A New Immunodot Assay for Multiplex Detection of Autoantibodies in a Cohort of Italian Patients With Idiopathic Inflammatory Myopathies.
J Clin Lab Anal
; 30(6): 859-866, 2016 Nov.
Article
in En
| MEDLINE
| ID: mdl-27074881
ABSTRACT
BACKGROUND:
Autoantibody detection has been assessed as tool for the diagnosis and the definition of idiopathic inflammatory myopathies (IIM). The aim of the study was to characterize the autoantibody profiling of a cohort of Italian patients with IIM.METHODS:
Sera of 53 adult patients with definite IIM, according to Bohan-Peter criteria, were tested for anti-nuclear autoantibodies (ANA), using indirect immunofluorescence (IIF) method, and for myositis-specific autoantibodies (MSAs) and myositis-associated autoantibodies (MAAs), using two new commercial immunodot assays.RESULTS:
MSAs and/or MAAs were detected in 29 of 53 (54.7%) patients with IIM. Twenty-three patients (43.4%) were positive for at least one MSAs 13 (24.5%) had anti-histidyl-tRNA synthetase autoantibodies (Jo1), 4 (7.5%) had other anti-aminoacyl-tRNA synthetases autoantibodies (anti-ARS), 1 (1.8%) had anti-transcription intermediary factor 1 gamma autoantibodies (anti-TIF1γ), 2 (3.7%) had anti-nuclear helicase protein Mi-2 autoantibodies (anti-Mi-2), 4 (7.5%) had anti-small ubiquitin like modifier activating enzyme heterodimer autoantibodies (anti-SAE). Moreover, 17 patients (32%) were positive for at least one MAAs. Coexisting MSAs and MAAs were observed in 9 of 53 (16.9%) patients, anti-Jo1/SS-A autoantibodies in most cases. Overall sensitivity of immunodot assays was 54.7%, the specificity was almost absolute. At cut-off value of 1160, the sensitivity of ANA-IIF was 52.8%, increasing to 66% if cytoplasmatic fluorescence reaction was reported. Notably, two (5.7%) ANA-IIF negative patients had MSAs, detected only by immunodot assays.CONCLUSION:
It was possible to identify MSAs otherwise undetectable because of the use of new assays. Immunodot can reveal MSAs even when IIF results are inconclusive or, in some cases, ANA negative.Key words
Full text:
1
Database:
MEDLINE
Main subject:
Autoantibodies
/
Immunologic Tests
/
Nuclear Proteins
/
Myositis
Type of study:
Diagnostic_studies
/
Etiology_studies
/
Incidence_studies
/
Observational_studies
/
Prognostic_studies
/
Risk_factors_studies
Limits:
Adult
/
Aged
/
Aged80
/
Female
/
Humans
/
Male
/
Middle aged
Country/Region as subject:
Europa
Language:
En
Journal:
J Clin Lab Anal
Journal subject:
TECNICAS E PROCEDIMENTOS DE LABORATORIO
Year:
2016
Type:
Article
Affiliation country:
Italy