were reactive to MSA.CONCLUSIONS:
Our findings suggest that when IIM is clinically suspected, the optimal diagnostic algorithm is to associate the ANA-IIF screening test with a specific test for anti-Ro52 and anti-Jo1 antibodies. Should all these tests be negative, serological tests for MSA are recommended.Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Ribonucleoproteins
/
Algorithms
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Antibodies, Antinuclear
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Fluorescent Antibody Technique, Indirect
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Myositis
Type of study:
Diagnostic_studies
/
Observational_studies
/
Prognostic_studies
/
Risk_factors_studies
Limits:
Adult
/
Aged
/
Aged80
/
Female
/
Humans
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Male
/
Middle aged
Language:
En
Journal:
Clin Chim Acta
Year:
2017
Document type:
Article